Study on comprehensive evaluation of drought resistance of Medicago sativa L. germplasm at seedling stage.

The drought resistance of 18 alfalfa germplasms at the seedling stage was evaluated under soil drought stress in the green house.The difference among three comprehensive evaluation methods,i.e.cluster analysis,grading method,and standard deviation coefficient allocation weighted method,was compared based on the measurements of morphological indices including survival rate,plant height,aboveground biomass,underground biomass,root to shoot ratio,and root length and meanwhile the strong drought resistance materials were screened.The results show that the drought resistance of 18 alfalfa germplasms from strong to weak was as follows: M7 M8 M3 M10 M9 M4 M11 M2 M12 810 M6 M14 M1 CK M15 M16 M13 M17 M5 according to the standard deviation coefficient allocation weighted method.This method not only considered the allocation weight of different indices but also evaluated the drought resistance of each material.