油茶巢式交配子代果实和油脂性状的遗传分析

目的 为选配油茶杂交育种最优亲本和最佳亲本组合，探索种间杂交策略，提升育种效率，获得最大遗传增益。 方法 以巢式交配的种内、种间杂交子代林为试材，测定单果质量、鲜果出籽率、干籽出仁率、种仁含油率以及脂肪酸成分含量等11个经济性状，分析母本的一般配合力（GCA）和杂交组合的特殊配合力（SCA），解析各性状的遗传控制模式。 结果 11个经济性状在12个杂交组合间均存在极显著差异，且变异主要来源于父本效应（P<0.01），母本效应仅硬脂酸和亚油酸含量差异显著 (P<0.05)。综合分析亲本主要经济性状的GCA与SCA表明，普通油茶种内杂交组合4 × 23在以单果质量、鲜果出籽率、干籽出仁率、种仁含油率和油酸含量等性状为育种目标时可作为优选杂交组合。普通油茶和小果油茶的种间杂交组合53 × 小3可在单果质量、棕榈酸、亚油酸和α-亚麻酸含量育种中加以利用；组合53 × 小2在鲜果出籽率、干籽出仁率、种仁含油率和油酸含量上具有育种优势。遗传效应分析表明，硬脂酸、油酸和亚油酸含量主要受加性遗传控制，其余8个经济性状的非加性遗传方差显著高于加性遗传方差。11个经济性状的单株遗传力大于家系遗传力，油茶杂交育种中应采用全同胞家系内选择优良单株的育种策略。 结论 油茶成林的经济性状主要受遗传控制，受环境影响较小。单果质量、鲜果出籽率、干籽出仁率、种仁含油率、棕榈酸、棕榈烯酸、α-亚麻酸和顺-11-二十碳烯酸含量等8个性状均以非加性基因效应控制为主，加性基因效应影响程度较低。在开展种间杂交工作时，双亲的SCA评估应放在首位。本研究首次以油茶杂交子代成林为材料，探索了普通油茶与小果油茶种间杂交的亲本配置及遗传效应规律，对指导油茶种间杂交育种奠定了理论基础。

Genetic Analysis of the Fruit and Oil Related Traits on Hybrid Offspring of Nested Mating of Camellia oleifera

Objective To Select the optimal parent and parental combination for improving breeding efficiency and maximize genetic gain in oil-tea hybrid breeding. Method In this study, 11 fruit and oil related traits were detected in the intraspecific and interspecific hybrid progeny in nest design, including weight of single fruit, seed rate of fresh fruit, kernel rate of dry seeds, oil content of kernel and seven kinds of fatty acid content in the oil. The general combining ability (GCA) of female parent and special combining ability (SCA) of hybridized combination were analyzed. The genetic control modes for 11 traits were analyzed. Result There were highly significant differences in 11 traits among 12 families. These differences mainly caused by paternal effects at the level of P < 0.01, and only the differences of stearic acid and linoleic acid content were affected by maternal effects at the level of P < 0.05. The GCA and SCA of the parents were comprehensively analyzed. The intraspecific hybridization ‘Changlin No.4’ × ‘Changlin No.23’ showed better combining ability in weight of single fruit, seed rate of fresh fruit, kernel rate of dry seeds, oil content of kernel and oleic acid content in oil. The interspecific hybridization of Camellia oleifera and C. meiocarpa ‘Changlin No. 53’ × ‘Xiao No.3’ had a better performance on weight of single fruit, palmitic acid, linoleic acid and linolenic acid content. The cross of ‘Changlin No. 53’ × ‘Xiao No.2’ had advantages in seed rate of fresh fruit, kernel rate of dry seeds, oil content of kernel and oleic acid content. The analysis of genetic effect showed that stearic acid, oleic acid and linoleic acid content were mainly controlled by additive genetic effect, while the other eight traits were mainly influenced by non-additive genetic effect. The heritability of 11 economic traits of per plant was greater than that of families. The breeding strategy of selecting excellent individual plants within the full-sib families should be adopted in the cross breeding of C. oleifera. Conclusion The economic traits of C. oleifera are mainly controlled by inheritance, and less affected by environment. Weight of single fruit, seed rate of fresh fruit, kernel rate of dry seeds, oil content of kernel, palmitic acid, palmitoleic acid, linolenic acid and cis-11-eicosenoic acid content were mainly controlled by non-additive gene effect, and the influence of additive gene effect is relatively low. In interspecific hybridization, SCA evaluation of hybridized combination should be given priority. In this study, we explored the parental allocation and genetic effects of interspecific hybridization between C. oleifera and C. meiocarpa, which laid a theoretical foundation for guiding interspecific hybridization breeding of C.oleifera.