Selection Method And Breeding Of Silkworm (Bombyx Mori L.) For Feeding Ability On Pellet Artificial Diet

It is a milestone of technical innovation in sericulture history to rear silkworm (Bombyx mori L.) with artificial diet. Rearing silkworm with artificial diet has incomparable superiority over mulberry leaf rearing. It would be also the major developing trend of the silkworm industry in the 21st century. At present, the low cost artificial diet recipes and processing have been developed successfully in China. But the breeding of silkworm on artificial diet rearing is relative behind, and it is one of the main limiting factors for the application of silkworm with artificial diet in our country. Therefore, in this research, the breeding stocks were systematically used to study the selection indexes and breeding methods how to improve the feeding ability on pellet artificial diet. The major achievements obtained in the experiments are as followings:1 In order to understand the differences of feeding ability among different silkworm varieties on pellet artificial diet, 36 silkworm varieties were tested. The result showed that great difference existed between Chinese strain and Japanese strain, the feeding ability of Chinese strains was poorer than that of Japanese strains. So the most important thing is to improve the feeding ability of Chinese strains.2 Four breeding indexes of 5 generations of variety Qiufeng were compared. The results showed that the newly molted of 3rd larva was the best, the rate of survival of 168h was the second, and the rate of setae dispersion of24h was the poorest. With the prolonging selection time and the increasing intensity, the selection effect is increased. Nevertheless, after several generations, there is little difference among the results of 4 selection methods.3 Variety Luqi and Guangshi, they are of high and lower ability of feeding on pellet artificial diet respectively as experiment material. The results showed that the systematical selection could improve the feeding ability, but the effect was small. Hybrid selection could improve the feeding ability on pellet artificial diet as compared with that of high parent. The effect of backcross breeding was also not exiting. The results are likely to be related with breeding materials.4 Resistance to Fluoride and NPV of 24 varieties were tested. The results showed that there were significant difference among different varieties, and were not related with feeding ability. There is no breeding stocks both with high resistance to Fluoride and NPV. However, such basic breeding material have been achieved in our breeding programs.5 The results of general combining ability analysis of the rate of 24h setae dispersion and newly molted of 96h, the relative weight of the 1st day in the 5th larva showed that the GCA of varieties Guangshi and R9506 were relatively high and they were good breeding materials. Seven crosses were determined and selected for their high special combining ability.6 From the seven selected cross combinations, two of them were defined of high feeding ability on pellet artificial diet.