Identification Of Multi-point Combined Drought Resistance Of Different Maize Inbred Lines

With global warming and increasing frequency of extreme climate,drought has become one of the important factors limiting agricultural production.Breeding drought-resistant varieties is an important measure to reduce the yield loss caused by drought.As a hybrid,the drought resistance of maize varieties mainly comes from the drought resistance of parental inbred lines.Therefore,it is necessary to select inbred lines with strong drought resistance to cope with the impact of drought environment on maize production.The multi-point drought resistance evaluation of maize inbred lines can provide a scientific basis for the selection of drought-resistant germplasms and the breeding of drought-resistant varieties.In this study,116 maize inbred lines collected in China were used as experimental materials.Agronomic traits,yield and yield components under drought and irrigation treatments were investigated in Yulin,Yinchuan and Zhangye.Drought resistance of different maize inbred lines was analyzed.The results were as follows :1、Through yield analysis under multi-environment,24 inbred lines such as328 M,PHPR5,1475,LYA49,DHJ026-12,DH244-4 and Long M1305 belonged to high yield and drought resistance type,and 46 inbred lines such as 328 M,35S,91227 and DH218-9 belonged to high yield and drought resistance type.2、Through DTI analysis of multi-environmental drought tolerance index,the seven inbred lines of Chang S25,PHPR5,C57,C102,JL133,C39 and DK517 F showed stable strong drought resistance.91227,DHJ030-11,798-1 and other 62 inbred lines showed stable moderate drought resistance.Drought tolerance types were classified based on BLUP drought tolerance index,and DH164-22,DH133-1,DK517 F,YCZ17188 and C102 were inbred lines with strong drought resistance.D201,09B-6-2,LYA52 and other 111 inbred lines belong to moderate drought resistance.3、Through principal component analysis and cluster analysis of seven drought resistance indexes,DHJ026-12,1601,KH11-26,F141,Long M1607,DH509-9,Zong31,DH218-9,H901,DH679-10 were selected as strong drought resistance inbred lines.35 S,PHR47 and other 106 inbred lines with moderate drought resistance.Further analysis showed that Long M1607,PHPR5,328 M,DK517F and other inbred lines had the characteristics of high and stable yield under different water treatments,and DTI value was large and stable.4 、 Through the analysis of agronomic characteristics of different drought-resistant materials,it was found that the variation amplitude of plant height,ear height,ear length,ear diameter,row number per ear,grain number per row,and bald tip length of inbred lines with strong drought resistance after drought stress were smaller than those of the materials with medium drought resistance.Especially,the materials with strong drought resistance after drought stress had higher ear height,thicker ear diameter,more row number per ear,and shorter bald tip length than the materials with medium drought resistance.In summary,ten inbred lines with strong drought resistance,namely,Chang S25,Long M1607,PHPR5,JL133,DK517 F,DH509-9,DH218-9,C39,C57 and C102,were screened out by four methods.The other tested materials had moderate drought resistance,which could be used as the basic germplasm for drought resistance breeding in arid and semi-arid ecological environment in northwest China.