基于Iodent种质玉米株系间杂种优势及配合力分析

Analysis of Heterosis and Combining Ability of Maize Inbred Lines Based on Iodent Germplasm

探讨种植密度对Iodent种质自交系杂种优势和配合力的遗传响应,为密植育种与高产栽培提供理论依据。采用NCⅡ设计30份杂交组合,研究Iodent种质的5个不同株系在不同密度下玉米株系间杂种优势和配合力表现。在6.0万、7.5万、9.0万株/hm^(2)密度下30份杂交组合单株产量杂种优势均值分别为128.5%、86.3%和60.4%,变异系数(CV)分别为30.8%、25.8%和29.9%;在6.0万株/hm^(2)密度下,Iodent株系单株产量一般配合力(GCA)效应JK1101最高(9.55),JK1103最低(-6.85);在7.5万株/hm^(2)密度下,JK1103最高(3.51),JK1102最低(-4.83);在9.0万株/hm^(2)密度下,JK1103最高(3.95),JK1102最低(-5.57)。仅丹340×JK1101、JK33×JK1102组合的SCA效应值在3种密度下为正值,分别为9.84、8.72、22.68、6.33、1.49和19.15。Iodent种质株系与Lancaster、改良Reid、塘四平头和旅大红骨四大类群自交系杂交时单株产量杂种优势普遍存在,同一杂交组合在不同密度下杂种优势存在较大差异,单株产量杂种优势呈现随密度增加而降低的趋势;Iodent种质株系间的GCA效应在不同密度下表现不同,单株产量GCA在密度为7.5万株/hm^(2)和9.0万株/hm^(2)时变化趋势相近,呈显著正相关;由Iodent种质株系组配的同一组合SCA效应增减与供试密度增减变化的方向不一致。

In order to explore the genetic response of planting density to the heterosis and combining ability of Io-dent inbred lines,and to provide a theoretical basis for dense planting and high yield cultivation.The NCII designwas applied to 30 cross combinations,and the heterosis and combining ability of 5 different lines of Iodent germ-plasm under different densities were studied.Under the density of 60 thousand,75 thousand and 90 thousandplants/ha,30 hybrid combinations yield strains of heterosis values were 128.5%,86.3%and 60.4%,CV were30.8%,25.8%and 29.9%.JK1101 GCA effect to yield was the highest under the density of 60 thousand plants/ha(9.55),while JK1103 was the lowest(-6.85);JK1103 GCA effect to yield was the highest(3.51)under the density of75 thousand plants/ha,while JK1102was the lowest(-4.83);JK1103 GCA effect to yield was the highest under thedensity of 90 thousand plants/ha(3.95),while JK1102 was the lowest(-5.57).It was the only that the SCA effect val-ues of Dan340×JK1101 and JK33×JK1102 were positive under 3 densities,which were 9.84,8.72,22.68,6.33,1.49 and 19.15,respectively.The GCA effect of Iodent germplasm in different strains was different under differentdensities.The yield of GCA under the density of 75 thousand and 90 thousand plants/ha had the same trend,whichwas a significant positive correlation;The SCA effect of the same combination that crossed by Iodent germplasmstrains was not consistent with the changing direction of the increase and decrease of the test density.