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6. Silkworm germplasm database

6.1 Management and utilization of database

The computerized information retrieval system for germplasm resource management could efficiently and accurately supply the complete data file of different stocks or target varieties for the breeders. This could be established only when relatively large germplasm resources had been maintained and been well investigated. The earliest Silkworm information retrieve system and silkworm variety database in Chinese output was establish in 1984 in China (Xia J.G., 1984; Wang S.K., 1983). In this system, there are 437 varieties included, which divided into five races: Chinese, Japanese, European, tropical and native breeds, and other breeds (sex-limited, trimolters, mutations). There are 94 items could be searched for, such as: breed No., race, origin, institute name for maintenance, larval number per gram newly hatched silkworm, hatchability, larva-pupa survival rate, cocoon weight, cocoon shell weight, cocoon shell ratio, 5th instar duration, life duration, filament weight, filament length, reelability, filament size, neatness, laid egg number per moth, moltinism, voltinism, body shape, color, marker, cocoon shape and color, egg color and egg shell color, etc.

The main functions of this data retrieve system are:

In 1995, a new silkworm germplasm database was set up by FoxPro 2.5 in the national Sericulture Research Institute. It can retrieve the information of mutation genes, gene strain, gene analysis, gene conservation, all characteristic of 1000 preserved silkworm accessions, and research data processing. It can be revised or increased if there is any new discovery. Unfortunately, there are all in Chinese. And the related information had not been uploading into Internet yet.

Another data source for germplasm resource in China is the book, Record of Silkworm Varieties in China, edited by Sericulture Research Institute of China Agricultural Science Academy, 1987, Agricultural Publication Press, recorded 510 silkworm varieties as mentioned in 4.1. However, it is also in Chinese. As a matter of fact, most of the reference listed in Annex 9 are written in Chinese. This is the major problem for foreign scientists to approach information on sericulture research in China though the tremendous achievement had been made. This situation might be changed in the near future, for more and more scientists on sericulture field came to know English very well. The new problem is lacking of fund to publish these information in English for the government does not encourage in this type of work.

6.2 Samples of germplasm catalogue

The electronic file of silkworm germplasm database is not formally supplied for public use yet. Here is an example for the description of silkworm germplasn strain in the book of Record of Silkworm Varieties in China.

Catalogue: retired variety

Serial number: 18

Variety name: Ou17 (Wu)

Description: Ou17 (Wu), also called Xihao, was handed over to Sericulture Research Institute by Wu County Parent Egg Station in 1953

This variety is a European race, monovoltine, tetra-molter. Egg color: deep gray, egg shell: white, good egg percentage 98.0%, unfertilized egg rate 2.0%, practical hatching rate 95.2. Newly hatched larvae: dark brown, inactive, about 1890 larva per gram newly hatched larvae. Young larvae have phototaxsis and tendency to density. Grown larval body are greenish white with little reddish, plain with few normal marking, body shape is thick and strong. Eating slowly, step on the leaves and inactive, but newly exuviated larvae are active. Mature larvae are transparent with a little reddish, uniform maturing, spin cocoons more on up layer. Cocoon shape: long with shallow narrowed waist, cocoon color: white, wrinkle media. Pupa color yellow, no black wing pupa. Moth eye black, moth body brown-rice color, moth wing no marking, uniform eclosion, female moth emergences first, lot of urine, good in mating ability, fast egg laying, long moth life, laid eggs number per moth 400.

Cocoon weight 1.77g, cocoon shell weight 0.29g, cocoon shell ratio 16.2%, filament length 771m, reelability 53.5%, neatness 90.8, filament size 2.40D, separated fibril of cocoon shell 99.6, degumming rate of shell 29.2%.

Incubation duration 10 days, fifth instar duration 7day 5 hour, larval duration 24day 1 hour, duration from cocooning to eclosion 19 day. Survival rate of larvae and pupae 97.8%, rate of dead worm cocoon 0.74. Adaptability of newly hatched larvae to artificial diet excellent. Isoenzyme of esterase of hemolympe A1A1.

Its hybrids characters: when crossed with Huawu to make hybrid, had been widely distributed in spring rearing season in Jiangsu, Zhejiang and Sichuang provinces in 1936.

Preserved institute: Sericulture Research Institute of China Agricultural Science Academy.

6.3 Promotion of global sharing of silkworm germplasm information

6.3.1 Sharing of germplasm information

It is very important to sharing information in silkworm germplasm resource, however, the most complete and well-studied germplasm is only maintained in a few countries, such as Japan, China. There are frequent information and visiting scholar exchanges between Japan and China, but not too much among other countries.

· The most difficulty part for global sharing of silkworm germplasm information is the language, especially in China. As already noticed, China had made great advance in silkworm germplasm research, unfortunately, most of the paper and books published is in Chinese, and similarly happened in Japan, most of the information available are in Japanese, both of the languages are not the common languages used in the international exchange.

· Difficulty to make connection: There is no existed pamphlet with the list of name silkworm breeders, fax, email etc.

· Lacking of experienced expert on germplasm maintenance: Generally the countries newly developed in sericulture, personnel dealt with the germpalsm maintenance are lacking of special knowledge and experience, which make hard to properly maintain the germpalsm, nerveless to say about exploitation of new resource.

6.3.2 Sharing silkworm genetic resources

Due to the unbalanced development of sericulture in countries, it is not possible to directly share germplasm resources. It is also not fair for unconditional sharing of some important materials while the owner country had spent so much human and material resources to developed it. However, international exchange in silkworm resources had been going all the time by one way or another. For example, China had use the hybrid rice resource to exchange a lot of silkworm resources with Japan during 80s, and bought the balanced-lethal gene strain from Russian 5 years ago. Some of the genetic materials can be exchanged based on a common interest if it is within the permission of the country administration. The problem is

6.3.3 Opinions and proposals

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