马缨杜鹃杂交胚胎发育/败育的差异发育机理研究

Yunnan is one of the distribution center and differentiation center of Rhododendron subgenus Hymenanthes,which is rich in Hymenanthes germplasm resources but poor in its utilization. Distant hybridization barriers are the important reasons for limited use of resources.The crosses of Rhododendron delavayi as female, the extremely endangered species of R. cyanocarpum and the near threatened species of R.sinofalconeri as male parent respectively have been carried out before. The results showed that the pre fertilization barriers appeared in both crosses. However, the hybrid embryos had different developments as embryo development of the former cross and embryo abortion of the latter. In order to find out the reason, the pollination experiments of R. delavayi × R. cyanocarpum and R. delavayi × R. sinofalconeri would be carried out. The changes of cell morphology in the embryos different development of both crosses would be observed to determine the critical period of different embryo developments. The changes of the content of endogenous hormones between the unpollinated ovaries and the ovaries in the critical period of the different embryo developments of both crosses would be compared. Meanwhile, the differentially expressed proteins at the same two periods would be analyzed by iTRAQ-coupled 2D LC-MSMS. Systematic and comprehensive study of the hybrid embryo different development of R. delavayi would be done and the physiological and biochemical mechanism and the molecular mechanism of it would be revealed. As a result, the important scientific basis would be provided to the distant hybridization barriers of rhododendron.

云南是常绿杜鹃亚属的分布中心及分化中心之一，常绿杜鹃种质资源众多但利用率低下。远缘杂交障碍是限制其资源利用的重要原因。针对前期以马缨杜鹃为母本，易危杜鹃物种蓝果杜鹃和受危杜鹃物种宽杯杜鹃分别为父本进行远缘杂交时，前期均发生受精前障碍但后期杂交胚胎却出现发育（前者）和败育（后者）的差异发育现象，拟开展马缨杜鹃与蓝果杜鹃、马缨杜鹃与宽杯杜鹃的杂交授粉试验，观察杂交胚胎差异发育过程中的细胞形态变化，确定杂交胚胎差异发育的关键时期，对未授粉子房和杂交胚胎差异发育关键期子房的内源激素含量变化进行比较，并利用iTRAQ标记结合二维液相色谱串联质谱技术对同一时期的差异表达蛋白进行对比分析，系统和全面地研究马缨杜鹃杂交胚胎差异发育的细胞形态、生理生化机制及分子机理，为杜鹃花远缘杂交障碍研究提供重要的科学依据。