In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts f...In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.展开更多
Elymus rectisetus(Nees in Lehm)A.Lo..veetConnor是目前小麦族中发现的唯一的无融合生殖种,为了鉴定和标记从普通小麦与E.rectisetusBC2F2衍生后代中选育的2n=44株系1026A1、1057A1和1035A2的外源染色体,应用细胞学、基因组原位杂交和...Elymus rectisetus(Nees in Lehm)A.Lo..veetConnor是目前小麦族中发现的唯一的无融合生殖种,为了鉴定和标记从普通小麦与E.rectisetusBC2F2衍生后代中选育的2n=44株系1026A1、1057A1和1035A2的外源染色体,应用细胞学、基因组原位杂交和RAPD方法进行了研究。经细胞学鉴定,3个株系花粉母细胞减数分裂中期Ⅰ(PMC MⅠ)染色体构型均为2n=22Ⅱ,与普通小麦Fukuhokomugi杂交F1的PMC MⅠ染色体构型均为2n=21Ⅱ+1Ⅰ,两两杂交F1的PMC MⅠ染色体构型均为2n=21Ⅱ+2Ⅰ,表明它们是分别附加了1对互不相同外源染色体的普通小麦-E.rectisetus二体异附加系。标记E.rectisetus品系1050的基因组DNA为探针DNA,对3个异附加系进行原位杂交,分别鉴定出附加的1对E.rectisetus染色体。应用13个引物对2个亲本和3个异附加系进行RAPD分析,获得了可分别用于检测1026A1和1057A1中所附加的E.rectisetus染色体遗传物质的分子标记OPB-14900bp、OPE-09750bp和OPB-141000bp。展开更多
The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected w...The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected within and among populations. The chromosome variations were mainly characterized as repeat deletions and amplifications along with inter-genomic translocations. The chromosomes of the St and Y genomes demonstrated higher polymorphism than those of the H genome. Six different intergenomic translocations were identified in 33.3% of individuals; type Ⅰ and Ⅱ translocations were detected with higher frequency. Further analysis revealed that type Ⅰ and Ⅱ translocations were distributed in different geographic regions. The origin of high karyotype variation of E. nutans in the Qinghai plateau is further discussed.展开更多
Potentilla anserina L.and Elymus nutans Griseb.are dominant species in the subalpine meadows of China.Grazing is one of the most important factors that influence community structure and productivity of subalpine meado...Potentilla anserina L.and Elymus nutans Griseb.are dominant species in the subalpine meadows of China.Grazing is one of the most important factors that influence community structure and productivity of subalpine meadows.Understanding how grazing changes photosynthetic capability is essential for preservation and restoration of grasslands.However,information about the effects of grazing on photosynthetic capability remains inadequate.Experiments were conducted in fencing and grazing areas in the Qilian Mountains,Northwest China.The leaf gas exchange and photosynthetic curves of P.anserina and E.nutans were measured at different growth stages.Results showed that grazing decreased the values of leaf gas exchange parameters,such as net photosynthetic rate,stomatal conductance,transpiration rate,and intercellular CO2 concentration of P.anserina and E.nutans.In addition,grazing decreased the values of net photosynthetic rate-photosynthetically active radiation(PN-PAR)curve parameters,such as light-saturated net photosynthetic rate,apparent quantum efficiency,light compensation point,light saturation point,and dark respiration rate.Our results demonstrated that grazing was the primary limiting factor for photosynthesis of dominant grassland species in the study area.展开更多
The non-rectangular hyperbola(NRH)equation is the most popular method that plots the photosynthetic light-response(PLR)curve and helps to identify plant photosynthetic capability.However,the PLR curve can't be plo...The non-rectangular hyperbola(NRH)equation is the most popular method that plots the photosynthetic light-response(PLR)curve and helps to identify plant photosynthetic capability.However,the PLR curve can't be plotted well by the NRH equation at different plant growth phases due to the variations of plant development.Recently,plant physiological parameters have been considered into the NRH equation to establish the modified NRH equation,but plant height(H),an important parameter in plant growth phases,is not taken into account.In this study,H was incorporated into the NRH equation to establish the modified NRH equation,which could be used to estimate photosynthetic capability of herbage at different growth phases.To explore photosynthetic capability of herbage,we selected the dominant herbage species Potentilla anserina L.and Elymus nutans Griseb.in the Heihe River Basin,Northwest China as the research materials.Totally,twenty-four PLR curves and H at different growth phases were measured during the growing season in 2016.Results showed that the maximum net photosynthetic rate and the initial slope of PLR curve linearly increased with H.The modified NRH equation,which is established by introducing H and an H-based adjustment factor into the NRH equation,described better the PLR curves of P.anserina and E.nutans than the original ones.The results may provide an effective method to estimate the net primary productivity of grasslands in the study area.展开更多
A molecular cytogenetic investigation was conducted on plants of the allohexaploid species Elymus nutans with varying fertility on the Qinghai-Tibet Plateau.Molecular karyotyping revealed that chromosome variants were...A molecular cytogenetic investigation was conducted on plants of the allohexaploid species Elymus nutans with varying fertility on the Qinghai-Tibet Plateau.Molecular karyotyping revealed that chromosome variants were distributed unevenly among genomes and among different homologue chromosomes in each genome.The plants with varying fertility exhibited significantly higher numbers of chromosome variants than did the normal fertility samples,although both kinds of plants showed the same pattern of high-to-low polymorphism from the Y to St and H genomes.Heterozygosis and karyotype heterozygosity in the plants with varying fertility were 3-and 13-fold higher than those in normal samples,respectively.Significant negative correlations were found not only between seed setting rates and total genome heterozygosity but also between seed setting rates and heterozygosity of each genome in the plants of varying fertility.Chromosome pairing analysis was performed using genomic in situ hybridization in selected plants of different fertility levels.The pairing of chromosomes at meiotic metaphase I was mostly bivalent,although univalent,trivalent,quadrivalent,and other polyvalents also occurred;in addition,chromosome configuration forms and frequencies varied among the studied samples.ANOVA results showed that the average number of ring bivalents in the Y genome was significantly higher than those in the St and H genomes.Significant positive correlations between pollen grain fertility and ring bivalent number were found in the St and H genomes but not in the Y genome.Furthermore,chromosome configuration parameters(total bivalents,numbers of ring and rod bivalents)were found to be significantly correlated with heterozygosity and seed setting rates in the St and H genomes,respectively,but not in the Y genome.It was inferred that the seed setting rate and pollen grain fertility in E.nutans are strongly influenced by the heterozygosity of each genome,but the Y genome differs from the St and H genomes due to chromosome pair alterations.The St and H genomes may contain more chromosome structural variations than the Y genome in E.nutans.展开更多
Wild native Elymus(Elymus dahuricus)is one of the most important and valuable forage grass on Qinghai-Tibetan Plateau(QTP)pasture of China.It mainly distributes above sea-level of 1700 to 3000 m on the QTP.The objecti...Wild native Elymus(Elymus dahuricus)is one of the most important and valuable forage grass on Qinghai-Tibetan Plateau(QTP)pasture of China.It mainly distributes above sea-level of 1700 to 3000 m on the QTP.The objective of this study was to investigate how the nutritive composition of Elymus responsed to the changes of altitude in local environments.Two test sites located at Minghe and Huangzhong counties,in which four sampling plots were arranged with sea levels of 1714,1872,2097 and 2185 m in Minhe County,while other four in Huangzhong County were with sea-level of 2560,2613,2668 and 2775 m.The whole plants of Elymus during anthesis stage were collected from all the plots for determining the indexes of crude protein(CP),crude fat(CF),neutral detergent fiber(NDF),acid detergent fiber(ADF),crude ash(ASH),calcium(Ca)and phosphorus(P).The results showed that the content of CP,crude ash and Ca changed irregularly corresponding to the altitude in the two counties,but significant higher with CP(1.09%),Ash(0.33%)and Ca(0.34%)in the low altitude areas(1714-2185 m)than those in the high altitude areas.NDF and ADF in the low altitude areas were significantly lower by 5.35% and 2.61% compared with those in the high altitude areas.There was no significant difference of CF as well as P in plant from different altitudes.Comprehensive evaluation revealed that superior nutritional composition of Elymus dahuricus presented at the sampling plots of altitude of 1714 m in Minhe County.展开更多
In order to reveal the effects of different altitudes on the nutritional quality of wild forage in Qinghai-Tibet Plateau,this study used Elymus nutans as the tested plants to evaluate the changes of nutrient contents ...In order to reveal the effects of different altitudes on the nutritional quality of wild forage in Qinghai-Tibet Plateau,this study used Elymus nutans as the tested plants to evaluate the changes of nutrient contents and the correlation between the nutrient contents and altitudes.Four sampling sites were set up at altitudes of 2562,2660,2775 and 2905 m with the vertical distance among each sampling point was about 100 m.The results showed that the crude protein,ash and phosphorus contents of Elymus nutans decreased significantly with an increase in altitudes.The crude protein contents decreased by 1.87%with each 100 m increase in altitudes.The variation rule of crude protein contents with altitudes in the simulated curve was"y=-0.0187x+63.244(R^(2)=0.9557)".The crude ash contents decreased by 1.77%with each 100 m increase in altitudes.The variation rule of crude ash contents with altitudes in the simulated curve was"y=-0.0177x+56.144(R^(2)=0.978)".Neutral detergent fiber(NDF)and acid detergent fiber(ADF)showed an overall increasing trend with the increase of altitudes,but the most obvious increase was at 2775 m.The contents of crude fat and Ca did not change regularly with altitudes.展开更多
[ Objective] To evaluate drought resistance of siberian wildrye ( Elymus sibiricus) from different producing areas. [ Method] Germplasm materials of siberian wildrye from Xinjiang (E01), Gansu (E02), Beijing (...[ Objective] To evaluate drought resistance of siberian wildrye ( Elymus sibiricus) from different producing areas. [ Method] Germplasm materials of siberian wildrye from Xinjiang (E01), Gansu (E02), Beijing (E03), Shanxi (E04) and Qinghai (E05) were used as experimental materials and treated under continuous drought stress. The external morphology of their leaves was observed. On Day 0, 5 and 10, the dynamic variations of relative conductivity, malondialdehyde (MDA) content, chlorophyll content, soluble sugar content and proline content were determined. Subordinate function values analysis was performed to evaluate their drought resistance comprehensively. [ Result] Under continuous drought stress, the experimental siberian wildrye showed different extemal morphology of leaves. With increasing intensity and extending time of drought stress, the chlorophyll content increased significantly (P 〈 0.05), and its differences between the siberian wildrye from different producing areas were significant ( P 〈 0.05) ; the relative electrical conductivity, malondialdehyde (MDA) content, soluble sugar content and proline content decreased significantly (P 〈 0.05), and their differences between the siberian wildrye from different producing areas were significant (P 〈 0.05). [Conclusion] The drought resistance of E04, E05, E01, E03 and E02 declines successively.展开更多
Fungal endophytes of some cultivated grasses can increase plant performance and competitive abilities,especially under stress. Far less is known about the influence of Epichlo? infections in wild populations of wild g...Fungal endophytes of some cultivated grasses can increase plant performance and competitive abilities,especially under stress. Far less is known about the influence of Epichlo? infections in wild populations of wild grasses. In this study, plants of three Elymus dahuricus ecotypes(WLS, QY and WTS) either infected with Epichlo? endophyte(E+) or uninfected(E–) were grown in the field. The activities of the antioxidant enzymes ascorbate peroxidase, catalase, peroxidase and superoxide dismutase, and concentrations of H_2O_2 and malondialdehyde were examined in the leaves of E+ and E– plants. We also determined photosynthesis parameters,leaf blade and sheath carbohydrate concentration and plant growth parameters of both E+ and E– plants. E+ plants from the WLS and QY populations had significantly higher antioxidant enzyme activities and photosynthetic capability(P < 0.05), superior growth characteristics including more abundant carbohydrate concentration than E– plants. In contrast, in plants from the WTS population,the endophyte had no significant effect on reactive oxygen species scavenging capability and growth performance(P > 0.05), and even displayed some negative effects on plant photosynthetic capability. Thus, endophyte infection significantly affected E. dahuricus antioxidant enzyme activities(P < 0.05), photosynthesis and growth capability,although, the effects varied with plant ecotypes.展开更多
Artificial planting is an important measure to promote the restoration of degraded grassland and protect the ecological environment. The objectives of the current study were to investigate the allocation pattern betwe...Artificial planting is an important measure to promote the restoration of degraded grassland and protect the ecological environment. The objectives of the current study were to investigate the allocation pattern between aboveground biomass(AGB) and belowground biomass(BGB) in different seeding types of artificially-planted pastures. We explored the variation in biomass and the relationship between above-and belowground biomass in four artificiallyplanted pastures with one species from Elymus nutans Griseb(EN, perennial), Elymus sibiricus Linn(ES, perennial), Medicago sativa Linn(MS, perennial), and Avena sativa Linn(AS, annual) and in six artificially-planted communities with mixtures of two species by seeding ratio 1:1 from the abovementioned grasses(EN + AS, MS + AS, EN + ES, MS + EN, MS + ES, AS + ES) in 2015 and 2016. The results showed that E. nutans is the most productive species with the highest biomass production among the single crops. MS + ES was the most productive group in 2015, while the group with the highest biomass production changed to AS + ES in 2016. AGB was positively correlated to BGB in the surface soil layer in the first year, but positively related to BGB in the subsoil layer in the second year. In the early stageof artificial grassland succession, plants allocated more biomass to aboveground parts, with a root to shoot(R/S) ratio of 1.98. The slope of the log-log relationship between AGB and BGB was 1.07 in 2016, which is consistent with the isometric theory. Different sowing patterns strongly affected the accumulation and allocation of biomass in artificiallyplanted grassland, E. sibiricus was the suitable plant in the alpine regions, which will be conducive to understanding vegetation restoration and plant interactions in the future.展开更多
Squirreltail (Elymus elymoides [Raf] Swezey) can grow in cheatgrass (Bromus tectorum L.) stands, and has reduced the biomass production of cheatgrass in its immediate vicinity. A field experiment was conducted to dete...Squirreltail (Elymus elymoides [Raf] Swezey) can grow in cheatgrass (Bromus tectorum L.) stands, and has reduced the biomass production of cheatgrass in its immediate vicinity. A field experiment was conducted to determine: 1) if competition for nitrogen resources occurs between seedlings of squirreltail and seedlings of cheatgrass, under low, medium, and high nitrogen levels, and;2) if competition for nitrogen resources in the seedling stage is a mechanism that allows squirreltail to establish in cheatgrass stands. Five accessions of squirreltail were each seeded with a single accession of cheatgrass in a cultivated field near Ephraim, Utah in the fall of 1995 and again in 1996. A completely randomized strip-plot design with 3 replications was used including the 5 joint seedings as well as pure seedings of each accession of both species. Three nitrogen levels representing high, medium (control), and low were applied. The study was replicated over 2 years in different areas of the same field. Harvests of above-ground biomass of squirreltail and cheatgrass within each treatment were conducted in July of 1996 and 1997. Using biomass production as a measure of efficient nitrogen use, cheatgrass competed for and used nitrogen resources more efficiently than squirreltail when nitrogen was not limiting. All squirreltail accessions were able to compete for and use nitrogen more efficiently than cheatgrass when there was low availability of nitrogen. Some accessions of squirreltail competed for nitrogen resources more efficiently than others both in the control and at the reduced nitrogen level. White Rocks and Sublette squirreltail accessions were the best competitors with cheatgrass at the low nitrogen level reducing the cheatgrasss biomass by as much as 75% and 67% respectively. An intermediate competitor with cheatgrass was the Gunnison accession. The Washakie and Pueblo accessions were poor competitors with cheatgrass at low nitrogen levels.展开更多
基金This work was supported by the Budgetary Project the Chinese Academy of Sciences Leads the Sub-Project of Class A Project(XDA26020202)the National“973”Program Project Topics(2014CB138702)+2 种基金the Basic Scientific Research Business Expenses of Central Universities(Lzujbky-2022-kb10)the 111 Wisdom Base(B12002)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Chinese Academy of Forestry)(CAFYBB2021ZD001).
文摘In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were studied.The results showed that both the extracts from aboveground and belowground parts of A.inebrians significantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of E.nutans,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of E.nutans seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of A.inebrians was stronger than that of the pre-cipitates.Aqueous extracts of the aboveground parts of A.inebrians decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,respectively.The above indexes were higher in live soil than in sterilized soil.Soil microorganisms increased the allelopathy of A.inebrians.The seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of E.nutans planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,respectively.Malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity of E.nutans planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,respectively.The existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of A.inebrians.A combination of microorganisms and aqueous extracts from the aboveground parts of A.inebrians had the strongest allelopathic effect on E.nutans.
基金supported by the National Natural Science Foundation of Qinghai Province (2015-ZJ-903)the National Natural Science Foundation of China (31072075)
文摘The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected within and among populations. The chromosome variations were mainly characterized as repeat deletions and amplifications along with inter-genomic translocations. The chromosomes of the St and Y genomes demonstrated higher polymorphism than those of the H genome. Six different intergenomic translocations were identified in 33.3% of individuals; type Ⅰ and Ⅱ translocations were detected with higher frequency. Further analysis revealed that type Ⅰ and Ⅱ translocations were distributed in different geographic regions. The origin of high karyotype variation of E. nutans in the Qinghai plateau is further discussed.
基金financially supported by the National Natural Science Foundation of China(91025015,51178209)the Project of Arid Meteorological Science Research Foundation of China Meteorological Administration(IAM201608)
文摘Potentilla anserina L.and Elymus nutans Griseb.are dominant species in the subalpine meadows of China.Grazing is one of the most important factors that influence community structure and productivity of subalpine meadows.Understanding how grazing changes photosynthetic capability is essential for preservation and restoration of grasslands.However,information about the effects of grazing on photosynthetic capability remains inadequate.Experiments were conducted in fencing and grazing areas in the Qilian Mountains,Northwest China.The leaf gas exchange and photosynthetic curves of P.anserina and E.nutans were measured at different growth stages.Results showed that grazing decreased the values of leaf gas exchange parameters,such as net photosynthetic rate,stomatal conductance,transpiration rate,and intercellular CO2 concentration of P.anserina and E.nutans.In addition,grazing decreased the values of net photosynthetic rate-photosynthetically active radiation(PN-PAR)curve parameters,such as light-saturated net photosynthetic rate,apparent quantum efficiency,light compensation point,light saturation point,and dark respiration rate.Our results demonstrated that grazing was the primary limiting factor for photosynthesis of dominant grassland species in the study area.
基金funded by the National Natural Science Foundation of China(91025015,51178209)the Project of Arid Meteorological Science Research Foundation of China Meteorological Administration(IAM201608)
文摘The non-rectangular hyperbola(NRH)equation is the most popular method that plots the photosynthetic light-response(PLR)curve and helps to identify plant photosynthetic capability.However,the PLR curve can't be plotted well by the NRH equation at different plant growth phases due to the variations of plant development.Recently,plant physiological parameters have been considered into the NRH equation to establish the modified NRH equation,but plant height(H),an important parameter in plant growth phases,is not taken into account.In this study,H was incorporated into the NRH equation to establish the modified NRH equation,which could be used to estimate photosynthetic capability of herbage at different growth phases.To explore photosynthetic capability of herbage,we selected the dominant herbage species Potentilla anserina L.and Elymus nutans Griseb.in the Heihe River Basin,Northwest China as the research materials.Totally,twenty-four PLR curves and H at different growth phases were measured during the growing season in 2016.Results showed that the maximum net photosynthetic rate and the initial slope of PLR curve linearly increased with H.The modified NRH equation,which is established by introducing H and an H-based adjustment factor into the NRH equation,described better the PLR curves of P.anserina and E.nutans than the original ones.The results may provide an effective method to estimate the net primary productivity of grasslands in the study area.
基金the Natural Science Foundation of Qinghai Province,China(2020-ZJ-914)the Second Tibet Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0303).
文摘A molecular cytogenetic investigation was conducted on plants of the allohexaploid species Elymus nutans with varying fertility on the Qinghai-Tibet Plateau.Molecular karyotyping revealed that chromosome variants were distributed unevenly among genomes and among different homologue chromosomes in each genome.The plants with varying fertility exhibited significantly higher numbers of chromosome variants than did the normal fertility samples,although both kinds of plants showed the same pattern of high-to-low polymorphism from the Y to St and H genomes.Heterozygosis and karyotype heterozygosity in the plants with varying fertility were 3-and 13-fold higher than those in normal samples,respectively.Significant negative correlations were found not only between seed setting rates and total genome heterozygosity but also between seed setting rates and heterozygosity of each genome in the plants of varying fertility.Chromosome pairing analysis was performed using genomic in situ hybridization in selected plants of different fertility levels.The pairing of chromosomes at meiotic metaphase I was mostly bivalent,although univalent,trivalent,quadrivalent,and other polyvalents also occurred;in addition,chromosome configuration forms and frequencies varied among the studied samples.ANOVA results showed that the average number of ring bivalents in the Y genome was significantly higher than those in the St and H genomes.Significant positive correlations between pollen grain fertility and ring bivalent number were found in the St and H genomes but not in the Y genome.Furthermore,chromosome configuration parameters(total bivalents,numbers of ring and rod bivalents)were found to be significantly correlated with heterozygosity and seed setting rates in the St and H genomes,respectively,but not in the Y genome.It was inferred that the seed setting rate and pollen grain fertility in E.nutans are strongly influenced by the heterozygosity of each genome,but the Y genome differs from the St and H genomes due to chromosome pair alterations.The St and H genomes may contain more chromosome structural variations than the Y genome in E.nutans.
基金Supported by the National Natural Science Foundation Project(31472145)
文摘Wild native Elymus(Elymus dahuricus)is one of the most important and valuable forage grass on Qinghai-Tibetan Plateau(QTP)pasture of China.It mainly distributes above sea-level of 1700 to 3000 m on the QTP.The objective of this study was to investigate how the nutritive composition of Elymus responsed to the changes of altitude in local environments.Two test sites located at Minghe and Huangzhong counties,in which four sampling plots were arranged with sea levels of 1714,1872,2097 and 2185 m in Minhe County,while other four in Huangzhong County were with sea-level of 2560,2613,2668 and 2775 m.The whole plants of Elymus during anthesis stage were collected from all the plots for determining the indexes of crude protein(CP),crude fat(CF),neutral detergent fiber(NDF),acid detergent fiber(ADF),crude ash(ASH),calcium(Ca)and phosphorus(P).The results showed that the content of CP,crude ash and Ca changed irregularly corresponding to the altitude in the two counties,but significant higher with CP(1.09%),Ash(0.33%)and Ca(0.34%)in the low altitude areas(1714-2185 m)than those in the high altitude areas.NDF and ADF in the low altitude areas were significantly lower by 5.35% and 2.61% compared with those in the high altitude areas.There was no significant difference of CF as well as P in plant from different altitudes.Comprehensive evaluation revealed that superior nutritional composition of Elymus dahuricus presented at the sampling plots of altitude of 1714 m in Minhe County.
基金Supported by the National Natural Fund(31872998)。
文摘In order to reveal the effects of different altitudes on the nutritional quality of wild forage in Qinghai-Tibet Plateau,this study used Elymus nutans as the tested plants to evaluate the changes of nutrient contents and the correlation between the nutrient contents and altitudes.Four sampling sites were set up at altitudes of 2562,2660,2775 and 2905 m with the vertical distance among each sampling point was about 100 m.The results showed that the crude protein,ash and phosphorus contents of Elymus nutans decreased significantly with an increase in altitudes.The crude protein contents decreased by 1.87%with each 100 m increase in altitudes.The variation rule of crude protein contents with altitudes in the simulated curve was"y=-0.0187x+63.244(R^(2)=0.9557)".The crude ash contents decreased by 1.77%with each 100 m increase in altitudes.The variation rule of crude ash contents with altitudes in the simulated curve was"y=-0.0177x+56.144(R^(2)=0.978)".Neutral detergent fiber(NDF)and acid detergent fiber(ADF)showed an overall increasing trend with the increase of altitudes,but the most obvious increase was at 2775 m.The contents of crude fat and Ca did not change regularly with altitudes.
基金supported by the Project of Conservation and Utilization of Forage Germplasm Resources in the Tibetan Plateau ( the Ministry of Agriculture of China,070401)Earmarked Fund for Modern Agro-industry Technology Research System
文摘[ Objective] To evaluate drought resistance of siberian wildrye ( Elymus sibiricus) from different producing areas. [ Method] Germplasm materials of siberian wildrye from Xinjiang (E01), Gansu (E02), Beijing (E03), Shanxi (E04) and Qinghai (E05) were used as experimental materials and treated under continuous drought stress. The external morphology of their leaves was observed. On Day 0, 5 and 10, the dynamic variations of relative conductivity, malondialdehyde (MDA) content, chlorophyll content, soluble sugar content and proline content were determined. Subordinate function values analysis was performed to evaluate their drought resistance comprehensively. [ Result] Under continuous drought stress, the experimental siberian wildrye showed different extemal morphology of leaves. With increasing intensity and extending time of drought stress, the chlorophyll content increased significantly (P 〈 0.05), and its differences between the siberian wildrye from different producing areas were significant ( P 〈 0.05) ; the relative electrical conductivity, malondialdehyde (MDA) content, soluble sugar content and proline content decreased significantly (P 〈 0.05), and their differences between the siberian wildrye from different producing areas were significant (P 〈 0.05). [Conclusion] The drought resistance of E04, E05, E01, E03 and E02 declines successively.
基金supported financially by the National Basic Research Program of China (2014CB138702)
文摘Fungal endophytes of some cultivated grasses can increase plant performance and competitive abilities,especially under stress. Far less is known about the influence of Epichlo? infections in wild populations of wild grasses. In this study, plants of three Elymus dahuricus ecotypes(WLS, QY and WTS) either infected with Epichlo? endophyte(E+) or uninfected(E–) were grown in the field. The activities of the antioxidant enzymes ascorbate peroxidase, catalase, peroxidase and superoxide dismutase, and concentrations of H_2O_2 and malondialdehyde were examined in the leaves of E+ and E– plants. We also determined photosynthesis parameters,leaf blade and sheath carbohydrate concentration and plant growth parameters of both E+ and E– plants. E+ plants from the WLS and QY populations had significantly higher antioxidant enzyme activities and photosynthetic capability(P < 0.05), superior growth characteristics including more abundant carbohydrate concentration than E– plants. In contrast, in plants from the WTS population,the endophyte had no significant effect on reactive oxygen species scavenging capability and growth performance(P > 0.05), and even displayed some negative effects on plant photosynthetic capability. Thus, endophyte infection significantly affected E. dahuricus antioxidant enzyme activities(P < 0.05), photosynthesis and growth capability,although, the effects varied with plant ecotypes.
基金supported by China Huaneng group technology project(Grant No.HNKJ14-H17)
文摘Artificial planting is an important measure to promote the restoration of degraded grassland and protect the ecological environment. The objectives of the current study were to investigate the allocation pattern between aboveground biomass(AGB) and belowground biomass(BGB) in different seeding types of artificially-planted pastures. We explored the variation in biomass and the relationship between above-and belowground biomass in four artificiallyplanted pastures with one species from Elymus nutans Griseb(EN, perennial), Elymus sibiricus Linn(ES, perennial), Medicago sativa Linn(MS, perennial), and Avena sativa Linn(AS, annual) and in six artificially-planted communities with mixtures of two species by seeding ratio 1:1 from the abovementioned grasses(EN + AS, MS + AS, EN + ES, MS + EN, MS + ES, AS + ES) in 2015 and 2016. The results showed that E. nutans is the most productive species with the highest biomass production among the single crops. MS + ES was the most productive group in 2015, while the group with the highest biomass production changed to AS + ES in 2016. AGB was positively correlated to BGB in the surface soil layer in the first year, but positively related to BGB in the subsoil layer in the second year. In the early stageof artificial grassland succession, plants allocated more biomass to aboveground parts, with a root to shoot(R/S) ratio of 1.98. The slope of the log-log relationship between AGB and BGB was 1.07 in 2016, which is consistent with the isometric theory. Different sowing patterns strongly affected the accumulation and allocation of biomass in artificiallyplanted grassland, E. sibiricus was the suitable plant in the alpine regions, which will be conducive to understanding vegetation restoration and plant interactions in the future.
文摘Squirreltail (Elymus elymoides [Raf] Swezey) can grow in cheatgrass (Bromus tectorum L.) stands, and has reduced the biomass production of cheatgrass in its immediate vicinity. A field experiment was conducted to determine: 1) if competition for nitrogen resources occurs between seedlings of squirreltail and seedlings of cheatgrass, under low, medium, and high nitrogen levels, and;2) if competition for nitrogen resources in the seedling stage is a mechanism that allows squirreltail to establish in cheatgrass stands. Five accessions of squirreltail were each seeded with a single accession of cheatgrass in a cultivated field near Ephraim, Utah in the fall of 1995 and again in 1996. A completely randomized strip-plot design with 3 replications was used including the 5 joint seedings as well as pure seedings of each accession of both species. Three nitrogen levels representing high, medium (control), and low were applied. The study was replicated over 2 years in different areas of the same field. Harvests of above-ground biomass of squirreltail and cheatgrass within each treatment were conducted in July of 1996 and 1997. Using biomass production as a measure of efficient nitrogen use, cheatgrass competed for and used nitrogen resources more efficiently than squirreltail when nitrogen was not limiting. All squirreltail accessions were able to compete for and use nitrogen more efficiently than cheatgrass when there was low availability of nitrogen. Some accessions of squirreltail competed for nitrogen resources more efficiently than others both in the control and at the reduced nitrogen level. White Rocks and Sublette squirreltail accessions were the best competitors with cheatgrass at the low nitrogen level reducing the cheatgrasss biomass by as much as 75% and 67% respectively. An intermediate competitor with cheatgrass was the Gunnison accession. The Washakie and Pueblo accessions were poor competitors with cheatgrass at low nitrogen levels.