家蚕春用品种莲·花、天·都的育成及其一代杂交种的选配

BKEEDING OF SPRING USE SILKWORM VARIETIES,LIAN·HUA AND TIAN·DOU AND THE PKEPARATION OF THEIR F1 HYBKID

采用杂交、定向培育、系统选择等方法，历经７年育成了多丝量、丝质优良的中系莲（中３）、花（中８）及日系天（日３）、都（日８），组配成四元杂交种莲·花×天·都（中３·８×日３·８）。经多次鉴定、中试表明：该杂交组合强健好养，茧层率２５％，茧丝长１３６６ｍ，解舒丝长１１２０ｍ，鲜毛茧出丝率２０．８１％，净度９６分，茧丝纤度偏差０．５６３ｄｔｅｘ，繁育系数较高。适合我国华东蚕区词养。

For the purpose of breeding a new spring-use highsilk-yielding silkworm varietyused in East of China,by using the methods of hybridization,fresh cocoon reeling,di-rective breeding and line selection,through 7 years'selection and breeding,we havebred two varieties of Chinese strain“Lian (C3)”and“Hua(C8 )”and two varieties ofJapanese Strain“Tian(J3)”and“Dou(J8)”.These varieties are vigorous and have highsilk yield and good silk quality. By using them as parental materials,we obtained afour-element hvbrid“Lian· Hua ×Tian·Dou(C3·8×J3·8)”.This hvbrid has beenidentified in laboratory and reared in countryside many times,The results showed thatsilkworms of this new variety were strong and healthy,its cocoon shell rate reached25%,filament length 1366m,non-breaking filament length 1120m,raw silk ratio offresh cocoon 20.81%,neatness 96 marks,size deviation 0.563dtex and reproductive co-efficient was high.