Screening Of Euryphagous Germplasm Resources And Optimization Of Artificial Feed For Young Silkworm,Bombyx Mori

The silkworm,Bombyx mori is an important model organism and silk-producing economic insect and is extensively used in in scientific research and agricultural production.In recent years,because of the rapid socio-economic development in China,the production cost of the sericulture industry is advancing to ever higher levels,and the advantages of the traditional sericulture industry are gradually declining.Artificial silkworm breeding is an important pathway to modernize the sericulture industry.Therefore,the research on silkworm feeding habits,cultivation of euryphagous germplasm resources and development of low-cost artificial feed is necessary.In this thesis,the genetic material of silkworm with euryphagous ability was selected from the existing germplasm resources library of silkworm in our laboratory,and the artificial feed for young silkworm was optimized by response surface methodology to achieve low-cost artificial feed preparation for young silkworm.The main results obtained are as follows:1.16 different silkworm strains,including H9,H11,JS,HY,B1,FX,C3,C31,PY,PS,P31,P50,P54,P55,5B and JH,were screened for their euryphagous germplasm resources potential by feeding them with mulberry leaves,romaine lettuce,asparagus lettuce and elm leaves.The euryphagous germplasm resources P54,PS,C3,HY,FX and JH were screened by comparing their intake during 1 hour.2.The effect of the odour of mulberry powder,soybean powder and corn powder on silkworm feeding was determined.Odour tests were conducted through 17 different proportions of artificial feeds for young silkworms Buy-tubes,using a small electric fan to enhance the speed of odour transmission,and it was finally determined that the strongest influence on the feeding of P54 was achieved when the proportion of mulberry leaf powder reached 40%,the proportion of soybean powder reached 25% and the proportion of corn powder reached 25%.The genetic material of P54,PS and C3 was screened for artificial feeding,and three strains of silkworm with high acceptance of artificial feeding were selected from H9,H11,JS,HY,B1,FX,C3,C31,PY,PS,P31,P50,P54,P55,5B and JH.The three silkworm strains with high acceptance of artificial feed were selected.The P54,PS and C3 silkworm strains were fed the artificial feed for young silkworms until the end of the third instar and then switched to mulberry leaves until the fifth instar when the cocoons were formed.The whole cocoon weight and cocoon layer weight after cocooning were then measured to determine P54 as the most suitable germplasm resource for silkworm artificial feed rearing.4.A low-cost artificial feed for young silkworms was prepared by optimizing the best formulation to produce artificial feed for young silkworms using the response surface methodology.The artificial feeds with different proportions of mulberry leaf powder 20%-40%,soybean powder 15%-35% and corn powder 15%-35% were prepared based on the single factor method.A response surface optimization scheme was produced by DesignExpert 13,and the optimum ratios for the preparation of artificial feed for silkworm were30% for mulberry leaf powder,25% for soybean powder and 25% for corn powder.The results of the response surface experiments showed that the effect of soybean powder >mulberry leaf powder > corn powder on the intake of the silkworm.