Alfalfa is the most widely cultivated perennial legume forage crop worldwide.Drought is one of the major environmental factors influencing alfalfa productivity.However,the molecular mechanisms underlying alfalfa respo...Alfalfa is the most widely cultivated perennial legume forage crop worldwide.Drought is one of the major environmental factors influencing alfalfa productivity.However,the molecular mechanisms underlying alfalfa responses to drought stress are still largely unknown.This study identified a drought-inducible gene of unknown function,designated as Medicago sativa DROUGHT-INDUCED UNKNOWN PROTEIN 1(MsDIUP1).MsDIUP1 was localized to the nucleus,chloroplast,and plasma membranes.Overexpression of MsDIUP1 in Arabidopsis resulted in increased tolerance to drought,with higher seed germination,root length,fresh weight,and survival rate than in wild-type(WT)plants.Consistently,analysis of MsDIUP1 over-expression(OE)alfalfa plants revealed that MsDIUP1 also increased tolerance to drought stress,accompanied by physiological changes including reduced malondialdehyde(MDA)content and increased osmoprotectants accumulation(free proline and soluble sugar),relative to the WT.In contrast,disruption of MsDIUP1 expression by RNA interference(RNAi)in alfalfa resulted in a droughthypersensitive phenotype,with a lower chlorophyll content,higher MDA content,and less osmoprotectants accumulation than that of the WT.Transcript profiling of alfalfa WT,OE,and RNAi plants during drought stress showed differential responses for genes involved in stress signaling,antioxidant defense,and osmotic adjustment.Taken together,these results reveal a positive role for MsDIUP1 in regulating drought tolerance.展开更多
In order to screen the Medicago sativa(alfalfa)varieties suitable for planting in Guangxi,six domestic and foreign heat-resistant alfalfa varieties,namely WL903,WL712,WL525HQ,59N59,Elite 9 and Longwei 6010,were select...In order to screen the Medicago sativa(alfalfa)varieties suitable for planting in Guangxi,six domestic and foreign heat-resistant alfalfa varieties,namely WL903,WL712,WL525HQ,59N59,Elite 9 and Longwei 6010,were selected and tested for growth performance,nutritional value and over-summer rate by the random block method.The results showed that the alfalfa varieties with better plant height and fresh grass yield were 59N59 and WL903,which showed the plant heights reaching 62.01 and 62.53 cm,respectively,and the fresh grass yields up to 40.93 and 38.38 t/hm 2,respectively,exhibiting extremely significant differences from the poorly performing Longwei 6010(P<0.01).The nutritional value of each tested variety was good,and the crude protein content was more than 20%.Among them,Elite 9 had a crude protein content as high as 28.43%.The over-summer rates of the six alfalfa varieties were all higher than 75%.It showed that the alfalfa varieties with fast growth,high yield,high nutritional value and high over-summer rate in this experimental area were 59N59 and WL903,which are suitable as the first varieties for planting in Guangxi.展开更多
[Objectives]The paper was better understand the mechanisms of Zn plant uptake in the presence of EDTA and to evaluate the contributions of Zn-EDTA complexes to Zn uptake.[Methods]Three alfalfa cultivars were cultivate...[Objectives]The paper was better understand the mechanisms of Zn plant uptake in the presence of EDTA and to evaluate the contributions of Zn-EDTA complexes to Zn uptake.[Methods]Three alfalfa cultivars were cultivated for 60 d before exposure to 0,250μg Zn and 250μg Zn+10μg EDTA per kg soil for 50 d.Zn concentrations in tissues were analyzed by flame atomic absorbance spectrometry.Subsequently,Zn amount per plant,translocation factor(TF)and bio-concentration factor(BCF)were calculated.Nonenzymatic compounds in tissues were analyzed spectrophotometrically.[Results]Application of Zn+EDTA expressively increased biomass of different tissues of three alfalfa cultivars.Among the three alfalfa cultivars,Medicago sativa ssp.displayed the highest Zn concentration in tissues,the largest Zn amount in aerial parts,and the highest BCF in aerial parts under Zn+EDTA exposure.Under Zn+EDTA stress,increases in free proline in roots,stem,and leaves of M.sativa ssp.were found.Inhibited O_(2)^(·-)production in stem and leaves,increases in soluble sugar,but decreases in soluble protein were observed in M.sativa ssp.[Conclusions]M.sativa ssp.is superior to other two cultivars for Zn phyto-remediation,and its well-coordinated physiological changes under Zn+EDTA exposure confer the great Zn tolerance of this cultivar.展开更多
Medicago sativa L.) is one of the most important forage crops in the world. The genetic variability analysis of 19 alfalfa populations collected from three sites in South Tunisia (Gabes, Kebili, Tozeur) and 1 from Nor...Medicago sativa L.) is one of the most important forage crops in the world. The genetic variability analysis of 19 alfalfa populations collected from three sites in South Tunisia (Gabes, Kebili, Tozeur) and 1 from North West China were carried out using Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. Five RAPD primers amplified 44 bands of which 22 were polymorphic;and five ISSR primers amplified 51 bands of which 33 were polymorphic. The percentage of polymorphic bands detected by RAPD and ISSR was 50% and 64.7%, respectively. The resolving power (Rp) varied between 0.6 and 4.1 with an average of 2.02 for RAPD marker and between 0.7 and 6.5 with an average of 2.28 for ISSR marker. However the Average Informativeness band (AvIb) was ranged from 0.2 to 0.9 with an average of 0.5 in RAPD marker and from 0.29 to 0.7 with an average of 0.624 in ISSR marker. The RAPD marker revealed less within population genetic diversity than ISSR marker. Although Cluster (UPGMA) and Correspondence Factorial Analyses (CFA) indicate that populations’ clustering made independently both from the geographical origin.展开更多
As the most famous perennial leguminous forage in the world, Medicago sativa L. ranks the first in both yield and nutritional value, and can be used for many years once planted in field production. However, root rot h...As the most famous perennial leguminous forage in the world, Medicago sativa L. ranks the first in both yield and nutritional value, and can be used for many years once planted in field production. However, root rot has become a very important reason for yield decrease and plant de-cline of alfalfa due to long service life. According to the research progress at home and abroad, the main pathogen distribution, harms and control methods of root rot in M. sativa at home and abroad were systematically expounded, in order to provide a theoretical basis for further research of the disease.展开更多
As the second most abundant natural polymer,accounting for approximately 30%of the organic carbon in the biosphere,lignin plays an essential role in plant development.However,a high lignin content affects the nutritio...As the second most abundant natural polymer,accounting for approximately 30%of the organic carbon in the biosphere,lignin plays an essential role in plant development.However,a high lignin content affects the nutritional quality of alfalfa(Medicago sativa L.),the most widely cultivated perennial legume forage crop.Histological analysis indicated that G-lignin and S-lignin were present in the stem,leaf,and petiole of alfalfa,and the deposition of lignin increased gradually in descending internodes.Neutral detergent fiber(NDF),acid detergent fiber(ADF),and acid detergent lignin(ADL)contents continually increased from the top to the bottom of the stem,and ADL content showed a similar trend in leaves.Alfalfa leaves and stems from five different nodes(1,2,4,6,and 8)were used as materials to investigate molecular regulatory mechanisms in lignin synthesis by RNA sequencing.Respectively 8074 and 7752 differentially expressed genes(DEGs)were identified in leaves and stems,and 1694 DEGs were common to the two tissues.‘‘Phenylpropanoid biosynthesis”was the most enriched pathway in both leaves and stems,and 134 key regulatory genes in lignin synthesis were identified by a weighted gene co-expression network analysis.The NAC family transcription factor MsNST1 gene was highly expressed in old leaf and stem tissues.The deposition pattern of G-and S-lignin differed among M.truncatula wild-type,nst1 mutants,and overexpression lines,and the transcription levels of lignin synthesis genes such as HCT,F5H,and COMT in these three materials also differed.These results suggest that MsNST1 affects lignin synthesis in alfalfa.These findings provide a genetic basis and abundant gene resources for further study of the molecular mechanisms of lignin synthesis,laying a foundation for low-lignin alfalfa breeding research.展开更多
Two-year-old Medicago sativa at budding initial stage was taken as research materials.Five methods were used to make green hay,including flatting stems ＋ spraying 2.5% K2CO3,flatting stems,sun curing,drying in shade ...Two-year-old Medicago sativa at budding initial stage was taken as research materials.Five methods were used to make green hay,including flatting stems ＋ spraying 2.5% K2CO3,flatting stems,sun curing,drying in shade and drying under 105 ℃ condition（CK）.Besides,effects of different green hay making methods on dry characteristics and nutritional quality of M.sativa green hay were studied,and a comprehensive evaluation of M.sativa green hays was conducted.Results showed that,except CK,the drying rates in other making methods were all fast at first,and then slow down.Both of drying under 105 ℃ condition and flatting stems ＋ spraying K2CO3 could speed up drying rate and reduce nutritional losses of green hay.Sun curing could also speed up drying rate,but it could not maintain the quality of green hay.The results of Grey Relational Analysis on five green hay making methods indicated that CK had the best comprehensive performance,followed by green hays made by flatting stems ＋ spraying K2CO3.Therefore,flatting stems ＋ spraying K2CO3 was a quick and easy method to make green hay,and it was worth to be recommended in practical production.展开更多
基金supported by the Strategic Pilot Projects of Chinese Academy of Sciences(XDA26030103)the National Natural Science Foundation of China(31722055 and 31672476)the Key Science and Technology Foundation of Gansu Province(19ZD2NA002)。
文摘Alfalfa is the most widely cultivated perennial legume forage crop worldwide.Drought is one of the major environmental factors influencing alfalfa productivity.However,the molecular mechanisms underlying alfalfa responses to drought stress are still largely unknown.This study identified a drought-inducible gene of unknown function,designated as Medicago sativa DROUGHT-INDUCED UNKNOWN PROTEIN 1(MsDIUP1).MsDIUP1 was localized to the nucleus,chloroplast,and plasma membranes.Overexpression of MsDIUP1 in Arabidopsis resulted in increased tolerance to drought,with higher seed germination,root length,fresh weight,and survival rate than in wild-type(WT)plants.Consistently,analysis of MsDIUP1 over-expression(OE)alfalfa plants revealed that MsDIUP1 also increased tolerance to drought stress,accompanied by physiological changes including reduced malondialdehyde(MDA)content and increased osmoprotectants accumulation(free proline and soluble sugar),relative to the WT.In contrast,disruption of MsDIUP1 expression by RNA interference(RNAi)in alfalfa resulted in a droughthypersensitive phenotype,with a lower chlorophyll content,higher MDA content,and less osmoprotectants accumulation than that of the WT.Transcript profiling of alfalfa WT,OE,and RNAi plants during drought stress showed differential responses for genes involved in stress signaling,antioxidant defense,and osmotic adjustment.Taken together,these results reveal a positive role for MsDIUP1 in regulating drought tolerance.
基金Supported by the Special Fund for the Development of Local Science and Technology Guided by Central Government(YDZX20174500004910,ZY18076011)the Key Research&Development of Guangxi Zhuang Autonomous Region(GKG15248003-21)the Guangxi Science and Technology Base and Specialized Talents(GKAD16450015).
文摘In order to screen the Medicago sativa(alfalfa)varieties suitable for planting in Guangxi,six domestic and foreign heat-resistant alfalfa varieties,namely WL903,WL712,WL525HQ,59N59,Elite 9 and Longwei 6010,were selected and tested for growth performance,nutritional value and over-summer rate by the random block method.The results showed that the alfalfa varieties with better plant height and fresh grass yield were 59N59 and WL903,which showed the plant heights reaching 62.01 and 62.53 cm,respectively,and the fresh grass yields up to 40.93 and 38.38 t/hm 2,respectively,exhibiting extremely significant differences from the poorly performing Longwei 6010(P<0.01).The nutritional value of each tested variety was good,and the crude protein content was more than 20%.Among them,Elite 9 had a crude protein content as high as 28.43%.The over-summer rates of the six alfalfa varieties were all higher than 75%.It showed that the alfalfa varieties with fast growth,high yield,high nutritional value and high over-summer rate in this experimental area were 59N59 and WL903,which are suitable as the first varieties for planting in Guangxi.
基金Supported by National Natural Science Foundation of China(41571300,31270540 and 31070455)Special Plan in the Major Research&Development of the 13th Five-Year Plan of China(2016YFD0800802)+3 种基金Open Fund of Cultivation State Key Laboratory of Qinba Biological Resources and Ecological Environment of Shaanxi University of Technology(SLGPT2019KF04-02)Scientific Research Project of City-University Co-construction of Shaanxi Province(SXJ-2101)Project of Foreign Experts Bureau of Shaanxi Province of China(2022WGZJ-20)Department of Education of Shaanxi Province(15JK1121)。
文摘[Objectives]The paper was better understand the mechanisms of Zn plant uptake in the presence of EDTA and to evaluate the contributions of Zn-EDTA complexes to Zn uptake.[Methods]Three alfalfa cultivars were cultivated for 60 d before exposure to 0,250μg Zn and 250μg Zn+10μg EDTA per kg soil for 50 d.Zn concentrations in tissues were analyzed by flame atomic absorbance spectrometry.Subsequently,Zn amount per plant,translocation factor(TF)and bio-concentration factor(BCF)were calculated.Nonenzymatic compounds in tissues were analyzed spectrophotometrically.[Results]Application of Zn+EDTA expressively increased biomass of different tissues of three alfalfa cultivars.Among the three alfalfa cultivars,Medicago sativa ssp.displayed the highest Zn concentration in tissues,the largest Zn amount in aerial parts,and the highest BCF in aerial parts under Zn+EDTA exposure.Under Zn+EDTA stress,increases in free proline in roots,stem,and leaves of M.sativa ssp.were found.Inhibited O_(2)^(·-)production in stem and leaves,increases in soluble sugar,but decreases in soluble protein were observed in M.sativa ssp.[Conclusions]M.sativa ssp.is superior to other two cultivars for Zn phyto-remediation,and its well-coordinated physiological changes under Zn+EDTA exposure confer the great Zn tolerance of this cultivar.
文摘Medicago sativa L.) is one of the most important forage crops in the world. The genetic variability analysis of 19 alfalfa populations collected from three sites in South Tunisia (Gabes, Kebili, Tozeur) and 1 from North West China were carried out using Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. Five RAPD primers amplified 44 bands of which 22 were polymorphic;and five ISSR primers amplified 51 bands of which 33 were polymorphic. The percentage of polymorphic bands detected by RAPD and ISSR was 50% and 64.7%, respectively. The resolving power (Rp) varied between 0.6 and 4.1 with an average of 2.02 for RAPD marker and between 0.7 and 6.5 with an average of 2.28 for ISSR marker. However the Average Informativeness band (AvIb) was ranged from 0.2 to 0.9 with an average of 0.5 in RAPD marker and from 0.29 to 0.7 with an average of 0.624 in ISSR marker. The RAPD marker revealed less within population genetic diversity than ISSR marker. Although Cluster (UPGMA) and Correspondence Factorial Analyses (CFA) indicate that populations’ clustering made independently both from the geographical origin.
基金Supported by Guiding Science and Technology Plan of Daqing City(zd-2017-69)
文摘As the most famous perennial leguminous forage in the world, Medicago sativa L. ranks the first in both yield and nutritional value, and can be used for many years once planted in field production. However, root rot has become a very important reason for yield decrease and plant de-cline of alfalfa due to long service life. According to the research progress at home and abroad, the main pathogen distribution, harms and control methods of root rot in M. sativa at home and abroad were systematically expounded, in order to provide a theoretical basis for further research of the disease.
基金supported by the National Natural Science Foundation of China(32071862 and 31722055)the China Postdoctoral Science Foundation(2020M683609)the Key Science and Technology Foundation of Gansu Province(19ZD2NA002).
文摘As the second most abundant natural polymer,accounting for approximately 30%of the organic carbon in the biosphere,lignin plays an essential role in plant development.However,a high lignin content affects the nutritional quality of alfalfa(Medicago sativa L.),the most widely cultivated perennial legume forage crop.Histological analysis indicated that G-lignin and S-lignin were present in the stem,leaf,and petiole of alfalfa,and the deposition of lignin increased gradually in descending internodes.Neutral detergent fiber(NDF),acid detergent fiber(ADF),and acid detergent lignin(ADL)contents continually increased from the top to the bottom of the stem,and ADL content showed a similar trend in leaves.Alfalfa leaves and stems from five different nodes(1,2,4,6,and 8)were used as materials to investigate molecular regulatory mechanisms in lignin synthesis by RNA sequencing.Respectively 8074 and 7752 differentially expressed genes(DEGs)were identified in leaves and stems,and 1694 DEGs were common to the two tissues.‘‘Phenylpropanoid biosynthesis”was the most enriched pathway in both leaves and stems,and 134 key regulatory genes in lignin synthesis were identified by a weighted gene co-expression network analysis.The NAC family transcription factor MsNST1 gene was highly expressed in old leaf and stem tissues.The deposition pattern of G-and S-lignin differed among M.truncatula wild-type,nst1 mutants,and overexpression lines,and the transcription levels of lignin synthesis genes such as HCT,F5H,and COMT in these three materials also differed.These results suggest that MsNST1 affects lignin synthesis in alfalfa.These findings provide a genetic basis and abundant gene resources for further study of the molecular mechanisms of lignin synthesis,laying a foundation for low-lignin alfalfa breeding research.
基金Supported by Tibet High Quality Freeze Resistance Bluegrass Varieties Breeding(Z2013C02N02_02)National Wool Sheep Grazing Grassland Ecological Position of Scientific Research Project(CARS-40-09B)
文摘Two-year-old Medicago sativa at budding initial stage was taken as research materials.Five methods were used to make green hay,including flatting stems ＋ spraying 2.5% K2CO3,flatting stems,sun curing,drying in shade and drying under 105 ℃ condition（CK）.Besides,effects of different green hay making methods on dry characteristics and nutritional quality of M.sativa green hay were studied,and a comprehensive evaluation of M.sativa green hays was conducted.Results showed that,except CK,the drying rates in other making methods were all fast at first,and then slow down.Both of drying under 105 ℃ condition and flatting stems ＋ spraying K2CO3 could speed up drying rate and reduce nutritional losses of green hay.Sun curing could also speed up drying rate,but it could not maintain the quality of green hay.The results of Grey Relational Analysis on five green hay making methods indicated that CK had the best comprehensive performance,followed by green hays made by flatting stems ＋ spraying K2CO3.Therefore,flatting stems ＋ spraying K2CO3 was a quick and easy method to make green hay,and it was worth to be recommended in practical production.
