Investigation On The Protospecies Silk Characters Of New Silkworm Variety "Su Xiu×Chun Feng"

Silk character is a class of important indexes to evaluate the performance of silkworm."Su xiu×Chun feng" the new variety of silkworm,is characterized by fine denier and long filament.Su xiu and Chun feng are the protospecies of "Su xiu× Chun feng",which is the fixed variety of Chinese and Japanese silkworm respectively.To study the specialties on heredity of the silk characters of "Su xiu × Chun feng",taking cocoon filament of Su xiu and Chun feng as the research material,this article tests the cocoon filament length of the two protospecies,analyzes and compares the protospecies silk characters of "Su xiu×Chun feng" accurately and in detail.In addition,by applying the test way of segment test,it compares and analyzes many indexes,like the cocoon filament denier and relative strength when the protospecies are at different cocoon shells.The test result is as below:1.The cocoon filament length range of Su xiuis 949.5-1307.25m and the average value is 1166.400m.The cocoon filament length rangeofChun feng is 946.125-1345.5 mand the average value is 1132.988m.The average cocoon filament length of Su xiu is 33.412m longer than that of Chun feng;2.The cocoon filament denier rangeof Su xiu is 1.9002-2.9104dtex and the average value is2.2198 dtex.The cocoon filament denier range ofChun feng is 2.0382-2.7399 dtex and the average value is 2.4370 dtex.Su xiu's cocoon filament denier is bigger that that of Chun feng while at the hundred circles of 3-8th and 10-12th;3.The relative strengthrange of Su xiuis 1.8291-3.7620CN/dtex and the average value is 3.6615 CN/dtex.The relative strength range ofChun feng is 3.1748-3.6488 CN/dtex and the average value is 3.4637 CN/dtex.There is no big difference between the relative strength of the two at the hundred circles of 1-11th;4.The breaking strength range of Su xiu at every hundred circles is 22.83-36.66%and the average value is 27.32%.The breaking strength range ofChun fengsit every hundred circles is 25.20₃5.02%and the average value is 29.53%.The breaking strength of Chun feng at the hundred circles of 2-1th is higher than that of Su xiu.This research result indicates that the silk characters of both the protospecies of "Su xiu×Chun feng",the new variety of mulberry silkworm,have their own advantages.Besides,at different cocoon filament positions,the silk characters are different,the denier gradually becomes smaller from outer layer to inner layer,while the relative strength at the middle layer is bigger than that at the outer and inner layer.This research can provide a theoretical basis to the future work on breed improvement and genetic breeding of new variety and has certain reference value to the improvement of the economic efficiency of the silk reeling industry.