黑土区紫花苜蓿根瘤菌特性研究与促生能力分析

摘要

本文通过采集东北黑土地区2龄紫花苜蓿(Medicago)根瘤菌菌株,经过根瘤菌的耐盐、耐碱、耐酸、溶磷能力、生长素分泌能力、代时、固氮酶活性等生物学特性测试;并进行回接试验,测定供试菌株促生植株的根瘤数、根瘤重、生物量及全氮量,旨在阐明黑土区苜蓿根瘤菌特性与促生植株地上生物量及其全氮的关系.结果表明:菌株促生植株的全氮量与根瘤菌泌酸能力、代时、促生植株根瘤数显著相关(P≤0.05);菌株促生植株地上生物量与菌株溶磷能力、泌酸能力、促生植株根瘤重呈极显著相关(P≤0.01).通过通径分和回归分析建立了苜蓿根瘤菌株促生植株地上生物量及其全氮量的最优多元线性回归方程,该方程可为优异菌株筛选及其促生能力判断提供科学依据.%Out of the rhizobium strains of 2 years old Alfalfa collected from black soil region in Heilongjiang province,we screened out some comprehensively excellent strains according to phenotype and metabolic characteristics.Results showed that the strain growth promoted plant nitrogen and rhizobium oxyntic capacity,generally,promoted root nodule significantly (P≤0.05);The strain growth also promoted aboveground biomass of plant and phosphorus solubilizing ability,and the capacity of acid secretion was significantly correlated with the weight of root nodule (P≤0.01).By path analysis and regression analysis,both alfalfa rhizobium strains of promoted plant growth of optimal biomass and total nitrogen are established in the multivariate linear regression equation,which was scientifically decided through the equation for selecting excellent strains and their growth promoting ability.