QTL Mapping for Anthocyanin and Melanin Contents in Maize Kernel

Abstract

Anthocyanin and melanin are important and beneficial chemical components in black maize kernel.It is important to comprehensively study the QTL mapping for anthocyanin and melanin,cloning and transfer of pigmentation-related genes and marker assistant breeding.In this study,two related F2:3 populations derived from crosses of Mu6×SDM(WD) and Mo17×SDM(YD) were used to identify QTLs for anthocyanin and melanin contents in maize kernels.The results showed that the phenotype and QTL identification of two populations were highly consistent.The anthocynian and melanin contents of SDM were signifi-cantly higher than those of Mu 6 and Mo17.The positive correlation between the two pigment contents in kernel was highly sig-nificant.A total of seventeen QTLs were identified,including eight QTLs for ACK and nine QTLs for MCK.For ACK,four QTLs were both detected in two populations,which were distributed on chromosomes 4,6,7,and 10.For MCK,four and five QTLs were identified in WD and YD populations,respectively,which were distributed on chromosomes 1,2,6,7,and 10.The number,distribution and effects of QTLs in two populations were highly consistent,and the major QTLs of ACK and MCK in two popula-tions were both clustered,which were detected in the intervals of umc1796-mmc2006(bin 6.04) and umc2043-bnlg1028(bins 10.04) and explained 12.7-21.3% and 8.6-21.3% of phenotype variation,respectively.These QTLs which were stable in different genetic backgrounds might be closely linked to each other,or a same pleiotropic QTL which could be used in fine mapping and cloning of pigmentation-related genes in maize.The result of epistasic analysis indicated that the number,position and effects of epistatic QTLs between two populations were much different,and epistasic effects were more obvious for WD than for YD.Some epistatic QTL pairs explaining more than 10% variation of phenotype play an important role in pigment production and should be further studied.