Amphidiploids/Synthetic Crop Species
Polyploids are the organisms possessing more than two sets of basic genome (3x, 4x, 5x, 6x, etc.) and occur abundantly in the plant kingdom. Approximately 30–50% species among angiosperms and of these, more than 75% members of the family Gramineae, are polyploids (Stebbins 1950). Polyploidy in animals is of rare occurrence as wide hybridization is uncommon in this group and thus there is no need of duplication of chromosomes to restore fertility as is prevalent in plant kingdom, and also because the change in chromosome number in animals highly disturbs the sex chromosome balance and in this way interferes with sex differentiation, tissue/organ differentation, and general development. Polyploid plant species, the product of failure of mitosis, resulting in doubling of chromosomes in somatic cells or fertilization of unreduced gametes either directly or followed by interspecific hybridization, generally possess a wider range of ecological adaptability than their diploid counterparts.
KeywordsInterspecific Hybrid Hexaploid Wheat Diploid Species Unreduced Gamete Homoeologous Chromosome
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