玉米苗期和萌发期抗旱指数筛选及评价OA北大核心CSTPCD

To screen the drought resistance indicators of the main maize hybrids for relatively large acreages at germination and seedling stages,the released maize hybrids were used as test materials.2 treatments were set up including control and drought stress(PEG-6000 with mass fraction of 20%).Germination rate,germination potential and germination index were measured at germination stage,and MDA content,chlorophyll content,root dry weight,canopy dry weight,plant dry weight,plant fresh weight,root to shoot dry weight ratio and dry to fresh ratio were measured from the seedling stage to the three leaf one heart stage.A comprehensive evaluation of drought resistance and screening of drought resistance indicators for maize varieties were conducted using drought resistance coefficient,weighted drought resistance coefficient,principal component analysis,membership function analysis and other methods.The results showed that the germination rate,germination potential and germination index of maize hybrids showed different degrees of decline during the germination period.The drought resistance coefficients of germination rate,germination potential and germination index varied widely,ranging from 7.33 to 97.78,14.81 to 97.69 and 33.25 to 98.59,respectively.Based on the drought coefficient and cluster analysis,the hybrids were divided into 3 categories:drought resistant,moderate and sensitive,which correspond to the total comprehensive evaluation values(Ti)of 0.00～0.35,0.53～0.66 and 0.77～0.96,respectively.There were 11 sensitive varieties during the germination period,including Zhengdan 958(V1),Jingdan 28(V3)and Huanong 138(V5)etc.There were 4 drought resistant varieties,including Xianyu 335(V2),Jingke 968(V4)and Xianyu 047(V7)etc.The MDA and chlorophyll contents in the leaves of the maize varieties at the seedling stage were significantly increased compared to the control(CK),while the other 6 traits showed varying degrees of change.Based on principal component analysis and cluster analysis of drought resistance coefficient and weighted drought resistance coefficient,the varieties were grouped into 3 categories:drought resistant,moderate and sensitive.The mean values of their total comprehensive evaluation values(Ti)were 0.30,0.49 and 0.55,respectively.There were 5 sensitive varieties during the seedling stage,including Xianyu 1140(V8),MC817(V16)and Zhengdan 958(V1)etc.There were 7 drought resistant varieties,including Jingke 968(V4),Xianyu 047(V7)and Nongda 372(V9)etc.Therefore,the identification of drought resistance at the germination and seedling stages of maize requires the application of comprehensive evaluation methods to effectively assess drought resistance,especially for maize production in Huanghuaihai region with scarce water resources and available water resources were severely limited.It was more important to study the drought resistance evaluation of maize varieties at the seedling and germination stages under the single seed sowing mode.