Evaluation on resistance to pathogenic fungus Embellisia astragali of 10 germplasms of Astragalus adsurgens at seedling stages

Yellow stunt and root rot of standing milkvetch (Astragalus adsurgens) caused by Embellisia astragali is the main factor reducing the perennial forages biomass. In this study, the resistance to pathogenic fungus of 10 germplasms of A. adsurgens was evaluated by measuring the seed germination rate, shoot and root length, plant dry weight, mycelium distribution, and mycelium invasion extent, incidence, mortality and disease severity index under very sterile conditions. This study showed that the inoculated treatments significantly increased the germination energy and root length of 10 germplasms (P0.05); did not affect germination rate; and significantly reduced the dry biomass and seedling length of 10 germplasms. The mycelium distribution and mycelium invasion extent showed a difference among varieties, indicating that the infection rate of Neimeng and Ningxia germplasms was higher than that of Shaxiyulin and Zhongsha No.1 germplasms. Based on disease incidence, mortality and disease severity index, the comprehensive evaluation on disease showed that the Shaxiyulin and Zhongsha No.1 germplasms performed well at seedling stage, that Neimeng and Ningxia germplasms followed, and other germplasms were in between.