高油玉米基础群体选择效果的评价及选择方法

Effects of Population Improvement of BHO for High Oil Content Maize and Selection Method Evaluation

对北农大高油（BHO）基础群体的不同选择周期C0，C3，C4，C5，C6，C7和C8，采用随机区组设计，于1992和1993两年进行比较试验，分析了含油量等16个品质和农艺性状，研究了这些性状的动态变化以及含油量与其它性状的相关关系，评价了BHO的选择效果，对选择方法进行了一些探讨。结果表明：①对BHO基础群体8个周期的选择使含油量从4．81％提高到9．24％，平均每周期提高0．55％。实现遗传力为0.4877±0．02。经8个周期的选择，群体内方差无明显变化，近交水平提高很少。BHO群体仍有丰富的遗传变异和改良潜力。②对含油量的选择，也导致BHO群体的籽粒蛋白质含量和赖氨酸含量显著提高，分别由9．84％和0．31％提高到12．02％和0．38％；产量、百粒重、穗重、穗粒重、株高、穗粗在选择前期（C0～C4）显著降低，以后变化则不显著；蛋白质品质、穗位高、稳行数、行粒数、稳长、出籽率则无显著变化。③含油量与蛋白质含量、赖氨酸含量存在极显著的正相关，与稳重、穗粒重、穗粗、百粒重、产量存在显著的负相关，而与株高及其它性状则不存在显著的相关关系。④对BHO采用的选择方法（家系内选择）是合理和有效的，但如果采用综合选择的话，则可使遗传进展提高近10％。

Different cycles of BHO population were grown in 1992 and 1993 with RCBD. Oilcontent and other 15 quality and agronomic traits were measured. Changes along with selec-tion on all traits were analyzed. Phenotypic correlation coefficients between oil content andother traits were calculated. The selection effects were evaluated and scvcral selection meth-ods were compared, and following results were obtained: ①The oil content had increasedfrom 4. 81 % in cycle 0 to 9. 24%; in cycle 8 with average increase of 0. 55% per cycle and therealized heritability was 0. 459 5. ②Along with selection of oil content, protein and lysinecontent in seeds increased significantly; yield, 100-kernel weight, ear weight, kernel weightper ear, plant height and ear diameter reduced significantly; other traits didn't change sig-nificantly. ③Highly significant positive correlations between oil content and protein/lysinecontent were detected; significant negative correlations with ear weight, kerne1 weight perear, eardiameter, 100-kernel weight and yield were also existed. ④The selection method i.e. within-ear selection used in BHO population for oil cantent improvement was reasonableand effective. But the genetic gain would be 10% higher than the level already obtained if acombined selection scheme was applied.