Breeding of sex-limited larval marking silkworm [Bombyx mori] race, N147 x C145

• Published in: Bulletin of the National Institute of Sericultural and Entomological Science (Japan) no. 2
• Main Authors: Mano, Y. (National Inst. of Sericultural and Entomological Science, Tsukuba, Ibaraki (Japan)), Ohyanagi, M, Nagayasu, K, Murakami, A
• Format: Journal Article
• Language: Japanese
• Published: 01.03.1991
• Subjects: AMELIORATION DES ANIMAUX; BOMBYX MORI; DIMORFISMO SEXUAL; DIMORPHISME SEXUEL; HIBRIDO F1; HYBRIDE F1; MEJORAMIENTO ANIMAL
• ISSN: 0915-2652

1) The Japanese parent race, N147, was bred in order to develop a suitable race for hybridization with the chinese parent race, C145 which was authorized in 1979. The hybrid, N147 x C145, was authorized as a suitable silkworm race for the spring rearing season by the Ministry of Agriculture, Forestry and Fisheries in November, 1984. 2) N147 was obtained by cross-breeding from the offspring of a hybrid between N140 and ANS75. In this race the cocoon weight, cocoon shell weight and raw silk percentage are higher than those of N140. The size of cocoon filament is thick. The sexes of this race can be easily distinguished by body markings (marked : female, plain : male) in the fourth and fifth larval in stars. 3) The N147 x C145 larvae have a pale blue skin with normal body markings in the female and plain body markings in the male. The duration of the larval period is almost the same as that of N134 x C135. The larvae are healthy. The color of the cocoon is white, the shape is oval though sometimes slightly constricted and bale like shape with ordinary wrinkle. The weight of the cocoon shell and the raw silk percentage of the cocoon shell are high. The cocoon filament is long and the neatness is good. The degumming loss is low and the size of the cocoon filament is about 3.0 denier