运用半同胞轮回选择法对‘运轮1号’相关性状的改良效果分析

Improvement Effects on Relative Traits of‘Yunlun 1'Using Half-Sib Recurrent Selection

为获取高配合力优良育种群体,对‘运轮1号’群体开展半同胞轮回选择改良。选择‘运轮1号’C4群体中优良单株自交,以‘昌7-2’为测验种配制对应的测交种,鉴定筛选20个优良单株,等量种子经混合授粉形成C_5群体。结果显示:C_5群体的株高、穗位、茎腐病率较C_4分别下降4 cm、2 cm和3.5%。群体内单株间产量配合力差异达极显著水平,预计C_5群体测交种产量增益为7.7%;与选择前相比,中选测交种穗位和茎腐病下降0.7 cm、6.3%,穗长、行粒数、出籽率、持绿度、株高、籽粒含水量分别增加0.1 cm、0.6粒、0.4%、0.3级、0.3 cm、0.2%,穗粗、穗行数、百粒重保持不变;除含水量和百粒重外,其余性状的变异系数呈下降趋势,且多数性状的变异系数仍然在10%以下。进一步改良需扩大群体,增加测验种数量,并加入新的种质;单株选择应严格控制株高、穗位及生育期。

To obtain excellent breeding groups with high combining ability,we carried out the half-sib recurrent selection using‘Yunlun1＇group.The superior individuals selected from the‘Yunlun1＇C4 group were used for selfing.‘Chang7-2＇as testers was used to compound the corresponding test cross species.20 superior lines were identified and selected.C5 group was produced by mixed pollination using the same amount of seeds.The results showed that the plant height,ear position and stem rot rate of C5 population decreased by 4 cm,2 cm and 3.5% respectively.The yield combination ability among the single lines in the groups had extremely significant difference.It was estimated that yield efficiency of the test cross species of C5 population increase by 7.7%.Compared with the pro-choice,ear position and stem rot rate of selected test cross species decreased by 0.7 cm and 6.3%,respectively.Ear length,kernel number per row,kernel ratio,stay-green degree,plant height and moisture content increased by 0.1 cm,0.6,0.4%,0.3,0.3 cm and 0.2%,respectively.Ear width,kernel row number,100-kernel weight remained the same.Except moisture content and 100-kernelweight,the variation coefficients of other traits showed a decreasing trend,and most variation coefficients were below 10%.Further improvement requires expanding the groups,increasing the number of testers and integrating new germplasms.For individual selection,we must control plant height,ear position and growth period strictly.