Analysis of yield combining ability of subtropical tropical quality protein maize inbred line and temperate normal maize inbred line

Four subtropical tropical quality protein maize(QPM) inbred lines were crossed with 10 temperate normal elite maize inbred lines by NCⅡ mating design in the study.The 40 crosses were evaluated in three different environments in Yunnan province for grain yield.The objective of this study was to determine combining ability and genetic relationship between subtropical tropical quality protein maize inbred lines and temperate normal maize inbred lines.Combined analysis of variance for grain yield showed that highly significant differences existed among environments,crosses and the interaction between crosses and environments.Differences of general combining ability(GCA) effects of QPM inbred lines(P1),normal inbred lines(P2) and of special combining ability(SCA) effects of P1×P2 were highly significant(P≤0.01).The combining ability effects of most inbred lines obtained from each environment were great different.Correlated analysis of SCA with grain yield showed that the contribution of yield SCA was not significant.Based on SCA effects and the known pedigree data.It could be concluded that the genetic relationships between LX9801,Ye107 and CML166,between K12,97P-69,97P-64 and CML161,CML171,between Shanwu2134,H84-89-1,K22,Yun147,90211 and CML194 were close.