Analysis of maize germplasm groups and heterosis utilization model in hilly areas

Ten newly bred inbred lines were crossed with five inbred lines with North Carolina Ⅱ (NCⅡ) crossing design to evaluate the combining ability and utilization potentiality of ten inbred lines.The results showed that PH99-10,PH99-2,PH99-1 and PH99-3 had successively higher general combining ability(GCA),and the combinations of PH99-9×Jiao50,PH99-9×Su37,PH99-1×7922 and PH99-3×Zi330 had higher specific combining ability(SCA) for the grain yield.On the basis of the yield SCA and GCA,ten inbred lines could be classified into five germplasm groups,in which Huangzaosi,Su37 and Jiao51 had higher GCA,then could be the heterosis groups with potential of utilization value in South west hilly areas.The common heterosis combination type was local germplasm line×exotic germplasm line and the combinations between local line or improved local line and Suwan line was the main heterosis model.