Study On Pollen Chromosome Doubling Of Ginkgo Biloba

Ginkgo biloba is a multiple-use economic tree species in China. Now availabling genetic improvement methods can increase its leaves and timber outputs; however, in terms of its economic, ecological and medical value the professionals are still on the process of discovering. The research on the technology using colchicines to manually induce 2n pollen was described This paper, and would establish a base for the triploids breeding by pollinating to female Ginkgo biloba with 2n pollen. The results are as follows:(1) The differences of environment and microclimate will lead to the different meiosis time for the buds in natural and in cultivated water, however, the correlation between meiosis process of microsporocyte and its external morphology character is consistent all the time. Therefore, we can easily identify the microsporocyte meiosis stage by its external morphology character, and determine the pollen chromosome doubling time correspondingly.(2) For the two different treatments in the experiment, the concentrations of colchicines in the soaked cotton is 0.6%~1.0%, and in the bottle of colchicines for dipping bud is about 0.6%~0.8%.(3) In the experiments, the large size pollen was obtained from both the buds in the natural and in the cultivated water, however, the percentages were relatively low with the highest among them being 7%.(4) The volume of large pollen obtained from the experiment is larger than the normal one. The DNA content of large pollen grains induced by colchicine was two times of haploidic pollen by using LSCM. Evidently, the large size pollen we got is unreduced diploid pollen.(5) The optimal culture medium in the experiment for the isolated pollen germination experiment is:agar1%+sucrose3%+boron60mg/L+ Ca2+100mg/L. In additional, TTC is the best one of three coloration methods which can be used to determine vitality of Ginkgo biloba pollen.