| Huayu 11,one of the main promotion varieties in the southwest area,altitude above600 meters,which has many advantages such as multi-resistance,high-yield,stable production,and high social economic benefits.However,there are also some problems such as limited area adaptation,high water content during harvest period,high ear and plant height,late tasselling and silking,and poor lodging resistance of seedling stage.In view of the existing problems of Huayu 11,11 elite inbred lines with excellent performance in domestic and exotic were selected to evaluate the breeding potential of improved Huayu 11.This research adopts the nested and split plot experiment design.In the fall of 2016,we used 11 domestic and exotic elite inbred lines to hybridize with the Huayu 11 parental inbred lines Q736 and Q1 to form 22 single cross combinations in Wuhan.In the winter of 2016,the group of AH(with Q736 as the male parent)single cross combinations using Q1 and HZ127 as the tester,and the group of BH(with Q1 as the male parent)single cross combinations using Q736 and HZ127 as the tester,and gained 44 three-way cross combinations in Hainan.In the spring of 2017,field trials were conducted to identify the three-way cross combinations,single-cross combinations,and testers at Shicaoxi(31°N;900m)and Miaotangping(31°N;1150m)in Xingshan County of Yichang City,in Lichuan City of Enshi City(29°N;1100m),and Fang County of Shiyan City(31°N;460m)in Hubei Province.Evaluate the potential of the improved Huayu 11 from 11 domestic and exotic elite inbred lines according to the combination of the field performance of these materials and the genetic parameters proposed by Dudely et al.the main conclusions are as follows:(1)The effect is not good for directly using Huayu 11 to test the breeding potential of exotic inbred lines.(2)It can reflect the breeding potential of exotic inbred lines more really,accurately,and comprehensively for the breeding potential evaluation of semi-exotic germplasms formed by crossing exotic inbred lines and local germplasms(3)It is difficult to achieve simultaneous improvement of all traits when using exotic germplasms to improve the elite single cross hybrids.The improvement of yield is an important goal of maize breeding.The above-mentioned potential evaluation of using exotic inbred lines to improve Huayu 11 are all based on the selection of yield,and then comprehensive evaluation of each agronomic performance.The research indicates H1(M54)and H11(Zheng 58)are the best donor inbred lines for improving Huayu 11.H1(M54)can simultaneously improve yield,harvest water conten,days to tasselling and silking of Huayu 11;H11(Zheng 58)can simultaneously improve yield,all growth period,days to tasselling,days to silking,plant height,and ear coefficient of Huayu 11.In addition,inbred lines H3(HZ127IM),H4(M5972),H5(PHG29),H6(PHVA9),H7(LH38),and H10(Recovered B73)also have certain utility value for improving Huayu11,but further evaluation is needed.The utilization of these exotic germplasms are as follows: H1(M54),H5(PHG29)crossed with Q736 directly and then self-pollination cultivate inbreds,and then crossed with Q1;H3(HZ127IM),H4(M5972),H6(PHVA9),H7(LH38),H10(Recovered B73),H11(Zheng 58)crossed with Q1 directly and then self-pollination cultivate inbreds,and then crossed with Q736.(4)The new heterosis pattern((Suwan × Tuxpeno)× U.S.germplasms)which has great yield potential in the southwest mountainous area,but it needs further verification.(5)The SS germplasms,especially the exotic inbred lines with the background of American corn germplasms are more useful to improve the heterosis pattern of Huayu 11(U.S.germplasms × Tuxpeno). |
