Anatomy of apomixis in ‘ Xinxin 2’ and ‘ Wen 185’ walnut
[Objective] To find out the developing features and types of the apomixis in Xinjiang walnut varieties,to shorten the walnut genetic purification cycle,and to provide theoretical basis for breedin.[Method] The organization structural changes in the process of the endosperm and embryo development of apomixis in the two Xinjiang walnut varieties were observed by paraffin method.[Result] The results showed that ten days were needed for the development and maturation of walnut embryo sac with seven cells and eight nucleus.The two polar nucleus became endosperm cells by the several times of division,which took about eight days after their fusion.The all of apomixis embryos of two tested varieties were achieved by the egg cell division and its development; the egg cells became two cell proembryo,four cell proembryo,eight cell proembryo and muhicellular proembryo by cell division; The postembryonic development went through the globular stage,heart-shaped stage,torpedo-stage and mature period,which needed about ten days.[Conclusion] The embryo sacs of two tested walnut varieties belonged to polygonum type,and the apomixis endosperm cells came from two polar nucleus by nuclear fusion and development which belonged to nuclear endosperm type.The apomixis embryos directly came from the egg cell development which belong to the parthenogenesis type.
国家科技期刊平台
NSTL
万方数据
维普
