Partial Dominance, Overdominance and Epistasis as the Genetic Basis of Heterosis in Upland Cotton (Gossypium hirsutum L.).
Partial Dominance, Overdominance and Epistasis as the Genetic Basis of Heterosis in Upland Cotton (Gossypium hirsutum L.).
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部分显性、过度显性和上位性作为陆地棉杂种优势的遗传基础（Gossypium hirsutum L.）
DOI：
10.1371/journal.pone.0143548
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Hua J
中科院分区：
文献类型：
--
作者：
Liang Q;Shang L;Wang Y;Hua J
杂种优势遗传基础的确定有助于促进陆地棉的杂交生产。以新杂1号为材料，研究了新杂1号F2: 3和F2: 4群体产量和产量成分杂种优势的遗传机制。在2008年和2009年进行了后代的重复产量田间试验。表型数据分析表明，F1在产量和产量成分上均为显性。利用基因组3814 cM的421个标记位点，分析了单位点水平上的加性和显性效应以及双位点水平上的上位互作效应。在F2: 3和F2: 4群体中分别鉴定出38个和49个控制产量和产量成分的qtl。这些qtl的分析表明，部分显性和超显性同时对陆地棉的杂种优势起作用。大多数qtl表现为部分显性，F2:3群体中有13个qtl表现为显性，F2:4群体中有19个qtl表现为显性。其中，有21个qtl在F2: 3和F2: 4群体中均存在。在两代中都检测到大量的产量和产量成分的双位点相互作用。AA（加性×加性）上位效应占上位效应的大部分。以单株结铃数计算，33个互补双位点纯合子（11/22和22/11）是AA互作的最佳基因型。双纯合子基因型11/22、22/11和22/22对AD/DA互作效果最好，基因型11/12对DD互作效果最好。这些结果表明：(1)单位点水平上的部分显性和超显性效应以及(2)双位点水平上的上位效应阐明了陆地棉杂种优势的遗传基础。
Determination of genetic basis of heterosis may promote hybrid production in Upland cotton (Gossypium hirsutum L.). This study was designed to explore the genetic mechanism of heterosis for yield and yield components in F2: 3 and F2: 4 populations derived from a hybrid ‘Xinza No. 1’. Replicated yield field trials of the progenies were conducted in 2008 and 2009. Phenotypic data analyses indicated overdominance in F1 for yield and yield components. Additive and dominance effects at single-locus level and digenic epistatic interactions at two-locus level were analyzed by 421 marker loci spanning 3814 cM of the genome. A total of 38 and 49 QTLs controlling yield and yield components were identified in F2: 3 and F2: 4 populations, respectively. Analyses of these QTLs indicated that the effects of partial dominance and overdominance contributed to heterosis in Upland cotton simultaneously. Most of the QTLs showed partial dominance whereas 13 QTLs showing overdominance in F2:3 population, and 19 QTLs showed overdominance in F2:4. Among them, 21 QTLs were common in both F2: 3 and F2: 4 populations. A large number of two-locus interactions for yield and yield components were detected in both generations. AA (additive × additive) epistasis accounted for majority portion of epistatic effects. Thirty three complementary two-locus homozygotes (11/22 and 22/11) were the best genotypes for AA interactions in terms of bolls per plant. Genotypes of double homozygotes, 11/22, 22/11 and 22/22, performed best for AD/DA interactions, while genotype of 11/12 performed best for DD interactions. These results indicated that (1) partial dominance and overdominance effects at single-locus level and (2) epistasis at two-locus level elucidated the genetic basis of heterosis in Upland cotton.