Genomic Relationships, Diversity, and Domestication of Ananas Taxa

Abstract

Ananas is home to cultivated pineapple (A. comosus var. comosus) and two taxa domesticated for fiber production (var. bracteatus and var. erectifolius). Ananas has undergone numerous taxonomic revisions over the past three centuries because of its leaky reproductive barriers and unclear origins. Early studies on Ananas genetic diversity found clear separation among the current two species and five botanical varieties, but indicated little variation exists within cultivated pineapple. This suggested much of the phenotypic variation in pineapple was due to somatic mutation rather than intense domestication and breeding efforts. The recent completion of the “F153” pineapple reference genome and resequencing of 89 diverse Ananas accessions provided insights into the relationships, diversity, and domestication history of Ananas. Cultivated pineapple has tremendous genetic diversity with extensive admixture and interbreeding. Pineapple was shaped primarily by sexual selection during its domestication, but evidence of asexual selection was also found. These findings challenged the notion of a one-step domestication in clonally propagated species. The wealth of new genomic resources within Ananas will be useful to further study the origins of this group and for establishing advanced pineapple breeding programs.