Reproductive Biology Of Carya Cathayensis Sarg.

This dissertation studies on some key processes of reproductiveness in order to improve hickory's quality and increase its yield, including morphological differentiation of flower bud, anatomy structure of gametophyte development, flower syndrome for anemophily, spatial- temporal variability of pollen dispersion, the relation between preservation condition and pollen viability, characteristics of seed setting and fruit development, and the results showed as follows.Both male flower morphological differentiation and gametophyte develpement can be divided into four periods. The former consists of formation of rachises, formation of bracts and male-flower primordia, dormancy period and the formation and development of stamens, and the latter includes formation of stamens, formation of anthers, formation of pollen, and development and maturation of pollen. Differentiation of female flower is also separated into four periods, flower bud differentiation prophase, formation of inflorescences rachises, formation of involucrum, and development of gynoecium. And the corresponding relationship between external forms and anatomical structure of flowers are established.We discuss the floral design and floral display which are adapted to increase pollination of anemophily: at the period of blossom, when up the slope of a hill, the concentration of pollen decreases at first and then increases, and the concentration of pollen on horizontal(the same altitude)have no significant difference. On the same test point, while elevation adds the concentration of pollen decreases.Both in vitro germination and TTC (2,3,4-triphenyl-2H-tetrazolium chloride) test are not adapted to measure pollen viability. Fluorescent staining analysis is effective, staining time and the concentration of sucrose has no significant to the test results of pollen viability. When pollen dispersion at the time of blossom, the diameter is the biggest, but the viability has no significant difference. Methods and time of preservation and their interaction all have significant difference to viability. The most favorable method is integrating low temperature about 4℃and dryness to preserve. The altitude, preservation methods and their interaction both have significant difference to viability too, and when the altitude decreases, the viability of pollen increases.Based on the phenology, the study of drop of flower and fruit, characteristics of seed setting, fruit development and so on, we conclude the rhythm of growth and development of hickory. At last, some suggestions were put forward to guide hickory's yield.