蚕业科学面向21世纪

本文作为第19届国际昆虫学大会养蚕学科组的主题报告,从丝蛋白结构与丝蛋白基因表达,分子连锁图与家蚕分子育种,性别控制与专养雄蚕,发育生理与昆虫激素蚕业应用,营养生理与人工饲料,蚕作为外源基因表达的宿主,蚕作为生物学基础研究的工具,病理学与蚕病防治,热带养蚕,综合利用等10个方面,概括地论述了当今蚕业科学研究前沿的闪光点及其发展趋势。特别强调了蚕生物学基础研究对未来蚕业科技进步的重要性。

AN OVERVIEW OF THE SERICULTURAL SCIENCE FACING THE 21ST CENTURY

The silkworm,originated from China,has served the mankind with silks and medicines for more than 5 000 years. Today,the sericologists and bacologists all of the world over come to the motherland of the silkworm for academic exchange: retrospect and prospect for development of sericultural science. I think that will exhibit historical significance. Sericulture as an agricultural industry was crudely divided into two technological systems, namely the labour intensive system and the knowledge intensive one. The main trend of current sericultural olevelopment is that the labour intensive transforms to knowledge intensive. This transformation in great degree depends upon the progress in basic researches of silkworm biology. All the resrarch frontiers of silkworms are characterized by the new age of biotechnology. Some of the exciting fields may be pointed out as followings; 1 SILK PROTEIN STRUCTURE AND SILK GENE EXPRESSION. Isolation and identification of fibroin mRNS by Dr. Y. Suzuki in 1970 opened the new age for elucidation the structure and function of fibroin gene. Discovery by professor K. Shimura about heavy and light chains of fibroin protein and cloning their genes stood another landmark for study on the silk protein structre and silk gene expression. The structure and organization of silk genes not only help us to understand the feature of amino acid sequence arrangement in fibroin molecule,but also to find the essential role plays the combination of heavy and lighe chains in secretion of silk protein. The spatio-temperal regulation of silk gene expression not only a good model for molecular biological research, but also very important for dissecting molecular basis of silk production. 2 MOLECULAR LINKAGE MAP AND GENETIC ENGINEERING IN THE SILKWORM. By using of recently devel oped RFIL(Restriction Fragment Length Polymorphisms)analysis and PCRCPolymerase Chain Reaction)technique,it is possible to construct a high density molecular linkage map and to localize the quantitative trait loci(QTLs)in the silkworm,in which has been established 28 linkage groups with more than 200 markers by the classic method of experimental genetics. This will open the new ways for cloning economic important genes and chromosomal fragments of interest for basic biological research .application of genetic engineering technique to develope molecular breeding strategies for silkworm race improvement. 3 SEX CONTROL AND REARING SOLELY MALE SILKWORM. It is generally known that the silk productivity of male silkworm is about 17 ?20 per cent higher than that of the usual bisexual brood with same origin. In the past half century, significant advances were obtained in basic and applied researches on sex control in the silkworm. Commercial methods for obtaining solely male hybrid Fl progeny in the silkworm have been established. Especially,construction of industrial breeds yielding exclusively male hybrid progeny by means of sex-linked balanced lethals enables commercial rearing solely male silkworm in a large scale. It is hoped that rearing solely male silkworm probably will be a popular technique for an important breakthrough in silk productivity of the silkworm in the coming 21st century. 4 DEVELOPMENTAL PHYSIOLOGY AND APPLICATION OF INSECT HORMONES IN SERICULTURE. Demonstration of the physiological function of corpora allata.prothoracic glands and suboesophageal ganglion in thd silkworm to ecdysis, metamorphosis and diapause,as well as determination of the chemical structure of silkworm ecdysone,Juvenile hormone,brain hormones,and diapause hormone made great contribution to insect endocrinology. Conversely, the advance in research on endocrino-logical basis of insect development promotes the application of insect hormones and physiologically active substances in sericulture for regulating growth,increasing silk yield,and producing superfine-sized cocoon filament. Recently, progress in research on hormonal mechanism controlling diapause of pharat first-instar larvae of the wild silk worm, AnUteraea yamanwd, leads to introduce the