Hou Meiying, Cai Caiping, Zhang Shuwen, Guo Wangzhen, Zhang Tianzhen, Zhou Baoliang
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Cotton Research Institute, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
J Genet. 2013 Dec;92(3):445-59. doi: 10.1007/s12041-013-0286-3.
Gossypium tomentosum, a wild tetraploid cotton species with AD genomes, possesses genes conferring strong fibers and high heat tolerance. To effectively transfer these genes into Gossypium hirsutum, an entire microsatellite (simple sequence repeat, SSR)-based genetic map was constructed using the interspecific cross of G. hirsutum x G. tomentosum (HT). We detected 1800 loci from 1347 pairs of polymorphic primers. Of these, 1204 loci were grouped into 35 linkage groups at LOD ≥ 4. The map covers 3320.8 cM, with a mean density of 2.76 cM per locus. We detected 420 common loci (186 in the At subgenome and 234 in Dt) between the HT map and the map of TM-1 (G. hirsutum) and Hai 7124 (G. barbadense; HB map). The linkage groups were assigned chromosome numbers based on location of common loci and the HB map as reference. A comparison of common markers revealed that no significant chromosomal rearrangement exist between G. tomentosum and G. barbadense. Interestingly, however, we detected numerous (33.7%) segregation loci deviating from 3:1 ratio (P < 0.05) in HT, mostly clustering on eight chromosomes in the Dt subgenome, with some on three chromosomes in At. Two morphological traits, leaf hairiness and leaf nectarilessness were mapped on chromosomes 6 (A6) and 26 (D12), respectively. The SSR-based map constructed in this study will be useful for further genetic studies on cotton breeding, including mapping loci controlling quantitative traits associated with fiber quality, stress tolerance and developing chromosome segment specific introgression lines from G. tomentosum into G. hirsutum using marker-assisted selection.
海岛棉（Gossypium tomentosum）是一种具有AD基因组的野生四倍体棉花物种，拥有赋予强纤维和高耐热性的基因。为了有效地将这些基因导入陆地棉（Gossypium hirsutum），利用陆地棉×海岛棉（HT）的种间杂交构建了一个基于微卫星（简单序列重复，SSR）的完整遗传图谱。我们从1347对多态性引物中检测到1800个位点。其中，1204个位点在LOD≥4时被归为35个连锁群。该图谱覆盖3320.8厘摩，平均位点密度为每2.76厘摩一个位点。我们在HT图谱与TM-1（陆地棉）和海7124（海岛棉；HB图谱）的图谱之间检测到420个共同位点（At亚基因组中有186个，Dt中有234个）。根据共同位点的位置和HB图谱作为参考，为连锁群分配染色体编号。对共同标记的比较表明，海岛棉和海岛棉之间不存在明显的染色体重排。然而，有趣的是，我们在HT中检测到大量（33.7%）偏离3:1比例（P<0.05）的分离位点，大多聚集在Dt亚基因组的8条染色体上，At的3条染色体上也有一些。两个形态性状，叶片多毛和叶片无蜜腺，分别定位在第6号染色体（A6）和第26号染色体（D12）上。本研究构建的基于SSR的图谱将有助于棉花育种的进一步遗传研究，包括定位控制与纤维品质和胁迫耐受性相关的数量性状的位点，以及利用标记辅助选择培育从海岛棉到陆地棉的染色体片段特异性渐渗系。
