Comprehensive Evaluation Of Drought Resistance For Elite Maize Inbred Lines Selected From Shaan A And Shaan B Group

Drought is a widespread problem that seriously affects maize production.Improving the drought tolerance of maize has become an urgent need to increase maize production.The drought tolerance of maize hybrids is inherited from their parents.It is an important way to cultivate high-yield and drought-tolerant maize varieties by accurately evaluating the drought tolerance of maize inbred lines.In order to select the best drought-tolerant inbred lines from the backbone inbred lines from Shaan A and Shaan B groups,and to clarify their drought tolerance characteristics.In this study,eight elite inbreds from Shaan A and Shaan B groups which have experienced long-term improvement thought many years,multiple points and high stress conditions,and four common inbred lines(PH6WC,PH4 CV,Zheng58,Chang 7-2)were selected as materials.Through the field water control experiment,seven drought resistance indicators were calculated based on the yield to identify the drought tolerance of 12 inbred lines by GGE Biplot.The agronomic traits(stalk strength,SPAD,plant height,ear height,ASI,dry matter and leaf area)were investigated for evaluate these inbred lines.The antioxidant enzymes(SOD,POD,CAT)and fluorescence parameters of maize inbred lines which were dealt with 15% PEG were investigated to explore the drought tolerance characteristics of different inbred lines.The main results are as follows:1.Based on the seven drought tolerance indicators calculated based the yields under two treatments(drought stress and normal control),eight maize inbred lines were divided into four groups by GGE Biplot,which include three high-yield drought-tolerant maize inbred lines(KB106,91227,KB588),3 high-yield drought-tolerant maize inbred lines(KA105,KB207,KA024),1 low-yield drought-tolerant maize inbred line(8147),1 low-yield drought-tolerant general maize inbred line(KA064),respectively.2.Six agronomic indicators including SPAD,leaf area,stem strength,plant height,ASI and dry matter were related to drought resistance.Hence,these indicators were used to evaluate the drought resistance of inbred lines.KB106,91227,KB588,KA105,KB207,KA024 had higher SPAD,stem strength,dry matter and lower ASI.And SPAD,leaf area,stem strength,plant height,ASI and dry matter of these inbred lines had good stability under drought stress.3.KB106,91227,KB588,KA105,KB207,KA024 have higher activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)under normal and drought stress conditions.Under the drought stress,the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)of KB106,91227,KB588,KA105,KB207,KA024 were significant increase.4.The non-photochemical quenching coefficient(NPQ)of KB106,91227,KB588,KA105,KB207 and KA024 under drought stress was significantly higher than that under normal control,and the relative chlorophyll content and actual photosynthetic rate were high and stable.