Identification and evaluation of drought resistance in different maize varieties widely grown in Yunnan

This research took eight main maize varieties in Yunnan( Tiannuo888,Yunnuo6,Yunrui999,Yunrui6,Yunrui47,Yunrui88,Yunyou105,and Yuntianyu2) as materials to investigate possible influences caused by water stress. A pot experiment was conducted to examine 14 morphological and biochemical indexes( plant height,fresh weight,ratio of root to shoot,POD,and SOD etc.) that were related to drought resistance under two levels of water content( 70% ~ 80% and 50% ~ 60% of field moisture capacity) at seedling,flowering and filling stages of the maize varieties. Capabilities in drought resistance of varieties under water stresses were scored by the drought coefficient and subordinate function value methods. The results showed that the same index of drought resistance characterized in different maize varieties at various stages existed differences,and 8 maize varieties were divided into three grades: high tolerant,weaker tolerant,and drought susceptible. The high-tolerant cultivars include Yunrui47,Yunyou105 and Yuntianyu2;The varieties with weaker drought resistance were Yunrui6,Yunrui88 and Yunrui999. However,Tiannuo888 and Yunnuo6 were drought susceptible. Moreover,all morphological and biochemical indexes and their comprehensive D- values could be taken as evaluation criteria at seedling stage of maize varieties under water stress. From seeding to floweringstages,under water stress,only plant height,leaf area,SOD and Pro showed significant correlations with drought resistance indexes. From flowering to filling stages,under water stress,significant correlations between shoot fresh weight,plant height and MDA and drought resistance could be observed. No matter what growth stages the maize varieties were at,seeding,florescence or filling stages,underwater stress,the comprehensive D- value of the indexes had a significant correlation with drought resistance,which could be used to identify maize drought resistance,nevertheless any single index.