接种丛枝菌根真菌对低温胁迫下垂穗披碱草影响的研究

摘要

低温是影响植物生长的主要限制因子.采用沙培法研究了接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)对2份不同海拔梯度下的购买自北京正道公司(ZD)和采集自西藏康马县(KM)垂穗披碱草(Elymus nutans)生长与生理特性的影响.结果表明:接种AMF的植株根系均受到不同程度的侵染,且侵染率随时间的变化呈先增加后减少的趋势.低温胁迫下,2种垂穗披碱草的生长均受到一定程度的抑制.然而,接种活性AMF能显著提高低温胁迫下ZD和KM的地上和地下生物量、根系形态结构指标、光合色素含量和抗氧化物酶类活性,且显著降低低温胁迫下植株相对电解质渗透率(REL)、丙二醛(MDA)含量、超氧阴离子(O2·-)含量和过氧化氢(H2O2)含量(P＜0.05).综上所述,接种活性AMF能够明显提高45 d垂穗披碱草ZD和KM幼苗对低温胁迫的耐受性.%Cold stress is one of the most important abiotic stresses affecting plant growth and metabolism.Arbuscular mycorrhizal fungi (AMF) are widespread symbiotic fungi,They could promote plant growth and development,and increase the ability of plant stress resistance.Two cultivars of Elymus nutans (ZD and KM) were subjected to 5℃ cold stress for 5 d after inoculated with or without Glomus mosseae (Nicolson & Gerdemann) and cultivated for 45 days in the pots.Seedling performances were estimated by AMF inoculation rate,changes in plant morphological and physiological performances.The results were as follows:AMF inoculation rates were quite different between the two E.nutans cultivars.From 0 to 45 d the inoculation rate increased steadily for both cultivars,and 45 d having the highest inoculation rates.However,from 45 to 60 d the inoculation rate showed a decrease.Under cold stress,plant growth was inhibited in both cultivars,however,plant shoot and root dry weight,root scanned morphology indexes,the content of total chlorophyll and carotenoid,and activities of antioxident enzymes tended to be higher with AMF inoculation.Moreover,the results showed that inoculated with AMF decreased relative electrolyte leakage (REL),malondialdehyde (MDA) content,O2·-content and H2O2 content in leaves of two cultivars of E.nutans.Our results suggested that AMF inoculation increased the cold tolerance in 45-day-old seedlings of ZD and KM.