Dissertation > Agricultural Sciences > Livestock, animal medicine,hunting,silkworm,bee > Sericulture > Genetic breeding and breeding of the silkworm

Studies on Creating Silkworm (Bombyx mori.L) Asexual Reproductive Lines and Its Hereditary Feature

Author WangYongQiang
Tutor XuMengKui;MengZhiQi
School Zhejiang University
Course Special Economic of animal husbandry
Keywords Silkworm Clones Building Genetic Resources The optimal Genetic effects Protein RAPD Use
CLC S882
Type PhD thesis
Year 2002
Downloads 102
Quotes 3
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Animal sexual reproduction is the nature universal genetic phenomenon, the offspring as an economically important insects silkworm. Silkworm sexual reproduction for breeding a wealth of genetic variation through the Crossbreeding other methods nurtured many excellent economic traits of silkworm varieties to promote varieties upgrading and improving the quality of cocoon production. However, with the re-use of the limited germplasm resources, bred gradual descent similar traits similar to the phenomenon, it is difficult to achieve a breakthrough. At the same time, with different needs in-depth study of silkworm breeding and production, always hope that the person wishes to regulate the offspring sex ratio, so as to achieve the purpose of sex control. As compared to the male the silkworm and female silkworm have food Sang Province, sericulture, low cost, and a silk superior characteristics of high and silk, Therefore the tertiary Yangxiong in rural silkworm than breeding female and male the silkworm and female of conventional varieties, can improve economic efficiency 10 % or more. Is different in the silkworm farm, hope to raise more female silkworm to improve the effectiveness of its seed. Therefore, to achieve \Sericultural Research Institute of Zhejiang Academy of Agricultural Sciences in 1996 from Russia to introduce the the silkworm gender control system, to carry out a balanced lethal turn sterile and improved. Has bred several economic traits excellent the male silkworm variety and to be successful in rural husbandry. However, due to the higher cost of production of the male silkworm hybrids, to a certain extent limit its large scale applications. If we have a high induction rate, high hatching rate and economic traits of good female silkworm clones as balanced lethal male silkworm female parent to pay, instead of the conventional varieties (male and female, the male not use), magnitude lower production of male silkworm hybrids seed costs, speed up the industrialization process specifically raise male silkworm. To do this, to carry out the research work of the silkworm construction of clones and their genetic characteristics. At the same time, this study is also in Silkworm asexual reproduction study further innovation and improvement in the academic, and enrich our silkworm germplasm resources; provide a new method for the genetic breeding of silkworm: for the study of gene expression, character formation, important theoretical problem of the mechanism of heterosis, and thus provide a new way to use them effectively. The main contents of this thesis include: Bombyx mori asexual reproduction optimization of inducing conditions; to get practical technology research unfertilized from silkworm Virgin moth; the bivoltine silkworm varieties vegetative propagation characteristics of genetic resources survey: bivoltine female silkworm clones build: silkworm asexual reproduction traits of the genetic effect analysis; silkworm asexual reproduction varieties of protein research: silkworm asexual breeding varieties with their gender, parental growth and development of comparative studies: control silkworm asexual reproduction traits of the gene of RAPD molecular markers to explore as well as Bombyx mori asexual reproduction Department's use of nine aspects of the research, the main results obtained are as follows: 1. Bivoltine existing varieties resources of 50 the incidence of asexual reproduction survey results show that of all varieties can be induced to a certain percentage of asexual reproduction and development of eggs and larvae, but there are large differences between the varieties, the incidence 11.99 1/3 of species of asexual reproduction incidence of 70 to 80% to 88.88%, while the asexual reproduction of the hybrids were significantly more than the level of the original species, therefore, our bivoltine silkworm varieties available estrogen The silkworm clones nurturing required Germplasm Resources. 2. The inducing conditions existing varieties of silkworm bivoltine material optimization study, for the first time proved the effect of temperature on the incidence of asexual reproduction in the hot water treatment was significantly more than the processing time. Between 40 ℃ ~ 50 ℃ temperature treatments are available to a certain percentage of asexual reproduction and development of eggs, but less than 40 ℃ or above 50 ℃ temperature treatment were significantly - down. For our country's the bivoltine silkworm current varieties, its vegetative propagation induced temperature is 44 'C ~ 46'C appropriate; asexual reproduction of processing time to adapt to a wide range of asexual reproduction and development of a certain percentage of eggs are available from 3min ~ 68min bivoltine silkworm our existing varieties, of asexual reproduction processing time 14 ~ 16min appropriate. 3. The research results show that the unfertilized eggs of different egg age and the incidence of asexual reproduction of bivoltine silkworm varieties 12 to 36hr egg age unfertilized eggs for processing, a higher incidence of asexual reproduction; our bivoltine silkworm varieties unfertilized different protection mode and the incidence of asexual reproduction study results show that the the asexual reproduction incidence of unfertilized eggs in vitro protection is slightly higher than the in vivo protection. 4. That simple to resolve the problem in the future asexual reproduction technology popularization and application of a large number of obtain unfertilized, prickly edges stimulated Virgin moth quickly spawn easy way a lot of innovative research work, the results show that Comparison of drastic changes with temperature. Ideal, that of the Virgin moth 5'C temperature refrigerated after 4d transferred to 30C high temperature ambient conditions spawning Virgin moth within 6hr output of eggs can be reached about 80% laid eggs The asexual reproduction induction higher incidence can be obtained. 5. 1 day before eclosion male pupae treated with 350G dose after emergence, mating with a virgin moth, can the female moth output of eggs with sexual reproduction, the development of eggs and induced to obtain a high proportion of asexual reproduction. The use of marker genes in the larval stage, confirmed that 45.94% of individuals for the future generations of asexual reproduction, and the rest is sexual reproduction offspring. The case of the former normal growth and development, while the latter generally can not complete the entire cohort; laid eggs as control i.e. without asexual reproduction processing, but also get a high proportion of developmental egg, larval stage marker gene confirmed 41.77% of individuals offspring of asexual reproduction, a slightly lower proportion. The test results show that the radiation although some sperm fertilizing capacity, but its effect can be considered to have a similar effect with fertilization and the role of hot water treatment. In addition, with 700G dose treatment after emergence, mating ability of male moths has been greatly affected. Therefore, using this method to stimulate the Virgin moths, the suitable doses need to be further refine explore 350G ~ 700G.

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