| Abalone livestock breeding holds an important position in the fishing industry. However, inthe process of abalone farming, germ plasm are degenerating severely due to long term incorrectbreeding technology, close breeding and poor environment. Hence, to achieve a steadydevelopment for the abalone breeding industry, it is necessary to have germ plasm homozygous.Studying how to improve and optimize the abalone germ plasm and enhancing its economicvalue are of great significance both in science and production. This paper used experiment ofpolyploid inducing based on technical principles on polyploid gynogenesis and induction, andcombined with Statistics and Analysis about growth rate and livability observed by micrologyduring embryonic development, so as to explore advantages and disadvantages of methodsthrough gynogenesis polyploid induction.Use germ plasm of sperm from inactivated Haliotis diverscolor supertexta of Ethylene ureain different concentration to ensure the optimal concentration and treating time. ApplyCytochalasin B (hereafter referred to as CB) to deal with inducing polyploidy in differentduration for the first and second polar body of Zygotes from germ plasm of inactive Haliotisdiverscolor supertexta sperm and Haliotis discus discus ovum. The results show that belowwater temperature24.8℃, it is appropriate to deal with0.5‰of Ethylene urea as the germ plasmof sperm from inactivated Haliotis diverscolor supertexta within10minutes of duration; After10minutes of using germ plasm of inactive Haliotis diverscolor supertexta sperm and Haliotisdiscus discus ovum to fertilize, deal with Zygotes with a concentration of the CB for24minutes,the apparent triploid is more than65%, with apparent tetraploid more than5%; In the ploidyexamination of juvenile abalone, gynogenesis polyploidy is80%of total, hybridizationpolyploidy is20%of total. Triploid of Haliotis discus discus gynogenesis alloploid has reached a93%, of which tetraploid around3%.Tests through comparison of the average shell length and weight between Haliotis discusdiscus polyploid and diploid found out that polyploidy abalone has obvious advantages ofgrowth. The result shows that after12months of artificial breeding, the average shell length andweight of triploid group reached5.59cm and16.49g respectively, with the control group only3.89cm and9.05g. Comparison of mortality between polyploidy abalone and diploid abalone insame conditions of temperature and water converted quantity in the experiment: Under sametemperature conditions, mortality between Haliotis discus discus diploid and triploid has almost no difference; while in the water exchange capacity tests the mortality rate of triploid is about15%different from diploid, which thus has better resistance. Throughout the year, the averagesurvival rate of juvenile abalone of Haliotis discus discus triploid from the test group is72.38%,while the comparison group60.97%.To breed larva with1L conical beaker and cement pit, use microscope kept undercontinuous observation the embryo development and record the individual malformations ofgynogenetic polyploidy abalone during the division; Take otomicrographs on deformityindividuals of the trochophore larva. The result shows that: gynogenetic eggs of polyploidyabalone shows unequal splitting in the division process, which appears to be atypical form.Generally, these abnormal individuals can not continue the development. Even very few whichcan develop to the next stage will not survive long. |
