Comparative study of wild and cultivated Astragali Radix in Daqingshan district in Wuchuan of Neimenggu Effects of drought stress on seedling growth and accumulation of secondary metabolites in the roots of Astragalus membranaceus var. mongholicus Effect of sowing quantity and method on seedling quality and yield of Astragalus membranaceus var. mongholicus in Weiyuan, Gansu Province, Chin Isolation and identification of the pathogens causing Astragalus membranaceus var. mongholicus root rot in Weiyuan of Gansu Province