Skin pattern sex-limited trans-breeding method for silkworm variety with common skin pattern

Abstract

The invention discloses a skin pattern sex-limited trans-breeding method for a silkworm variety with a common skin pattern. The skin pattern sex-limited trans-breeding method comprises the following steps of: carrying out hybridization to obtain F1 by taking a base skin pattern sex-limited variety as a female parent and taking a practical common skin pattern variety as a male parent; back-crossing the F1 and a male individual of the practical common skin pattern variety to obtain BC1, selecting out the common skin pattern individual which is most easily to discriminate by naked eyes at a larval stage from the BC1, selecting an excellent female individual by discriminating pupas, and continuously back-crossing the excellent female individual to BCn; continuously selecting out the individual with a thick common skin pattern from the BCn, and self-crossing and sub-culturing other progeny individuals to Fm-1, self-crossing and carrying out single batch rearing from Fm, selecting an excellent moth area which is in accordance with skin pattern sex-limited characteristics through a pupa discriminating method to perform subculture, and carrying out sex discrimination on every generation by taking the individuals with skin patterns as the female and taking the individuals without skin patterns as the female. According to the method disclosed by the invention, the practicability of a new variety can be improved by continuous back-crossing; the difficulties that the skin pattern depth of a target individual is difficult to discriminate and most of later generations cannot participate in subculture are solved by adopting a method of selecting out the individual with the thickest skin pattern in the later generations; the process is simplified; the operation is simple; the genetic background is wide; and the aim of realizing rapid practical trans-breeding is fulfilled.

Description

technical field [0001] The invention belongs to the field of silkworm breeding, and in particular relates to a marking-limited transgenic method for common spot varieties of silkworms. Background technique [0002] The stripe-limited gene is translocated to the W sex chromosome (this chromosome has a completely decisive effect on females in silkworms, and any individual with a W chromosome is For female), it is a sex-restricting gene that makes it fully linked to the sex-determining gene. Utilizing the stripe-limited gene can transform common silkworm varieties into stripe-limited varieties, that is, all the larvae individuals with stripes are females, and all the larvae individuals without stripes (white silkworm, silkworm, silkworm) are male. It can identify the sex of different individuals with the naked eye according to the presence or absence of larval markings, reduce the traditional process of artificially "identifying pupae" to distinguish male and female at the pup...

AI Technical Summary

Problems solved by technology

[0007] One of the purposes of the present invention is to solve the problem that in the existing method, the proportion of the blood components of the practical variety selected for breeding is low, most of the individuals of the hybrid offspring cannot participate in the offspring, and the differences in the depth of markings between the individuals of the offspring are difficult to distinguish, which affects the quality of all offspring. Various problems that require accurate selection of genotyped target individuals provide a stripe-limited transfer method for silkworm common spot varieties

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