Evaluation And Association Analysis Of Lodging Resistance Of Maize Inbred Lines Selected From Shaan A Group And Shaan B Group

Lodging is the main factor for affecting the growth in maize yield.The research shows that lodging reduce 5-25% of maize yield every year.With the transformation of agricultural mode of production,dense planting,high yield and mechanization have become the main way of maize production,meanwhile higher requirements are put forward for the ability of varieties to resist down.Therefore,it has become an important research to clarify the genetic basis of lodging resistance among different maize varieties at harvest time,and enhance the stalk standing ability of maize.In this study,an associated population(AM153)consisted of 153 elite maize inbred lines from Shaan A and B groups were selected to perform several analysis.This study analysis and evaluate the lodging resistance characteristics of 153 maize inbred lines in 2 years(plant height,ear height,ear position coefficient,stem strength).A genome-wide association analysis was conducted with high-throughput SNP marker data,and molecular markers corresponding to resistance of maize were mined,providing scientific basis for amplification,improvement and utilization of corn germplasm resources.The results are as follows:1.Phenotypic analysis inbred lines from Shaan A and B groups showed that the lodging resistance characters,such as plant height,spike height and stem strength,were varied from 9.57-10.41% to 12.93-15.78%,and from 6.37-14.13% respectively.And it has high generalized heritability,which is 92.16% for plant height,88.45 for spike height,and 69.30% for stalk strength.2.Cluster analysis was conducted using spike height,plant height ratio and stem strength as indexes.The maize inbred lines selected from Shaan A group and Shaan B group are divided into three types: highly lodging resistance,better lodging resistance and general lodging resistance,which based on ear height and stalk strength.we identified 15 inbred lines with highly lodging resistance from Shaan A group,including KA203,KA147,KA60,KA229,KA225,Z140353,2015KB031,KB204,KB154,2016KB-35,KB109.Besides,48 inbred lines from Shaan A group performed better lodging resistance,which include KA105,2013KA-58,2013XCA-1,KB024,KB227,KB082,KB106.3.We identified 11 maize inbred lines that selected from strong ane stronger lodging resistance with low grain moisture content during the harvest period,such as 2015KA37,KA225,KA60,Z141257-1,2014TCB-2.L1661335,KB228,L170459,L170685,KB154,Z140594.4.Based on genome-wide association analysis,25 SNPs significantly associated with lodging resistance traits are detected,including 18 SNPs closely related to plant height and ear height,and 7 SNPs significantly associated with stem strength.In the candidate interval of significant SNPs,we identified 24 candidate genes potentially related to lodging resistance,and 5 of candidate genes have been shown to be linked to lodging resistance.