Combining Ability and Heterosis of the Inbred Lines in Exotic Maize Population

In order to compare with the combining ability and heterosis of the maize inbred lines from the exotic maize population(PF6J155),sixty crosses were composed according to NCⅡdesign using 12 inbred lines as female and five as male parents from different heterosis groups,and trailed under split block design at four locations in Liaoning province.The effects of combining ability on ear traits were evaluated in this research.The results showed that the significant differences in GCA effects existed among female parents.The inbred lines ZL2116,ZL2436 and ZL8344 were the highest in per plant yield GCA effect,and the GCA effects of the part of the yield components(ear length,kernel number,100-seed weight and produced seed ratio) were higher than the other,they were more desirable inbred lines.The SCA effects were also significantly different among crosses,and the crosses ZL8344×chang 7-2 had the highest SCA effects in per plant yield.The exotic maize population(PF6J155) was divided in Reid heterotic groups.Based on the experimental result,the main heterosis pattern of the exotic maize population was summarized,that was PF6J155×Ludahonggu,PF6J155×Tangsipingtou and PF6J155×Lancaster.