بررسی مقایسه استراتژی های مختلف انتخاب برای رشد ژنتیکی صفات اقتصادی کرم ابریشم

In order to determine the most optimum selection strategy applied to great grand parent lines, from each of 110 and 107 lines which are in commercial egg production, 450 Cocoons (225 males and 225 females) which were product of season rearing of GGP farms, were sampled randomly to establish base population. Then they were individually recorded for Cocoon weight, Cocoon shell weight, cocoon shell percentage, and mated randomly. Selection basis in the difterent groups included: 1- random mating (control group), 2. seleclion based on Cocoon appearance, 3- individual selection based on Cocoon weight, 4- individual selection based on Cocoon shell weight, 5- base selection index (sum of products economic value and corrected phenolype for each trait), 6. conventional selection index (based on individual records for Cocoon weight, cocoon shell weight, Cocoon shell percentage). In each group, top cocoons were selected with similar selection intensily. Genetic and environmental parameters of the populations for the three traits were estimated using REML method based On animal model,and genetic-economic improvements related to each selection strategy were predicted. After predicting animals breeding values in the BLUP way, genetic gains of traits were estimated as subtraction of mean animal breeding values in two successive generations. As a result efficiency of different selection strategies was evaluated in 110 and 107 lines after performing selection programme in two generations. Results obtained from this study imply that in 107 line, the highest mean Cocoon weight was observed in sixth strategy (1.330 g) and the lowest one in fourth and fifth strategies (1.310 g). The maximum mean Cocoon shell weight was obtained in sixt strategy (0.271 g) and the minimum one in second strategy (0.260 g). The highest mean Cocoon shell percentage was observed in sixth strategy (20.64 %) and tiJe lowest one in second strategy (19.75 %). Also in 110 line, for Cocoon weight, the highest mean was indicalcd in third strategy (1.441 g) and the lowest in second one (1.377 g), for Cocoon shell weight, the highest mean in third strategy (0.295 g) and the lowest one in second strategy (0.275 g), finally for Cocoon shell percentage, the highest mean was observed in sixth strategy (20.85 %) and the lowest one in second strategy (20.12 %). All the differences were statistically significant at 5% level.

کلیدواژه ها:

کرم ابریشم ، ژنتیک ، اقتصاد ، آمیزش ، خصوصیات ظاهری ، قشر پیله ، پیله