| Early-senescence is one of the main limit factors to further improve yield in the spring maize area.Breeding excellent senescance varieties is an important guarantee for the stable,safe production.Therefore,study of genetic mechanism of maize leaf stay-green has the vital significance for high and stable yield in Northeast spring maize area.In this study,188 F2:4 lines from a cross between Si287 and Si144 were developed.QTL analysis for leaf stay-green related traits in the whole stages of maize was carried out to determine the relationship between marker genotype and the traits evaluated.The major results were as follow:1.A genetic linkage map containing 152 SSR markers was constructed,covering total maize 10 chromosomes.The map spanned a total of 1268.1cM with an average interval of 8.34cM.2.Utilizing data of field tests and molecular markers,composite interval mapping(CIM)method was used to identify the QTL for stay-green related traits.A total of 27 QTLs were identified on chromosomes for first,on chromosomes for second,on chromosomes for third,on chromosomes for forth,on chromosomes for sixth,on chromosomes for seventh,on chromosomes for eighth and on chromosomes for tenth.Among these,the QTL on chromosome 3 for stay-green traits was all detected in the whole stages of maize,and the phenotypic variation for the QTL was relatively higher.The LOD value of all QTLs deteted ranged from 3.7 to 16.9,and the total phenotypic variation ranged from 4.2%to 21.6%.3.Compared with the results of previous study,25 of 27 QTLs located the similar region for maize stay-green related QTLs,but 2 QTLs have not been identified in previous QTL studies in this study.The QTLs detected in this study could offer new information for understanding genetic basis of maize leaf senescence related traits,also provide a potential starting point for marker assisted selection of maize leaf senescence. |
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