樟子松种子园传粉期外来花粉污染格局研究

Scots pine (Pinus sylvestris var. mongolica) was often used as important timber production and afforestation tree species at northeast cold area in China. This research will be conducted in seed orchard of Scots pine in Jiagedaqi of Great Xing’an Mountains, through monitoring the pollination process and flowering phenology of seed orchard for years, to get the relationship between the seed orchard reproductive phenology and the pollination process; SSR molecular marker echnique will be used to analyze the genetic relationship of the selected female parent and undetermined male parents, explicit propagation distance and spread pattern of the pollen; to explore the effects that inbreeding and outcrossing among the clones on reproductive success, and the pollen pollution extent of the genetic structure of seed orchard. Synthesize the above results, pollination and genetic variation of seed orchard of Scots pine will be basically understood, then the relationship between pollen and seed orchard recession will also could be deduced. The research aims to provide a scientific reference for seed orchard of Scots pine and other northern coniferous seed orchard, via targeted seed orchard pollination process and mating model for scientific and quantitative research, and also provide optimized selection gene combinations and pollen effective management measures for seed orchard operator, thus to improve seeds genetic quality and yield of seed orchard.

樟子松(Pinus sylvestris var. mongolica)是我国东北高寒林区重要的用材和造林树种。本项目拟通过对大兴安岭加格达奇樟子松种子园的传粉过程和花期物候进行连年监测，得到种子园生殖物候与传粉过程的关系；使用SSR分子标记技术对选定母本和周围待定父本进行亲缘分析，明确种子园内花粉的传播距离和散布模式；探讨自交和无性系间的异交对繁殖成功率的影响，以及花粉污染对种子园遗传结构的作用程度。综合以上研究结果，基本可以掌握樟子松种子园的传粉规律及遗传变异模式，从而在一定程度上推断花粉传播与种子园衰退的关系。本项目希望通过有针对性的种子园传粉过程和交配模式进行科学定量的研究，为樟子松种子园乃至其它北方针叶树种子园提供一些研究参考，并为种子园经营者提供经过优化筛选的基因组合及有效花粉管理措施，从而达到提高樟子松种子园内种子的遗传品质和产量的最终目的。

樟子松（Pinus sylvestris var. mongolica）因其较强的环境适应能力广泛分布于我国大兴安岭、呼伦贝尔地区和辽宁部分地区。在营造林过程中，遗传品质优良的樟子松种子主要来源于无性系种子园，而樟子松种子园的衰退已成为限制其在林业生态建设中发挥重要作用的关键因素。本研究以大兴安岭加格达奇樟子松无性系种子园为研究对象，对12个相邻小区中不同种源、无性系和截顶处理方案的樟子松母树的花粉活力及散播规律、结实规律和松塔解剖形态等进行了调查和分析，从而推断导致种子园呈衰退趋势的诱因。研究结果表明，外源花粉污染率仅为5%~17%，目前并不能造成该种子园的大规模衰退。但是花粉散播受到潮湿天气干扰以及母树自身品质的下降很可能会大幅提升败育率和自交率，从而整体上降低樟子松种子的产量和质量。同时母树由于长期缺乏树体管理导致个体不断增大、树冠密度升高，造成了光照、养分的供需不平稳。对种子园进行截顶处理可以暂时缓解上述不利因素造成的影响。本研究还发现，不同无性系种实性状对截顶的响应程度存在明显差异，因而有针对性的开展截顶和修枝可以起到节约成本、事半功倍的效果。本研究可以为樟子松及其它针叶树种子园管理者提供有益的科学参考，从而达到提高种子园内种子遗传品质和产量，服务林业生态建设的最终目的。