Studies On Artificial Gynogenesis In Haliotis Diversicolor

Haliotis diversicolor (S for short) is one of most economically important mollusks cultured in the coast of Southern China. To support sustainable development of the culture industry of abalone, genetic improvement program have been proposed. Gynogenesis induction is an important chromosome set manipulation techniques with potential applications including of rapid establishment of inbred lines or strains with high degree of homozygosity, sex-control, and accelerated elimination of recessive deleterious genes from aquaculture population. Nevertheless, studies on gynogenesis in mollusks were still preliminary. The purpose of this dissertation was: (1) to investigate the conditions and cellular mechanism of artificial induction gynogenetic diploid in the H. diversicolor with UV and CB treatment; (2) to overcome the prezygotic reproduction isolation between the H. diversicolor and the H. discus discus (J for short); (3) to confirm the viable hybrid F1 of the cross of H. diversicolor and H. discus discus were gynogens; (4) to reveal the mechanism how gynogens were produced from hybridization. Results were as follows:1 Gynogenetic diploid induction in the H. diversicolor with UV and CB treatment1.1 The condition and effect of UV irradiationUV irradiation had effect not only on the sperm genome, but also on the functions of sperm and the development of progenies. Considered the effect of genetic inactivation, the fertilization rate, the normality rate of progenies and the stability of various batches, the conditions to genetic inactive sperm of the Small abalone were: 1mm depth layer of 5×106 cell·mL-1 semen irradiated for 50-90 sec with UV at intensity of 1075μW·cm-2·s-1. In addition, excessive sperm and prompt insemination were recommended after irradiation, since that ability to fertilize the egg was declined and the age of sperm speeded up after UV irradiation. Dense chromatin body (DCB) instead of male parental chromosomes existed in gynogenetic egg at the first mitosis, while the process of the formation of male pronucleus was normal, which suggested the condense process...