Study On Lodging Resistance Related Traits Of Core Collection And Improved Lines Of Maize Reid Group

This test used core germplasms,PH6 WC,Zheng 58 of Reid group and their improved lines,J1590,J1595,J172,J1047,J1050 as female parent,fine inbred lines of No-Reid group,PH4CV?PHB1M?J1518?J1577,Dom Qun Chang7-2,J1633 as male parent,collocated 7×6,total 42 incomplete diallel cross combination.The test set three densities,60 thousand/hm2,80 thousand/hm2,10 thousand/hm2,carried on the research on lodging related characters,combining ability and heterosis pattern.Ten representative cross combinations were selected to study the main factors affecting lodging and the improvement effect by using split plot test method and regression analysis of lodging rate.The control varieties were set as Zhengdan 985 and Xianyu 335.The results are as follows.1.With the rising of planting density,the plant height and ear position of most hybrid combinations increased with the increase of density,some of them showed the trend of decreasing,or rising first and then falling,decreasing first and then rising,while the ear position coefficient of each combination increased with the increase of density.2.Under three densities,the lodging rate of BY2(PH6WC × Chang7-2),BY7(Zheng58 × PH4CV),BY25(J172 × PH4CV),BY31(J1047 × PH4CV),BY32(J1047 × Chang7-2)and BY37(J1050 × PH4CV)was lower than that of Xianyu 335(BY1),but higher than that of Zhengdan 985(BY8),which indicated that the improvement of lodging resistance related characters was obvious;the combination of better improvement of lodging resistance was BY26(J172 × Chang7-2),the best improvement of plant height,ear position was BY2(PH6WC × Chang7-2).3.The results of heterosis analysis showed that grain weight per plant exceeded that of the combination of control varieties,Xianyu 335(CK1),Zhengdan 985(CK2),in which,there were two dominant combinations with over-standard dominance value greater than 10%,respectively were BY23(J1595×J1577)?BY24(J1595×PHB1M).As far as hetero-optimal mode is concerned,the dominant pattern with better heterosis performance is Reid × Non-Reid,which had higher potential of increasing production in the aspects of the combination of Reid group with Non-Reid group and Dom group,yield and other characters.4.The analysis of general combining ability showed that: the inbred line with better general combining ability of all characters were improved lines J1590?J1595 and elite lines PH6 WC,Zheng 58.The analysis of special combining ability showed that there were 8 combinations with better comprehensive character performance of special combining ability,include Zheng58 × J1518?Zheng 58 × PHB1M?J1590 × J1577?J1595 × PH4CV?J1595 × Chang7-2?J1595 × J1577?J1047 × Chang7-2?J1047 × J1577.The genetic models of Zheng 58 × PHB1 M and J1595 × PH4 CV was Reid × Non-Reid,the model of J1595 × Chang 7-2 and J1047 × Chang 7-2 was Reid× Dom in the 42 collected cross combination.