Isolation Of Silkworm Suitable For Artificial Diet Rearing And Preparation Of Hybridity Groups

It is a technical reformation that rearing silkworm with artificial diet in history. As for its superiority to mulberry it is the direction of silk market in future. Granule artificial diet is a kind of new artificial diet which was studied successfully recently. Compared with the past boiled diet, there are lots of superiorities, such as simple to process and confect, convenient to store and transfer, not easy to be polluted and deteriorated, convenient to rearing, can fully improve the efficiency and be prone to practice. Rearing silkworm with granule artificial diet is not only an advanced technology but also an important approach to achieve silk modernization. However, most silkworm varieties in production have low adaptability to granule artificial diet. Compared with mulberry rearing, there are more distance, for example, disorderliness in growth, more weak and small silkworm, and higher elimination. Therefore, we studied the comprehensive adaptability to granule artificial diet with 28 varieties of silkworm. Varieties with good properties were selected and cross combination with good adoption was selected by combining ability test. The results are as followed.1. The adaptability to granule artificial diet was distinct different among silkworm varieties. Chinese varieties were superior to Japanese, and cross combination was superior to their parents.2. Compared to mulberry rearing with the granule artificial diet rearing, the course of growth prolonged for 24-40h, the weight of 2nd and 3rd instar moulting silkworm was lowered for 10%—34%, and the index of vitality, cocoon weight, cocoon shell weight, cocoon crop from 10000 worms and cocoon shell weight from 10000 worms were lower than that of mulberry rearing.3. The adaptability to granule artificial diet of Japanese ZG, Chun 54, Qiu54, Chun and Qiu and Chinese ZHGB, He ,ZHG and Yue are better.4. Comparing to combining ability of kinds of character index. The general availability value of 54,Chun,ZHG and Yue was the highest, and the special availability value of ZHG ×Chun 54, He × Qiu and Yue× Chun was the highest.5. The adaptability to granule artificial diet of ZHG × Chun 54 was the strongest. Rearing silkworm with granule artificial diet in 1st and 2nd instar, and mulberry in 3rd-5th instar, its cocoon spinning percentage for 4th instar worms was the highest and the percentage of dead worm cocoon was the lowest. The cocoon weight, cocoon shell weight, cocoon yield from 10000 worms and cocoon shell weight from 10000 worms were higher than Jingsong × Haoyue for 7.18%, 6.54%, 9.02% and 8.38% respectively. The percentage of cocoon shell weight has no distinct difference with Jingsong ×Haoyue.6. A new variety Yue×Chun was also selected. Its cocoon weight and cocoon shell were the highest and cocoon weight, cocoon shell weight, cocoon yield from 10000 worms and cocoon shell weight from 10000 worms were higher than the control variety Jingsong×Haoyue with mulberry rearing for 9.0%, 7.59%, 6.01 %and 6.34% respectively.