Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 248

As previously stated, inbreeding or crossing closely related parents results in reduced fitness or vigor of individuals in the progenitor population, a condition called inbreeding depression. Reduction in fitness is usually manifested as a reduction in vigor, fertility, and productivity, and seen as lower biomass per plant, lower fecundity, malformation of organs, and lower germination of seeds. The effect of inbreeding is more severe in the early generations (five to eight) than in later generations. Just like heterosis, inbreeding depression is not uniformly manifested in plants. Plants including onions, sunflower, cucurbits, maize, and rye are rather tolerant of inbreeding with low or no inbreeding depression. On the other hand, crops such as alfalfa and carrot are highly intolerant of inbreeding.