Reaserch of American Maize Germplasm on Improvement of Inbred Lines of Reid Group in North China

Five improved maize inbreds were crosses with five testers representing key inbreds of Tangsipingtou group by NC-Ⅱ mating design.The improvement effects and utilization potential of improved lines were evaluated based on analysis of combining ability in 60 000 plant/ha.The results were that inbred lines J1129 and J1110 had higher general combining ability(GCA) on kernel yield per plant,and they crossed three high yield hybridized combi-nation,and they showed a high yielding potential.The GCA of kernel yield per plant of J1018 and J1150 was lower,but it crossed a high yield combination respectively.The combination pattern of improved inbred ×Tangsipingtou group was in accordance with the heterotic pattern of PA×Tangsipingtou group,it could be used to breeding maize variety with high yield and dense planting.