Study On Flower Bud Differentiation And Embryonic Development Morphological Of Kumquat

In this study, we have the kumquat planted in Baisha town of Yangshuo County, Guangxi as the object of study, carried out flower bud differentiation and embryonic development morphological studies of kumquat, the purpose is to lay the theoretical foundation of new varieties of kumquat and breeding theoretical basis. Using paraffin sections technique conducted cytological observation on kumquat flower bud differentiation, megaspores and microspores qccurrence and growth and development of embryos, using decolorization aniline blue staining and fluorescence microscopy watched the germination of pollen on the stigma and pollen tube growth in the style, using and emasculation bagging method to explore the ability of the of parthenocarpy of kumquat, Mature seed abortion and embryo were observed and statistics, and analyze the causes of ovule abortion of kumquat, we obtained the following results:1、The floral bud differentiation period of kumquat is early May until mid and late June, mid and late June is the fast flower bud differentiation period. According to the order of the tissue formation it can be divided into six periods, Each period has differentiated overlap in time and there is a certain correlation in the size of the flower and bud differentiation process. The main burl of the flower bud differentiation is 2 to 6, the number of flower bud differentiation accounted for 79.82% of the total, fhe case of a burl of two flower bud differentiation in the majority, accounting for 43.50% of the total.2、The type of anther wall development of o kumquat is basic, middle layer degenerate in the formation process of pollen grains, tapetum is multi-core glandular tapetum, after microspores forming gradually disintegrated, When pollen grains ripening, anther wall leave only highly vacuolated epidermis and radial thickening fibrosis endothecium. Microspore mother cell takes the meanwhile meiosis, forming a tetrahedral tetrads,in mononuclear aside period they take unequal division and form vegetative cells and germ cells, mature pollen is 2 cells type, with four germination ditch, shaped like bayberry Microspore mother cells developed normally, and can develop into a very large number of mature pollen grains, natural pollination, there is no male sterility.3、Pollen of kumquat could germinate on the stigma and twining grow in the stigma, in 1/4-1 /2 length of the style they stop growing, showing self-incompatibility4、The setting rate of kumquat’s natural parthenocarpy is low, and all the ovules were abortion, the ovaries have not developed or slowly development.5、Female gametophyte development is later than male gametophyte development, functional megaspore continuously mitosis to form a linear arrangement of tetrads, megasporocyte were continuously mitosis to form a linear arrangement of tetrads, functional megaspore is located in far micropyle, in the third day after flowering, most development into 7 cells 8-nucleate embryo sac, sac is fertile, embryo sac development before flowering and bud in longitudinal diameter have some relevance. in the third day after flowering, nucellar embryo original cells specialization out from one to several layers of cells near the embryo sac, there are more the original cells in the micropylar side original cells have the ability to divide and differentiate into nucellar embryos, in the 13th to 16th days after flowering, with fruit diameter of 7-8mm, the zygote develops into globular embryos, nucellar embryo original cells divide but have not invade to sac. kumquat ovule abortion for two reasons: First, the bad fertilized caused by incompatibility between pollen and style failure to make sac sterilized; and second, the endosperm developmental abnormalities lead to a lack of nutrition in the process of embryo development and abortion midway. Ripe fruit has an average of 3.44 plump seeds, the seeds are multi-type,3.14 shriveled seeds had embryos, and 5.82 no embryos seeds, seed abortion rate was 72.26%.