Study On The Development Of Male And Female Gametophytes And Characteristics Of Flowering And Pollination Of Phyllanth Emblica L. PingDan-1

This article studies on the microspores and megaspores, the male and female gametophytes' development, the flowering characteristics, the fruiting laws, and the pollination biology of Phyllanth emblica L. pingdan-1 to find out its sexual reproduction mechanism, flowering and fruiting laws, so that the theoretical and applied basis can be provided for some technology to promote stable and high yield of Phyllanth emblica L. pingdan-1.(1) Development of the microspores and megaspores, the male and female gametophytes: Development of the anther wall of Phyllanth emblica L. pingdan-1 follows the dicotyledonous type. The tapetum is glandular tapetum. The cytokinesis is of the simultaneous type and also tetrads with tetrahedrons come into being during microsporocyte' s meiosis; The mature pollen grain is the two-celled type; the gynoecia of Phyllanth emblica L. pingdan-1 has epigynous ovary, 3 carpels, 3 loculuses respectively with 2 anatropous ovules which are crassinucellate, and the embryo sac of the gynoecia of Phyllanth emblica L pingdan-1 is of Polygonum type. The observations proved that if the megasporocytes, the megaspores and the embryo sac of Phyllanth emblica L. pingdan-1 grow abnormally, the female flowers cannot create the normal egg cells and process fertilization. (2) The characteristics of flowering and the development rules of fruiting: Phyllanth emblica L. pingdan-1 belongs to hermaphrodite trees, the flowers grow in the leaf axils of flowering branches, and the female flowers mainly grow in 7th-9th leaf axils; compared with male flowers, the production of female flowers is very low, the proportional relations between female and male flowers in Spring and Autumn are 1:29.83 and 1:90.18 respectively; the florescence of spring and autumn are 28d and 25d respectively and fruit setting ratio of 40d after flowering are 41.14% and 0 respectively. Thus, the quantity of flowers in spring is the key for the annual output of fruits; to a certain degree, low temperatures can harmfully affect on the flowering of female flower; the characteristics of low-growing and seriously fruit falling on the fruits of Phyllanth emblica L. pingdan-1 are mainly caused by poorly pollination and fertilization, and competition for nutrition.(3) Pollination biology: Pollen grains of Phyllanth emblica L. pingdan-1 are spheroidal, 18.80μm in average diameter, reticulate on face, has 4 prolate apertures in shape; both vitality and germination rate of pollen on the day when the flowers bloom are high, reaching 78.6% and 73.8% respectively; the temperature condition of -18°C is good for pollen to maintain a stable germination rate, so the pollen stored even for 30 days can still maintain a high germination rate of 28.7%; the value of p/o is 8444.5. The visiting insects consist of 11 kinds from 4 orders and 7 families, among which Hymenoptera and Diptera are the most ones with 4 orders in each, and occupying 36.4% respectively; 24.9~28.3°C is the good temperature for insects like bees to visiting the flowers; it has a close connection between wind pollination and weather condition, then dry days with the right amount of wind are necessary for effective wind pollination.