triploidt

Triploidt, often spelled triploid, refers to an organism or cell with three complete sets of chromosomes (3n). In most animals and plants, somatic cells are diploid (2n); triploids carry three homologous chromosome sets, typically arising through hybridization between species or genome duplication events that yield an odd number of chromosome sets.

Occurrence and formation: In plants, triploidy is common and often intentional in breeding. It can arise when a diploid gamete fuses with a haploid gamete, or from hybridization between two species followed by genome duplication (allopolyploidy) that results in a triploid or near-triploid genome. Many seedless fruits are triploid, notably watermelons, and some cultivars of banana and grape.

Reproduction and fertility: The presence of three homologous chromosome sets disrupts normal pairing during meiosis, so most triploids are sterile or produce mostly unbalanced gametes. They are typically propagated vegetatively; in some cases, seeds can form via rare unreduced gametes or apomixis.

Genetic and agricultural significance: Triploidy is exploited to produce seedless fruits and to create sterile hybrids that reduce crossbreeding with wild relatives. In research and breeding, triploids help study chromosome behavior and genome evolution. Detection methods include flow cytometry to estimate DNA content, cytogenetics to observe chromosome number, and sequencing.

Terminology: Triploidt is a rarely used variant; the standard term is triploid, and the adjective is triploid or triploidy.