Small unmanned aerial vehicle(UAV),a timely and effective pesticide sprayer,can be used to spray pesticide in a high efficiency without harming the crop,and is especially suitable for spraying for small farms and hill...Small unmanned aerial vehicle(UAV),a timely and effective pesticide sprayer,can be used to spray pesticide in a high efficiency without harming the crop,and is especially suitable for spraying for small farms and hills in Asian countries.In recent years,it has been chosen as a key and new technique for pesticide application.This paper studied the impact of UAV(UAV N-3)spraying parameters(different working height and different spraying concentrations)on the deposition of droplets on the wheat canopy and the prevention of powdery mildew.Water sensitive paper was used as the sampler to collect the pesticide droplets and image processing software Deposit Scan was used to compute the coverage rate of droplets on the wheat top layer to acquire the proportional distribution of droplets on the wheat lower layer.The experimental results showed the impact of spraying height on the distribution of droplets on the wheat upper layer was quite significant,when the spraying height was 5.0 m and the spraying speed was 4 m/s,the coverage rate of droplets on the wheat lower layer was the largest,as it was 45.6%of that on the upper layer,the droplets distribution was the most uniform,and the coefficient of variation was 33.13%.450 g/hm^(2)(dosage registered)of triadimefon SC(44%)was sprayed by the UAV,the control efficiency reached 55.1%after applying which was better than 20%and 40%of dosage decreased for each hectare,and the applying effect(35.6%)of 20%dosage decreased for each hectare had no significant difference from the applying effect(34.6%)applied by a knapsack-type electric sprayer.At 10 d after applying,the prevention effect realized by UAV was lower than that realized by a knapsack-type electric sprayer,and it may be correlated to the meteorological condition and water amount in the pesticide sprayed.Thus,when UAV spraying was chosen to prevent wheat powdery mildew under a serious disease situation,an auxiliary agent for spraying could be added to prolong the retention of pesticide on the plant surface to extend the pest展开更多
[Objective] This study was carried out to determine the induction effect of jasmonic acid（JA）on powdery mildew resistance in wheat,the activation effect on the expressions of plant disease resistance related genes,a...[Objective] This study was carried out to determine the induction effect of jasmonic acid（JA）on powdery mildew resistance in wheat,the activation effect on the expressions of plant disease resistance related genes,and to investigate the relationship between the induced resistance and the gene expression patterns.[Method] Three powdery mildew susceptible cultivars of ＂Chinese Spring＂,＂Pumai 9＂ and ＂Zhoumai 18＂ typically representing different phenotypes in the field were employed.The powdery mildew was assessed by detached leaf assay,and real time quantitative RT-PCR was used to determine the expression patterns of 9 disease resistance related genes of PR1（PR1.1）,PR2（β,1-3 glucanase）,PR3（chitinase）,PR4（wheatwin1）,PR5（thaumatin-like protein）,PR9（TaPERO,peroxidase）,PR10,TaGLP2a（germin-like）and Ta-JA2（jasmonate-induced protein）in leaf of the three cultivars.[Result] MeJA application enhanced the powdery mildew resistances of ＂Chinese Spring＂,＂Pumai 9＂ and ＂Zhoumai 18＂.The induced powdery mildew resistance could be detected from 12 h to 96 h after MeJA treatment,and the peak value was at 24 h.Though there were differences between the three cultivars,MeJA significantly effect on the expressions of the 8 disease resistance related genes except TaGLP2a,and the peak values were at 12 h,24 h or 48 h after treatments.The strongest activation of MeJA was on PR9 and PR1 that their expressions could reach more than 100 times of the untreated samples.MeJA strongly activated PR2、PR4、PR5、PR3、PR10 and Ta-JA2,their expression could reach 10 to 70 times,and there was almost no activation effect on TaGLP2a.The induced powdery mildew resistance positively correlated with the induced expressions of the 8 disease related genes.[Conclusion] The induced powdery mildew resistance positively correlated with the induced expressions of the disease related genes.Jasmonate signalling plays a role in defence against Blumeria graminis f.sp.tritici.and future manipulation of this展开更多
Stilbene, a kind of phytoalexin, plays an important role in resistance to fungal and bacterial infection in plants. It strongly inhibits the growth of fungi and sprout of spore. Stilbene synthase gene (Vst1) obtained ...Stilbene, a kind of phytoalexin, plays an important role in resistance to fungal and bacterial infection in plants. It strongly inhibits the growth of fungi and sprout of spore. Stilbene synthase gene (Vst1) obtained from grapevine has been transferred into common spring wheat Jinghong 5 by using the biolistic transformation method. Five transgenic plants (T0) were obtained from the bombarded 2014 immature embryos. One immune plantlet and 3 plantlets with mid-resistance to powdery mildew were identified from the transgenic plants of T3 generation which came from 2 T0 transgenic plants.展开更多
: Wide cross and molecular cytogenetic methods were used to transfer the powdery mildew resistance gene from Thinopyron intermedium(Host) Barkworth & DR Dewey to wheat. Among the progeny of crossing common wheat (...: Wide cross and molecular cytogenetic methods were used to transfer the powdery mildew resistance gene from Thinopyron intermedium(Host) Barkworth & DR Dewey to wheat. Among the progeny of crossing common wheat (Triticum aestivum L.) Yannong 15 with Th. intermedium, a partial amphiploid E990256, with resistance to powdery mildew, was developed. It had 56 chromosomes and could form 28 bivalents in pollen mother cells at metaphase I of meiosis. Resistance verification by race 15 at the seedling stage and by mixed strains of Erysiphales gramnis DC. f. sp. tritici Em. Marchal at the adult stage showed it was immune to powdery mildew at both stages. Gene postulation via 21 isolates of E. gramnis f. sp. tritici and 29 differential hosts showed it was nearly immune to all the isolates used, and its resistance pattern was different from all the mildew resistance genes used, which indicated it probably contained a new resistance gene to powdery mildew. Biochemical verification showed it might convey different Th. intermedium chromosomes from those of the wheat- Th. intermedium partial amphiploids Zhong 1–5. Genomic in situ hybridization analysis by using St genomic DNA as the probe showed E990256 contained a recombination genome of St and E.展开更多
Two powdery mildew resistance genes were Identified from Aegilops tauschll accessions Y201 and Y212 and mapped using two different F2 populations derived from the crosses between susceptible accession Y2272 and Y201, ...Two powdery mildew resistance genes were Identified from Aegilops tauschll accessions Y201 and Y212 and mapped using two different F2 populations derived from the crosses between susceptible accession Y2272 and Y201, and susceptible accession Y2263 and Y212. Genetic analysis of resistance to powdery mildew Indicated that the resistance of Y201 was controlled by a single dominant gene, whereas the resistance of Y212 was controlled by a single recessive gene. We have temporarily designated these genes as PmY201 and PmY212, respectively. By bulk segregation analysis, six mlcrosatelllte markers Including Xgwm174, cfd26, cfd57, cfdl02, Xgwm583 and Xgwm639 were found to be linked to PraY201 with genetic distances of 5.2, 7.7, 9.6, 12.5, 20.2 and 22.1 cM, respectively. Five SSR markers, including cfd57, Xgwm182, cfd7, cfd102, and cfd12, were found to be linked to PmY212 with distances of 5.6, 7.2, 11.5, 14.7, and 18.5 cM, respectively. According to the locations of the linked markers, the two resistance genes were located In the 5DL region. Based on the chromosomal locations and the resistance patterns of the two genes, we propose that PmY201 and PmY212 are two novel powdery mildew resistance genes, and are suitable for marker-assisted selection.展开更多
Cucumber powdery mildew is one of the most destructive diseases of cucumber throughout the world. In the present study, inheritance of powdery mildew resistance in three crosses, and linkage of resistance with amplifi...Cucumber powdery mildew is one of the most destructive diseases of cucumber throughout the world. In the present study, inheritance of powdery mildew resistance in three crosses, and linkage of resistance with amplified fragment length polymorphism （AFLP） markers are studied to formulate efficient strategies for breeding cultivars resistant to powdery mildew. The joint analysis of multiple generations and AFLP technique has been applied in this study. The best model is the one with two major genes, additive, dominant, and epistatic effects, plus polygenes with additive, dominant, and epistatic effects （E-l-0 model）. The heritabilities of the major genes varied from 64.26% to 97.82%, and susceptibility was incompletely dominant for the two major genes in the three crosses studied. The additive effects of the two major genes and the dominant effect of the second major gene were high, and the epistatic effect of the additive-dominant between the two major genes was the highest in cross I . In cross II, the absolute value of the additive effect, dominant effect, and potential ratio of the first major gene were far higher than those of the second major gene, and the epistatic effect of the additive-additive was the highest. The genetic parameters of the two major genes in cross III were similar to those in cross II. Correlation and regression analyses showed that marker E25/M63-103 was linked to a susceptible gene controlling powdery mildew resistance. The marker could account for 19.98% of the phenotypic variation. When the marker was tested on a diverse set of 29 cucumber lines, the correlation between phenotype and genotype was not significant, which suggested cultivar specialty of gene expression or different methods of resistance to powdery mildew. The target DNA fragment was 103 bp in length, and only a small part was found to be homologous to DNA in the other species evaluated, which indicated that it was unique to the cucumber genome.展开更多
Powdery mildew （Blumeria graminis） is one of the most destructive crop diseases infecting winter wheat plants, and has devastated millions of hectares of farmlands in China. The objective of this study is to detect ...Powdery mildew （Blumeria graminis） is one of the most destructive crop diseases infecting winter wheat plants, and has devastated millions of hectares of farmlands in China. The objective of this study is to detect the disease damage of powdery mildew on leaf level by means of the hyperspectral measurements, particularly using the continuous wavelet analysis. In May 2010, the reflectance spectra and the biochemical properties were measured for 114 leaf samples with various disease severity degrees. A hyperspectral imaging system was also employed for obtaining detailed hyperspectral information of the normal and the pustule areas within one diseased leaf. Based on these spectra data, a continuous wavelet analysis （CWA） was carried out in conjunction with a correlation analysis, which generated a so-called correlation scalogram that summarizes the correlations between disease severity and the wavelet power at different wavelengths and decomposition scales. By using a thresholding approach, seven wavelet features were isolated for developing models in determining disease severity. In addition, 22 conventional spectral features （SFs） were also tested and compared with wavelet features for their efficiency in estimating disease severity. The multivariate linear regression （MLR） analysis and the partial least square regression （PLSR） analysis were adopted as training methods in model mildew on leaf level were found to be closely related with the development. The spectral characteristics of the powdery spectral characteristics of the pustule area and the content of chlorophyll. The wavelet features performed better than the conventional SFs in capturing this spectral change. Moreover, the regression model composed by seven wavelet features outperformed （R2=0.77, relative root mean square error RRMSE=0.28） the model composed by 14 optimal conventional SFs （R2---0.69, RRMSE--0.32） in estimating the disease severity. The PLSR method yielded a higher accuracy than the MLR method. A combination o展开更多
Many fungal and oomycete pathogens differentiate a feeding structure named the haustorium to extract nutrition from the plant epidermal cell. The atypical resistance （R） protein RPW8.2 activates salicylic acid （SA...Many fungal and oomycete pathogens differentiate a feeding structure named the haustorium to extract nutrition from the plant epidermal cell. The atypical resistance （R） protein RPW8.2 activates salicylic acid （SA）-dependent, haustorium-targeted defenses against Golovinomyces spp., the causal agents of powdery mildew diseases on multiple plant species. How RPW8.2 activates defense remains uncharacterized. Here, we report that RPWS.2 interacts with the phytochrome-associated protein phosphatase type 2C （PAPP2C） in yeast and in planta as evidenced by co- immunoprecipitation and bimolecular fluorescence complementation assays. Down-regulation of PAPP2C by RNA interfer- ence （RNAi） in Col-0 plants lacking RPWS.2 leads to leaf spontaneous cell death and enhanced disease resistance to powdery mildew via the SA-dependent signaling pathway. Moreover, down-regulation of PAPP2C by RNAi in the RPW8.2 background results in strong HR-like cell death, which correlates with elevated RPWS.2 expression. We further demonstrate that hemagglutinin （HA）-tagged PAPP2C prepared from tobacco leaf cells transiently transformed with HA-PAPP2C possesses phosphatase activity. In addition, silencing a rice gene （Os04g0452000） homologous to PAPP2C also results in spontaneous cell death in rice. Combined, our results suggest that RPW8.2 is functionally connected with PAPP2C and that PAPP2C negatively regulates SA-dependent basal defense against powdery mildew in Arabidopsis.展开更多
Wheat-related species Th. intermedium was used to cross with common wheat Yannong 15. In the self progenies of the hybrid, two addition lines, II -1-7-1 and II -3-3-2, stable in cytology, were developed by cytology an...Wheat-related species Th. intermedium was used to cross with common wheat Yannong 15. In the self progenies of the hybrid, two addition lines, II -1-7-1 and II -3-3-2, stable in cytology, were developed by cytology and powdery mildew resistance identification. Their chromosome number were 2n = 44 and formed 22 bivalents at PMC MI. In F1 of the two addition lines crossing with Yannong 15, there appeared about one univalent at PMC MI, respectively. Resistance identification in greenhouse and field using the No. 15 and mixed strains of E. gramnis f. sp. tritici showed that they were immune to powdery mildew. Chromosome number and resistance identification using the F2 single plants of the addition line crossing with Yannong 15 indicated that the resistant gene was located on the alien chromosomes. In situ hybridization using St and E genomic DNA as probe showed that the added chromosome in the two addition lines probably came from the E genome of Th. intermedium, which indicated that a pair of E genome展开更多
The Pm18 gene of wheat confers resistance to the powdery mildew which is one of the mostserious diseases in many regions of the world. In this study, bulked segregant analysis(BSA) was used to develop randomly amplifi...The Pm18 gene of wheat confers resistance to the powdery mildew which is one of the mostserious diseases in many regions of the world. In this study, bulked segregant analysis(BSA) was used to develop randomly amplified polymorphic DNA (RAPD) markers linked toPm18 gene. Three hundred and twenty decamer primers were screened and one of them wasidentified as RAPD marker (S411600) linked to Pm18. Using the F2 mapping population fromthe cross Pm18Chancellor, the marker S411600 was shown to co-segregate with the genePm18. This marker can be conveniently used for marker-assisted selection in wheatbreeding programs for the identification or pyramiding of Pm18 with other resistancegenes.展开更多
As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivat...As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;展开更多
Barley powdery mildew caused by Blumeria graminis f. sp. hordei （Bgh） is one of the most destructive foliar diseases of barley in the winter barley region of China. The evaluation and assessment of the virulence and...Barley powdery mildew caused by Blumeria graminis f. sp. hordei （Bgh） is one of the most destructive foliar diseases of barley in the winter barley region of China. The evaluation and assessment of the virulence and diversity of Bgh populations help to determine effective sources of resistance to the pathogen. 515 isolates were collected from seven populations of Bgh on cultivated barley in seven geographically distant locations in 2006. Their virulence was determined by inoculation onto 26 differential host lines. All of the isolates belonged to 58 pathotypes and 13 of which included 81% of these isolates. The most abundant pathotype was pathotype 0047 （18.3%）, the second most abundant was pathotype 0045 （11.8%） and the third most abundant was pathotype 0057 （7.8%）. Most of virulent genes investigated in this study showed similar frequencies in the seven different areas. These indicate that the seven locations may be in a uniform epidemiological region and barley cultivars in these areas may have similar genetic background. Diversities within these populations and distances between these populations measured by KOIND package were different. Correlations were not found between the genetic distance and the geographical distances between different locations. This suggested that long distance spread and local epidemics existed in the major winter barley growing regions in China.展开更多
Different concentrations of jasmonic acid(JA)and benzothiadiazole(BTH) were sprayed on 2-year-old Rosa rugosa‘Plena’ seedlings. The induced resistance of JA and BTH to Sphaerotheca pannosa(Wallr.) and the changes of...Different concentrations of jasmonic acid(JA)and benzothiadiazole(BTH) were sprayed on 2-year-old Rosa rugosa‘Plena’ seedlings. The induced resistance of JA and BTH to Sphaerotheca pannosa(Wallr.) and the changes of their related physiological indices were investigated. Results showed that JA and BTH treatments had inhibitory impacts on S. pannosa infection. The optimal concentration of JA and BTH was 0.5 mmol/L for the disease-resistance induction of the leaves, its inductive effect was up to 66.36% for BTH and 54.49% for JA. Our results confirmed that exogenous JA and BTH significantly improved R. rugose ‘Plena’ resistance to S. pannosa. When treated with JA and BTH, activities of the three defense enzymes(POD, PPO, and PAL) increased significantly.Contents of total phenolics, flavonoids, and lignin also increased significantly. It is inferred from these results that exogenous JA and BTH could improve the resistance of R.rugose ‘Plena’ to S. pannosa through enhancing activities of the defensive enzymes and accumulation of secondary metabolites in the leaves.展开更多
Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi pa...Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi parasitizing wheat are the rust and powdery mildew pathogens, but their obligate biotrophic lifestyles and pathogenicity mechanisms are not well understood at the molecular level. With the advent of next generation sequencing technology, increasing numbers of pathogen genomes are becoming available. Research in plant pathology has entered a new genomics era. This review summarizes recent progress in understanding the biology and pathogenesis of biotrophic fungal pathogens attacking wheat based on pathogen genomics. We particularly focus on the three wheat rust and the powdery mildew fungi in regard to genome sequencing, avirulence gene cloning, effector discovery, and pathogenomics. We predict that coordinated study of both wheat and its pathogens should reveal new insights in biotrophic adaptation, pathogenicity mechanisms,and population dynamics of these fungi that will assist in development of new strategies for breeding wheat varieties with durable resistance.展开更多
Powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici(Bgt), is a global disease that poses a serious threat to wheat production. To explore additional resistance gene, a wheatDasypyrum villo...Powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici(Bgt), is a global disease that poses a serious threat to wheat production. To explore additional resistance gene, a wheatDasypyrum villosum 1 V#5(1 D) disomic substitution line NAU1813(2 n = 42) with high level of seedling resistance to powdery mildew was used to generate the recombination between chromosomes 1 V#5 and1 D. Four introgression lines, including t1 VS#5 ditelosomic addition line NAU1815, t1 VL#5 ditelosomic addition line NAU1816, homozygous T1 DL·1 VS#5 translocation line NAU1817, and homozygous T1 DS·1 VL#5 translocation line NAU1818 were developed from the selfing progenies of 1 V#5 and 1 D double monosomic line that derived from F1 hybrids of NAU1813/NAU0686. All of them were characterized by fluorescence in situ hybridization, genomic in situ hybridization, 1 V-specific markers analysis, and powdery mildew tests at different developmental stages. A new powdery mildew resistance gene named Pm67 was physically located in the terminal bin(FL 0.70–1.00) of 1 VS#5. Lines with Pm67 exhibited seedling stage immunity and tissue-differentiated reactions at adult plant stage. The sheaths, stems, and spikes of the Pm67 line were still immune, but the leaves showed a low degree of susceptibility.Microscopic observation showed that most penetration attempts were stopped in association with papillae on the sheath, and colonies cannot form conidia on the susceptible leaf of Pm67 line at adult plant stage, suggesting that the defence layers of the Pm67 line is tissue-differentiated. Thus, the T1 DL·1 VS#5 translocation line NAU1817 provides a new germplasm in wheat breeding for improvement of powdery mildew resistance.展开更多
Wheat powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is a devastating disease that threatens wheat production worldwide.Pm12,which originated from Aegilops speltoides,a wild relative of wheat,confers str...Wheat powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is a devastating disease that threatens wheat production worldwide.Pm12,which originated from Aegilops speltoides,a wild relative of wheat,confers strong resistance to powdery mildew and therefore has potential use in wheat breeding.Using susceptible mutants induced by gamma irradiation,we physically mapped and isolated Pm12 and showed it to be orthologous to Pm21 from Dasypyrum villosum,also a wild relative of wheat.The resistance function of Pm12 was validated via ethyl methanesulfonatemutagenesis,virus-induced gene silencing,and stable genetic transformation.Evolutionary analysis indicates that the Pm12/Pm21 loci in wheat species are relatively conserved but dynamic.Here,we demonstrated that the two orthologous genes,Pm12 and Pm21,possess differential resistance against the same set of Bgt isolates.Overexpression of the coiledcoil domains of both PM12 and PM21 induces cell death in Nicotiana benthamiana leaves.However,their full-length forms display different cell death-inducing activities caused by their distinct intramolecular interactions.Cloning of Pm12 will facilitate its application in wheat breeding programs.This study also gives new insight into two orthologous resistance genes,Pm12 and Pm21,which show different race specificities and intramolecular interaction patterns.展开更多
In order to transfer useful genes of Hordeum californicum into common wheat （Triticum aestivum L.）, the T. aestivum c.v. Chinese Spring （CS）-H. californicum amphiploid was crossed to CS, and its backcrossing and s...In order to transfer useful genes of Hordeum californicum into common wheat （Triticum aestivum L.）, the T. aestivum c.v. Chinese Spring （CS）-H. californicum amphiploid was crossed to CS, and its backcrossing and self-fertilized progenies were analyzed by morpho- logical observation, cytological, biochemical and molecular marker techniques. Alien addition lines with two H. californicum chromo- somes were identified and their genetic constitution was characterized. STS-PCR analysis using chromosome 2B specific markers indi- cated that chromosome H3 of H. californicum belongs to homoeologous group 2, and was thus designated 2H. SDS-PAGE showed that chromosome H2 of H. californicum belongs to homoeologous group 5, and was designated 5H. The CS-H. californicum amphiploid and the chromosome addition lines （DA2H and MA5H） identified were evaluated for powdery mildew （Erysiphe graminis f. sp. triticii） resis- tance in field. The preliminary results indicated that the amphiploid showed higher powdery mildew resistance than CS. However, chro- mosome addition lines DA2H and MA5H were highly susceptible to powdery mildew, indicating that major powdery mildew resistant genes of H. californicum should be located on chromosomes other than 2H and 5H.展开更多
Wild species have a potential value in crop breeding. Explore MLO gene which related with powdery mildew natural resistance is very important for improving the quality of melon. Resistance to powdery mildew was examin...Wild species have a potential value in crop breeding. Explore MLO gene which related with powdery mildew natural resistance is very important for improving the quality of melon. Resistance to powdery mildew was examined in cultivar and wild species by leaf inoculation. The wild germplasms showed resistance to powdery mildew Race1. Cloning and sequence analysis of the Cm MLO2 gene identified an 85 bp difference between the wild and cultivated species. The Cm MLO2 gene was expressed in the wild germplasm after fluorescence-labeled Agrobacterium-mediated transformation. A positive transgenic plant showed successful invasion by powdery mildew Race1. These results suggested that the wild species might have failed to encode the MLO protein, thereby resulting in the MLO-negative regulation of powdery mildew, which in turn resulted in the broad-spectrum resistance of the wild species to powdery mildew.展开更多
基金supported by the National Key Research and Development Plan(2016YFD0200700)Natural Science Foundation of Jiangsu Province,China(BK20151074)+1 种基金the Pesticide Applying Intelligent Operating System based on Beidou Automatic Navigation by UAV(1610372016008)the Chinese Academy of Agricultural Sciences Special Basic Scientific Research Business Expenses(Y2017PT32).
文摘Small unmanned aerial vehicle(UAV),a timely and effective pesticide sprayer,can be used to spray pesticide in a high efficiency without harming the crop,and is especially suitable for spraying for small farms and hills in Asian countries.In recent years,it has been chosen as a key and new technique for pesticide application.This paper studied the impact of UAV(UAV N-3)spraying parameters(different working height and different spraying concentrations)on the deposition of droplets on the wheat canopy and the prevention of powdery mildew.Water sensitive paper was used as the sampler to collect the pesticide droplets and image processing software Deposit Scan was used to compute the coverage rate of droplets on the wheat top layer to acquire the proportional distribution of droplets on the wheat lower layer.The experimental results showed the impact of spraying height on the distribution of droplets on the wheat upper layer was quite significant,when the spraying height was 5.0 m and the spraying speed was 4 m/s,the coverage rate of droplets on the wheat lower layer was the largest,as it was 45.6%of that on the upper layer,the droplets distribution was the most uniform,and the coefficient of variation was 33.13%.450 g/hm^(2)(dosage registered)of triadimefon SC(44%)was sprayed by the UAV,the control efficiency reached 55.1%after applying which was better than 20%and 40%of dosage decreased for each hectare,and the applying effect(35.6%)of 20%dosage decreased for each hectare had no significant difference from the applying effect(34.6%)applied by a knapsack-type electric sprayer.At 10 d after applying,the prevention effect realized by UAV was lower than that realized by a knapsack-type electric sprayer,and it may be correlated to the meteorological condition and water amount in the pesticide sprayed.Thus,when UAV spraying was chosen to prevent wheat powdery mildew under a serious disease situation,an auxiliary agent for spraying could be added to prolong the retention of pesticide on the plant surface to extend the pest
基金Supported by The Key Project of Science and Technology of HenanProvince(102102110040)Innovation Scientists and the Innovation Fund for Outstanding Scholars of Henan Province(104200510013)~~
文摘[Objective] This study was carried out to determine the induction effect of jasmonic acid（JA）on powdery mildew resistance in wheat,the activation effect on the expressions of plant disease resistance related genes,and to investigate the relationship between the induced resistance and the gene expression patterns.[Method] Three powdery mildew susceptible cultivars of ＂Chinese Spring＂,＂Pumai 9＂ and ＂Zhoumai 18＂ typically representing different phenotypes in the field were employed.The powdery mildew was assessed by detached leaf assay,and real time quantitative RT-PCR was used to determine the expression patterns of 9 disease resistance related genes of PR1（PR1.1）,PR2（β,1-3 glucanase）,PR3（chitinase）,PR4（wheatwin1）,PR5（thaumatin-like protein）,PR9（TaPERO,peroxidase）,PR10,TaGLP2a（germin-like）and Ta-JA2（jasmonate-induced protein）in leaf of the three cultivars.[Result] MeJA application enhanced the powdery mildew resistances of ＂Chinese Spring＂,＂Pumai 9＂ and ＂Zhoumai 18＂.The induced powdery mildew resistance could be detected from 12 h to 96 h after MeJA treatment,and the peak value was at 24 h.Though there were differences between the three cultivars,MeJA significantly effect on the expressions of the 8 disease resistance related genes except TaGLP2a,and the peak values were at 12 h,24 h or 48 h after treatments.The strongest activation of MeJA was on PR9 and PR1 that their expressions could reach more than 100 times of the untreated samples.MeJA strongly activated PR2、PR4、PR5、PR3、PR10 and Ta-JA2,their expression could reach 10 to 70 times,and there was almost no activation effect on TaGLP2a.The induced powdery mildew resistance positively correlated with the induced expressions of the 8 disease related genes.[Conclusion] The induced powdery mildew resistance positively correlated with the induced expressions of the disease related genes.Jasmonate signalling plays a role in defence against Blumeria graminis f.sp.tritici.and future manipulation of this
文摘Stilbene, a kind of phytoalexin, plays an important role in resistance to fungal and bacterial infection in plants. It strongly inhibits the growth of fungi and sprout of spore. Stilbene synthase gene (Vst1) obtained from grapevine has been transferred into common spring wheat Jinghong 5 by using the biolistic transformation method. Five transgenic plants (T0) were obtained from the bombarded 2014 immature embryos. One immune plantlet and 3 plantlets with mid-resistance to powdery mildew were identified from the transgenic plants of T3 generation which came from 2 T0 transgenic plants.
文摘: Wide cross and molecular cytogenetic methods were used to transfer the powdery mildew resistance gene from Thinopyron intermedium(Host) Barkworth & DR Dewey to wheat. Among the progeny of crossing common wheat (Triticum aestivum L.) Yannong 15 with Th. intermedium, a partial amphiploid E990256, with resistance to powdery mildew, was developed. It had 56 chromosomes and could form 28 bivalents in pollen mother cells at metaphase I of meiosis. Resistance verification by race 15 at the seedling stage and by mixed strains of Erysiphales gramnis DC. f. sp. tritici Em. Marchal at the adult stage showed it was immune to powdery mildew at both stages. Gene postulation via 21 isolates of E. gramnis f. sp. tritici and 29 differential hosts showed it was nearly immune to all the isolates used, and its resistance pattern was different from all the mildew resistance genes used, which indicated it probably contained a new resistance gene to powdery mildew. Biochemical verification showed it might convey different Th. intermedium chromosomes from those of the wheat- Th. intermedium partial amphiploids Zhong 1–5. Genomic in situ hybridization analysis by using St genomic DNA as the probe showed E990256 contained a recombination genome of St and E.
文摘Two powdery mildew resistance genes were Identified from Aegilops tauschll accessions Y201 and Y212 and mapped using two different F2 populations derived from the crosses between susceptible accession Y2272 and Y201, and susceptible accession Y2263 and Y212. Genetic analysis of resistance to powdery mildew Indicated that the resistance of Y201 was controlled by a single dominant gene, whereas the resistance of Y212 was controlled by a single recessive gene. We have temporarily designated these genes as PmY201 and PmY212, respectively. By bulk segregation analysis, six mlcrosatelllte markers Including Xgwm174, cfd26, cfd57, cfdl02, Xgwm583 and Xgwm639 were found to be linked to PraY201 with genetic distances of 5.2, 7.7, 9.6, 12.5, 20.2 and 22.1 cM, respectively. Five SSR markers, including cfd57, Xgwm182, cfd7, cfd102, and cfd12, were found to be linked to PmY212 with distances of 5.6, 7.2, 11.5, 14.7, and 18.5 cM, respectively. According to the locations of the linked markers, the two resistance genes were located In the 5DL region. Based on the chromosomal locations and the resistance patterns of the two genes, we propose that PmY201 and PmY212 are two novel powdery mildew resistance genes, and are suitable for marker-assisted selection.
文摘Cucumber powdery mildew is one of the most destructive diseases of cucumber throughout the world. In the present study, inheritance of powdery mildew resistance in three crosses, and linkage of resistance with amplified fragment length polymorphism （AFLP） markers are studied to formulate efficient strategies for breeding cultivars resistant to powdery mildew. The joint analysis of multiple generations and AFLP technique has been applied in this study. The best model is the one with two major genes, additive, dominant, and epistatic effects, plus polygenes with additive, dominant, and epistatic effects （E-l-0 model）. The heritabilities of the major genes varied from 64.26% to 97.82%, and susceptibility was incompletely dominant for the two major genes in the three crosses studied. The additive effects of the two major genes and the dominant effect of the second major gene were high, and the epistatic effect of the additive-dominant between the two major genes was the highest in cross I . In cross II, the absolute value of the additive effect, dominant effect, and potential ratio of the first major gene were far higher than those of the second major gene, and the epistatic effect of the additive-additive was the highest. The genetic parameters of the two major genes in cross III were similar to those in cross II. Correlation and regression analyses showed that marker E25/M63-103 was linked to a susceptible gene controlling powdery mildew resistance. The marker could account for 19.98% of the phenotypic variation. When the marker was tested on a diverse set of 29 cucumber lines, the correlation between phenotype and genotype was not significant, which suggested cultivar specialty of gene expression or different methods of resistance to powdery mildew. The target DNA fragment was 103 bp in length, and only a small part was found to be homologous to DNA in the other species evaluated, which indicated that it was unique to the cucumber genome.
基金the National Natural Science Foundation of China (41101395, 41071276, 31071324)the Beijing Municipal Natural Science Foundation, China (4122032)the National Basic Research Program of China (2011CB311806)
文摘Powdery mildew （Blumeria graminis） is one of the most destructive crop diseases infecting winter wheat plants, and has devastated millions of hectares of farmlands in China. The objective of this study is to detect the disease damage of powdery mildew on leaf level by means of the hyperspectral measurements, particularly using the continuous wavelet analysis. In May 2010, the reflectance spectra and the biochemical properties were measured for 114 leaf samples with various disease severity degrees. A hyperspectral imaging system was also employed for obtaining detailed hyperspectral information of the normal and the pustule areas within one diseased leaf. Based on these spectra data, a continuous wavelet analysis （CWA） was carried out in conjunction with a correlation analysis, which generated a so-called correlation scalogram that summarizes the correlations between disease severity and the wavelet power at different wavelengths and decomposition scales. By using a thresholding approach, seven wavelet features were isolated for developing models in determining disease severity. In addition, 22 conventional spectral features （SFs） were also tested and compared with wavelet features for their efficiency in estimating disease severity. The multivariate linear regression （MLR） analysis and the partial least square regression （PLSR） analysis were adopted as training methods in model mildew on leaf level were found to be closely related with the development. The spectral characteristics of the powdery spectral characteristics of the pustule area and the content of chlorophyll. The wavelet features performed better than the conventional SFs in capturing this spectral change. Moreover, the regression model composed by seven wavelet features outperformed （R2=0.77, relative root mean square error RRMSE=0.28） the model composed by 14 optimal conventional SFs （R2---0.69, RRMSE--0.32） in estimating the disease severity. The PLSR method yielded a higher accuracy than the MLR method. A combination o
基金grants from the National Research Initiative of the USDA Cooperative State Research,Education and Extension Service to S.X.，G.L.W.，a grant from the National Science Foundation (grant number IOS-0842877) to S.X
文摘Many fungal and oomycete pathogens differentiate a feeding structure named the haustorium to extract nutrition from the plant epidermal cell. The atypical resistance （R） protein RPW8.2 activates salicylic acid （SA）-dependent, haustorium-targeted defenses against Golovinomyces spp., the causal agents of powdery mildew diseases on multiple plant species. How RPW8.2 activates defense remains uncharacterized. Here, we report that RPWS.2 interacts with the phytochrome-associated protein phosphatase type 2C （PAPP2C） in yeast and in planta as evidenced by co- immunoprecipitation and bimolecular fluorescence complementation assays. Down-regulation of PAPP2C by RNA interfer- ence （RNAi） in Col-0 plants lacking RPWS.2 leads to leaf spontaneous cell death and enhanced disease resistance to powdery mildew via the SA-dependent signaling pathway. Moreover, down-regulation of PAPP2C by RNAi in the RPW8.2 background results in strong HR-like cell death, which correlates with elevated RPWS.2 expression. We further demonstrate that hemagglutinin （HA）-tagged PAPP2C prepared from tobacco leaf cells transiently transformed with HA-PAPP2C possesses phosphatase activity. In addition, silencing a rice gene （Os04g0452000） homologous to PAPP2C also results in spontaneous cell death in rice. Combined, our results suggest that RPW8.2 is functionally connected with PAPP2C and that PAPP2C negatively regulates SA-dependent basal defense against powdery mildew in Arabidopsis.
基金This work was supported by the National Natural Science Foundation of China (Grant No.39970458)。
文摘Wheat-related species Th. intermedium was used to cross with common wheat Yannong 15. In the self progenies of the hybrid, two addition lines, II -1-7-1 and II -3-3-2, stable in cytology, were developed by cytology and powdery mildew resistance identification. Their chromosome number were 2n = 44 and formed 22 bivalents at PMC MI. In F1 of the two addition lines crossing with Yannong 15, there appeared about one univalent at PMC MI, respectively. Resistance identification in greenhouse and field using the No. 15 and mixed strains of E. gramnis f. sp. tritici showed that they were immune to powdery mildew. Chromosome number and resistance identification using the F2 single plants of the addition line crossing with Yannong 15 indicated that the resistant gene was located on the alien chromosomes. In situ hybridization using St and E genomic DNA as probe showed that the added chromosome in the two addition lines probably came from the E genome of Th. intermedium, which indicated that a pair of E genome
文摘The Pm18 gene of wheat confers resistance to the powdery mildew which is one of the mostserious diseases in many regions of the world. In this study, bulked segregant analysis(BSA) was used to develop randomly amplified polymorphic DNA (RAPD) markers linked toPm18 gene. Three hundred and twenty decamer primers were screened and one of them wasidentified as RAPD marker (S411600) linked to Pm18. Using the F2 mapping population fromthe cross Pm18Chancellor, the marker S411600 was shown to co-segregate with the genePm18. This marker can be conveniently used for marker-assisted selection in wheatbreeding programs for the identification or pyramiding of Pm18 with other resistancegenes.
基金supported by a grant from the National High Technology Research and Development Program("863" Program) of China(No. 2011AA100103)
文摘As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;
基金support from the National Natural Science Foundation of China (30671289)the National Key Tech-nologies R&D Program (2006B BAD0 2B 04)+1 种基金the Nationnal Special Fund for Agro-Scientific Research inthe Public Interest (nyhyzx017-001-barley)the Ear-marked Fund for Modern Agro-Industry Technology Research System,China
文摘Barley powdery mildew caused by Blumeria graminis f. sp. hordei （Bgh） is one of the most destructive foliar diseases of barley in the winter barley region of China. The evaluation and assessment of the virulence and diversity of Bgh populations help to determine effective sources of resistance to the pathogen. 515 isolates were collected from seven populations of Bgh on cultivated barley in seven geographically distant locations in 2006. Their virulence was determined by inoculation onto 26 differential host lines. All of the isolates belonged to 58 pathotypes and 13 of which included 81% of these isolates. The most abundant pathotype was pathotype 0047 （18.3%）, the second most abundant was pathotype 0045 （11.8%） and the third most abundant was pathotype 0057 （7.8%）. Most of virulent genes investigated in this study showed similar frequencies in the seven different areas. These indicate that the seven locations may be in a uniform epidemiological region and barley cultivars in these areas may have similar genetic background. Diversities within these populations and distances between these populations measured by KOIND package were different. Correlations were not found between the genetic distance and the geographical distances between different locations. This suggested that long distance spread and local epidemics existed in the major winter barley growing regions in China.
基金supported by the Science Foundation of Heilongjiang Province of China(No.QC2014C012)the Fundamental Research Funds for the Central Universities(NO.2572016CA11)
文摘Different concentrations of jasmonic acid(JA)and benzothiadiazole(BTH) were sprayed on 2-year-old Rosa rugosa‘Plena’ seedlings. The induced resistance of JA and BTH to Sphaerotheca pannosa(Wallr.) and the changes of their related physiological indices were investigated. Results showed that JA and BTH treatments had inhibitory impacts on S. pannosa infection. The optimal concentration of JA and BTH was 0.5 mmol/L for the disease-resistance induction of the leaves, its inductive effect was up to 66.36% for BTH and 54.49% for JA. Our results confirmed that exogenous JA and BTH significantly improved R. rugose ‘Plena’ resistance to S. pannosa. When treated with JA and BTH, activities of the three defense enzymes(POD, PPO, and PAL) increased significantly.Contents of total phenolics, flavonoids, and lignin also increased significantly. It is inferred from these results that exogenous JA and BTH could improve the resistance of R.rugose ‘Plena’ to S. pannosa through enhancing activities of the defensive enzymes and accumulation of secondary metabolites in the leaves.
基金supported by the National Basic Research Program of China (2013CB127700)National Natural ScienceFoundation of China (31371882, 31401693)the 111 Project of the Ministry of Education of China (B07049)
文摘Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi parasitizing wheat are the rust and powdery mildew pathogens, but their obligate biotrophic lifestyles and pathogenicity mechanisms are not well understood at the molecular level. With the advent of next generation sequencing technology, increasing numbers of pathogen genomes are becoming available. Research in plant pathology has entered a new genomics era. This review summarizes recent progress in understanding the biology and pathogenesis of biotrophic fungal pathogens attacking wheat based on pathogen genomics. We particularly focus on the three wheat rust and the powdery mildew fungi in regard to genome sequencing, avirulence gene cloning, effector discovery, and pathogenomics. We predict that coordinated study of both wheat and its pathogens should reveal new insights in biotrophic adaptation, pathogenicity mechanisms,and population dynamics of these fungi that will assist in development of new strategies for breeding wheat varieties with durable resistance.
基金supported by the National Natural Science Foundation of China(31971938)the Natural Science Foundation of Jiangsu Province(BK20181316)+1 种基金the Special Fund for Independent Innovation of Agricultural Science and Technology in Jiangsu,China(CX(19)1001)Fundamental Research Funds for the Central Universities(KYZ201809)。
文摘Powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici(Bgt), is a global disease that poses a serious threat to wheat production. To explore additional resistance gene, a wheatDasypyrum villosum 1 V#5(1 D) disomic substitution line NAU1813(2 n = 42) with high level of seedling resistance to powdery mildew was used to generate the recombination between chromosomes 1 V#5 and1 D. Four introgression lines, including t1 VS#5 ditelosomic addition line NAU1815, t1 VL#5 ditelosomic addition line NAU1816, homozygous T1 DL·1 VS#5 translocation line NAU1817, and homozygous T1 DS·1 VL#5 translocation line NAU1818 were developed from the selfing progenies of 1 V#5 and 1 D double monosomic line that derived from F1 hybrids of NAU1813/NAU0686. All of them were characterized by fluorescence in situ hybridization, genomic in situ hybridization, 1 V-specific markers analysis, and powdery mildew tests at different developmental stages. A new powdery mildew resistance gene named Pm67 was physically located in the terminal bin(FL 0.70–1.00) of 1 VS#5. Lines with Pm67 exhibited seedling stage immunity and tissue-differentiated reactions at adult plant stage. The sheaths, stems, and spikes of the Pm67 line were still immune, but the leaves showed a low degree of susceptibility.Microscopic observation showed that most penetration attempts were stopped in association with papillae on the sheath, and colonies cannot form conidia on the susceptible leaf of Pm67 line at adult plant stage, suggesting that the defence layers of the Pm67 line is tissue-differentiated. Thus, the T1 DL·1 VS#5 translocation line NAU1817 provides a new germplasm in wheat breeding for improvement of powdery mildew resistance.
基金supported by grants from the National Natural Science Foundation of China(32171990,32072053,31971874,31872009,and U1604116)the Key Research and Development Program of Zhenjiang(NY2021001)+3 种基金the State Key Laboratory of Plant Cell and Chromosome Engineering(PCCE-KF-2021-05,PCCE-KF-2022-07)the State Key Laboratory of Crop Biology in Shandong Agricultural University(2021KF01)the Taishan Scholars Project(tsqn201812123)the Key Research and Development Program of Yantai(2019YT06000470).
文摘Wheat powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is a devastating disease that threatens wheat production worldwide.Pm12,which originated from Aegilops speltoides,a wild relative of wheat,confers strong resistance to powdery mildew and therefore has potential use in wheat breeding.Using susceptible mutants induced by gamma irradiation,we physically mapped and isolated Pm12 and showed it to be orthologous to Pm21 from Dasypyrum villosum,also a wild relative of wheat.The resistance function of Pm12 was validated via ethyl methanesulfonatemutagenesis,virus-induced gene silencing,and stable genetic transformation.Evolutionary analysis indicates that the Pm12/Pm21 loci in wheat species are relatively conserved but dynamic.Here,we demonstrated that the two orthologous genes,Pm12 and Pm21,possess differential resistance against the same set of Bgt isolates.Overexpression of the coiledcoil domains of both PM12 and PM21 induces cell death in Nicotiana benthamiana leaves.However,their full-length forms display different cell death-inducing activities caused by their distinct intramolecular interactions.Cloning of Pm12 will facilitate its application in wheat breeding programs.This study also gives new insight into two orthologous resistance genes,Pm12 and Pm21,which show different race specificities and intramolecular interaction patterns.
文摘In order to transfer useful genes of Hordeum californicum into common wheat （Triticum aestivum L.）, the T. aestivum c.v. Chinese Spring （CS）-H. californicum amphiploid was crossed to CS, and its backcrossing and self-fertilized progenies were analyzed by morpho- logical observation, cytological, biochemical and molecular marker techniques. Alien addition lines with two H. californicum chromo- somes were identified and their genetic constitution was characterized. STS-PCR analysis using chromosome 2B specific markers indi- cated that chromosome H3 of H. californicum belongs to homoeologous group 2, and was thus designated 2H. SDS-PAGE showed that chromosome H2 of H. californicum belongs to homoeologous group 5, and was designated 5H. The CS-H. californicum amphiploid and the chromosome addition lines （DA2H and MA5H） identified were evaluated for powdery mildew （Erysiphe graminis f. sp. triticii） resis- tance in field. The preliminary results indicated that the amphiploid showed higher powdery mildew resistance than CS. However, chro- mosome addition lines DA2H and MA5H were highly susceptible to powdery mildew, indicating that major powdery mildew resistant genes of H. californicum should be located on chromosomes other than 2H and 5H.
基金The National Natural Science Foundation of China(3136043431471896+1 种基金31301795)Innovation Project Team of the Gansu Academy of Agricultural Science(2015GAAS01)supported this study
文摘Wild species have a potential value in crop breeding. Explore MLO gene which related with powdery mildew natural resistance is very important for improving the quality of melon. Resistance to powdery mildew was examined in cultivar and wild species by leaf inoculation. The wild germplasms showed resistance to powdery mildew Race1. Cloning and sequence analysis of the Cm MLO2 gene identified an 85 bp difference between the wild and cultivated species. The Cm MLO2 gene was expressed in the wild germplasm after fluorescence-labeled Agrobacterium-mediated transformation. A positive transgenic plant showed successful invasion by powdery mildew Race1. These results suggested that the wild species might have failed to encode the MLO protein, thereby resulting in the MLO-negative regulation of powdery mildew, which in turn resulted in the broad-spectrum resistance of the wild species to powdery mildew.
