Response of Different Maize Germplasms to Drought Stress at Germination Stage and Seedling Stage

In order to investigate the difference of drought resistance of different maize germplasm at germination and seedling stage, 20 tropical, temperate and warm maize germplasm were used as experimental materials, and normal treatment and drought stress treatment were carried out at germination and trileaf stage（seedling stage）, respectively. Germination rate, germination index, radicle number, radicle length, germ length, radicle dry weight and germ dry weight were measured on the 8 th day after seeding. Plant height, root dry weight, leaf area, root-shoot ratio, chlorophyll content, F_v/F_o and F_v/F_m were measured after 7 days of drought treatment at seedling stage. The results showed that there were significant differences in 14 traits among different germplasm and 14 traits among different materials, and drought stress significantly affected the performance of 14 traits. The variation trend of drought stress response at germination stage and seedling stage was the same among different maize germplasm. Germ length and leaf area were the most responsive traits at germination stage and seedling stage, respectively. The drought resistance coefficient of different maize germplasm was significantly different in most traits. Compared with temperate germplasm, tropical germplasm had higher drought resistance at germination stage and seedling stage, and tropical germplasm had more high resistance materials. There were 8, 5 and 7 excellent drought resistance materials in tropical, temperate and warm germplasm, respectively. TroG04, TemG15 and MixG02 had strong drought resistance at germination and seedling stages, and could be used to select varieties with good drought resistance at germination and seedling stages.