Gamete And Zygote Chromosome Doubling Of Eucommia Ulmoides Oliv

Eucommia ulmoides Oliv., which is the only species of Eucommiaceae, Eucommia Oliv., is a rubber-producing plant and can be used as a replacement of caoutchouc. The deciduous leaves of E. ulmoides possess excellent properties such as great amount, easy collection, and so on. Therefore, it is feasible to use deciduous leaves as the material of gutta-percha extraction. Improvement of the concentration of gutta-percha in leaves through selecting and breeding polyploid is of great significance to the industrialization related to gutta-percha. Based on the gametogenesis and development of microgamete, megagamete and embryo of E. ulmoides, chromosome doubling of microgamete, megagamete and zygote of E. ulmoides were studied. The results of these researches included five points showed as follows.(1) The meiosis stages of pollen mother cells (PMCs) were observed, which was correlative with the length of male flower and diversification of the anthers. Usually, the PMCs meiosis of E. ulmoides finishes at the end of March. It took short time to finish what happened from metaphase I to telophase II. The synchronization of meiosis were greatly different in different clones, floral branches from the same clones, male flowers from the same floral branches and even anthers of the same flower of E. ulmoides. Commonly, at the bouquet stage or pochytene, the anthers began to outspread and the anther outgrew 1/5-1/4 scale when flower was 1.1-1.2cm. At the diakinesis or metaphase I, the anther outgrows 1/4-1/3 scale when the flower was 1.2-1.3cm.(2) The meiosis stages of megaspore mother cells (MMCs) and development process of embryo sac of E. ulmoides were found to be correlative with development stages of...