根瘤菌共生对紫花苜蓿耐碱能力的影响

Effect of rhizobium symbiosis on the alkali resistanc of alfalfa

以紫花苜蓿龙牧806为试验材料,设置未接种菌(NI)和接种耐碱苜蓿中华根瘤菌CCBAU 81024(RI)两组,采用p H 8.5 100 mmol·L-1NaHCO3溶液碱胁迫处理,分别测定胁迫0、5、8 d时生长及生理指标,确定接种耐碱根瘤菌对紫花苜蓿耐碱性的影响。结果表明,正常培养条件下,RI组紫花苜蓿叶绿素和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)酶活性、脯氨酸(Pro)和可溶性糖含量均高于NI组,且丙二醛(MDA)含量低于NI组。碱胁迫处理后,RI组与NI组植株相比,其MDA含量,相对电导率均保持在较低水平,脯氨酸积累,可溶性糖含量增加;SOD、POD、CAT表现出较NI更高的酶活。接种耐碱根瘤菌可提高紫花苜蓿耐碱性及抗氧化能力,增强渗透调节能力,降低细胞膜损伤程度。

Two groups of uninoculated(NI)and alkali-resistant Chinese rhizobia CCBAU81024(RI)of alfalfa were set as materials,the NaHCO3solution with a concentration of100mmol?L-1(pH8.5)was used for alkali stress treatment.At0,5and8d of stress,the growth and physiological indices were measured to determine the effect of inoculation of alkali-resistant rhizobia on improving alkaline resistance of alfalfa.The results showed that under normal culture conditions,chlorophyll,SOD,POD and CAT activities,proline and soluble sugar of alfalfa in the RI group were higher than those in the NI group,and MDA content were lower than those in the NI group.After the treatment of alkali stress,the MDA content and relative conductivity of the RI group remained at a low level compared with the NI group,with the accumulation of proline and the increase of soluble sugar content.SOD,POD and CAT showed higher enzyme activities than NI.It concluded that the inoculation of alkali-resistant rhizobia could improve the alkali resistance of alfalfa,increase the antioxidant capacity of alfalfa,enhance the ability of osmotic regulation and reduce the damage degree of cell membrane.