Fertile, advanced generation hybrids derived from crosses between Texas (Poa arachnifera Torr.) and Kentucky (Poa pratensis L.) bluegrass have been selected. The hybrids are currently being evaluated for low-input tur...Fertile, advanced generation hybrids derived from crosses between Texas (Poa arachnifera Torr.) and Kentucky (Poa pratensis L.) bluegrass have been selected. The hybrids are currently being evaluated for low-input turf potential. Since they are derived from hand-harvested seed from first-generation hybrids located in field nurseries their exact genetic origin is unknown. This experiment was conducted to determine if there are still genetic relationships among the advanced generation hybrids and some of the Texas and Kentucky parents in their pedigrees. Four Inter Simple Sequence Repeat (ISSR) primer combinations resolved on 6% nondenaturing polyacrylamide gels resulted in 179 polymorphic bands that were scored to create a genetic similarity matrix and dendrogram based on Jaccard’s coefficient. The clustering of the advanced generation hybrids was generally in agreement with what would be expected based on their pedigrees and indicated it was more likely to select a fertile hybrid from an advanced generation, rather than the F1 generation.展开更多
Embryogenic calli of Kentucky bluegrass, named Md, were induced from mature seeds and embryos, and proliferated on medium K3 containing 2,4-dichlorophenoxyacetic acid (2,4-D, 10.0 mumol/L), 6-benzylaminopurine (BAR, 0...Embryogenic calli of Kentucky bluegrass, named Md, were induced from mature seeds and embryos, and proliferated on medium K3 containing 2,4-dichlorophenoxyacetic acid (2,4-D, 10.0 mumol/L), 6-benzylaminopurine (BAR, 0.5 mumol/L) and K5 which was the K3 medium supplemented with cupric sulfa (0.5 mumol/L) under dim-light condition (20-30 mumol.m(-2).s-1, 16 h light) at 24 degreesC. Embryogenic calli were transformed with plasmids pDM805 Carring bar and gus genes, Which was mediated by an Agrobacterium strain AGL1, four transgenic lines were obtained. The important factors that affect the transformation efficiency and obtain desirable number of transgenic plants included: (1) the quality of embryogenic calli; (2) light condition and time of co-cultivation; (3) concentration of antibiotics used for suppressing the overgrowth of Agrobacterium in the course of transformed plant regeneration; (4) selection pressure, etc. The micro nutrient of cupric had significant influence on the quality of embryogenic calli. This presentation is the first successful protocol of Kentucky bluegrass transformation mediated by Agrobacterium.展开更多
Valeriana officinalis L.is a plant from the Caprifoliaceae family,which is widely distributed in various parts of the world,especially in Europe and Asia.All species of Valeriana are distinguished by their ability to s...Valeriana officinalis L.is a plant from the Caprifoliaceae family,which is widely distributed in various parts of the world,especially in Europe and Asia.All species of Valeriana are distinguished by their ability to synthesize essen-tial oil,which has a powerful effect on the physiological and mental aspects of the human body.The aim was to study the qualitative and quantitative composition of essential oil from valerian roots,collected in different coun-tries,using the gas chromatography method,and to establish marker compounds for valerian species.13 samples of commercial roots with rhizomes of V.officinalis from nine countries of the world and a sample of Valeriana pratensis and Valeriana stolonifera growing in Ukraine were selected for the study.The essential oil was obtained from dried valerian roots by the distillation method described in the European Pharmacopoeia.To determine the component composition of the essential oils of the selected samples,the methods of gas chromatography with a mass spectrometric detector and capillary gas chromatography were used.The commercial samples of V.offici-nalis from different countries yielded 0.21%–1.03%of essential oil.Only six of 13 samples contained essential oil in an amount that satisfies the requirement of the European Pharmacopoeia standard(not less than 4 mL/kg).150 compounds were identified in the essential oils of 13 samples of V.officinalis essential oils.The range and average content and coefficients of variation of the identified compounds were determined.The principal com-pounds of V.officinalis essential oils were bornyl acetate(1.6%–27.1%),valeranone(0.5%–17.9%),valerenal(0%–14.7%),camphene(0%–14.6%),α-fenchene(0%–10.6%),and valerenic acid(0%–8.5%).The samples of V.pratensis and V.stolonifera yielded rather high levels of essential oil(1.18%and 0.93%,respectively).Three chemotypes of V.officinalis samples were determined-bornyl acetate/valerenal,valeranone,and isovaleric acid.The composition of the three essential oils compared展开更多
High embryogenic calli of three cutivars of Kentucky bluegrass, Md, Bd, and Gm, were induced from mature embryos, and were proliferated on medium K3 and K5. Embryogenic calli were transformed with plamids pDM803 and p...High embryogenic calli of three cutivars of Kentucky bluegrass, Md, Bd, and Gm, were induced from mature embryos, and were proliferated on medium K3 and K5. Embryogenic calli were transformed with plamids pDM803 and pBY520 by microprojectile bombardment. Fourty-two transgenic lines had been obtained. The highest efficiency of transformation reached to 3.7% for cv. Md, 2.8% for cv. Gm, and 5 % for cv. Bd. The micro nutriment of Cupric had significant effect on transformation. The embryogenic callus cultured in dim-light condition had higher transformation efficiency than the green callus cultured in light condition for one month before transformation. The selective regime and selective pressure on the putative transgenic plants were important for obtaining the desire number of transgenic plants. It also affected the copy number of integrated genes in the genomic DNA of transgenic plants.展开更多
Drought stress is one of the major constraints on turf growth and performance in northern China. Based on previous assessments of drought tolerance levels, four varieties of Kentucky bluegrass （Poa pratensis L.） rep...Drought stress is one of the major constraints on turf growth and performance in northern China. Based on previous assessments of drought tolerance levels, four varieties of Kentucky bluegrass （Poa pratensis L.） representing different types （＇Baron＇, BVMG type; ＇Blackstone＇, Cheri type; ＇Kenblue＇, Midwest type; and ＇Bluemoon＇, Midnight type） were chosen for this study. Grass materials were established in a glasshouse, and the changes in their photosynthetic and metabolic characteristics were analyzed during a period of imposed drought stress. Drought stress led to decrease in chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate in all four cultivars, but the relative changes in each characteristic varied among varieties. The results also showed that changes in the photosynthetic and metabolic characteristics of different varieties under drought stress were related to the morphological characteristics of the plants. Varieties with longer narrow leaves, longer roots, higher root-to-shoot ratios, and higher chlorophyll contents showed greater rates of photosynthesis and stomatal conductance, and lower transpiration rates.展开更多
Total RNA from leaves of Poapratensis cultivars under drought stress was extracted for reversing transcription to cDNA and then cDNA as template for PCR reaction by designing primer of cds of Hordeum valgare HVA1 drou...Total RNA from leaves of Poapratensis cultivars under drought stress was extracted for reversing transcription to cDNA and then cDNA as template for PCR reaction by designing primer of cds of Hordeum valgare HVA1 drought resistance gene from GenBank. The amplified products were positive recon identified by using procedures of recovery, connection, transformation and enzyme separation. The length of cloned gene sequence was 324 bp, identity reached 79.27% with Barley HVA1 gene that meaned the cloned gene sequence was the partial HVA1 gene of Poapratensis.展开更多
In order to explore the influence of arbuscular mycorrhizal(AM)fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem,rhizosphere soils were coll...In order to explore the influence of arbuscular mycorrhizal(AM)fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem,rhizosphere soils were collected from eight different poisonous plants in degraded grasslands and one from pasture grass in non-degraded grasslands(CK).The collected soils were used as inocula to assess the influence of indigenous AM fungi on the growth of two typical pasture grass species,Elymus nutans and Poa pratensis,in a bioassay experiment.Five growth parameters and two AM parameters were determined.The mycorrhizal responsiveness and the importance value were calculated.Significant differences between the eight poisonous plants and CK were observed.Compared to CK,rhizosphere soil from the eight poisonous plants had lower AM fungal spore densities.The growth of E.nutans and P.pratensis seedlings was depressed with the inoculation from poisonous plants rhizosphere soil.This study demonstrated that the presence of poisonous plants with grassland degradation altered inherent AM fungal community abundance,and could exert inhibition effects on the growth of pasture grasses.It may attribute to discover the important role of rhizosphere soil of different poisonous plants to AM fungal community on the Alpine meadow.展开更多
A protocol was discussed for high efficient plant regeneration from seven bluegrass （Poa pratensis L.） cultivars via an in- direct callus induction and somatic embryogenesis method. Mature seeds were used as explant...A protocol was discussed for high efficient plant regeneration from seven bluegrass （Poa pratensis L.） cultivars via an in- direct callus induction and somatic embryogenesis method. Mature seeds were used as explants for callus initiation. Callus induction and proliferation efficiencies were investigated on NB, modified MS （MMS） and MS media, supplemented with 2.0 mg·L^-1 2,4-dichlorophenoxyacetic acid （2,4-D）. The MMS medium performed best. Based on the MMS medium, direct and indirect callus induction effects of bluegrass from mature seeds were compared at the range of 1-5 mg·L^-1 2,4-D contained in the medium. Under the direct callus induction method, the most suitable 2,4-D concentrations varied among cultivars. Under the indirect callus induction method, a significantly high callus induction frequency （93.33%-98.33%） was obtained and there were barely any statistically sig- nificant differences among the tested genetically diverse cultivars. Somatic embryos were promoted on the MMS medium supple- mented with 3 mg·L^-1 2,4-D, 0.1 mg·L^-1 kinetin and 0.8 mg·L^-1 CuSO4. Embryogenetic calli developed into plantlets on the MMS medium containing different concentrations of thidiazuron （TDZ）, and the differentiation frequencies varied in the range from 20.15% to 77.65%. The 0.25 mg·L^-1 TDZ was generally the most suitable concentration for the tested cultivars.展开更多
Semen characteristics of naturally fertile pairs and their correlation with fertility of eggs in Florida sandhill crane (Grus canadensis pratensis) were examined. Six pairs were used in this experiment, and all of the...Semen characteristics of naturally fertile pairs and their correlation with fertility of eggs in Florida sandhill crane (Grus canadensis pratensis) were examined. Six pairs were used in this experiment, and all of them that had bred before were housed in open individual pens. These pairs were isolated physically each other but not visually and audibly. Semen was collected twice (Tuesday morning and Friday afternoon) from February 26 to June 4, 1993. The standard methods at Patuxent Wildlife Research Center were used collecting and evaluating the semen and spermatozoa. and incubating the eggs. There were statistically individual variations (p<0.05) about successful collecting attempts, semen volume, semen concentration, spermatozoon’s motility,spermatozoon’s number per collection, live spermatozoon’s number, male’s response to semen collection, and morphology of spermatozoa except the giant cell. There was a significantly (p<0.05, correlation coefficient was (0.73 or (1 .00) negative correlation between fertility of eggs and the multiple value of semen (sperm) characteristics of naturally fertile pairs in Florida sandhill crane.展开更多
Lolines are a group of saturated pyrrolizidine alkaloids that possess broad bioactivity against a wide array of herbivorous insects. However, they do not exhibit toxicity to ruminants such as cattle and sheep. In orde...Lolines are a group of saturated pyrrolizidine alkaloids that possess broad bioactivity against a wide array of herbivorous insects. However, they do not exhibit toxicity to ruminants such as cattle and sheep. In order to study the direct and potential physiological effects on ruminants and the mechanism of insecticide/insectifuge, the distribution of loline alkaloids in endophyte-infected meadow fescue and the seasonal change of the distribution were analyzed. The crowns, roots and leaves of endophyte-infected meadow fescue at its four different growth periods, i.e., spring, summer, early autumn and late autumn, in New Zealand were colleted. After powdering, organic solvent extraction and purification by column chromatography, all loline alkaloid samples were analyzed by capillary gas chromatography with 4-phenylmorpholine （PM） as an internal standard. The analytic results showed that the loline contents in the roots, crowns and leaves of endophyte-infected meadow fescue vary with seasons. Even within the same season, the distribution of lolines in endophyte-infected meadow fescue varies. During summer, lolines mainly existed in the leaves and roots, but in early autumn, they are produced in the crowns. It was concluded that, lolines were mainly produced in the leaves and roots of endophyte-infected meadow fescue. In gas chromatographic analysis, N-formylloline, the major component of loline alkaloid in the plant, was employed to assay the alkaloids.展开更多
Aims Invasive plants commonly occupy disturbed soils,thereby provid-ing a stage for understanding the role of disturbance-enhanced resources in plant invasions.Here,we addressed how soil space and soil nutrients affec...Aims Invasive plants commonly occupy disturbed soils,thereby provid-ing a stage for understanding the role of disturbance-enhanced resources in plant invasions.Here,we addressed how soil space and soil nutrients affect the growth and competitive effect of inva-sive plants and whether this effect varies with different invaders.Methods We conducted an experiment in which two invasive plants(Bromus tectorum and Centaurea maculosa)and one native species(Poa pratensis)were grown alone or together in four habitats consisting of two levels of soil space and nutrients.at the end of the experiment,we determined the total biomass,biomass allocation and relative interaction intensity of B.tectorum,C.maculosa and P.pratensis.Important Findingsacross two invaders,B.tectorum and C.maculosa,increased soil nutrients had greater positive effects on their growth than increased soil space,the effects of soil space on root weight ratio were greater than those of soil nutrients,and their competitive effect decreased with soil space but increased with soil nutrients.these findings sug-gest that changing soil space and nutrients differentially influence the growth and competitive advantages of two invaders.Bromus tectorum benefited more from increased soil resources than C.mac-ulosa.soil space and nutrients affected the biomass allocation of C.maculosa but not B.tectorum.the competitive effect of B.tecto-rum was unaffected by soil space and soil nutrients,but the opposite was the case for C.maculosa.thus,the effects of soil space and nutrients on growth and competitive ability depend on invasive species identity.展开更多
Fifty two accessions of Festuca pratensis Huds. were analysed of which 18 had been collected in Switzerland and 32 in Bulgaria. SDS-PAGE of seed proteins was implemented to detect genetic variation among ecotype popul...Fifty two accessions of Festuca pratensis Huds. were analysed of which 18 had been collected in Switzerland and 32 in Bulgaria. SDS-PAGE of seed proteins was implemented to detect genetic variation among ecotype populations using a modification of UPOV method for barley. The modification concerns mainly protein extracting procedure as detailed described in the protocol. The two cultivars Preval and Cosmolit were used as standards. Cluster analyses and correspondence analyses/scatter plot were used as statistic approaches for determining genetic diversity among individual ecotypes and groups of ecotypes. Electrophoretic spectra of proteins show clear differences among local accessions in relation to their origin. In Swiss ecotypes 32 protein fragments were determined whereas in Bulgarian local populations their number was 68. Each of the two eco-groups possesses fragments that appear in all accessions of the group. The number of monomorphic bands within Bulgarian local ecotypes is four whereas their number in Swiss ecotypes is 12. Four monomorphic bands appearing in all proteinograms no difference of eco-groups was identified with Rm values of： 0.43, 0.55, 0.58, 0.82. A higher level of protein band polymorphism was proven in Bulgarian ecotypes in comparison with Swiss ecotypes. Thirty seven polymorphic bands occurred exclusively in the Bulgarian local ecotypes and had a frequency of 0.03 or higher whereas within Swiss ecotypes was detected one unique protein fragment. SDS-PAGE ＂fingerprinting＂ is suggested as a fast and easy approach to differentiate F. pratensis ecotypes by their origin as well for detection of foreign germplasm for inclusion in breeding programs.展开更多
文摘Fertile, advanced generation hybrids derived from crosses between Texas (Poa arachnifera Torr.) and Kentucky (Poa pratensis L.) bluegrass have been selected. The hybrids are currently being evaluated for low-input turf potential. Since they are derived from hand-harvested seed from first-generation hybrids located in field nurseries their exact genetic origin is unknown. This experiment was conducted to determine if there are still genetic relationships among the advanced generation hybrids and some of the Texas and Kentucky parents in their pedigrees. Four Inter Simple Sequence Repeat (ISSR) primer combinations resolved on 6% nondenaturing polyacrylamide gels resulted in 179 polymorphic bands that were scored to create a genetic similarity matrix and dendrogram based on Jaccard’s coefficient. The clustering of the advanced generation hybrids was generally in agreement with what would be expected based on their pedigrees and indicated it was more likely to select a fertile hybrid from an advanced generation, rather than the F1 generation.
文摘Embryogenic calli of Kentucky bluegrass, named Md, were induced from mature seeds and embryos, and proliferated on medium K3 containing 2,4-dichlorophenoxyacetic acid (2,4-D, 10.0 mumol/L), 6-benzylaminopurine (BAR, 0.5 mumol/L) and K5 which was the K3 medium supplemented with cupric sulfa (0.5 mumol/L) under dim-light condition (20-30 mumol.m(-2).s-1, 16 h light) at 24 degreesC. Embryogenic calli were transformed with plasmids pDM805 Carring bar and gus genes, Which was mediated by an Agrobacterium strain AGL1, four transgenic lines were obtained. The important factors that affect the transformation efficiency and obtain desirable number of transgenic plants included: (1) the quality of embryogenic calli; (2) light condition and time of co-cultivation; (3) concentration of antibiotics used for suppressing the overgrowth of Agrobacterium in the course of transformed plant regeneration; (4) selection pressure, etc. The micro nutrient of cupric had significant influence on the quality of embryogenic calli. This presentation is the first successful protocol of Kentucky bluegrass transformation mediated by Agrobacterium.
基金supported by the European Union in the MSCA4Ukraine Project“Design and Development of 3D-Printed Medicines for Bioactive Materials of Ukrainian and Estonian Medicinal Plants Origin”(ID Number 1232466).
文摘Valeriana officinalis L.is a plant from the Caprifoliaceae family,which is widely distributed in various parts of the world,especially in Europe and Asia.All species of Valeriana are distinguished by their ability to synthesize essen-tial oil,which has a powerful effect on the physiological and mental aspects of the human body.The aim was to study the qualitative and quantitative composition of essential oil from valerian roots,collected in different coun-tries,using the gas chromatography method,and to establish marker compounds for valerian species.13 samples of commercial roots with rhizomes of V.officinalis from nine countries of the world and a sample of Valeriana pratensis and Valeriana stolonifera growing in Ukraine were selected for the study.The essential oil was obtained from dried valerian roots by the distillation method described in the European Pharmacopoeia.To determine the component composition of the essential oils of the selected samples,the methods of gas chromatography with a mass spectrometric detector and capillary gas chromatography were used.The commercial samples of V.offici-nalis from different countries yielded 0.21%–1.03%of essential oil.Only six of 13 samples contained essential oil in an amount that satisfies the requirement of the European Pharmacopoeia standard(not less than 4 mL/kg).150 compounds were identified in the essential oils of 13 samples of V.officinalis essential oils.The range and average content and coefficients of variation of the identified compounds were determined.The principal com-pounds of V.officinalis essential oils were bornyl acetate(1.6%–27.1%),valeranone(0.5%–17.9%),valerenal(0%–14.7%),camphene(0%–14.6%),α-fenchene(0%–10.6%),and valerenic acid(0%–8.5%).The samples of V.pratensis and V.stolonifera yielded rather high levels of essential oil(1.18%and 0.93%,respectively).Three chemotypes of V.officinalis samples were determined-bornyl acetate/valerenal,valeranone,and isovaleric acid.The composition of the three essential oils compared
基金This project is supported by the Foundation of State Key Laboratory of Freshwater Ecology and Biotechnology,China(2001FB10)Young Foundation of Shanxi,China(20001038)+2 种基金Shanxi Scholarship Foundation,Chinathe Hational Natural Science Foundation of China(30270204)DLF-Trifolium,Research Division,Denmark.
文摘High embryogenic calli of three cutivars of Kentucky bluegrass, Md, Bd, and Gm, were induced from mature embryos, and were proliferated on medium K3 and K5. Embryogenic calli were transformed with plamids pDM803 and pBY520 by microprojectile bombardment. Fourty-two transgenic lines had been obtained. The highest efficiency of transformation reached to 3.7% for cv. Md, 2.8% for cv. Gm, and 5 % for cv. Bd. The micro nutriment of Cupric had significant effect on transformation. The embryogenic callus cultured in dim-light condition had higher transformation efficiency than the green callus cultured in light condition for one month before transformation. The selective regime and selective pressure on the putative transgenic plants were important for obtaining the desire number of transgenic plants. It also affected the copy number of integrated genes in the genomic DNA of transgenic plants.
基金Supported by the National Natural Science Foundation of China (30871735 31272191)+1 种基金the Natural Science Foundation of Heilongjiang Province(C0207 C200619)
文摘Drought stress is one of the major constraints on turf growth and performance in northern China. Based on previous assessments of drought tolerance levels, four varieties of Kentucky bluegrass （Poa pratensis L.） representing different types （＇Baron＇, BVMG type; ＇Blackstone＇, Cheri type; ＇Kenblue＇, Midwest type; and ＇Bluemoon＇, Midnight type） were chosen for this study. Grass materials were established in a glasshouse, and the changes in their photosynthetic and metabolic characteristics were analyzed during a period of imposed drought stress. Drought stress led to decrease in chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate in all four cultivars, but the relative changes in each characteristic varied among varieties. The results also showed that changes in the photosynthetic and metabolic characteristics of different varieties under drought stress were related to the morphological characteristics of the plants. Varieties with longer narrow leaves, longer roots, higher root-to-shoot ratios, and higher chlorophyll contents showed greater rates of photosynthesis and stomatal conductance, and lower transpiration rates.
基金Supported by Committee of Nature Science Foundation of Heilongjiang Province (C0207)
文摘Total RNA from leaves of Poapratensis cultivars under drought stress was extracted for reversing transcription to cDNA and then cDNA as template for PCR reaction by designing primer of cds of Hordeum valgare HVA1 drought resistance gene from GenBank. The amplified products were positive recon identified by using procedures of recovery, connection, transformation and enzyme separation. The length of cloned gene sequence was 324 bp, identity reached 79.27% with Barley HVA1 gene that meaned the cloned gene sequence was the partial HVA1 gene of Poapratensis.
基金TThis study was supported by National Natural Science Foundation of China(31270558)Natural Science Foundation of Shanghai(18ZR1425400)the Research Funds for the Introduction of Talents of Shanghai Science and Technology Museum.
文摘In order to explore the influence of arbuscular mycorrhizal(AM)fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem,rhizosphere soils were collected from eight different poisonous plants in degraded grasslands and one from pasture grass in non-degraded grasslands(CK).The collected soils were used as inocula to assess the influence of indigenous AM fungi on the growth of two typical pasture grass species,Elymus nutans and Poa pratensis,in a bioassay experiment.Five growth parameters and two AM parameters were determined.The mycorrhizal responsiveness and the importance value were calculated.Significant differences between the eight poisonous plants and CK were observed.Compared to CK,rhizosphere soil from the eight poisonous plants had lower AM fungal spore densities.The growth of E.nutans and P.pratensis seedlings was depressed with the inoculation from poisonous plants rhizosphere soil.This study demonstrated that the presence of poisonous plants with grassland degradation altered inherent AM fungal community abundance,and could exert inhibition effects on the growth of pasture grasses.It may attribute to discover the important role of rhizosphere soil of different poisonous plants to AM fungal community on the Alpine meadow.
文摘A protocol was discussed for high efficient plant regeneration from seven bluegrass （Poa pratensis L.） cultivars via an in- direct callus induction and somatic embryogenesis method. Mature seeds were used as explants for callus initiation. Callus induction and proliferation efficiencies were investigated on NB, modified MS （MMS） and MS media, supplemented with 2.0 mg·L^-1 2,4-dichlorophenoxyacetic acid （2,4-D）. The MMS medium performed best. Based on the MMS medium, direct and indirect callus induction effects of bluegrass from mature seeds were compared at the range of 1-5 mg·L^-1 2,4-D contained in the medium. Under the direct callus induction method, the most suitable 2,4-D concentrations varied among cultivars. Under the indirect callus induction method, a significantly high callus induction frequency （93.33%-98.33%） was obtained and there were barely any statistically sig- nificant differences among the tested genetically diverse cultivars. Somatic embryos were promoted on the MMS medium supple- mented with 3 mg·L^-1 2,4-D, 0.1 mg·L^-1 kinetin and 0.8 mg·L^-1 CuSO4. Embryogenetic calli developed into plantlets on the MMS medium containing different concentrations of thidiazuron （TDZ）, and the differentiation frequencies varied in the range from 20.15% to 77.65%. The 0.25 mg·L^-1 TDZ was generally the most suitable concentration for the tested cultivars.
文摘Semen characteristics of naturally fertile pairs and their correlation with fertility of eggs in Florida sandhill crane (Grus canadensis pratensis) were examined. Six pairs were used in this experiment, and all of them that had bred before were housed in open individual pens. These pairs were isolated physically each other but not visually and audibly. Semen was collected twice (Tuesday morning and Friday afternoon) from February 26 to June 4, 1993. The standard methods at Patuxent Wildlife Research Center were used collecting and evaluating the semen and spermatozoa. and incubating the eggs. There were statistically individual variations (p<0.05) about successful collecting attempts, semen volume, semen concentration, spermatozoon’s motility,spermatozoon’s number per collection, live spermatozoon’s number, male’s response to semen collection, and morphology of spermatozoa except the giant cell. There was a significantly (p<0.05, correlation coefficient was (0.73 or (1 .00) negative correlation between fertility of eggs and the multiple value of semen (sperm) characteristics of naturally fertile pairs in Florida sandhill crane.
基金the National Natural Science Foundation of China （30371067） Fok Ying Tung Education Foundation, China （91033） Foundation for Excellent Talents in Northwest A＆F University, China （11241）.
文摘Lolines are a group of saturated pyrrolizidine alkaloids that possess broad bioactivity against a wide array of herbivorous insects. However, they do not exhibit toxicity to ruminants such as cattle and sheep. In order to study the direct and potential physiological effects on ruminants and the mechanism of insecticide/insectifuge, the distribution of loline alkaloids in endophyte-infected meadow fescue and the seasonal change of the distribution were analyzed. The crowns, roots and leaves of endophyte-infected meadow fescue at its four different growth periods, i.e., spring, summer, early autumn and late autumn, in New Zealand were colleted. After powdering, organic solvent extraction and purification by column chromatography, all loline alkaloid samples were analyzed by capillary gas chromatography with 4-phenylmorpholine （PM） as an internal standard. The analytic results showed that the loline contents in the roots, crowns and leaves of endophyte-infected meadow fescue vary with seasons. Even within the same season, the distribution of lolines in endophyte-infected meadow fescue varies. During summer, lolines mainly existed in the leaves and roots, but in early autumn, they are produced in the crowns. It was concluded that, lolines were mainly produced in the leaves and roots of endophyte-infected meadow fescue. In gas chromatographic analysis, N-formylloline, the major component of loline alkaloid in the plant, was employed to assay the alkaloids.
基金National Natural Science Foundation of China(31170507)State Key Laboratory of Vegetation and Environmental Change(2011zyts02).
文摘Aims Invasive plants commonly occupy disturbed soils,thereby provid-ing a stage for understanding the role of disturbance-enhanced resources in plant invasions.Here,we addressed how soil space and soil nutrients affect the growth and competitive effect of inva-sive plants and whether this effect varies with different invaders.Methods We conducted an experiment in which two invasive plants(Bromus tectorum and Centaurea maculosa)and one native species(Poa pratensis)were grown alone or together in four habitats consisting of two levels of soil space and nutrients.at the end of the experiment,we determined the total biomass,biomass allocation and relative interaction intensity of B.tectorum,C.maculosa and P.pratensis.Important Findingsacross two invaders,B.tectorum and C.maculosa,increased soil nutrients had greater positive effects on their growth than increased soil space,the effects of soil space on root weight ratio were greater than those of soil nutrients,and their competitive effect decreased with soil space but increased with soil nutrients.these findings sug-gest that changing soil space and nutrients differentially influence the growth and competitive advantages of two invaders.Bromus tectorum benefited more from increased soil resources than C.mac-ulosa.soil space and nutrients affected the biomass allocation of C.maculosa but not B.tectorum.the competitive effect of B.tecto-rum was unaffected by soil space and soil nutrients,but the opposite was the case for C.maculosa.thus,the effects of soil space and nutrients on growth and competitive ability depend on invasive species identity.
文摘Fifty two accessions of Festuca pratensis Huds. were analysed of which 18 had been collected in Switzerland and 32 in Bulgaria. SDS-PAGE of seed proteins was implemented to detect genetic variation among ecotype populations using a modification of UPOV method for barley. The modification concerns mainly protein extracting procedure as detailed described in the protocol. The two cultivars Preval and Cosmolit were used as standards. Cluster analyses and correspondence analyses/scatter plot were used as statistic approaches for determining genetic diversity among individual ecotypes and groups of ecotypes. Electrophoretic spectra of proteins show clear differences among local accessions in relation to their origin. In Swiss ecotypes 32 protein fragments were determined whereas in Bulgarian local populations their number was 68. Each of the two eco-groups possesses fragments that appear in all accessions of the group. The number of monomorphic bands within Bulgarian local ecotypes is four whereas their number in Swiss ecotypes is 12. Four monomorphic bands appearing in all proteinograms no difference of eco-groups was identified with Rm values of： 0.43, 0.55, 0.58, 0.82. A higher level of protein band polymorphism was proven in Bulgarian ecotypes in comparison with Swiss ecotypes. Thirty seven polymorphic bands occurred exclusively in the Bulgarian local ecotypes and had a frequency of 0.03 or higher whereas within Swiss ecotypes was detected one unique protein fragment. SDS-PAGE ＂fingerprinting＂ is suggested as a fast and easy approach to differentiate F. pratensis ecotypes by their origin as well for detection of foreign germplasm for inclusion in breeding programs.
