不同pH值下接种根瘤菌对紫花苜蓿产量和品质的影响(简报)

Effects on yield and quality of Medicago sativa by Rhizobium inoculation under different pH value conditions

采用正交试验法研究了2个苜蓿品种在不同环境pH值(pH值4.8,5.2,5.6)下接种6株苜蓿根瘤菌株的效果。结果显示,pH值和接种菌株对苜蓿整株鲜重、有效根瘤数、固氮酶活性和全氮含量的影响均较显著。pH值从5.6降低到4.8,苜蓿整株鲜重、固氮酶活性、全氮含量平均降低约66.64%,39.20%,25.84%,有效根瘤数平均减少约8个。接种菌株4(91512)对整株鲜重(0.517 1 g)和有效根瘤数(19.888 9个)影响最大,菌株5(91522)对整株鲜重(0.554 4 g)、固氮酶活性(C2H416.809 3μg/g.h)和全氮含量(3.307 0%)影响最大。植株品种对有效根瘤数和固氮酶活性的影响均不显著,但整株鲜重和全氮含量均以苜蓿“露”的效果优于保定苜蓿。上述结果说明,在酸性环境中,环境pH值是影响苜蓿产量和品质的主要因子,接种高效耐酸苜蓿根瘤菌、选择优良的苜蓿植株品种可以在一定程度上降低环境pH值对苜蓿生长的负效应。

An orthogonal test was used to examine the relationships between the growth of M. sativa and its Rhizobium strains, pH value of the environment and M. sativa variety under acidic conditions. The pH value and Rhizobium strains significantly affected fresh weight, effective nodules, nitrogenase activity and total nitrogen. When the pH value was lowered from 5.6 to 4.8, fresh weight, nitrogenase activity and total nitrogen decreased to about 66.64%, 39.20%, 25.84% respectively, and the effective nodules were reduced to about eight. Strain 4 （91512） mainly affected fresh weight and effective nodules （0. 517 1 g and 19. 888 9 respectively） while strain 5 （91522） significantly influenced fresh weight, nitrogenase activity and total nitrogen, （0. 554 4 g, C2H416. 809 3μg/g ·h and 3. 307 0% respectively）. Plant variety did not significantly influence effective nodules and nitrogenase activity, but did significantly affect fresh weight and total nitrogen. The effectiveness on M. sariva ＂Lu＂ was more obvious. It is concluded that under acidic conditions, pH value was the major factor affecting yield and quality and that inoculating a M. sativa variety with acid-tolerant Rhizobiurn could alleviate to some extent the negative effects of an unfavourable pH value.