鲁棉研15号纤维品质性状QTL定位研究

以陆地棉(Gossypium hirsutum L.)杂交种鲁棉研15号的F2群体为作图群体,利用SSR标记和Join-Map3.0软件构建遗传连锁图谱;利用复合区间作图法分别对随机组成的3个鲁棉研15号的F2:3家系亚群体进行纤维品质性状QTL定位。构建的遗传连锁图谱包含116个多态位点,25个连锁群,全长892.25 cM,覆盖棉花总基因组的20.05%,平均每个连锁群4.64个标记,标记间平均距离7.76 cM;根据已有图谱的定位结果 ,19个连锁群与染色体建立了联系。在3个F2:3家系亚群体中共检测到46个QTL,其中16个为纤维长度(FL)QTL、7个为纤维强度(FS)、12个为麦克隆值(FM)、6个为伸长率(FE),5个为整齐度指数(FU)。发现在Ah05、Ah08、Ah09、Dh02染色体上QTL有成簇分布的现象,并在3个亚群体中检测到一些受环境影响较小、稳定遗传的QTL。这些QTL可以在今后应用于分子标记辅助选择。

Genetic Diversity Analysis and Constructing Core Collection Based on Phenotypes in Cotton

In that DNA diversity detected nowadays could not mean phenotypic diversity,it is the precondition of breeding project and basic research of crop improvement that genetic diversity analysis and sampling of core collection by phenotypes.Phenotyping and statistic analysis on 9 traits of 92 accessions of cotton germplasm resource from three species（Gossypium hirsutum L.,Gossypium barbadence L.and Gossypium arboreum L.）were conducted.And the statistics（variation coefficient,proportion of special accessions and Shannon-Weaver information index）indicated that initial collection had abundant phenotypic diversity;software NTSYS-pc and the unweighted pair group method of arithmetic（UPGMA）were used for the cluster analysis on genetic similarity coefficient and genetic distance matrix,and the result showed that the genetic relationship among accessions was highly consistent with the pedigree;22 accessions of core collection were selected by software QGAStation,four statistics,such as variance difference percentage（VD%）,mean difference percentage（MD%）,coincidence rate（CR%）and variable rate（VR%）,showed that the genetic diversity of core collection was approximately equal to the initial collection.The results of genetic diversity analysis based on phenotypic data and sampling of core collection would provide reference for breeding projects and basic research.

Identification of Quantitative Trait Loci (QTLs) Affecting Yield and Fiber Properties in Chromosome 16 in Cotton Using Substitution Line

Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substitution line in which a pair of intact chromosomes of TM_1 ( G. hirsutum ) were replaced by a pair of homozygous chromosomes of 3_79 ( G. barbadense ) is an excellent material for genetic research and molecular tagging. In this study, substitution line 16 (Sub 16) was used to evaluate the performance of the 16th chromosome in G. barbadense in TM_1 background. The genetic analysis using the major gene plus polygene mixed inheritance model in F 2∶3 family revealed that there might exist 2 QTLs respectively for boll size, lint percentage, lint index, fiber length and the first fruit branch node, 1 QTL for fiber elongation and flowering date, and no QTL for seed index, fiber strength and Micronaire in chromosome 16. However, 9 QTLs (LOD (logarithm of odds)≥3.0) controlling 6 quantitative traits were significantly identified in linkage group of chromosome 16 constructed in (TM_1×3_79) F 2by interval mapping. Among them, 1 QTL for boll size, fiber length, flowering date and fiber elongation could explain 15.2%, 19.7%, 12.1%, and 11.7% phenotypic variance respectively, 2 QTLs for lint index could explain 11.6% and 41.9%, and 3 QTLs for lint percentage could explain 8.7%, 9.6% and 29.2% phenotypic variance respectively. One unlinked SSR marker was associated with one QTL respectively for boll size and flowering date and they could explain 1.60% and 4.63% phenotypic variance. The traits associated significantly with chromosome 16 from Sub 16 were boll weight, lint percentage, lint index, fiber length, fiber elongation and flowering days.

Correlation Analysis on Main Agronomic Traits and Yield and Quality of Hybrid Cotton

ObjectiveThis study aimed to analyze the correlations of the main agronomic traits, yield and quality of hybrid cotton cultivars. MethodThe growth period, main agronomic traits, yield components, yield and quality of 13 hybrid cotton cultivars were compared, and the correlations of their main agronomic traits, yield components, yield and quality were analyzed. ResultThe growth period of the 13 cultivars was about 123 d, and all of them presented strong growth potential throughout the growth period. The ginned cotton yield shared an extremely significant positive correlation with the first fruiting branch position, plant height, number of fruiting branches, number of bolls per plant, number of bolls per hectare and seed cotton yield; the first fruiting branch position and micronaire value shared a significant positive correlation. Keza No.1 and Chunzamian No.1 had the lowest micronaire value, 4.5. The specific strength of all the cotton cultivars ranged from 27 cN/tex to 30 cN/tex, presenting significant difference. In addition, there was extremely significant difference in the ginned cotton yield among all the cotton cultivars. ConclusionThe study provides theoretical reference for the cultivation of high-yield hybrid cotton.

Evaluation on Ideal Test Sites and Regional Characteristics of Cotton Fiber Quality in Jiangsu Province

[Objective] The aim of this study was to explore the dominant fiber quality traits of test sites in cotton regional trials, by analyzing the regional characteristics of cotton fiber quality in Jiangsu province, in order to provide the theory background for cotton fiber quality improvement. [Method] The dominant fiber quality traits of test locations were analyzed with eight main fiber quality indexes of hybrid cotton regional trials during 2009-2013 in Jiangsu province by use of the "ideal test site" view of GGE biplot. [Result] The test locations with the best integrative fiber quality were proved to be Yanliang, and followed by Dongxin and Guanyun; The better test locations in terms of the major fiber quality indexes, including fiber strength, fiber Length and micronaire value, were Guanyun, Xinyang and Yanliang; To sum up, the best test location with balanced fiber quality was Yanliang. The test locations with specialties in fiber quality index were listed as bellow: Dafeng, Xinghua and Dongtai performance better in fiber length; Qidong, Liuhe and Yanhai locations were of better fiber length uniformity; Sheyang and Dongxin were better in micronaire value;while Sheyang along was better in fiber elongation and reflectance. Moreover, the correlation between fiber yellowness and other traits was significant(P<0.01). [Conclusion] The regional characteristic of cotton fiber quality index in Jiangsu province was obvious and fiber yellowness was worthy an indicator trait to assist the comprehensive improvement of cotton fiber quality.