Drought Resistance of Eight Maize Varieties at Seed- ling Stage in Yunnan Province

Using eight maize varieties （Tiannuo 888, Yunnuo 6, Yunrui 999, Yunrui 6, Yunrui 47, Yunrui 88, Yunyou 105, Yuntianyun 2） as the research ma- terials, this paper aimed to figure out the possible influence caused by repeated drought treatment. A pot experiment was conducted to investigate the changes in 13 phenotypic characters and physiological and biochemical indexes （plant height, fresh mass, root shoot ratio, POD activity, SOD activity） related to drought resist- ante, under two levels of water supply （repeated drought treatment and CK） at seedling stage of maize varieties, and evaluated drought resistanee comprehensively by standard deviation coefficient allocation weighed method. The results showed that the survival rate, leaf area, plant height, shoot fresh mass, root fresh mass, shoot dry mass and root dry mass of seedling maize decreased at varying degrees after repeated drought stress. However, the MDA molality, root shoot ratio, Pro content and soluble protein content increased under repeated drought stress. There were significant difference in morphological, physiological and biochemical inde- xes among different maize varieties. The drought resistances of different maize varieties successively were Yunrui 47 〉 Yuntianyu 2 〉 Yunyou 105 〉 Yunnuo 6 〉 Tianuo 888 〉 Yunrui 6 〉 Yunrui 999 〉 Yunrui 88. These results provide references for maize drought-resistant breeding and maize production.