Genetic Diversity of Pineapple

Abstract

All pineapple germplasm are regrouped into one genus Ananas Miller with two species: the self-incompatible diploid A. comosus (L.) Merr. and the self-fertile tetraploid A. macrodontes Morren. There are five botanical varieties, comosus, microstachys, parguazensis, erectifolius, and bracteatus, found in A. comosus. Pineapple germplasm characterization and genetics studies indicate that A. comosus is widely considered to be heterozygous, and consequently there is much diversity in plant and fruit characteristics between cultivars. Pineapple cultivars are normally diploids but exhibit a wide variety of diverse and useful traits. The genetic diversity in pineapple was driven by a system of outcrossing and a high frequency of somaclonal variation. The five cultivars for commercial production include Perola, Queen, Abacaxi, Red Spanish, and Cayenne. The important traits in cultivated pineapples are usually related to yield, fruit size and quality, or production efficiency. The genetic divergence between A. macrodontes and A. comosus and the genetic differentiation among the botanical varieties of A. comosus were explored by using biochemical and molecular marker techniques. DNA-based molecular markers, such as RAPD, RFLP, AFLP, SSR, and SNP, have been widely utilized in the detection and the evaluation of genetic diversity in pineapple. The results from SSR and SNP analysis suggested that there was abundant genetic variation within existing pineapple germplasm for commercial cultivars. The increasing use of SNPs as the markers will facilitate accurate identification and further studies of the genetic diversity in pineapple.