陆地棉低酚棉种子品质性状的遗传及其杂种优势利用的研究(英文)

Studies of the Inheritance of Seed Qualities and the Exploitation of F_2 Heterosis in Low Gossypol Strains in Upland Cotton

通过配制 ４个隐性无腺体品系 （ｇｌ２ｇｌ２ ｇｌ３ｇｌ３）作母本与 ５个显性无腺体品系（Ｇｌｅ２Ｇｌｅ２Ｇｌ３Ｇｌ３）杂交产生的 ２０个组合的 Ｆ２、Ｆ３，利用二倍体种子遗传模型，研究了棉花种子的含油量、蛋白质含量、油分指数、蛋白质指数等５个种子性状的遗传变异。结果表明所有研究的性状主要由加性遗传效应所控制，其中含油量主要由母体加性遗传效应所控。按群体平均数计算，这些性状 Ｆ２的中亲优势仅为－１．９９％～ １．１１％，这揭示出 Ｆ２、 Ｆ３近交衰退很少。有７５％的 Ｆ２和 ６０％的 Ｆ３天然授粉异交组合棉酚含量低于 ０．４ｇ／ｋｇ，因此有可能筛选出棉酚含量低于规定标准、而种子品质不降低、可综合利用的Ｒ２高产杂交种。

Twenty cross combinations were made with 4 recessive glandless lines (gl2gl2 gl3gl3) used as females and 5 dominant glandless lines (Gle2Gle2 Gl3Gl3) used as male parents to estimate the genetic variance components of kernel oil and protein content of seeds, oil and protein index, and kernel index using a genetic model for parents, F2 and F3. The results showed that all the analyzed traits were mainly controlled by additive effects. Oil content was controlled mainly by maternal additive effect, and other traits by direct additive effect. The average heterosis of F2 over mid -parent based on population mean was - 1.99% to 1.11% for all these traits. It suggests that little inbreeding depression exists for F2 and F3 seeds. There were 75% and 60% of the F2 and the F3 combinations in which open-pollinated seeds contained gossypol levels lower than 0.4gkg-1. This result indicated that it is possible to screen and select high yielding F2 hybrids with a gossypol content lower than the regulated criterion and without lowering seed quality.