【作者】 胡守林；

【导师】 张改生；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2007， 硕士

【摘要】 本文选用不同生态来源的11个海岛棉亲本按NCII交配设计,采用加性-显性遗传模型对海岛棉结铃基本特性、不同发育时期铃数的遗传规律、不同发育时期铃数与产量及其构成因素、不同发育时期铃数与品质性状间的关系进行研究,结论如下:1、从调查日起,铃数随着时间的推移而逐渐增加,铃数的变化进程符合Logistic生长方程。F1铃数在各个时期多于亲本铃数,海岛棉棉铃主要集中于中部节间,具有较为明显的中部优势。海岛棉日结铃数在8月3日之后,明显减少。2.非条件方差分析发现,海岛棉铃数性状的发育变化同时受加性和显性效应控制,加性效应在结铃的前期和后期表达,而显性效应主要在结铃中后期表达。从加性效应、显性效应占基因型方差的比值看,显性效应对铃数影响更大。从条件方差分析的结果看,加性效应和显性效应在海岛棉的结铃过程中,在不同时期对铃数起着交替作用。非条件方差分析和条件方差分析表现并不完全一致,条件方差分析由于其渐成性反映了不同时段不同基因效应的作用,更为严谨和灵敏。3、遗传率分析表明,无论非条件遗传率还是条件遗传率,大部分时期铃数的广义遗传率达到显著或极显著水平,而狭义遗传率只有少数时期达到显著、极显著水平,在育种过程中对铃数的选择比较困难,对铃数的选择应该放在自交晚代进行遗传改良。对产量性状和品质性状的遗传率分析表明,对纤维长度和纤维强度的选择可早代进行,而衣分、铃重、马克隆值的选择应于中代进行,单株皮棉产量、单株铃数则应于晚代进行选择。4、从有效铃数与产量、品质性状的相关分析看,最终有效铃数的提高,有利于高产、优质海岛棉品种的选育。不同时期铃数与产量、品质有着各不相同的相关关系,可以根据不同发育阶段的海岛棉铃数对部分产量、品质性状进行间接选择,并在选择过程中,要全面考虑某一性状选择对相关的诸多产量性状、品质性状的正向和负向的影响,平衡其作用,以达到同步改良的目的。5、海岛棉F1及F2铃数在结铃中后期有着显著的的群体优势,F2群体优势有所衰退,超亲优势在结铃前期有明显衰退。不同亲本对产量、品质性状的遗传效应不同,合理选配亲本有助于海岛棉杂交育种和杂种优势的利用。海岛棉大多数产量、品质性状有不显著的中亲优势和极显著负向的超亲优势,必须加强早熟性的选择,生产上应及早多结棉铃,以利于铃数杂种优势的发挥和海岛棉高产、优质品种的培育。综上,海岛棉铃数变化规律表明,铃数主要受显性效应的影响,部分时期还存在较显著的基因加性效应;正确对铃数的选择有利于高产、优质海岛棉品种的选育;根据不同发育时期铃数的遗传特性,制定相应的选择及利用策略,达到改良产量和品质的目的。更多还原

【Abstract】 In order to study basic characteristic of the boll, hereditary law of the boll number in different development period, the relationship between the boll number and yield , and yield component traits, and quality properties, according to NCII mating design,using additive-dominant genetic model.11 Island Cotton parents with different ecological sources was selected for researching. The conclusion is as follows:1. The boll number is increasing gradually with the time, the developmental patterns of it are similar with the way of Logistic growth equation. The boll number of F1 is more than parents’in each period. The bolls of Island Cotton usually concentrate on the middle part of joint, the boll number has comparatively obvious middle part advantages. The result indicates that the boll number of Island Cotton reduces obviously after August 3.2. The unconditional genetic variance analysis showed that the development change of Island Cotton’s boll number traits is controlled by additive and dominant effects. Additive effects express in the earlier and later stage of the boll, while dominant effects express in the middle. According to the ratio of genotype variance, the boll number is controlled mainly by dominance effects. From the the result of variance analysis, in the course of the Island Cotton’s boll, the adding effects and dominant effects play a replacing role in different stage. The unconditional genetic variance and conditional genetic variance analysis are not completely the same. The conditional variance analysis is stringent and sensitive owing to reflecting the different genetic gradually effects in the different stages.3. The heritabilities analysis showed that, whether unconditional heredity rate or conditional heredity rate, the broad-sense heritabilites of boll number is reached significant or highly significant level in many stages, while the narrow sense heritablity reach prominent or extremely prominent level only in few satges. It is more difficulty to select the boll number in the course of breeding, so we should improve heredity to select the boll number. Analysising the traits of yield and quality hereditary rate, the result indicates that fiber length and fibrous should be selected in early stage, but lint percentage, boll weight, micronaire should be selected in middle stage. 4. Between the boll number and yield quality traits ,the correlation analysis showed that the boll number will help for select high yield, high-quality Island cotton varieties. There are different correlationships between the boll number and yield, and quality traits in different stage, so we can select yield and quality traits indirectly according to the boll number in different development stage. In the course of indirect selection, the positive and negative effects of the boll-part traits to the finally yields traits and qualities traits must be paied more attention in order to synchronization improve both yields and qualities traits.5. The boll number of F1and F2 has significant population heterosi in the middle and later stages in Island Cotton, the population heterosi of F2 will decline to some extent, better-parent heterosi will decline obviously in earlier stage. Different parent have different hereditary effects of yield and quality traits. Rational select the parent will help to crossbreed of Island Cotton and to use hybrid heterosi. In order to be help for boll number, breed Island Cotton of high yield and high quality, we must strengthen getting early-maturing choice, form more cotton boll early.In conclusion, the regular change of the boll number and the boll number mainly controlled by dominant effects, meanwhile controlled by significant gene adding effects some time. Select the boll number correctly will favorable to breeding high yield and high qualities of Island Cotton. According to the hereditary characteristic of the boll number in different development period, we should make the corresponding selection and use tactics to achieve the goal of improving yield and qualities.更多还原