Studies on the origin of silkworm, Bonbyxmori, and an evaluation of its genetic differentiation

我们在中国和印度对家蚕的起源和遗传分化进行了调查。1995年，我们访问了中国浙江和印度迈索尔进行初步调查。本课题的主要工作是弄清两国家蚕品种的遗传特性，比较两国各研究所保存的家蚕品种之间的亲缘关系。由于被任何国家认定为重要遗传资源，不允许将其作为活蚕种、幼虫、蛹、蛾等带出国外。目前，在这些国家的任何一个研究机构都很难开展细胞遗传学这样的研究工作。因此，我们的工作只能局限于观察研究所饲养的家蚕驯化品系和收集的野桑蚕品系的遗传性状。1996年，在中国的“丝绸之路”和印度的南部和东部地区进行了沿着更详细的调查。通过对适应热带、温带、干旱区、高湿区等不同环境的各国地方蚕品种的观察，证实了这些蚕品种间遗传和生理特性的差异。除此之外，我还收集了大量的茧样，并将它们带到日本，因为它们不是活体，所以我可以利用我最近开发的图像处理系统来测量它们的茧形。统计分析主要采用聚类分析，并根据茧形变量的面积应变及其相似性，成功地将它们分成若干组。

Our investigation was carried out in China and India on the origin of silkworm and its genetic differentiation. In 1995 we visited to Zhejiang in China and to Mysore in India for preliminary investigation. Our main works were planned to make clear the some genetic traits of silkworm strains to compare the relationship among these strains preserved at each institute of both countries. It is not permitted to take out abroad the materials as living silkworm eggs, larvae, pupae and moths because it is evaluated as important genetic resources at any countries. At present it is very difficult to do such a research work as cytogenetical one at any institutes of these countries. Then, our works were obliged to be limited to observe the genetic traits of domesticated strains maintained at institute and wild silkworm strains collected there. In 1996 the more detailed investigation was carriered out along the "Silkroad" in China and southern and eastern parts in India. As a result of observation on local silkworm strains at each country adapted to such different environments as the tropical or temperate zone, dried or high humitity area, we could have confirmed on the difference in genetic and physiological properties between these strains. The informations may help to estimate the presence of special genes, their genefrequency, physiological difference in larval development and so on. In addition to that, I have collected many cocoon samples and taken them out to Japan, because it is not a living body, so that I could measure their cocoon shape by use of image processing system which I had developed recentrly. The data were analyzed statistically by cluster analysis mainly, and I have succeeded to separate them into some groups according to area strain and its similariy of cocoon shape variables.