Studies On Embryonic Development And Genetic Diversity In Castanopsis Chinensis (Castanea Henryi Rehd. & Wils.)

Castanopsis chinensis(Castanea henryi Rehd. & Wils.) has very high edible and the medicinal value, which is a characteristic fruit tree resource in Fujian. Because of long-term grown directly from seed reproduction, its heredity background is complex and varieties are confused. In addition, there is seedless phenomenon in produces, which makes the output drop and the quality reduces. This research took the fruits, the shoots, the pollens as the materials, explored the embryonic development and the genetic diversity of Castanopsis chinensis , to provide the basis for overcoming the seedless question and the reasonable use in resources. The results were as follows:1. Verifies the embryonic development of Castanopsis chinensis initiallyThe embryogenesis of Castanopsis chinensis was mainly studied on the variety of 'huang zhen' .Materials were dehydrated, embedded and cut in Paraffin wax. The result were as follows: The embryonic development began in the nucellus tissue from a archesporium cell which would divide to a sporogenous cell and a parietal cell. The sporogenous cell functioned as the megaspore mother cell. The tetrad of megaspores was linear shaped, with one of them being functional. The development of the embryo sac belongs to the 'polygonum' type. The female gametophyte consists of egg apparatus, central cell and three antipodal cell at the mature embryo sac stage. Embryonic development experienced golbular embryo, heart-shape embryo, torpedo-shape embryo to cotyledonary embryo.2. The genetic diversity of Castanopsis chinensis analisis by scanning electron microscope17 Castanopsis chinensis pollen varieties were gathered from main production area-Jianou as the materials. The results were as follows: the pollens belonged to small pollen type, prolate, circular AMB with 3 laesurae, three types equator- Oblong, wide ellipse, diamond , nomotreme belonged to N₃P₄C₅. The pollen characteristics of these varieties differred in the sizes, shapes, especially in the exine ornamentations, so they could provide scientific bases for variety and identification of Castanopsis chinensis. According to the exine ornamentations, these 17 varieties were classified to 5 types-circular process, hole, striate, hole - striate, wrinkle. Moreover, the smooth→hole → wrinkle → striate tendency of the exine ornamentations development would borrow this to extrapolate the Castanopsis chinensis...