The Study on Crosses Performance Among P Colony Germplasm Lines and Chinese Key Lines in Maize

P colony germplasm lines,derived successfully from exotic germplasm,were widely applied in maize production at present.The objectives of this study were to analyse the combining ability and heterosis between P colony germplasm lines and key lines from Chinese major groups through a 8×9 NCⅡmating system.72 crosses were evaluated in Spring and Autumn two ecological conditions in Beijing.The results indicated that the crosses of P germplasm with 8 key lines showed strong heterosis,which suggested P colony germplasm was a relatively special group.Especially,the crosses of P×lines representable for Tangsipingtou group and Ludahonggu group had better performances.The analysis of combining ability showed that the GCA of P colony germplasm lines1127,Shen 137,1145 and Qi 319 were high,and the GCA of Chinese traditional lines Dan340,Chang7-2 and Ye8112 were also high,The main agronomic traits of the crosses of P lines×key lines were analyzed.These results provided significant information to understand P colony germplasm lines and make them useful in maize breeding practice.