Learn about the comparison between inbreeding depression and hybrid vigour. 1. Increase in Homozygosity vs. Development of Heterozygosity: Due to inbreeding each line becomes increasingly homozygous, as a consequence the variation within a line decrease rapidly. After 7-8 generations of selfing, the lines becomes almost uniform (99% homozygosity) which are called inbred lines. Hybridization always favours hetrozysity; the species which [...]
In this article we will discuss about:- 1. Manifestation of Heterosis 2. Genetic Basis of Heterosis 3. Applications. Manifestation of Heterosis: Performance or expression of any character or trait is influenced by many genetic factors — some are positive (stimulating) and others are negative (decreasing). Expressivity of the genes or the degree of manifestation of a character is the result [...]
The following points highlight the four main steps of hybrid seed production. The steps are: 1. Choice and Development of Seed Parent (A-Line) 2. Choice and Development of Restorer or Male Parent (R-Line) 3. Maintenance and Multiplication of Parental Seeds 4. Production and Improvement of F1 Hybrids. Step # 1. Choice and Development of Seed Parent (A-Line): The seed parent [...]