Shang Lianguang, Wang Yumei, Cai Shihu, Wang Xiaocui, Li Yuhua, Abduweli Abdugheni, Hua Jinping
Department of Plant Genetics and Breeding, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
Research Institute of Cash Crops, Hubei Academy of Agricultural Sciences, Wuhan 430064, Hubei, China.
G3 (Bethesda). 2015 Dec 29;6(3):499-507. doi: 10.1534/g3.115.025809.
Based on two recombinant inbred line (RIL) populations, two corresponding backcross (BC) populations were constructed to elucidate the genetic basis of heterosis in Upland cotton (Gossypium hirsutum L.). The yield, and yield components, of these populations were evaluated in three environments. At the single-locus level, 78 and 66 quantitative trait loci (QTL) were detected using composite interval mapping in RIL and BC populations, respectively, and 29 QTL were identified based on mid-parental heterosis (MPH) data of two hybrids. Considering all traits together, a total of 50 (64.9%) QTL with partial dominance effect, and 27 (35.1%) QTL for overdominance effect were identified in two BC populations. At the two-locus level, 120 and 88 QTL with main effects (M-QTL), and 335 and 99 QTL involved in digenic interactions (E-QTL), were detected by inclusive composite interval mapping in RIL and BC populations, respectively. A large number of QTL by environment interactions (QEs) for M-QTL and E-QTL were detected in three environments. For most traits, average E-QTL explained a larger proportion of phenotypic variation than did M-QTL in two RIL populations and two BC populations. It was concluded that partial dominance, overdominance, epistasis, and QEs all contribute to heterosis in Upland cotton, and that partial dominance resulting from single loci and epistasis play a relatively more important role than other genetic effects in heterosis in Upland cotton.
基于两个重组自交系（RIL）群体，构建了两个相应的回交（BC）群体，以阐明陆地棉（Gossypium hirsutum L.）杂种优势的遗传基础。在三种环境下对这些群体的产量及其构成因素进行了评估。在单基因座水平上，分别在RIL群体和BC群体中使用复合区间作图法检测到78个和66个数量性状基因座（QTL），并根据两个杂种的中亲杂种优势（MPH）数据鉴定出29个QTL。综合考虑所有性状，在两个BC群体中总共鉴定出50个（64.9%）具有部分显性效应的QTL和27个（35.1%）具有超显性效应的QTL。在双基因座水平上，分别在RIL群体和BC群体中通过包容性复合区间作图法检测到120个和88个具有主效应的QTL（M-QTL）以及335个和99个涉及双基因互作的QTL（E-QTL）。在三种环境下检测到大量M-QTL和E-QTL的基因座与环境互作（QE）。对于大多数性状，在两个RIL群体和两个BC群体中，平均而言E-QTL比M-QTL解释了更大比例的表型变异。得出的结论是，部分显性、超显性、上位性和QE都对陆地棉的杂种优势有贡献，并且单基因座产生的部分显性和上位性在陆地棉杂种优势中比其他遗传效应发挥着相对更重要的作用。
