QTL mapping of eight yield-relative traits in maize

A F2:3 population composing 200 families was developed from the combination of NX531×SIL8.The composite lnterval mapping(CIM) method was used to identify QTL and significant interaction pairs for the eight yield-relative traits.A total of 34 QTL for the eight traits was detected,each QTL explained phenotypic variation from 5.21% to 26.62%,and the accumulative phenotypic variation explained by QTL for single trait was from 21.33% to 74.10%.Sixteen QTL detected were mapped in six QTL clusters on chromosome 1,3,4,5 and 6.Those QTL with the large phenotype contribution for certain trait were located in the QTL clusters.In addition,26 epistatic QTL pairs were identified including only 1 pair QTL x QTL interaction.The phenotypic variation explained by single interaction pair ranging from 5.98% to 15.93%,accumulatively from 15.93% to 61.64% for single trait.Most of yield-relative traits display a complex genetic basis and epistasis play a key role in the genetic controlling of yield-associated traits of maize.The detected QTL clusters could provide valuable information for gene cloning and genetic improvement to maize yield-relative traits.