Mahdi Tajalifar
Student PhD genetics and plant breeding, Qazvin, Iran
Publications
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Research Article
Important heterosis on hybridization
Author(s): Mahdi Tajalifar
An understanding of heterosis in genetic terms had to await the rediscovery of Mendel’s laws in 1900. It was immediately apparent that hybrids are more heterozygous than their parents. A decrease in the number of heterozygote’s implied an increase in the number of homozygote’s. This immediately gave rise to two explanations. The `dominance` hypothesis notes that most recessive mutants are deleterious, so inbred lines are weakened by having an increase in the number of homozygous recessive genes. Hybrids, in contrast, are stronger because the recessives from each parent are usually concealed by dominants from the other. The over dominance hypothesis assumes that there are some loci at which the heterozygote is superior to either homozygote. Although the two ideas are not mutually exclusive, the dominance hypothesis is now generally favored. This explanation also appli.. Read More»