水稻品种9311的螟虫抗性改良和抗螟虫杂交稻组合选育

 【目的】将抗螟虫的cry1C*转入优良水稻品种9311中,培育具有9311遗传背景的高产、优质、抗螟虫水稻品种,再以改良的抗虫株系作父本配制抗螟虫的杂交水稻组合。【方法】以含有cry1C*的抗螟虫转基因材料T1C-19为供体,9311为受体,通过1次杂交、3次回交和3次以上自交,每个世代进行标记选择,改良的稳定株系和杂交组合进行田间螟虫抗性鉴定、CRY1C*蛋白表达量测定、产量、主要农艺性状、生育期和稻米品质分析。【结果】育成了8个具有9311遗传背景并含有cry1C*抗螟虫的近等基因系、配制了56个杂交组合,田间螟虫抗性与供体亲本T1C-19一样,稻纵卷叶螟抗性达到100%,而9311的稻纵卷叶螟危害率达到20%;改良株系的CRY1C*蛋白表达量与T1C-19基本一致,杂交组合分蘖期的表达量略低于父本株系,拨节期的表达量高于父本株系。育成的8个抗螟虫9311近等基因系的生育期、主要农艺性状和稻米品质与9311相似,产量有一定的提高,筛选出3个比扬两优6号明显增产的抗螟虫迟熟杂交稻组合,筛选出产量和米质明显优于Q优6号的抗螟虫中熟中稻组合,筛选出1个产量和生育期与金优207相当的抗螟虫中熟晚稻组合。【结论】通过杂交、回交和分子标记辅助选择,已经将抗螟虫的cry1C*渗入到优良水稻品种9311中,育成株系除了高抗螟虫以外,在生育期、产量、主要农艺性状、稻米品质和配合力等方面与受体亲本9311一致,测配筛选出一批抗螟虫的高产、优质中晚稻组合。

Improvement of Insect-Resistance of 9311 and Development of Insect-Resistant Rice Hybrids

【Objective】To introgress insect-resistance gene cry1C* into 9311, an elite indica rice variety, for developing new rice lines and hybrids which are resistant against rice stem borers and leaffolders.【Method】T1C-19 harbouing cry1C*, a transgenic rice material, was used as donor of insect-resistance in the study. cry1C* was introgressed into the genetic background of 9311 by hybridizing, backcrossing and MAS. Improved new lines and hybrids were carried out for identifying insect-resistance in field, testing protein content of CRY1C*, evaluating yield, main agronomic traits, growth duration and rice quality in improved lines and hybrids.【Result】Eight near-isogenic lines (improved lines) with genetic background of 9311 and insect-resistance gene cry1C* were developed and 56 crosses were made. Identification in field showed that the levels of stem borer- and leaffolder-resistance were the same as that of the donor parent T1C-19. Improved new breeding lines and T1C-19 were not damaged by leaffolders, compared to the twenty percents in damage in 9311 in the same field. The expressing protein contents of CRY1C* in improved lines were the same as T1C-19. The expressing protein contents of CRY1C* of hybrids were lower than that of their male lines at tillering stage, but higher at elongation stage. The growth duration, main agronomic traits and rice quality of improved lines were the same as 9311, but the grain yield per plant was higher. Three insect-resistant combinations with long growth duration were screened for one cropping with higher yield over check hybrid Yangliangyou 6. Five insect-resistant combinations with higher yield and quality over check hybrid Q-you 6 were selected for one cropping with medium growth duration. One insect-resistant combination with the same yield and growth duration as check hybrid Jinyou 207 was selected for second cropping. 【Conclusion】 The insect-resistance gene cry1C* has been introgressed into the genetic background of 9311 by hybridization, backcrossing and MAS. The developed lines with insect-resistance have the same characters as 9311 in growth duration, yield, main agronomic traits, rice quality and combining ability. Several insect-resistant hybrids were selected for one or second cropping.