高级检索

    基于BWB的油松初级种子园混合子代优树选择与配置设计

    BWB-assisted plus tree selection and deployment design for bulked progenies of the first-cycle Chinese pine seed orchard

    • 摘要: 当前甘肃中湾油松良种基地正处于由第一育种周期向第二育种周期发展的关键转折时期,如何以前期改良成果为基础,结合现代林木育种的先进理论和技术,更高效地筛选和利用第二育种周期种质资源已经成为亟待解决的重要问题。本研究以甘肃中湾油松良种基地大规模初级种子园无谱系自由授粉混合子代群体为研究对象,详细阐述了基于种子园自由授粉混合子代的油松高育种周期优良种质资源选择、评价及配置利用策略等问题。结果表明,按照单株材积优势比的相对大小从中湾自由授粉混合子代中选出40个优良单株,其平均材积优势比为0.83;优良单株群体具有较高的遗传多样性,其平均多态性信息含量为0.620 2。基于SSR分子标记的亲缘分析结果表明,40个单株间亲缘关系不同,分属于23个同源组;为有效控制近交,进行了同源组内优良单株的二次选择,最终入选23个优良单株,并将之用作第二育种周期种子园的建园亲本。结合建园亲本材积优势比和亲缘分析的结果,制定了中湾第二育种周期种子园的分组、不平衡、完全、固定区组配置设计策略,兼顾了种子园子代材积遗传增益的提高和遗传多样性的维持。研究结果为油松高育种周期优良种质资源的高效选择及合理利用提供了新的思路,为缩短油松育种周期、提高油松育种效率奠定了基础。

       

      Abstract: Genetic improvement of Chinese pine in Zhongwan Improved Variety Base, Gansu Province of northwestern China, is in the key transition period from the first breeding cycle to the second breeding cycle. How to effectively select and utilize germplasm resources of the second breeding cycle, based on the previous improvement results and combined modern theories and technologies in tree breeding, has become important issues to be addressed immediately. Using large-scale no-peditree open-pollinated bulked progeny population from the first-generation seed orchard of Chinese pine in Zhongwan Improved Variety Base, Gansu Province, as study materials, this study elaborates issues about open-pollinated bulked progenies based elite germplasm resource selection, evaluation and utilization strategies for advanced cycle improvement of Chinese pine. Results showed that 40 superior individuals were selected based on the relative growth of stem volume, with the mean volume dominance ratio of 0.83. Population consisting 40 individuals had high levels of genetic diversity, with the mean polymorphism information content of 0.620 2. Results from SSR molecular markers based phylogenetic analysis showed that the 40 individuals had varying phylogenetic relationships, belonged to 23 homogenous groups. To effectively control inbreeding, the 40 individuals were conducted within-homogenous group selection and finally only 23 superior individuals were remained and used for parents of seed orchard in the second breeding cycle. Combined with the results of volume dominance ratios and phylogenetic analysis of these parents, seed orchard in the second breeding cycle of Zhongwan Improved Variety Base was suggested to adopt the grouped, unbalanced, complete, fixed block design, which had taken the increase of volume genetic gain and the maintenance of genetic diversity of seed orchrd progenies into consideration simultaneously. Results from this study will provide new insights into effective selection and rational utilization of elite germplasm resources in advanced breeding cycles of Chinese pine, and will lay the foundation for shortening breeding cycle and increasing breeding efficiency in genetic improvement of Chinese pine.

       

    /

    返回文章
    返回