PDF(Pubmed)
Abstract：
Landraces are an important reservoir of genetic variation that can expand the narrow genetic base of cultivated cotton. In this study, quantitative trait loci (QTL) analysis was conducted using an F2 population developed from crosses between the landrace Hopi and inbred TM-1. A high-density genetic map spanning 2253.11 and 1932.21 cM for the A and D sub-genomes, respectively, with an average marker interval of 1.14 cM, was generated using the CottonSNP63K array. The linkage map showed a strong co-linearity with the physical map of cotton. A total of 21 QTLs were identified, controlling plant height (1), bract type (1), boll number (1), stem color (2), boll pitting (2), fuzz fiber development (2), boll shape (3), boll point (4), and boll glanding (5). In silico analysis of the novel QTLs for boll glanding identified a total of 13 candidate genes. Analysis of tissue-specific expression of the candidate genes suggests roles for the transcription factors bHLH1, MYB2, and ZF1 in gland formation. Comparative sequencing of open reading frames identified early stop codons in all three transcription factors in Hopi. Functional validation of these genes offers avenues to reduce glanding and, consequently, lower gossypol levels in cottonseeds without compromising the defense mechanisms of the plant against biotic stresses.
摘要：
地方品种是重要的遗传变异库，可以扩大栽培棉花狭窄的遗传基础。在这项研究中,使用地方品种Hopi和近交TM-1之间的杂交形成的F2种群进行了数量性状基因座（QTL）分析。A和D亚基因组的高密度遗传图谱跨越2253.11和1932.21cM，分别,平均标记间隔为1.14cM，使用CottonSNP63K阵列生成。连锁图谱与棉花的物理图谱表现出较强的共线性。总共确定了21个QTL，控制植物高度(1)，苞片类型（1），棉铃编号(1),茎颜色(2),棉铃点蚀(2),绒毛纤维的发展(2)，铃形(3),铃点(4),和棉铃粘合（5）。对新的QTL进行模拟分析，鉴定出总共13个候选基因。候选基因的组织特异性表达的分析表明转录因子bHLH1，MYB2和ZF1在腺体形成中的作用。开放阅读框的比较测序在Hopi中的所有三种转录因子中确定了早期终止密码子。这些基因的功能验证提供了减少眩光的途径，因此,降低棉籽中的棉酚水平，而不损害植物对生物胁迫的防御机制。
