【作者】 孟庆雷；

【导师】 陈彦惠；

【作者基本信息】 河南农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 种质遗传基础狭窄是我国玉米育种中存在的突出问题,群体改良是拓宽我国玉米种质遗传基础的有效途径。本研究以半姊妹和相互半姊妹轮回选择改良的豫综5号五个轮次群体为材料,通过一年两点的改良群体产量比较试验,同时,采用NC-II遗传交配设计,以豫综5号五个轮次改良群体为父本,以黄早4、丹340、中综5号、齐319、掖478、Mo17为测验种配制成30个测交组合,通过一年两点的产量配合力评价试验,从群体本身产量性状、配合力等不同角度研究了轮回选择对豫综5号群体的改良效果。主要结果如下:1.半姊妹和相互半姊妹轮回选择方法可以有效地改良豫综5号群体本身的产量。C₃与C₀相比,豫综5号群体本身单株平均产量有较大提高,达到极显著水平;C₄与C₃相比,增加了5.51%。C₁-C₄各轮次与C₀相比,分别增加了6.15%、13.62%、18.90%和25.45%,逐轮增加,平均每轮增加6.36%。2.从产量的构成因素的改良效果来看,C₃与C₀相比,主要产量性状均有所增加,C₄与C₃相比,秃尖长度有所下降,行粒数增加4.63%。说明改良群体在群体产量得到提高的同时,其主要产量构成因素也得到了相应的改良,表现出果穗较长、行粒数较多、百粒重较高、株高和穗位适中、成熟较早的优点,在育种上具有较高的潜在利用价值,但该群体还存在着果穗较细、穗行数较小的不足,应进行重点改良和提高。3.对豫综5号改良群体变异系数分析发现,随着改良轮次的增加,变异系数略有下降,单株产量变异系数从C₀的15.43%下降到C₄的12.80%,但是改良群体中单株平均产量150g以上的个体总数明显大于C₀,说明改良群体仍能保持相对较高的遗传变异,有进一步改良提高的潜力。C₄改良群体穗部性状变异系数由大到小依次为百粒重、行粒数、穗长、穗行数、穗粗、出籽率,因此,群体在提高百粒重、行粒数方面的选择潜力仍较大。4. 30个测交组合单株产量平均值分析表明,单株产量最高的前三位高产组合中黄早4作测验种的组合占2个,齐319作测验种的组合占1个;前十位高产组合中黄早4作测验种的组合占4个,齐319作测验种的组合占3个。产量最低的后三个组合分别为Mo17×豫综5号C₀、掖478×豫综5号C₀和掖478×豫综5号C₁,低产组合中掖478作测验种的占2个。说明豫综5号与唐四平头杂优类群的优势最大,而与Reid杂优类群的优势最小。5.配合力分析结果表明,采用半姊妹轮回选择对豫综5号群体进行了3轮的选择后,C₃群体与C₀相比,一般配合力效应从-11.63增加到5.57,达到极显著水平;经1轮相互半姊妹轮回选择后,群体的一般配合力效应也相应从C₃的5.57增加到C₄的9.75。说明两种选择方法均可以有效地提高豫综5号群体的一般配合力。特殊配合力分析发现,豫综5号改良群体与黄早4的特殊配合力得到一定的提高,逐轮朝着Reid×唐四平头杂优模式水平提高的方向稳定发展。更多还原

【Abstract】 In China, the narrow of the germplasm genetic base is the prominent question in maize breeding, the population improvement is the efficient way to expand the the germplasm genetic base of our country .This research took five circler populations of Yu Syn5 which were improved by half-Sib recurrent selection and half-Sib reciprocal recurrent selection as material, by the two-site performance test of improvement population’s output in one year, simultaneously, using the NC-II genetic design, taking the improvement populations of the Yu Syn5’s five circle as the male parent, taking Huangzao4, Dan340, Zhong Syn 5, Qi 319, Ye478, Mo17 as testers to match 30 test crosses through one year two-site appraising test of yied combining ability effect, Yu Syn5 improvement effect was appraised from different angle of a population’s output character and the combining ability and so on with recurrent selection. The main results as follows:1. The method of half-half and full-sib recurrent selection could improve t Yu Syn5’ yied effectively. To compare C₀ with C₃ , the single average plant’s yied of Yu Syn5 was enhanced greatly and reached highly significant probability level; using C₄ comparison C₃, the yied was increased 5.51%. usin every circle of C₁-C₄ comparison C₀, the yied was increased 6.15%, 13.62%, 18.90% and 25.45% respectively, and the average circle was increased 6.36% .2. From the improvement effect of the yied component,comparing C₃ with C₀, the main yied characters were increased, comparing C₄ with C₃, the length of ear tip-barrenness has moderate drop, kernels perrow increased 4.63%. the results indicated that the main yied components were improvedt correspondingly with the enhancement of improvement population , simultaneously . The advantages as follows: the ear to be longer than before, kernels perrow o be more, 100 grains weight to be higher and the maturing stage to be earlier than before, plant height and ear height to be moderate, the good traits had the high latent utilization in the breeding, but the population also had the insufficiency that the era was slender and the number of row per ear lessened. So the traits as highlight should be improved and enhanced.3. Through the analysis of Yu Syn5 improved population coefficient of variation ,the results indicated that the coefficient of variation has slight drop with the increase of improvement circle, the coefficient of variation of the average single plant yied lowered from C₀ 15.43% to C₄ 12.80%, but the individual total of average single yied which above 150g was more than C₀ obviously, the results stated that the improvement population still maintained the higher genetic variation relatively and had the potential of further improvement. The variation coefficient of inproved C₄ ear characters from large to small were 100 grain weight, the number of row per ear, kernels per row, ear length, ear diameter, kernel percentage. therefore, the population had the huge potential in enhancing 100 grain weight and kernels per row.4. The analysis of the average single yied of the 30 test-crosses indicated that the first three high yied test-crosses in the single output were Huangzao 4 as tester accounted for 2, Qi 319 as tester r accounted for1; In the first ten high yied test-crosses were Huangzao 4 as tester accounted for 4, Qi 319 as tester accounted for 3. The lowest three test-crosses respectively were Mo17×Yu C₀, Ye 478×C₀ and Ye 478×C₁, in the low yied test-crosses Ye 478 as tester accounted for 2. The results indicated that Yu Syn5×SiPT was the strongest heterotic pattern , but Syn5×Reid group hybrid was the smallest.5. The analysis of the combining ability effect indicated that after Yu Syn5 was improved 3 circles with the half-sib recurrent selection, the combining ability effect enhanced from -11.63 to 5.57 by C₃ compared with C₀ and reached highly significant probability level; After 1 circle selected with half-sib reciproal recurrent selection, the general combining ability effect enhanced from C₃ 5.57 to C₄ 9.75. the results showed the two methods enhanced the combining ability effect of Yu Syn5. The analysis of special combining ability effect showed that the special combining abilities of improved Yu Syn 5×Huangzao 4 had certain enhancement, which developed steadily toward Reid×SiPT mixed superior pattern.更多还原