结合态氮对根瘤菌生长液诱导的苜蓿根毛变形的抑制

Studies of the Inhibtion of Combined N on the Root Hair Deformation Induced by the Supernatant of the Culture Solution of Rhizobium meliloti

以苜蓿根瘤菌和其宿主苜蓿为材料，由结合态氮影响苜蓿根瘤菌生长液诱导宿主根毛变形的功能发现，硝态氮和铵态氮均能有效地抑制根瘤菌生长液诱导的宿主根毛变形。而其抑制作用随结合态氮浓度的增加、作用时间的延长而增强。该抑制作用发生在结合态氮浓度和作用时间分别达到1mmol/L和12h时，或当其浓度和作用时间分别为6mmol/L和48h时，根瘤菌生长液引起根毛变形的植株百分率下降到10％。硝态氮与铵态氮抑制根瘤菌生长液诱导根毛变形的作用相类似。

The idebitmg effect of combmed N on met hair defonnaion of alfalfa mduced by the supematan of the cultUre solution of Rhizobium meliloti was studied Nitrae and ammonia could ef fectively inhibit root hair deformation(Fig. 1 ). The mhibitmg effect was Proportional to the amount of combined N supplied(Fig. 2) and the hme of combined N-root interaction(Fig. 3), at combined N concentration over 1 mmol/L(Fig. 2) and the time of combined N-rootinteration over 12 h(Fig. 3), The Per centag of seedlings with root hair deformation was lowered Wth 48 h exposure of plan root to 6 mmol/L combined N, the percentage of seedlings with root hairderformation dropped 10% (Fig. 2). The inhibitory effect of nitrate on roothair deformation was similar to that of ammonia