重要桉属树种杂交亲本选配遗传基础研究

Cross breeding is the most important and effective traditional method for fostering new high-yielding, good-quality and stable species, meanwhile parent selection is the key factor in breeding process. However, much less clones were selected in the past decades. The main reasons may be due to simple breeding strategy, lack of long-term and stable research program, simple mating design and lack of genetically-improved planting material. This research project will focus on Eucalyptus urophylla, E. grandis, E. camaldulensis, E. pellita and other important species in southern China. Growth traits and wood properties will be assessed and analyzed on the former finished full diallel and half diallel mating among 12 E. urophylla parents, inter-specific factorial mating among E.grandis, E. camaldulensis and E.pellita with E.urophylla, the positive and negative factorial mating among E. urophylla and E. camaldulensis. Combining ability, hybrid force, genetic ability and breeding value will be assessed to reveal male effect, female effect, selfing effect, outcross effect and heterosis, and then to discuss the traits genetic control pattern. The research results will be used to offer theory evidence for parent selection, utilization of heterosis and draft of breeding strategy in eucalyptus breeding.

杂交育种是培育高产、优质和稳定的植物新品种的一种最有成效的常规方法，亲本选配是杂交育种成败的关键因素。华南地区桉树遗传改良工作由于缺乏系统的交配设计，亲本的遗传基础研究滞后，造成新品种选育工作基本停滞不前。本研究以华南地区的主要桉属树种-尾叶桉、巨桉、赤桉和粗皮桉为研究对象，重点利用前期建立的尾叶桉12个亲本种内（半双列和全双列）交配设计试验，尾叶桉与巨桉、赤桉、粗皮桉的种间析因交配设计（108个组合）试验以及尾叶桉和赤桉正反析因交配设计（72个组合）试验等，开展生长和木材材性等重要性状的测定与数量遗传学分析。通过估算配合力、杂交力、遗传力和育种值等重要遗传参数，揭示父本和母本效应、自交和异交效应以及杂种优势，探讨性状的遗传控制方式。研究结果将为桉树杂交育种的亲本选配、杂种优势的利用以及制定杂交育种策略提供重要的理论依据。

亲本选配是杂交育种成败的关键因素，我国桉树遗传改良工作由于缺乏系统的交配设计，亲本的遗传基础研究滞后，新品种选育工作进展不大。本项目以主要栽培的桉属树种为研究对象，重点利用前期建立的尾叶桉亲本种内双列交配设计，尾叶桉种间析因以及尾叶桉和赤桉正反析因交配设计试验等，开展了生长和木材材性等重要性状的测定与数量遗传学分析。具体结论如下：（1）完成了192个组交配设计组合的样品采集与材性指标的测定；（2）对尾叶桉赤桉正反析因交配设计中的生长、形质与材性性状指标的数据处理与分析；对尾叶桉种内交配效应、尾叶桉种间析因交配效应以及尾叶桉赤桉正反析因交配效应进行了遗传分析与重要的遗传参数估算，估算了配合力、杂交力、遗传力和育种值等重要遗传参数，揭示了父本和母本效应、自交和异交效应以及杂种优势，探讨性状的遗传控制方式。（3）对杂交组合试验开展了遗传稳定性分析与生长－抗风联合选择，评价出高产稳定型组合6个。（4）发表SCI论文两篇，获授权专利4个；（5）邀请澳大利亚专家David博士访华，项目组2人出国交流，6人次参加国内学术会议交流。