botanyone
The gene pool of Citrus and related genera of Aurantioideae is essentially diploid but tetraploid plants are frequently encountered in seedlings of diploid apomictic genotypes. Aleza et al. demonstrate that tetraploidization by chromosome doubling of nucellar cells is a frequent event in apomictic citrus, and is affected by genotypic and environmental factors, with colder conditions in marginal climatic areas appearing to enhance tetraploidization rates. Factors limiting the evolutionary role of polyploidization in citrus are probably related to problems of establishment and persistence of new polyploids.
