[Objective] This study aimed to study the structure and functions of SRP gene and variation in its expression under abiotic stresses. [Method] Using the SRP sequence obtained from transcriptome sequencing as the templ...[Objective] This study aimed to study the structure and functions of SRP gene and variation in its expression under abiotic stresses. [Method] Using the SRP sequence obtained from transcriptome sequencing as the template, the full-length cDNA sequence of SRP gene in Festuca arundinacea was amplified using the 3＇RACE and 5＇RACE methods. [Result] The cDNA sequence of SRP gene has a full length of 1 165 bp, and it contains an open reading frame in full length of 855 bp. The encoded protein by SRP gene is composed of 284 amino acids, and contains a REF domain. The bioinformatic researches on structures and functions of SRPs show that the SRP gene in Festuca arundinacea （FaSRP） has relatively high ho- mologies with SRPs in monocots. Under low nitrogen, drought, high temperature and high salt stresses, the variations in expression of FaSRP gene were studied using fluorescence quantitative PCR. The results showed that FaSRP gene makes responses to low nitrogen, drought and high temperature stresses, but the relevant response mechanisms are not the same, indicating different pathways regulating re- sistance of plants. The expression of FaSRP gene is insensitive to high salt stress. [Conclusion] This study will provide certain candidate gene and technical reserve for breeding of drought- and high temperature-tolerant, nutritious and highly efficient Festuca arundinacea cultivars.展开更多
[Objective] The paper was to understand the physiological response of space flight mutation new strains of Festuca arundinacea to high temperature stress. [Method] The influence of high temperature stress on eco-physi...[Objective] The paper was to understand the physiological response of space flight mutation new strains of Festuca arundinacea to high temperature stress. [Method] The influence of high temperature stress on eco-physiological characteristics of 11 F. arundinacea materials was studied in a pot experiment.Physiological and biochemical indexes,including soluble protein content,superoxide dismutase( SOD),peroxidase( POD) and catalase( CAT) activities,were measured and analyzed once every 4 d for a total of three times. Subordinate function and grey rational analysis were used to comprehensively evaluate the heat resistance of 11 materials. [Result] The soluble protein content decreased with the extension of heat resistance stress,while SOD,POD and CAT activities showed an upward trend. The high temperature resistance of 11 F. arundinacea materials was evaluated by subordinate function method. The resistance order was SP5-85> SP5-60 > SP5-71 > SP5-42 > SP5-94 > SP5-7 > SP5-88 > F. arundinacea cv Shuicheng > SP5-5 > SP5-89 = F. arundinacea cv Qiancao No. 1. The relational order of various heat resistance indexes and heat resistance obtained by grey rational analysis was SOD > CAT > POD > soluble protein content. [Conclusion]The result provides a theoretical basis for stress physiology and stress breeding of cold season grass in southwest region.展开更多
The cDNA of PHYC gene of tall fescue ( Festuca arundinacea ) was cloned by RT-PCR,named FaPHYC.The sequence was analyzed by bioinformatic software,and the results showed that the full-length cDNA(3816 bp) was obtained...The cDNA of PHYC gene of tall fescue ( Festuca arundinacea ) was cloned by RT-PCR,named FaPHYC.The sequence was analyzed by bioinformatic software,and the results showed that the full-length cDNA(3816 bp) was obtained with an open reading frame predicated to be 3 411 bp,which encoded 1 136 amino acids.By BLASTP analysis,the N-terminal of FaPHYC was composed of GAF and pPhytochrome domains,and its C-terminal included two repeated PAS domains,one histidine kinase A domain and one histidine kinase-like ATPase domain.The phylogenetic analysis showed that FaPHYC was closely related to PHYCs from other Gramineae plants.The qRT-PCR results showed that FaPHYC expression was regulated by drought stress,heat stress,salt stress and nitrogen stress.The real-time quantitative PCR assay showed the expression of FaPHYC in tall fescue seedlings was continuously up-regulated during the light period and down-regulated in the dark.The results suggest that FaPHYC is photoperiod sensitive and plays a functional role in flowering regulation by photoperiod in tall fescue.The FaPHYC gene was cloned and reported from tall fescue for the first time,which lays a foundation for the investigation of the stress mechanism of FaPHYC in tall fescue plant.展开更多
We report here a damping-off disease occurring at the seedling stage of the grass Festuca arizonica (Arizona fescue) that is caused by the soil-borne fungal pathogen Rhizoctonia solani.
Microbial inoculants were isolated from sewage sludge and applied to turfgrass medium. Effects of microbial inoculants on seed germination and initial growth of Festuca arundinacea L. were analyzed to investigate the ...Microbial inoculants were isolated from sewage sludge and applied to turfgrass medium. Effects of microbial inoculants on seed germination and initial growth of Festuca arundinacea L. were analyzed to investigate the optimal proportion of compound microbial inoculants. Significant differences were found in various growth indices and chlorophyll content of F. arundinacea between microbial treatment and control The combination of Pseudomonas stutzeri and Trichoderma reesei exhibited the best results. Compared with the control, seed germination rate, seedling height, shoot dry weight, root weight, chlorophyll a content and chlorophyll b content of F. arundinacea treated with the combination of Pseudomonas stutzeri and Trichoderma reesei were improved by 11.60%, 43.47%, 148%, 159%, 144% and 136%, respectively. Based on comprehensive analysis of various indicators, the optimal proportion （V/V） of microbial combination was Pseudomonas stutzeri： Tfichoderma reesei = 1： 1, which was the most conducive to plant growth and development.展开更多
We report here a damping-off disease occurring at the seedling stage, resulting in severe loss of the seedling stands caused by an important soil-borne fungal pathogen, Fusarium oxysporum. Endophyte-infected plants ap...We report here a damping-off disease occurring at the seedling stage, resulting in severe loss of the seedling stands caused by an important soil-borne fungal pathogen, Fusarium oxysporum. Endophyte-infected plants appear to be more resistant to the damping-off disease than uninfected plants.展开更多
In this paper, domestic and foreign advances in breeding situation and conventional breeding methods of Festuca arundinacea Schreb. and the applica- tion of modem biological techniques （ somaclonal variation, somatic...In this paper, domestic and foreign advances in breeding situation and conventional breeding methods of Festuca arundinacea Schreb. and the applica- tion of modem biological techniques （ somaclonal variation, somatic cell hybridization, genetic map construction, genetic diversity, gene cloning and expression, ge- netic engineering） in breeding of new varieties of F. arundinacea were summarized, which proposed new ideas for the development of F. arundinacea breeding and provided reference for breeding of new varieties of F. arundinacea.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
[Objectives] This study was conducted to provide a scientific basis for the utilization of municipal solid waste resources, the remediation of contaminated substrates and the ecological safety of urban lawn planting. ...[Objectives] This study was conducted to provide a scientific basis for the utilization of municipal solid waste resources, the remediation of contaminated substrates and the ecological safety of urban lawn planting. [Methods] Graphene, multi-layer graphene oxide and multi-walled carbon nanotubes were added to municipal solid waste(MSW) compost as turf substrate to determine the morphological indicators such as turfgrass biomass, chlorophyll contents and plant height. [Results] There were no significant differences in the plant height of Festuca arundinacea between different treatment groups in the first 30 d. The effects of adding different carbon nanomaterials on the fresh and dry weights of F. arundinacea were not significantly different. The aboveground biomass of F. arundinacea was the largest after adding graphene oxide, and the underground fresh weight decreased significantly in the hydroxyl multi-walled carbon nanotube treatment compared with the control. As to the chlorophyll content, the graphene oxide treatment was the highest, but there were no significant differences between all the treatment groups and the control group. [Conclusions] This study can provide data support for MSW compost substrate, lawn planting system and heavy metal pollutant passivating agents.展开更多
[Objectives]This study was conducted to obtain the best solution for sterilizing tall fescue(Festuca arundinacea)and ryegrass(Lolium perenne)seeds by heating in a water bath for a short time.[Methods]The tall fescue a...[Objectives]This study was conducted to obtain the best solution for sterilizing tall fescue(Festuca arundinacea)and ryegrass(Lolium perenne)seeds by heating in a water bath for a short time.[Methods]The tall fescue and ryegrass seeds infected with endophytic fungi were sterilized by heating in a water bath to compare seed germination and initial growth of turfgrass seedlings under different treatment time.[Results]Sterilization in a 60℃water bath for 20 and 30 min both inhibited the germination of tall fescue and ryegrass seeds,while the 20 min treatment did not significantly affect the lengths of stems,leaves and roots of seedlings.The 20 min water bath sterilization treatment had no effects on the plant heights and biomass of the two turfgrass seedlings and the tiller number of ryegrass,but sterilization for 30 min significantly reduced the aboveground and total biomass of seedlings and the tiller number of ryegrass.[Conclusions]Sterilization in a water bath at 60℃ for 20 min achieved rapid sterilization in a short time,without significantly negatively affecting the growth of seedlings.展开更多
The morphology, physicochemical, humic substances and micromorphological characteristics of four soil profiles of the steppe dominant by Festuca lenensis (F. lenensis) at the high mountain and mountain of Khuvsgul, Mo...The morphology, physicochemical, humic substances and micromorphological characteristics of four soil profiles of the steppe dominant by Festuca lenensis (F. lenensis) at the high mountain and mountain of Khuvsgul, Mongolia were studied. Soils were classified as Regosols and Leptosols at high mountain steppe, Leptosols and Cambisols at mountain steppe. On a high mountain, the plant root distribution, OC, N and moisture contents were high due to its high precipitation and low temperature. The soils show immature characteristics with low available nutrients, weakly developed crumb structure, many semi- and undecomposed plant residues, and few little organic pigments with few excrements. The humic acids with immature to degraded characteristics indicate that the climatic condition of high mountains inhibits the soil decomposition process. Due to extremely different landform positions, there a sharp difference was observed between studied soils on high mountain steppe. On the summit with a flat position, the soil of TSO1 showed finer soil texture with higher CEC, exchangeable Mg<sup>2+</sup> and humification degree of SOM compared with the soil of TSO2, which located on the steep slope. This confirms that the abrupt changes in landform on high mountain strongly affect the properties of topsoil. On the mountain steppe, the soil contains higher exchangeable Na<sup>+</sup>, exchangeable K<sup>+</sup> and water soluble at topsoil;however, the plant root distribution, OC, N and moisture contents were lower than that of high mountain soil. Because of warmer air and soil temperature in comparison with that of high elevation, active turnover in humic horizon and chemical weathering process lead to higher available nutrients in mountain steppe. The degraded to well humified characteristics of humic acid, moderately developed crumb structure, a higher component of little organic pigment and many intact excrements indicate that the soil decomposition process and biological activity were higher than that of the high mountain steppe. Our finding suggests that the climatic condition dependent on altitude and landform position at the high mountain and mountain of Khuvsgul had a large impact and played a key role in the soil properties and characteristics of steppe dominant by F. lenensis.展开更多
Background:The endophyte Epichloëfestucae var.lolii forms mutualistic symbiosis with perennial ryegrass,and their relationship under heavy metal stress needs to be more clearly defined.Methods:This study assessed...Background:The endophyte Epichloëfestucae var.lolii forms mutualistic symbiosis with perennial ryegrass,and their relationship under heavy metal stress needs to be more clearly defined.Methods:This study assessed the growth and physiological response of perennial ryegrass with(E+)and without endophyte(E−)under CdCl_(2)(0,50,100,200 mg L^(-))and ZnCl_(2)(0,500,750,1000 mg L^(-))treatments.Results:Higher concentrations of CdCl_(2)(200 mg L^(-))and ZnCl_(2)(1000mg L^(-))treatments typically suppressed ryegrass growth and physiological activity,but for many traits,particularly under ZnCl_(2)stress,the presence of endophyte ameliorated heavy metal suppression.Specifically,E+perennial ryegrass had significantly greater plant height,tiller number,biomass,water content,and root volume(p<0.05)than E−perennial ryegrass under stress.Across the tested concentration ranges,a hormesis effect was observed for some ryegrass traits,and under Zn stress,the presence of endophyte enhanced the hormesis effect for malondialdehyde concentration.Conclusions:These results indicate that Epichloëmodulated growth and physiology to enhance heavy metal stress tolerance of its ryegrass host.The present study extends the understanding of how Epichloëendophyte forms a mutualistic symbiosis with perennial ryegrass.展开更多
Symbiotic relationships between fungal endophytes and grass species are known to increase stress resistance in the grass host;however,there is little evidence to suggest that the positive effects occur early in the gr...Symbiotic relationships between fungal endophytes and grass species are known to increase stress resistance in the grass host;however,there is little evidence to suggest that the positive effects occur early in the grass life cycle.In this study,we explored the effects of the endophyte Epichloe¨festucae on the growth and survival of Festuca eskia seedlings under drought and frequent cutting stress.Methods Festuca eskia seedlings were collected from the western part of the plant repartition area in a non-symbiotic population located in a mesic and heavily grazed site(W-NS)and from the eastern part in a symbiotic population from a xeric and lightly grazed site(E-S).The E-S population was experimentally freed from its endophyte(E-F).Two greenhouse experiments were conducted to compare growth and survival between the three seedling types under drought stress and frequent cutting.In the first experiment,126 seedlings per seedling type(n=378)were grown for 6 weeks under non-limiting conditions before the cessation of watering.After 3 weeks without irrigation,full irrigation was restored for 10 days to measure the survival rate.Leaf length,leaf elongation rate and survival rate were assessed per population.In the second experiment,156 seedlings per seedling type(n=468)were grown under non-limiting conditions.All seedlings were cut to 3 cmhigh,twice a week,during the first month of growth.Leaf elongation and tillering were monitored on 52 seedlings per seedling type.For each type,seedling survival rate was determined by the number of plants alive after 10 days of regrowth,without cutting.Important Findings The drought experiment revealed a phenotypic differentiation to drought in 30 F.eskia populations,suggesting adaptive differentiation:the eastern seedlings showed the highest survival rate.A tradeoff between growth and survival was highlighted:the highest drought survival rate was associated with the lowest leaf elongation rate under non-limiting water conditions.Endophyte presence in the eastern population increased seedling drought survival.In contrast,cutting survival rate was similar between W-NS and E-S because the presence of the endophyte increased seedling survival to frequent cutting.However,this positive effect came with a cost:the endophyte reduced seedling tillering rate.展开更多
基金Supported by National Natural Science Foundation of China(31360576)~~
文摘[Objective] This study aimed to study the structure and functions of SRP gene and variation in its expression under abiotic stresses. [Method] Using the SRP sequence obtained from transcriptome sequencing as the template, the full-length cDNA sequence of SRP gene in Festuca arundinacea was amplified using the 3＇RACE and 5＇RACE methods. [Result] The cDNA sequence of SRP gene has a full length of 1 165 bp, and it contains an open reading frame in full length of 855 bp. The encoded protein by SRP gene is composed of 284 amino acids, and contains a REF domain. The bioinformatic researches on structures and functions of SRPs show that the SRP gene in Festuca arundinacea （FaSRP） has relatively high ho- mologies with SRPs in monocots. Under low nitrogen, drought, high temperature and high salt stresses, the variations in expression of FaSRP gene were studied using fluorescence quantitative PCR. The results showed that FaSRP gene makes responses to low nitrogen, drought and high temperature stresses, but the relevant response mechanisms are not the same, indicating different pathways regulating re- sistance of plants. The expression of FaSRP gene is insensitive to high salt stress. [Conclusion] This study will provide certain candidate gene and technical reserve for breeding of drought- and high temperature-tolerant, nutritious and highly efficient Festuca arundinacea cultivars.
基金Supported by United Fund of Guizhou Province(QKH J LKN[2013]24)Key Special Project of Guizhou Province(QKHZDZX[2014]6017)High-level Innovative Talents Training of Guizhou Province(QKHRC[2016]4024)
文摘[Objective] The paper was to understand the physiological response of space flight mutation new strains of Festuca arundinacea to high temperature stress. [Method] The influence of high temperature stress on eco-physiological characteristics of 11 F. arundinacea materials was studied in a pot experiment.Physiological and biochemical indexes,including soluble protein content,superoxide dismutase( SOD),peroxidase( POD) and catalase( CAT) activities,were measured and analyzed once every 4 d for a total of three times. Subordinate function and grey rational analysis were used to comprehensively evaluate the heat resistance of 11 materials. [Result] The soluble protein content decreased with the extension of heat resistance stress,while SOD,POD and CAT activities showed an upward trend. The high temperature resistance of 11 F. arundinacea materials was evaluated by subordinate function method. The resistance order was SP5-85> SP5-60 > SP5-71 > SP5-42 > SP5-94 > SP5-7 > SP5-88 > F. arundinacea cv Shuicheng > SP5-5 > SP5-89 = F. arundinacea cv Qiancao No. 1. The relational order of various heat resistance indexes and heat resistance obtained by grey rational analysis was SOD > CAT > POD > soluble protein content. [Conclusion]The result provides a theoretical basis for stress physiology and stress breeding of cold season grass in southwest region.
基金Supported by project of High-level Innovative Talents Project in Guizhou Province([2018]5634)Youth Fund of Guizhou Academy of Agricultural Sciences(2018-80)Guizhou Province S&T Contract Basics([2019]1302)
文摘The cDNA of PHYC gene of tall fescue ( Festuca arundinacea ) was cloned by RT-PCR,named FaPHYC.The sequence was analyzed by bioinformatic software,and the results showed that the full-length cDNA(3816 bp) was obtained with an open reading frame predicated to be 3 411 bp,which encoded 1 136 amino acids.By BLASTP analysis,the N-terminal of FaPHYC was composed of GAF and pPhytochrome domains,and its C-terminal included two repeated PAS domains,one histidine kinase A domain and one histidine kinase-like ATPase domain.The phylogenetic analysis showed that FaPHYC was closely related to PHYCs from other Gramineae plants.The qRT-PCR results showed that FaPHYC expression was regulated by drought stress,heat stress,salt stress and nitrogen stress.The real-time quantitative PCR assay showed the expression of FaPHYC in tall fescue seedlings was continuously up-regulated during the light period and down-regulated in the dark.The results suggest that FaPHYC is photoperiod sensitive and plays a functional role in flowering regulation by photoperiod in tall fescue.The FaPHYC gene was cloned and reported from tall fescue for the first time,which lays a foundation for the investigation of the stress mechanism of FaPHYC in tall fescue plant.
文摘We report here a damping-off disease occurring at the seedling stage of the grass Festuca arizonica (Arizona fescue) that is caused by the soil-borne fungal pathogen Rhizoctonia solani.
基金Supported by Key Project of Science and Technology Support Program of Tianjin(13ZCZDNC00200)
文摘Microbial inoculants were isolated from sewage sludge and applied to turfgrass medium. Effects of microbial inoculants on seed germination and initial growth of Festuca arundinacea L. were analyzed to investigate the optimal proportion of compound microbial inoculants. Significant differences were found in various growth indices and chlorophyll content of F. arundinacea between microbial treatment and control The combination of Pseudomonas stutzeri and Trichoderma reesei exhibited the best results. Compared with the control, seed germination rate, seedling height, shoot dry weight, root weight, chlorophyll a content and chlorophyll b content of F. arundinacea treated with the combination of Pseudomonas stutzeri and Trichoderma reesei were improved by 11.60%, 43.47%, 148%, 159%, 144% and 136%, respectively. Based on comprehensive analysis of various indicators, the optimal proportion （V/V） of microbial combination was Pseudomonas stutzeri： Tfichoderma reesei = 1： 1, which was the most conducive to plant growth and development.
文摘We report here a damping-off disease occurring at the seedling stage, resulting in severe loss of the seedling stands caused by an important soil-borne fungal pathogen, Fusarium oxysporum. Endophyte-infected plants appear to be more resistant to the damping-off disease than uninfected plants.
基金Supported by Outstanding Young Talent Training Program of Guizhou Province(QKHRZ[2011]1182013BAD01B03-20)
文摘In this paper, domestic and foreign advances in breeding situation and conventional breeding methods of Festuca arundinacea Schreb. and the applica- tion of modem biological techniques （ somaclonal variation, somatic cell hybridization, genetic map construction, genetic diversity, gene cloning and expression, ge- netic engineering） in breeding of new varieties of F. arundinacea were summarized, which proposed new ideas for the development of F. arundinacea breeding and provided reference for breeding of new varieties of F. arundinacea.
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.
基金Supported by National Natural Science Foundation of China(31870484)
文摘[Objectives] This study was conducted to provide a scientific basis for the utilization of municipal solid waste resources, the remediation of contaminated substrates and the ecological safety of urban lawn planting. [Methods] Graphene, multi-layer graphene oxide and multi-walled carbon nanotubes were added to municipal solid waste(MSW) compost as turf substrate to determine the morphological indicators such as turfgrass biomass, chlorophyll contents and plant height. [Results] There were no significant differences in the plant height of Festuca arundinacea between different treatment groups in the first 30 d. The effects of adding different carbon nanomaterials on the fresh and dry weights of F. arundinacea were not significantly different. The aboveground biomass of F. arundinacea was the largest after adding graphene oxide, and the underground fresh weight decreased significantly in the hydroxyl multi-walled carbon nanotube treatment compared with the control. As to the chlorophyll content, the graphene oxide treatment was the highest, but there were no significant differences between all the treatment groups and the control group. [Conclusions] This study can provide data support for MSW compost substrate, lawn planting system and heavy metal pollutant passivating agents.
基金the National Natural Science Foundation of China(31870484).
文摘[Objectives]This study was conducted to obtain the best solution for sterilizing tall fescue(Festuca arundinacea)and ryegrass(Lolium perenne)seeds by heating in a water bath for a short time.[Methods]The tall fescue and ryegrass seeds infected with endophytic fungi were sterilized by heating in a water bath to compare seed germination and initial growth of turfgrass seedlings under different treatment time.[Results]Sterilization in a 60℃water bath for 20 and 30 min both inhibited the germination of tall fescue and ryegrass seeds,while the 20 min treatment did not significantly affect the lengths of stems,leaves and roots of seedlings.The 20 min water bath sterilization treatment had no effects on the plant heights and biomass of the two turfgrass seedlings and the tiller number of ryegrass,but sterilization for 30 min significantly reduced the aboveground and total biomass of seedlings and the tiller number of ryegrass.[Conclusions]Sterilization in a water bath at 60℃ for 20 min achieved rapid sterilization in a short time,without significantly negatively affecting the growth of seedlings.
文摘The morphology, physicochemical, humic substances and micromorphological characteristics of four soil profiles of the steppe dominant by Festuca lenensis (F. lenensis) at the high mountain and mountain of Khuvsgul, Mongolia were studied. Soils were classified as Regosols and Leptosols at high mountain steppe, Leptosols and Cambisols at mountain steppe. On a high mountain, the plant root distribution, OC, N and moisture contents were high due to its high precipitation and low temperature. The soils show immature characteristics with low available nutrients, weakly developed crumb structure, many semi- and undecomposed plant residues, and few little organic pigments with few excrements. The humic acids with immature to degraded characteristics indicate that the climatic condition of high mountains inhibits the soil decomposition process. Due to extremely different landform positions, there a sharp difference was observed between studied soils on high mountain steppe. On the summit with a flat position, the soil of TSO1 showed finer soil texture with higher CEC, exchangeable Mg<sup>2+</sup> and humification degree of SOM compared with the soil of TSO2, which located on the steep slope. This confirms that the abrupt changes in landform on high mountain strongly affect the properties of topsoil. On the mountain steppe, the soil contains higher exchangeable Na<sup>+</sup>, exchangeable K<sup>+</sup> and water soluble at topsoil;however, the plant root distribution, OC, N and moisture contents were lower than that of high mountain soil. Because of warmer air and soil temperature in comparison with that of high elevation, active turnover in humic horizon and chemical weathering process lead to higher available nutrients in mountain steppe. The degraded to well humified characteristics of humic acid, moderately developed crumb structure, a higher component of little organic pigment and many intact excrements indicate that the soil decomposition process and biological activity were higher than that of the high mountain steppe. Our finding suggests that the climatic condition dependent on altitude and landform position at the high mountain and mountain of Khuvsgul had a large impact and played a key role in the soil properties and characteristics of steppe dominant by F. lenensis.
基金National Natural Science Foundation of China,Grant/Award Number:U21A20239Natural Science Foundation of Gansu Province,Grant/Award Number:22JR5RA411Gansu Provincial Science and Technology Major Projects,Grant/Award Number:23ZDNA009。
文摘Background:The endophyte Epichloëfestucae var.lolii forms mutualistic symbiosis with perennial ryegrass,and their relationship under heavy metal stress needs to be more clearly defined.Methods:This study assessed the growth and physiological response of perennial ryegrass with(E+)and without endophyte(E−)under CdCl_(2)(0,50,100,200 mg L^(-))and ZnCl_(2)(0,500,750,1000 mg L^(-))treatments.Results:Higher concentrations of CdCl_(2)(200 mg L^(-))and ZnCl_(2)(1000mg L^(-))treatments typically suppressed ryegrass growth and physiological activity,but for many traits,particularly under ZnCl_(2)stress,the presence of endophyte ameliorated heavy metal suppression.Specifically,E+perennial ryegrass had significantly greater plant height,tiller number,biomass,water content,and root volume(p<0.05)than E−perennial ryegrass under stress.Across the tested concentration ranges,a hormesis effect was observed for some ryegrass traits,and under Zn stress,the presence of endophyte enhanced the hormesis effect for malondialdehyde concentration.Conclusions:These results indicate that Epichloëmodulated growth and physiology to enhance heavy metal stress tolerance of its ryegrass host.The present study extends the understanding of how Epichloëendophyte forms a mutualistic symbiosis with perennial ryegrass.
文摘Symbiotic relationships between fungal endophytes and grass species are known to increase stress resistance in the grass host;however,there is little evidence to suggest that the positive effects occur early in the grass life cycle.In this study,we explored the effects of the endophyte Epichloe¨festucae on the growth and survival of Festuca eskia seedlings under drought and frequent cutting stress.Methods Festuca eskia seedlings were collected from the western part of the plant repartition area in a non-symbiotic population located in a mesic and heavily grazed site(W-NS)and from the eastern part in a symbiotic population from a xeric and lightly grazed site(E-S).The E-S population was experimentally freed from its endophyte(E-F).Two greenhouse experiments were conducted to compare growth and survival between the three seedling types under drought stress and frequent cutting.In the first experiment,126 seedlings per seedling type(n=378)were grown for 6 weeks under non-limiting conditions before the cessation of watering.After 3 weeks without irrigation,full irrigation was restored for 10 days to measure the survival rate.Leaf length,leaf elongation rate and survival rate were assessed per population.In the second experiment,156 seedlings per seedling type(n=468)were grown under non-limiting conditions.All seedlings were cut to 3 cmhigh,twice a week,during the first month of growth.Leaf elongation and tillering were monitored on 52 seedlings per seedling type.For each type,seedling survival rate was determined by the number of plants alive after 10 days of regrowth,without cutting.Important Findings The drought experiment revealed a phenotypic differentiation to drought in 30 F.eskia populations,suggesting adaptive differentiation:the eastern seedlings showed the highest survival rate.A tradeoff between growth and survival was highlighted:the highest drought survival rate was associated with the lowest leaf elongation rate under non-limiting water conditions.Endophyte presence in the eastern population increased seedling drought survival.In contrast,cutting survival rate was similar between W-NS and E-S because the presence of the endophyte increased seedling survival to frequent cutting.However,this positive effect came with a cost:the endophyte reduced seedling tillering rate.
