[Effects of inoculating AM fungi on physiological characters and nutritional components of Astragalus membranaceus under different N application levels].

A pot culture with unsterilized soil as growth substrate showed that AM fungi had significant effects on the growth of Astragalus membranaceus (Fabaceae) under different N application levels. Inoculation with AM fungi promoted the AM infection of A. membranaceus roots, but high N application level suppressed the infection. Inoculating AM fungi increased the growth rate, soluble protein and sugar contents, and SOD, POD and CAT activities of A. membranaceus. Under 50 and 100 mg x kg(-1) of N application, new bands of POD isozyme occurred in inoculated plants, and the contents of flavonoid, N, and P in A. membranaceus also had definite increase. The best inoculation effect was observed under the N application level of 50-100 mg N x kg(-1) soil.