11份玉米自交系单株产量等性状的配合力与遗传参数研究

旨在研究玉米自交系单株产量等性状的配合力、遗传力及反交效应,为玉米自交系的选育和杂交种的组配提供依据。以11份玉米自交系为试材,按Griffing Ⅲ完全双列杂交法组配110个组合,观测杂交种的单株产量、株高、穗位高、雄穗分支数、雄穗主轴长、抽丝期和开花期等7个性状的表型数据,并对上述性状的一般配合力、特殊配合力、广义遗传力、狭义遗传力和反交效应进行估算。供试材料除雄穗主轴长的特殊配合力差异不显著外,其余性状的一般配合力和特殊配合力差异均达到极显著水平。JZ3和JZ6两个自交系单株产量的一般配合力为极显著正值,两对组合JZ9×JZ2和JZ2×JZ9、JZ6×JZ3和JZ3×JZ6的单株产量具有最大的正向SCA效应值,分别为40.68 g和35.24 g。单株产量的反交效应差异极显著,部分自交系的反交效应方差较大。7个性状的广义遗传力从大到小依次为,雄穗分支数、株高、开花期、穗位高、抽丝期、单株产量和雄穗主轴长;狭义遗传力从大到小依次为,雄穗分支数、株高、穗位高、开花期、雄穗主轴长、抽丝期和单株产量。试验结果表明单株产量性状的显性遗传方差占比最大,狭义遗传力最小,易受环境条件的影响,对该性状的选择适宜在晚代进行;单株产量性状具有显著的反交效应,故部分自交系需严格控制正反交方式。

The Combining Ability and Genetic Parameters of Yield per Plant and Other Characters of 11 Maize Inbred Lines

The combining ability, heritability and reciprocal effects of yield per plant and other characters of maize inbred lines were studied to provide a basis for the selection of maize inbred lines and the combination of maize hybrids. Using 11 maize inbred lines as test materials, we matched 110 combinations according to Griffing III complete diallel hybridization method. Seven phenotypic characters, i.e., yield per plant, plant height, ear height, branch number and spindle length of tassel, silking and anthesis stages of the inbred lines were observed, and the general combining ability (GCA), special combining ability (SCA), reciprocal effects (REC), broad- sense heritability (H2B) and narrow- sense heritability (H2N) of the above characters were estimated. The results showed that both GCA and SCA of all the tested traits were significantly different except the SCA of spindle length of tassel. The GCA of yield per plant of JZ3 and JZ6 inbred lines was significantly positive. Two pairs of the combinations, JZ9×JZ2 and JZ2×JZ9, JZ6×JZ3 and JZ3×JZ6, had the largest positive SCA effect values of 40.68 g and 35.24 g, respectively. The REC of yield per plant had significant difference; however, some inbred lines had large variances in the REC. The H2B of the seven characters in the descending order was tassel branching number, plant height, the anthesis stage, ear height, the silking stage, yield per plant, and spindle length of tassel. The H2N, ranging from big to small was tassel branching, plant height, ear height, the anthesis stage, spindle length of tassel, silking stage, and yield per plant. The results suggest that the dominant genetic variance accounts for the largest proportion, H2N of yield per plant is the smallest; therefore, the yield per plant is easy to be affected by environmental conditions and suitable for selection in later generations. Because of the significant REC in yield per plant, the way of crossing in some inbred lines need to be strictly controlled.