Genome size and chromosome number of Dipteryx alata (Leguminosae): a model candidate for comparative genomics in Papilionoideae

Abstract

Genome size and chromosome number are basic biological characteristics that reveal a wide diversity in plants. The most widely used method to estimate genome size is flow cytometry; however, genomic estimation is only available for a small number of species. In this context, the DNA content of plants distributed in areas rich in species and endemism, such as the Brazilian Cerrado, remains little known. We examined genome size and number of chromosomes for the legume Dipteryx alata (popularly known as “baru”), a tree used for food, medicine, forage, recovery of degraded areas, landscaping and wood extraction. Dipteryx alata showed 2n = 16, with small chromosomes. Genome size or C-value was estimated at 1C = 0.825 pg which corresponds to 807.2 Megabases. This species is an important genetic resource, though it has a very small genome. In addition, this species is phylogenetically positioned in the first diverging lineage of Papilionoideae. Therefore, D. alata is a strong candidate among the tree species of the Brazilian Cerrado to be a model species in studies of comparative genomics of Leguminosae.