Two recently engineered SpCas9 variants, namely xCas9 and Cas9-NG, show promising potential in improving targeting specificity and broadening the targeting range. In this study, we evaluated these Cas9 variants in the...Two recently engineered SpCas9 variants, namely xCas9 and Cas9-NG, show promising potential in improving targeting specificity and broadening the targeting range. In this study, we evaluated these Cas9 variants in the model and crop plant, rice. We first tested xCas9-3.7, the most effective xCas9 variant in mammalian cells, for targeted mutagenesis at 16 possible NGN PAM (protospacer adjacent motif) combinations in duplicates. xCas9 exhibited nearly equivalent editing efficiency to wild-type Cas9 (Cas9-WT) at most canonical NGG PAM sites tested, whereas it showed limited activity at non-canonical NGH (H = A, C, T) PAM sites. High editing efficiency of xCas9 at NGG PAMs was further demonstrated with C to T base editing by both rAPOBECI and PmCDAI cytidine deaminases. With mismatched sgRNAs, we found that xCas9 had improved targeting specificity over the Cas9-WT. Furthermore, we tested two Cas9-NG variants, Cas9-NGv1 and Cas9-NG, for targeting NGN PAMs. Both Cas9-NG variants showed higher editing efficiency at most non-canonical NG PAM sites tested, and enabled much more efficient editing than xCas9 at AT-rich PAM sites such as GAT, GAA, and CAA. Nevertheless, we found that Cas9-NG variants showed significant reduced activity at the canonical NGG PAM sites. In stable transgenic rice lines, we demonstrated that Cas9-NG had much higher editing efficiency than Cas9-NGv1 and xCas9 at NG PAM sites. To expand the base-editing scope, we developed an efficient C to T base-editing system by making fusion of Cas9-NG nickase (D10A version), PmCDAI, and UGI. Taken together, our work benchmarked xCas9 as a high-fidelity nuclease for targeting canonical NGG PAMs and Cas9-NG as a preferred variant for targeting relaxed PAMs for plant genome editing.展开更多
Dear Editor CRISPR from Prevotella and Francisella 1 （Cpfl） is an emerging RNA-guided endonuclease system that relies on thymidine-rich protospacer adjacent motif （PAM） for DNA targeting （Zetsche et al., 2015）. ...Dear Editor CRISPR from Prevotella and Francisella 1 （Cpfl） is an emerging RNA-guided endonuclease system that relies on thymidine-rich protospacer adjacent motif （PAM） for DNA targeting （Zetsche et al., 2015）. CRISPR-Cpfl has unique features that could be advantageous over the CRISPR-Cas9 system. For example, Cpfl requires only a 42 nt crRNA, while Cas9 uses 100 nt gRNA. While Cas9 generates blunt ends of DNA breaks, the Cpfl cleavage results in 5＇ overhangs distal from the protospacer, which may improve efficiency for NHEJ-based gene insertion. Interestingly, Cpfl proteins also have RNase activity （Fonfara et al., 2016）, which was utilized to process crRNA arrays for multiplexed genome editing in both mammalian systems and plants （Wang et al., 2017; Zetsche et al., 2017）.展开更多
OBJECTIVE: To analyze the essential oils from flowers, leaves, stems, roots, and fruits of Chaihu(Radix Bupleuri Chinensis).METHODS: We extracted essential oils from different parts of Chaihu(Radix Bupleuri Chinensis)...OBJECTIVE: To analyze the essential oils from flowers, leaves, stems, roots, and fruits of Chaihu(Radix Bupleuri Chinensis).METHODS: We extracted essential oils from different parts of Chaihu(Radix Bupleuri Chinensis) using a steam distillation method. The essential oils were analyzed by gas chromatography-mass spectrometry(GC-MS). Data were collected in full scan mode(m/z 60-600). Volatile components were identified based on their retention indices and by comparing their mass spectra with those in the National Institute of Standards and Technology 2005 database assisted by tandem mass spectrometry information. The relative content of each constituent wasdetermined by area normalization.RESULTS: We identified 111 components, of which12 were common to all 5 parts, 30 were found only in roots, 14 were found only in flowers, 6 were found only in leaves, 4 were found only in stems,and 17 were found only in fruits.CONCLUSION: Our results show that the stems,flowers, leaves, and fruits of Chaihu(Radix Bupleuri Chinensis)contain a high concentration of essential oils, and that the exact composition of the essential oils differs among the plant parts. To develop new medicines and make full use of the Chaihu(Radix Bupleuri Chinensis)resource, it is important to characterize the essential oils from different parts of the plant. In future research, it will be important to determine the pharmacological effects of the various components and the essential oil mixtures.展开更多
ATP-binding cassette(ABC)transporters are integral membrane proteins that have evolved diverse func-tions fulfilled via the transport of various substrates.In Arabidopsis,the G subfamily of ABC proteins is particularl...ATP-binding cassette(ABC)transporters are integral membrane proteins that have evolved diverse func-tions fulfilled via the transport of various substrates.In Arabidopsis,the G subfamily of ABC proteins is particularly abundant and participates in multiple signaling pathways during plant development and stress responses.In this study,we revealed that two Arabidopsis ABCG transporters,ABCG16 and ABCG25,engage in ABA-mediated stress responses and early plant growth through endomembrane-specific dimerization-coupled transport of ABA and ABA-glucosyl ester(ABA-GE),respectively.We first revealed that ABCG16 contributes to osmotic stress tolerance via ABA signaling.More specifically,ABCG16 induces cellular ABA efflux in both yeast and plant cells.Using FRET analysis,we showed that ABCG16 forms oblig-atory homodimers for ABA export activity and that the plasma membrane-resident ABCG16 homodimers specifically respond to ABA,undergoing notable conformational changes.Furthermore,we demonstrated that ABCG16 heterodimerizes with ABCG25 at the endoplasmic reticulum(ER)membrane and facilitates the ER entry of ABA-GE in both Arabidopsis and tobacco cells.The specific responsiveness of the ABCG16-ABCG25 heterodimer to ABA-GE and the superior growth of their double mutant support an inhib-itory role of these twoABCGs in early seedling establishment via regulation of ABA-GE translocation across the ER membrane.Our endomembrane-specific analysis of the FRET signals derived from the homo-or heterodimerized ABcG complexes allowed us to link endomembrane-biased dimerization to the transloca-tion of distinct substrates by ABcG transporters,providing a prototypic framework for understanding the omnipotence of ABcG transporters in plant development and stress responses.展开更多
Wheat is one of the most important cereals in the world, serving as a staple for millions globally. In the wake of the geopolitical crisis between Russia and Ukraine, it has become incumbent for many countries to inve...Wheat is one of the most important cereals in the world, serving as a staple for millions globally. In the wake of the geopolitical crisis between Russia and Ukraine, it has become incumbent for many countries to invest in wheat production. Improving cropping systems for wheat production is paramount. Intercropping cereals with legumes has tremendous advantages. Therefore, this study was designed to optimize wheat production by intercropping it with soybean at different densities. Between March and August 2023, a randomized complete block design trial was conducted in Bambili, North West of Cameroon with treatments T1 (wheat monocrop at 200,000 plants ha<sup>−</sup><sup>1</sup>), T2 (soybean monocrop at 250,000 plants ha<sup>−</sup><sup>1</sup>), T3 (200,000 wheat and 125,000 soybean ha<sup>−</sup><sup>1</sup>), T4 (100,000 wheat and 250,000 soybean ha<sup>−</sup><sup>1</sup>), T5 (200,000 wheat and 250,000 soybean ha<sup>−</sup><sup>1</sup>) and T6 (100,000 wheat and 125,000 soybean ha<sup>−</sup><sup>1</sup>). Results revealed that growth parameters of wheat were not significantly influenced by monocrop or intercrop. The yield of wheat was significantly higher in the monocrop than the intercrop treatments, with slight variation amongst the intercrop treatments. Soybean yield was higher in the monocrop than in the intercrop, with no variations amongst the intercrop treatments. Only the land equivalence ratio (LER) for T5 was greater than 1.0. The competitive ratio for T5 was 0.54 for wheat and 1.90 for soybean, comparatively lower than the other monocrop treatments. Intercropping wheat and soybean at 200,000:250,000 ratio is recommended.展开更多
Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller are...Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs.In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants.The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.展开更多
Agriculture is amongst the major occupations in Cameroon where over 70% of citizens are involved and it contributes enormously to the economy of the country. Wheat is one of the most consumed cereals in Cameroon with ...Agriculture is amongst the major occupations in Cameroon where over 70% of citizens are involved and it contributes enormously to the economy of the country. Wheat is one of the most consumed cereals in Cameroon with very high importation rate. However, the adoption of wheat production in the cropping system could have the potential to pull farmers out of poverty. It is essential in human foods and animal feeds. This study aims to investigate on the adaptability of wheat varieties based on growth traits and yield as well as to estimate the gluten content in each of the tested variety in the North-West region. Eight wheat varieties (five from CIMMYT, two from IRAD and one local variety) were evaluated in a factorial design with two types of fertilization (organic and inorganic), in two site (Santa and UBa farm) and five environments. Agro-morphological data were collected and were subjected to the analysis of variance using R software. The gluten content related to the baking quality of wheat flour was estimated per tested variety. Highly significant differences were observed among varieties, sites, environment and fertilization for all parameters estimated. The general mean of all the traits evaluated was significantly higher when using organic fertilizer than inorganic, meaning that the application of organic fertilizer provides better performance of wheat growth. The elevated number of tillers found in Santa could inform on the high level of soil fertility for wheat production in that area. Environment 1 was found to be the best follow by environment 3 and 5. IRAD I gave the highest yield followed by Alexander Wonder and IRAD II. 11SATYND and 29SAWYT were promising introduced varieties in term of grain weight when using organic fertilization. Wet and dry gluten yield varied from 3.8 (ALEXANDER Wonder) to 5.5 (IRAD I) and from 3.7 (IRAD II) to 7.9 (IRAD I) respectively. All the introduced wheat varieties expressed low wet and dry gluten yield as compare to the check Amigo. IRAD I was the best variety to be produ展开更多
A field experiment was carried out to determine the effect of variety and plant spacing on yield and growth of groundnuts. The field experiment was laid in a 3 × 3 factorial experiment in a Randomized Complete Bl...A field experiment was carried out to determine the effect of variety and plant spacing on yield and growth of groundnuts. The field experiment was laid in a 3 × 3 factorial experiment in a Randomized Complete Block Design (RCBD) with three (3) replications. The factor A included three (3) groundnut varieties (Nkatie Sari, Sum Nutt 22 and Yenyawoso) and Factor B was the three (3) spacing of 30 cm × 15 cm, 30 cm × 30 cm and 30 cm × 40 cm. All recommended agronomic practices were followed. Data was collected from eight (8) tagged plants. Growth data were recorded on plant height, number of branches, number of leaves, and the number of flowers while yield data were collected on the number of flowers, number of pods per plant, 100 seeds weight and the pod yield (kg/ha). The plant spacing significantly influenced (P < 0.05) the growth and yield parameters. Groundnut grown at a spacing of 30 cm × 15 cm produced the maximum plant height, whereas the maximum number of leaves, number of branches and number of flowers were produced from 30 cm × 40 cm. Yenyawoso variety with a wider plant spacing performed better vegetatively among all the varieties. The Yenyawoso variety produced the highest number of pods, 100 seeds weight and pod yield as compared to the other varieties. Also, Yenyawoso at 30 cm × 40 cm spacing and Nkatie Sari at 30 cm × 15 cm spacing produced the maximum pod yield.展开更多
Salt stress is one of the major limitations to modern agriculture that negatively influences plant growth and productivity.Salt tolerant cultivar can provide excellent solution to enhance stress tolerance with plantfitn...Salt stress is one of the major limitations to modern agriculture that negatively influences plant growth and productivity.Salt tolerant cultivar can provide excellent solution to enhance stress tolerance with plantfitness to unfavorable environments.Therefore,this study was aimed to screen salt tolerant sorghum genotypes through evaluating of different morphological,biochemical,and physiological attributes in response to salinity stress.In this study,we have been evaluated total six sorghum genotypes including Hybrid sorgo,Debgiri,BD-703,BD-706,BD-707,and BD-725 under salt stress(12 dS m^(-1) NaCl).The response variables included length and weight of root and shoot,root:shoot ratio(RSR),photosynthesis(A),transpiration rate(E),elemental concen-trations(K^(+),Na^(+) and K^(+)/Na^(+)),photochemical efficiency of photosystem II(F_(v)/F_(m)),water use efficiency(WUE)and pigment content(chlorophyll a,and b).The results revealed that saline environment significantly reduced all response variables under study of sorghum genotypes,however,Hybrid sorgo remained unmatched by recording the maximum root and shoot traits.The same genotype recorded higher photosynthetic efficiency which was attributed to Na^(+) extrusion,K^(+) uptake and higher K^(+)/Na^(+) ratio(1.8 at stress),while these mechanisms were not fully active in rest of genotypes.Moreover,this study also implies the involvement of proline in imparting tolerance against saline environment in Hybrid sorgo genotype.Overall,BD-703 remained the most salt sensitive genotype as evident from the minimum morphological growth traits and the least biosynthesis of osmoprotectants.Thesefindings open new research avenues for salt stress alleviation by identifying elite salt-to-lerant genotypes of sorghum for breeding programs.展开更多
Barley(Hordeum vulgare ssp.vulgare)is one of the first crops to be domesticated and is adapted to a wide range of environments.Worldwide barley germplasm collections possess valuable allelic variations that could furt...Barley(Hordeum vulgare ssp.vulgare)is one of the first crops to be domesticated and is adapted to a wide range of environments.Worldwide barley germplasm collections possess valuable allelic variations that could further improve barley productivity.Although barley genomics has offered a global picture of allelic variation among varieties and its association with various agronomic traits,polymorphisms from East Asian varieties remain scarce.In this study,we analyze exome polymorphisms in a panel of 274 barley varieties collected worldwide,including 137 varieties from East Asian countries and Ethiopia.We reveal the underlying population structure and conduct genome-wide association studies for 10 agronomic traits.Moreover,we examin genome-wide associations for traits related to grain size such as awn length and glume length.Our results demonstrate the value of diverse barley germplasm panels containing Eastern varieties,highlighting their distinct genomic signatures relative to Western subpopulations.展开更多
Rubidium chloride(RbCl)was used as a tracer tank-mixed with active ingredients to profile downwind deposition of aerially applied crop protection and production materials to characterize off-target drift,which helps i...Rubidium chloride(RbCl)was used as a tracer tank-mixed with active ingredients to profile downwind deposition of aerially applied crop protection and production materials to characterize off-target drift,which helps improve spray efficiency and reduce environmental contamination.Mylar sheets were placed on a holder in the field at each sampling station to collect sprayed solution.RbCl tracer was used to assess downwind drift of nozzles mounted on the booms installed and controlled on both sides of an agricultural airplane.The experiment was conducted on a field covered by Bermuda grass(Cynodon dactylon).During the experiment,the airplane was planned to fly three passes with three replications at each of three different altitudes,3.7 m,4.9 m,and 6.1 m for total of 27 flight runs.The results indicated that sampling station location had a significant effect on RbCl concentration.However,application release altitude was not significant to the change of RbCl.Another practical application in the same aerial application system was used to assess crop injury from the off-target drift of aerially applied glyphosate.RbCl concentrations measured from Mylar sheets were correlated with visual injury,plant height,shoot dry weight,leaf chlorophyll content,and shikimate,which were measured from the leaves and plant samples collected.Overall,RbCl is an effective tracer for monitoring spray applications from agricultural aircraft and unmanned aerial vehicles to intensify agriculture output and minimize environmental impact.展开更多
Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. ...Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. This study was carried out at International Institute of Tropical Agriculture (IITA) Yaounde and Institute of Agricultural Research for Development (IRAD) Bambui to assess different substrates for acclimatization of tissue culture taro plantlets in apropagator. No information is available on acclimatization of Cameroonian taro plantlets in different substrates. Taro plantlets from tissue culture were acclimatised in a propagator for six weeks under different substrates, the first substrate consisted of sterile three parts of soil and one part of river sand mixed together (3:1), the second substrate consisted of sterile two parts of soil and two parts of river sand mixed together (2:2), the third substrate consisted of sterile two parts of soil, one part of rice husk and one part of river sand mixed together (2:1:1) and the fourth substrate consisted of sterile one part of soil and three parts of river sand mixed together (1:3). After acclimatisation of the different taroplantlets (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves (L4) in these four substrates, it was observed that the best growth rate of plant was recorded on substrate sand + soil (1:3). The other substrates showed moderate growth of plants. Substrate sand + soil (1:3) can be recommended for acclimatization of Cameroonian taro plantlets.展开更多
In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a ...In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.展开更多
Soil fertility continues to decline in Ghana due to unsustainable human activities like bush burning, quarrying, improper farming practices, among others. To resolve this challenge, crop farmers resort to continuous u...Soil fertility continues to decline in Ghana due to unsustainable human activities like bush burning, quarrying, improper farming practices, among others. To resolve this challenge, crop farmers resort to continuous use of mineral fertilizers in Ghana, which contaminates the environment and makes crop farming less sustainable and productive. One of the strategies to improve soil fertility and productivity for sustainable crop yields is intercropping. Studies were, therefore, undertaken at Miminaso in the Ejura-Sekyedumase municipality of Ashanti Region of Ghana during the 2020 cropping seasons to determine the effects of spatial row arrangement and time of planting maize and groundnut intercrops on productivity of maize and land equivalent ratio (LER). One row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize (M) and sole groundnut (G) were factorially arranged with concurrent planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP) in a Randomized Complete Block Design with three replicates. There were significant treatment interaction (P < 0.05) effects for shelling percentage for maize in both seasons of the trial. In the major season of 2020, the highest shelling percentage of 79.30% was associated with 0 WAP × M, while in the minor season of 2020, the highest shelling percentage of 75.02% was recorded by 0 WAP × 2M1G. The treatment interaction effects for maize grain yield were significant only in the minor season of 2020 with the highest maize grain yield of 6341 kg/ha being produced by the sole maize treatment, followed by 1 WAP × 2M2G (6152 kg/ha). The highest LER of 3.05 was associated with 1 WAP × 2M2G in the minor season of 2020. Planting groundnuts within the first week of planting maize (1 WAP) increased maize seed yield and LER in two rows of maize 展开更多
Target detection is one of research focuses for precision chemical application.This study developed a method to identify seedling cabbages and weeds using hyperspectral imaging.In processing the image data with ENVI s...Target detection is one of research focuses for precision chemical application.This study developed a method to identify seedling cabbages and weeds using hyperspectral imaging.In processing the image data with ENVI software,after dimension reduction,noise reduction,de-correlation for high-dimensional data,and selection of the region of interest,the SAM(Spectral Angle Mapping)model was built for automatic identification of cabbages and weeds.With the HSI(Hyper Spectral Imaging)Analyzer,the training pixels were used to calculate the average spectrum as the standard spectrum.The parameters of the SAM model,which had the best classification results with 3-point smoothing,zero-order derivative,and 6-degrees spectral angle,was determined to achieve the accurate identification of the background,weeds,and cabbages.In comparison,the SAM model can completely separate the plants from the soil background but not perfect for weeds to be separated from the cabbages.In conclusion,the SAM classification model with the HSI analyzer could completely distinguish weeds from background and cabbages.展开更多
Cereals, including barley, have been playing a key role in human diet for a long time. The objective of the present study was to determine the effect of nanosilver(nAg) on limitation of infections, morphological featu...Cereals, including barley, have been playing a key role in human diet for a long time. The objective of the present study was to determine the effect of nanosilver(nAg) on limitation of infections, morphological features, and their chemical composition of young barley seedlings under in vitro condition. Addition of 0, 2, 4, 6 and 8 mg dm^–3 nAg into MS medium was used.Obtained results showed that the effect on the morphological features depended on the nAg concentration. The addition of 6 and 8 mg dm^–3 nAg into MS medium limited the number of infected barley embryos in vitro, whereas 4 and 8 mg dm^–3 nAg resulted in the highest seedlings with the longest roots. nAg in the medium affected the colour of leaves and increased the contents of chlorophyll and β-carotene, in particular in seedlings growing in MS medium supplied with 6 mg dm^–3 nAg.The addition of 8 mg dm^–3 had the greatest effect on the contents of vitamin C and E in young barley seedlings. It was found that the contents of K and Ca in the young barley leaves were lower, as compared to control plants. The presence of 6 mg dm^–3 nAg in the medium resulted in an increased contents of N, Mg, Zn, Cu, and P. Hence, a diversified effect of nAg on individual groups of polyphenolic compounds was noticed. The presence of 2 and 8 mg dm^–3 nAg caused higher content values of polyphenolic compounds in young barley leaves.展开更多
In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the...In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the root and stem yield of these varieties together with an old improved variety currently in farmers＇ field. In all the locations, root yield of all the new materials were significantly higher （P 〈 0.05） than the old improved variety. The root yields of the new varieties were between 40%-50% higher than the old improved varieties. Overall yield advantages of the new materials over the old improved material ranged between 40%-150%. Stem yield figures showed significant variations with few of the new varieties producing higher stem yield in comparison with the old improved variety due to inherent growth pattern. Figures for tuber girth and node numbers per unit of stem were similar. The high yield levels of the new varieties might lead to high demand for stems indicating the likely wider spread and higher demand for varieties with high stem yield potentials.展开更多
Amaryllis plants (Hippeastrum hybrid, in the family Amaryllidaceae) are cultivated in Brazil mainly for bulb export. Studies about the nutrient accumulation dynamics by the species are yet incipient when considering B...Amaryllis plants (Hippeastrum hybrid, in the family Amaryllidaceae) are cultivated in Brazil mainly for bulb export. Studies about the nutrient accumulation dynamics by the species are yet incipient when considering Brazilian cultivation conditions. The objective was to determine the nutrient accumulation in amaryllis “Orange Souvereign” cultivated in the field. The experimental design was entirely randomized with four replications and 14 collection periods (at 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, and 420 days after planting). Sampled plants were divided into leaves, bulb, and roots, which were used for determination of nutrient accumulation by leaves (aerial part) and bulb + roots (underground part). Nutrient accumulation of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn was calculated for each collection period, and then represented by curves of macro and micronutrient accumulation, as well as accumulation percentages for each plant part. For most macro and micronutrients, the interval of maximum accumulation fell from 301 to 420 days after planting, matching with the cycle final stage of plants cultivated in the field. Accumulated macronutrients by amaryllis plants along the cultivation cycle was, in g·plant-1: 1.57 N;0.19 P;2.58 K;0.64 Ca;0.20 Mg;and 0.29 S, following the descending order: K > N > Ca > S > Mg > P. Accumulated micronutrients, in mg·plant-1, was: 2.18 B;1.17 Cu;22.33 Fe;2.19 Mn;and 4.09 Zn, following the descending order: Fe > Zn > Mn > B > Cu.展开更多
The demand for rice to meet the dietary need in low-income countries is expected to witness an exponential rise as the population increases.Meeting the rice demand domestically has remained challenging due to signific...The demand for rice to meet the dietary need in low-income countries is expected to witness an exponential rise as the population increases.Meeting the rice demand domestically has remained challenging due to significant yield loss caused by several biotic and abiotic factors.Among these factors,one of the most important is the high weed pressure that ravages the upland rice ecology.In Nigeria,several independent weed control techniques,such as physical,chemical and cultural methods,have been recommended and adopted for weed control across varying rice upland ecologies.However,outcomes of these approaches when used independently have not consistently led to an increase in yield.There remains an outstanding deficit between the actual yield and the potential rice yield.This review aimed to identify potential research gaps,and quest effective and sustainable weed management strategies in smallholder upland rice farming systems in Nigeria.A critical analysis of studies suggests the potential of sustainable weed management practices if adopted and adapted smartly in different upland ecologies in Nigeria.Competitiveness of upland rice against weeds can be enhanced through strategic integration of weed competitive cultivars,optimum nitrogen application timings(within weed-free periods),uniform plant spacing,and high seeding rates,with conventional herbicide/manual weed control practices.However,such management practices can only be engaged where inputs are supplied on time and the technical know-how is extended to farmers.The review equally highlights potential research gaps for further studies.展开更多
Essential oil （EO） of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry （GCMS） and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Si...Essential oil （EO） of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry （GCMS） and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Sixteen compounds predominated by monoterpenes were identified. The major compounds were Eucalyptol （28.36%）, α-Terpineol （25.99%）, γ-Terpinene （15.24%）, α-Pinene （5.08%）, 1H-Cyclopropa[a]naphthalene （4.25%） and 1, 3, 6, 10-Dodeeatetraene （3.74%）. Percentage mortality due to fumigant toxicity was dose- and exposure period-dependent. One hour after treatment （HAT）, application of L. adoensis leaf EO at 107 μL· L^-1 air caused significantly （p〈0.05） higher mortality （50.00%） than 0.00% mortality observed at 0-53 μL· L^-1 air, but not significantly （p〉0.05） different from 22.50% observed in 80 μL· L^-1 air. At 3 HAT, application ofL. adoensis EO at 80 μL· L^-1 air caused significantly higher mortality （90.00 %） than mortality observed at 0 μL· L^-1 air. At 6 HAT, application of L. adoensis EO at 53-107 μL· L^-1 air caused significantly higher mortality （100.00 %） than that was observed in the control. The same trend was observed at 12 HAT where 100 % mortality observed in 27-107 μL· L^-1 air was significantly greater than 13.33 % observed in the control. At 3 HAT, percentage repellence was significantly （p〈0.05） affected by doses. Application of EO at 10-30 μL· cm^2 caused class V repellence （86.67%-100%） compared with the control which caused class I repellence （0-20%）.展开更多
基金National Transgenic Major Project (2018ZX08020-003)the Sichuan Youth Science and Technology Foundation (2017JQ0005)+3 种基金the National Science Foundation of China (31771486)the Science Strength Promotion Program of UESTC to Y.Z.the Open Foundation of Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding (PL201801) to Y.Z. and T.Z.and the National Science Foundation Plant Genome Research Program (IOS-1758745) and USDA-NIFA Biotechnology Risk Assessment Research Program (2018-33522- 28789) to Y.Q.
文摘Two recently engineered SpCas9 variants, namely xCas9 and Cas9-NG, show promising potential in improving targeting specificity and broadening the targeting range. In this study, we evaluated these Cas9 variants in the model and crop plant, rice. We first tested xCas9-3.7, the most effective xCas9 variant in mammalian cells, for targeted mutagenesis at 16 possible NGN PAM (protospacer adjacent motif) combinations in duplicates. xCas9 exhibited nearly equivalent editing efficiency to wild-type Cas9 (Cas9-WT) at most canonical NGG PAM sites tested, whereas it showed limited activity at non-canonical NGH (H = A, C, T) PAM sites. High editing efficiency of xCas9 at NGG PAMs was further demonstrated with C to T base editing by both rAPOBECI and PmCDAI cytidine deaminases. With mismatched sgRNAs, we found that xCas9 had improved targeting specificity over the Cas9-WT. Furthermore, we tested two Cas9-NG variants, Cas9-NGv1 and Cas9-NG, for targeting NGN PAMs. Both Cas9-NG variants showed higher editing efficiency at most non-canonical NG PAM sites tested, and enabled much more efficient editing than xCas9 at AT-rich PAM sites such as GAT, GAA, and CAA. Nevertheless, we found that Cas9-NG variants showed significant reduced activity at the canonical NGG PAM sites. In stable transgenic rice lines, we demonstrated that Cas9-NG had much higher editing efficiency than Cas9-NGv1 and xCas9 at NG PAM sites. To expand the base-editing scope, we developed an efficient C to T base-editing system by making fusion of Cas9-NG nickase (D10A version), PmCDAI, and UGI. Taken together, our work benchmarked xCas9 as a high-fidelity nuclease for targeting canonical NGG PAMs and Cas9-NG as a preferred variant for targeting relaxed PAMs for plant genome editing.
文摘Dear Editor CRISPR from Prevotella and Francisella 1 （Cpfl） is an emerging RNA-guided endonuclease system that relies on thymidine-rich protospacer adjacent motif （PAM） for DNA targeting （Zetsche et al., 2015）. CRISPR-Cpfl has unique features that could be advantageous over the CRISPR-Cas9 system. For example, Cpfl requires only a 42 nt crRNA, while Cas9 uses 100 nt gRNA. While Cas9 generates blunt ends of DNA breaks, the Cpfl cleavage results in 5＇ overhangs distal from the protospacer, which may improve efficiency for NHEJ-based gene insertion. Interestingly, Cpfl proteins also have RNase activity （Fonfara et al., 2016）, which was utilized to process crRNA arrays for multiplexed genome editing in both mammalian systems and plants （Wang et al., 2017; Zetsche et al., 2017）.
基金Breeding Research Project of Chinese Medical Herbs in Sichuan Province:Study on the breeding of new Chaihu variety and cultivation and the related techniques(No.2011NZ0098-12-11)China Spark Program in 2010(No.2010GA810056)
文摘OBJECTIVE: To analyze the essential oils from flowers, leaves, stems, roots, and fruits of Chaihu(Radix Bupleuri Chinensis).METHODS: We extracted essential oils from different parts of Chaihu(Radix Bupleuri Chinensis) using a steam distillation method. The essential oils were analyzed by gas chromatography-mass spectrometry(GC-MS). Data were collected in full scan mode(m/z 60-600). Volatile components were identified based on their retention indices and by comparing their mass spectra with those in the National Institute of Standards and Technology 2005 database assisted by tandem mass spectrometry information. The relative content of each constituent wasdetermined by area normalization.RESULTS: We identified 111 components, of which12 were common to all 5 parts, 30 were found only in roots, 14 were found only in flowers, 6 were found only in leaves, 4 were found only in stems,and 17 were found only in fruits.CONCLUSION: Our results show that the stems,flowers, leaves, and fruits of Chaihu(Radix Bupleuri Chinensis)contain a high concentration of essential oils, and that the exact composition of the essential oils differs among the plant parts. To develop new medicines and make full use of the Chaihu(Radix Bupleuri Chinensis)resource, it is important to characterize the essential oils from different parts of the plant. In future research, it will be important to determine the pharmacological effects of the various components and the essential oil mixtures.
基金supported by the National Natural Science Foundation of China(grant 32070292)the Shenzhen Science and Technology Program (grant KQTD20190929173906742)+2 种基金the Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes(grant 2019KSYS006)Shenzhen government for fundamental research(grant JCYJ20170817104523456)Scientific research funding for postdoctoral researchers staying at Shenzhen(grant K20227507).
文摘ATP-binding cassette(ABC)transporters are integral membrane proteins that have evolved diverse func-tions fulfilled via the transport of various substrates.In Arabidopsis,the G subfamily of ABC proteins is particularly abundant and participates in multiple signaling pathways during plant development and stress responses.In this study,we revealed that two Arabidopsis ABCG transporters,ABCG16 and ABCG25,engage in ABA-mediated stress responses and early plant growth through endomembrane-specific dimerization-coupled transport of ABA and ABA-glucosyl ester(ABA-GE),respectively.We first revealed that ABCG16 contributes to osmotic stress tolerance via ABA signaling.More specifically,ABCG16 induces cellular ABA efflux in both yeast and plant cells.Using FRET analysis,we showed that ABCG16 forms oblig-atory homodimers for ABA export activity and that the plasma membrane-resident ABCG16 homodimers specifically respond to ABA,undergoing notable conformational changes.Furthermore,we demonstrated that ABCG16 heterodimerizes with ABCG25 at the endoplasmic reticulum(ER)membrane and facilitates the ER entry of ABA-GE in both Arabidopsis and tobacco cells.The specific responsiveness of the ABCG16-ABCG25 heterodimer to ABA-GE and the superior growth of their double mutant support an inhib-itory role of these twoABCGs in early seedling establishment via regulation of ABA-GE translocation across the ER membrane.Our endomembrane-specific analysis of the FRET signals derived from the homo-or heterodimerized ABcG complexes allowed us to link endomembrane-biased dimerization to the transloca-tion of distinct substrates by ABcG transporters,providing a prototypic framework for understanding the omnipotence of ABcG transporters in plant development and stress responses.
文摘Wheat is one of the most important cereals in the world, serving as a staple for millions globally. In the wake of the geopolitical crisis between Russia and Ukraine, it has become incumbent for many countries to invest in wheat production. Improving cropping systems for wheat production is paramount. Intercropping cereals with legumes has tremendous advantages. Therefore, this study was designed to optimize wheat production by intercropping it with soybean at different densities. Between March and August 2023, a randomized complete block design trial was conducted in Bambili, North West of Cameroon with treatments T1 (wheat monocrop at 200,000 plants ha<sup>−</sup><sup>1</sup>), T2 (soybean monocrop at 250,000 plants ha<sup>−</sup><sup>1</sup>), T3 (200,000 wheat and 125,000 soybean ha<sup>−</sup><sup>1</sup>), T4 (100,000 wheat and 250,000 soybean ha<sup>−</sup><sup>1</sup>), T5 (200,000 wheat and 250,000 soybean ha<sup>−</sup><sup>1</sup>) and T6 (100,000 wheat and 125,000 soybean ha<sup>−</sup><sup>1</sup>). Results revealed that growth parameters of wheat were not significantly influenced by monocrop or intercrop. The yield of wheat was significantly higher in the monocrop than the intercrop treatments, with slight variation amongst the intercrop treatments. Soybean yield was higher in the monocrop than in the intercrop, with no variations amongst the intercrop treatments. Only the land equivalence ratio (LER) for T5 was greater than 1.0. The competitive ratio for T5 was 0.54 for wheat and 1.90 for soybean, comparatively lower than the other monocrop treatments. Intercropping wheat and soybean at 200,000:250,000 ratio is recommended.
文摘Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs.In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants.The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.
文摘Agriculture is amongst the major occupations in Cameroon where over 70% of citizens are involved and it contributes enormously to the economy of the country. Wheat is one of the most consumed cereals in Cameroon with very high importation rate. However, the adoption of wheat production in the cropping system could have the potential to pull farmers out of poverty. It is essential in human foods and animal feeds. This study aims to investigate on the adaptability of wheat varieties based on growth traits and yield as well as to estimate the gluten content in each of the tested variety in the North-West region. Eight wheat varieties (five from CIMMYT, two from IRAD and one local variety) were evaluated in a factorial design with two types of fertilization (organic and inorganic), in two site (Santa and UBa farm) and five environments. Agro-morphological data were collected and were subjected to the analysis of variance using R software. The gluten content related to the baking quality of wheat flour was estimated per tested variety. Highly significant differences were observed among varieties, sites, environment and fertilization for all parameters estimated. The general mean of all the traits evaluated was significantly higher when using organic fertilizer than inorganic, meaning that the application of organic fertilizer provides better performance of wheat growth. The elevated number of tillers found in Santa could inform on the high level of soil fertility for wheat production in that area. Environment 1 was found to be the best follow by environment 3 and 5. IRAD I gave the highest yield followed by Alexander Wonder and IRAD II. 11SATYND and 29SAWYT were promising introduced varieties in term of grain weight when using organic fertilization. Wet and dry gluten yield varied from 3.8 (ALEXANDER Wonder) to 5.5 (IRAD I) and from 3.7 (IRAD II) to 7.9 (IRAD I) respectively. All the introduced wheat varieties expressed low wet and dry gluten yield as compare to the check Amigo. IRAD I was the best variety to be produ
文摘A field experiment was carried out to determine the effect of variety and plant spacing on yield and growth of groundnuts. The field experiment was laid in a 3 × 3 factorial experiment in a Randomized Complete Block Design (RCBD) with three (3) replications. The factor A included three (3) groundnut varieties (Nkatie Sari, Sum Nutt 22 and Yenyawoso) and Factor B was the three (3) spacing of 30 cm × 15 cm, 30 cm × 30 cm and 30 cm × 40 cm. All recommended agronomic practices were followed. Data was collected from eight (8) tagged plants. Growth data were recorded on plant height, number of branches, number of leaves, and the number of flowers while yield data were collected on the number of flowers, number of pods per plant, 100 seeds weight and the pod yield (kg/ha). The plant spacing significantly influenced (P < 0.05) the growth and yield parameters. Groundnut grown at a spacing of 30 cm × 15 cm produced the maximum plant height, whereas the maximum number of leaves, number of branches and number of flowers were produced from 30 cm × 40 cm. Yenyawoso variety with a wider plant spacing performed better vegetatively among all the varieties. The Yenyawoso variety produced the highest number of pods, 100 seeds weight and pod yield as compared to the other varieties. Also, Yenyawoso at 30 cm × 40 cm spacing and Nkatie Sari at 30 cm × 15 cm spacing produced the maximum pod yield.
基金This research was funded by the Researchers Supporting Project No. (RSP2023R390),King Saud University, Riyadh, Saudi Arabia.
文摘Salt stress is one of the major limitations to modern agriculture that negatively influences plant growth and productivity.Salt tolerant cultivar can provide excellent solution to enhance stress tolerance with plantfitness to unfavorable environments.Therefore,this study was aimed to screen salt tolerant sorghum genotypes through evaluating of different morphological,biochemical,and physiological attributes in response to salinity stress.In this study,we have been evaluated total six sorghum genotypes including Hybrid sorgo,Debgiri,BD-703,BD-706,BD-707,and BD-725 under salt stress(12 dS m^(-1) NaCl).The response variables included length and weight of root and shoot,root:shoot ratio(RSR),photosynthesis(A),transpiration rate(E),elemental concen-trations(K^(+),Na^(+) and K^(+)/Na^(+)),photochemical efficiency of photosystem II(F_(v)/F_(m)),water use efficiency(WUE)and pigment content(chlorophyll a,and b).The results revealed that saline environment significantly reduced all response variables under study of sorghum genotypes,however,Hybrid sorgo remained unmatched by recording the maximum root and shoot traits.The same genotype recorded higher photosynthetic efficiency which was attributed to Na^(+) extrusion,K^(+) uptake and higher K^(+)/Na^(+) ratio(1.8 at stress),while these mechanisms were not fully active in rest of genotypes.Moreover,this study also implies the involvement of proline in imparting tolerance against saline environment in Hybrid sorgo genotype.Overall,BD-703 remained the most salt sensitive genotype as evident from the minimum morphological growth traits and the least biosynthesis of osmoprotectants.Thesefindings open new research avenues for salt stress alleviation by identifying elite salt-to-lerant genotypes of sorghum for breeding programs.
基金supported by a Grant-in-Aid for Scientific Research(B)(grant no.15KT0038 to K.M.)a Grant-in-Aid for Scientific Research(C)(grant no.19K11861 to K.M.and R.N.)of the Japan Society for the Promotion of Scienceby CREST(grant no.JPMJCR16O4 to K.M.)of the Japan Science and Technology Agency。
文摘Barley(Hordeum vulgare ssp.vulgare)is one of the first crops to be domesticated and is adapted to a wide range of environments.Worldwide barley germplasm collections possess valuable allelic variations that could further improve barley productivity.Although barley genomics has offered a global picture of allelic variation among varieties and its association with various agronomic traits,polymorphisms from East Asian varieties remain scarce.In this study,we analyze exome polymorphisms in a panel of 274 barley varieties collected worldwide,including 137 varieties from East Asian countries and Ethiopia.We reveal the underlying population structure and conduct genome-wide association studies for 10 agronomic traits.Moreover,we examin genome-wide associations for traits related to grain size such as awn length and glume length.Our results demonstrate the value of diverse barley germplasm panels containing Eastern varieties,highlighting their distinct genomic signatures relative to Western subpopulations.
文摘Rubidium chloride(RbCl)was used as a tracer tank-mixed with active ingredients to profile downwind deposition of aerially applied crop protection and production materials to characterize off-target drift,which helps improve spray efficiency and reduce environmental contamination.Mylar sheets were placed on a holder in the field at each sampling station to collect sprayed solution.RbCl tracer was used to assess downwind drift of nozzles mounted on the booms installed and controlled on both sides of an agricultural airplane.The experiment was conducted on a field covered by Bermuda grass(Cynodon dactylon).During the experiment,the airplane was planned to fly three passes with three replications at each of three different altitudes,3.7 m,4.9 m,and 6.1 m for total of 27 flight runs.The results indicated that sampling station location had a significant effect on RbCl concentration.However,application release altitude was not significant to the change of RbCl.Another practical application in the same aerial application system was used to assess crop injury from the off-target drift of aerially applied glyphosate.RbCl concentrations measured from Mylar sheets were correlated with visual injury,plant height,shoot dry weight,leaf chlorophyll content,and shikimate,which were measured from the leaves and plant samples collected.Overall,RbCl is an effective tracer for monitoring spray applications from agricultural aircraft and unmanned aerial vehicles to intensify agriculture output and minimize environmental impact.
文摘Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. This study was carried out at International Institute of Tropical Agriculture (IITA) Yaounde and Institute of Agricultural Research for Development (IRAD) Bambui to assess different substrates for acclimatization of tissue culture taro plantlets in apropagator. No information is available on acclimatization of Cameroonian taro plantlets in different substrates. Taro plantlets from tissue culture were acclimatised in a propagator for six weeks under different substrates, the first substrate consisted of sterile three parts of soil and one part of river sand mixed together (3:1), the second substrate consisted of sterile two parts of soil and two parts of river sand mixed together (2:2), the third substrate consisted of sterile two parts of soil, one part of rice husk and one part of river sand mixed together (2:1:1) and the fourth substrate consisted of sterile one part of soil and three parts of river sand mixed together (1:3). After acclimatisation of the different taroplantlets (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves (L4) in these four substrates, it was observed that the best growth rate of plant was recorded on substrate sand + soil (1:3). The other substrates showed moderate growth of plants. Substrate sand + soil (1:3) can be recommended for acclimatization of Cameroonian taro plantlets.
文摘In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.
文摘Soil fertility continues to decline in Ghana due to unsustainable human activities like bush burning, quarrying, improper farming practices, among others. To resolve this challenge, crop farmers resort to continuous use of mineral fertilizers in Ghana, which contaminates the environment and makes crop farming less sustainable and productive. One of the strategies to improve soil fertility and productivity for sustainable crop yields is intercropping. Studies were, therefore, undertaken at Miminaso in the Ejura-Sekyedumase municipality of Ashanti Region of Ghana during the 2020 cropping seasons to determine the effects of spatial row arrangement and time of planting maize and groundnut intercrops on productivity of maize and land equivalent ratio (LER). One row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize (M) and sole groundnut (G) were factorially arranged with concurrent planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP) in a Randomized Complete Block Design with three replicates. There were significant treatment interaction (P < 0.05) effects for shelling percentage for maize in both seasons of the trial. In the major season of 2020, the highest shelling percentage of 79.30% was associated with 0 WAP × M, while in the minor season of 2020, the highest shelling percentage of 75.02% was recorded by 0 WAP × 2M1G. The treatment interaction effects for maize grain yield were significant only in the minor season of 2020 with the highest maize grain yield of 6341 kg/ha being produced by the sole maize treatment, followed by 1 WAP × 2M2G (6152 kg/ha). The highest LER of 3.05 was associated with 1 WAP × 2M2G in the minor season of 2020. Planting groundnuts within the first week of planting maize (1 WAP) increased maize seed yield and LER in two rows of maize
基金This research was financially supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA101904)the National High Technology Research and Development Program of China(984 Program)(2011-G32).
文摘Target detection is one of research focuses for precision chemical application.This study developed a method to identify seedling cabbages and weeds using hyperspectral imaging.In processing the image data with ENVI software,after dimension reduction,noise reduction,de-correlation for high-dimensional data,and selection of the region of interest,the SAM(Spectral Angle Mapping)model was built for automatic identification of cabbages and weeds.With the HSI(Hyper Spectral Imaging)Analyzer,the training pixels were used to calculate the average spectrum as the standard spectrum.The parameters of the SAM model,which had the best classification results with 3-point smoothing,zero-order derivative,and 6-degrees spectral angle,was determined to achieve the accurate identification of the background,weeds,and cabbages.In comparison,the SAM model can completely separate the plants from the soil background but not perfect for weeds to be separated from the cabbages.In conclusion,the SAM classification model with the HSI analyzer could completely distinguish weeds from background and cabbages.
基金supported by the grant of West Pomeranian University of Technology in Szczecin, Poland (518-07-0143171-03/18)
文摘Cereals, including barley, have been playing a key role in human diet for a long time. The objective of the present study was to determine the effect of nanosilver(nAg) on limitation of infections, morphological features, and their chemical composition of young barley seedlings under in vitro condition. Addition of 0, 2, 4, 6 and 8 mg dm^–3 nAg into MS medium was used.Obtained results showed that the effect on the morphological features depended on the nAg concentration. The addition of 6 and 8 mg dm^–3 nAg into MS medium limited the number of infected barley embryos in vitro, whereas 4 and 8 mg dm^–3 nAg resulted in the highest seedlings with the longest roots. nAg in the medium affected the colour of leaves and increased the contents of chlorophyll and β-carotene, in particular in seedlings growing in MS medium supplied with 6 mg dm^–3 nAg.The addition of 8 mg dm^–3 had the greatest effect on the contents of vitamin C and E in young barley seedlings. It was found that the contents of K and Ca in the young barley leaves were lower, as compared to control plants. The presence of 6 mg dm^–3 nAg in the medium resulted in an increased contents of N, Mg, Zn, Cu, and P. Hence, a diversified effect of nAg on individual groups of polyphenolic compounds was noticed. The presence of 2 and 8 mg dm^–3 nAg caused higher content values of polyphenolic compounds in young barley leaves.
文摘In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the root and stem yield of these varieties together with an old improved variety currently in farmers＇ field. In all the locations, root yield of all the new materials were significantly higher （P 〈 0.05） than the old improved variety. The root yields of the new varieties were between 40%-50% higher than the old improved varieties. Overall yield advantages of the new materials over the old improved material ranged between 40%-150%. Stem yield figures showed significant variations with few of the new varieties producing higher stem yield in comparison with the old improved variety due to inherent growth pattern. Figures for tuber girth and node numbers per unit of stem were similar. The high yield levels of the new varieties might lead to high demand for stems indicating the likely wider spread and higher demand for varieties with high stem yield potentials.
文摘Amaryllis plants (Hippeastrum hybrid, in the family Amaryllidaceae) are cultivated in Brazil mainly for bulb export. Studies about the nutrient accumulation dynamics by the species are yet incipient when considering Brazilian cultivation conditions. The objective was to determine the nutrient accumulation in amaryllis “Orange Souvereign” cultivated in the field. The experimental design was entirely randomized with four replications and 14 collection periods (at 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, and 420 days after planting). Sampled plants were divided into leaves, bulb, and roots, which were used for determination of nutrient accumulation by leaves (aerial part) and bulb + roots (underground part). Nutrient accumulation of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn was calculated for each collection period, and then represented by curves of macro and micronutrient accumulation, as well as accumulation percentages for each plant part. For most macro and micronutrients, the interval of maximum accumulation fell from 301 to 420 days after planting, matching with the cycle final stage of plants cultivated in the field. Accumulated macronutrients by amaryllis plants along the cultivation cycle was, in g·plant-1: 1.57 N;0.19 P;2.58 K;0.64 Ca;0.20 Mg;and 0.29 S, following the descending order: K > N > Ca > S > Mg > P. Accumulated micronutrients, in mg·plant-1, was: 2.18 B;1.17 Cu;22.33 Fe;2.19 Mn;and 4.09 Zn, following the descending order: Fe > Zn > Mn > B > Cu.
文摘The demand for rice to meet the dietary need in low-income countries is expected to witness an exponential rise as the population increases.Meeting the rice demand domestically has remained challenging due to significant yield loss caused by several biotic and abiotic factors.Among these factors,one of the most important is the high weed pressure that ravages the upland rice ecology.In Nigeria,several independent weed control techniques,such as physical,chemical and cultural methods,have been recommended and adopted for weed control across varying rice upland ecologies.However,outcomes of these approaches when used independently have not consistently led to an increase in yield.There remains an outstanding deficit between the actual yield and the potential rice yield.This review aimed to identify potential research gaps,and quest effective and sustainable weed management strategies in smallholder upland rice farming systems in Nigeria.A critical analysis of studies suggests the potential of sustainable weed management practices if adopted and adapted smartly in different upland ecologies in Nigeria.Competitiveness of upland rice against weeds can be enhanced through strategic integration of weed competitive cultivars,optimum nitrogen application timings(within weed-free periods),uniform plant spacing,and high seeding rates,with conventional herbicide/manual weed control practices.However,such management practices can only be engaged where inputs are supplied on time and the technical know-how is extended to farmers.The review equally highlights potential research gaps for further studies.
基金Supported by the Senate of Ladoke Akintola University of Technology(LAUTECH)Ogbomoso,Nigeria Under the University Senate Research(LAU/SRG/13/045)
文摘Essential oil （EO） of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry （GCMS） and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Sixteen compounds predominated by monoterpenes were identified. The major compounds were Eucalyptol （28.36%）, α-Terpineol （25.99%）, γ-Terpinene （15.24%）, α-Pinene （5.08%）, 1H-Cyclopropa[a]naphthalene （4.25%） and 1, 3, 6, 10-Dodeeatetraene （3.74%）. Percentage mortality due to fumigant toxicity was dose- and exposure period-dependent. One hour after treatment （HAT）, application of L. adoensis leaf EO at 107 μL· L^-1 air caused significantly （p〈0.05） higher mortality （50.00%） than 0.00% mortality observed at 0-53 μL· L^-1 air, but not significantly （p〉0.05） different from 22.50% observed in 80 μL· L^-1 air. At 3 HAT, application ofL. adoensis EO at 80 μL· L^-1 air caused significantly higher mortality （90.00 %） than mortality observed at 0 μL· L^-1 air. At 6 HAT, application of L. adoensis EO at 53-107 μL· L^-1 air caused significantly higher mortality （100.00 %） than that was observed in the control. The same trend was observed at 12 HAT where 100 % mortality observed in 27-107 μL· L^-1 air was significantly greater than 13.33 % observed in the control. At 3 HAT, percentage repellence was significantly （p〈0.05） affected by doses. Application of EO at 10-30 μL· cm^2 caused class V repellence （86.67%-100%） compared with the control which caused class I repellence （0-20%）.
