南疆海岛棉品种（系）铃部主要性状的遗传分析及QTL定位

South Xinjiang is only one production regions of island cotton in china. In recently, island cotton has become the regional feature advantage industry. There is closely relationship between main traits of cotton boll and yield, fiber quality, therefore, it is necessary for us to study the genetic mechanisms of the main traits of island cotton bolls, mastering law of developmental genetics of quantitative traits, which can provide theoretical basis for high yield, high quality breeding of island cotton and genetic improvement of main characters of bell. But at present many studies focus on the cotton varieties of the cotton boll traits.To the issue of island cotton breeding in South Xinjiang, we use 30 island cotton varieties (lines ) and its preparing 300 hybrids as experimental materialwith the method of conventional breeding and molecular marker assisted selection,study combining ability and heritability of the main traits of island cotton bolls,study the genetic relationship of the island boll major traits and yield, quality, and determine the long fruit branch and zero fruiting branches island cotton has excellent traits; constructed molecular genetic linkage map of island cotton by means of molecular markers, and on this basis, major traits of the island cotton boll are analysised by QTL mapping; determine the genotypes with desirable traits, and explore the genetic improvement strategy of island cotton boll traits,these can clarify the genetic mechanisms of major traits of the southern border island cotton boll, and provide a theoretical basis for the major traits of island cotton boll with molecular marker-assisted selection.

南疆是我国唯一的海岛棉生产基地。棉花铃部主要性状与产量、纤维品质关系密切，目前对海岛棉铃部主要性状的遗传机制研究较少。因此，有必要深入研究海岛棉铃部主要性状的遗传基础，掌握数量性状发育遗传规律，为海岛棉高产、优质育种提供理论依据。本课题针对南疆海岛棉育种中存在的问题，拟以前期研究获得的30个海岛棉品种（系）及其配制的300份杂交组合为试验材料，采用常规育种与分子标记辅助选择相结合的方法，对铃部主要性状在不同发育时期的配合力和遗传效应分析，研究海岛棉铃部主要性状与产量、品质的遗传及相关关系，确定长果枝与零式果枝海岛棉具有优良铃部性状的指标；通过分子标记的手段构建海岛棉分子遗传连锁图谱，在此基础上，对海岛棉铃部主要性状进行QTL分析并进行初步定位；确定具有优良性状的基因型，探讨海岛棉铃部性状的遗传改良策略，阐明海岛棉铃部主要性状的遗传机制，为海岛棉铃部主要性状的分子标记辅助选择提供理论基础。

海岛棉株形性状与加性和显性遗传效应相关，没有检测到上位性遗传效应。各个株形性状的狭义遗传力存在较大差别。不同亲本在8个株形性状上表现正负加性效应。F1群体平均优势和群体超亲优势在不同株形性状上表现不同。株形性状间存在基因型正相关或负相关。.铃长、铃宽和和株高对产量性状表现增进或限制作用，铃长宽比对四个产量性状均表现为限制作用。铃柄长、果枝数、铃柄粗和总节数对单株籽棉表现出增进作用，铃柄粗对4个产量性状具有增进作用。.铃长、铃柄粗的遗传改良需要适当。适当提高铃宽可改良海岛棉的单株有效铃、单株籽棉和单铃重。铃长宽比改良负向影响单株有效铃、单株籽棉和单铃重。铃柄长改良可提高单株籽棉、衣分和单铃重。.株高对纤维长度表现增进作用，铃长、铃宽和铃长宽比为限制作用。铃长、铃宽、铃长宽比和株高对整齐度为限制作用。铃长、铃宽和铃长宽比对纤维强度为限制作用，株高为增进作用。铃长、铃宽、铃长宽比和株高对马克隆值为增进作用。铃柄长、铃柄粗、果枝数和总节数对4个纤维品质性状表现不同作用。海岛棉株形性状与4个纤维品质性状存在遗传正负相关。.海岛棉产量品质性状狭义和广义遗传率较高，产量性状高于品质性状。不同亲本和组合对产量品质性状的效应存在差异。海岛棉产量品质性状具有较强的群体平均优势，无正向的超亲优势。单株有效铃、单株籽棉和单铃重对4个品质性状表现为增进或限制作用，提高衣分的表现型值，对4个品质性状有增进作用。.对海岛棉株形差异明显的2个亲本及F1进行了SSR、SRAP分子标记的筛选，种内的多态性表现低。F2-BSA法分析与海岛棉铃形相关的位点,获得4个SNPs及片段，Gbscaffold8292.3、Gbscaffold433.3、Gbscaffold433.9、Gbscaffold8662.11，位于2条染色体上（3758、1951、500和1954bp）。6个InDels及5个片段，Gbscaffold12294.1、Gbscaffold8048.5、Gbscaffold18436.4、Gbscaffold18191.7、Gbscaffold18191.8，位于4条染色体上（617、1665、2952、1377和3569bp），在cottongen数据库中没有相应的功能注释信息，需要下一步的详细功能验证。