Identification of Discolobium species indigenous to the Brazilian Pantanal ecosystem by microsatellite (SSRs) markers.

The genus Discolobium comprises forage legumes indigenous to the Brazilian Pantanal. Over 80% of the Pantanal areas flood during the wet season, and stem and root nodules showing high biological N2 fixation rates result in high protein content in Discolobium plants, representing a major component of the animals’ diet in this area. In nature it is possible to recognize Discolobium species based on some phenotypic properties, as the size, shape and viscosity of the leaflets and fruit morphology. However, when cropped under controlled environmental conditions such characteristics do not express, making species discrimination difficult. In this study, the DNA of four Discolobium species – D. pulchellum, D. psoraleaefolium, D. leptophyllum and Discolobium sp. (non-identified species) – were amplified by PCR with eight microsatellites primers (SSRs, Simple Sequence Repeats), previously identified as effective for discriminating soybean genotypes. One of those primers, Satt 251, detected polymorphism between the Discolobium species, allowing their correct identification under any environmental condition. The use of molecular markers in studies with ecological and economical importance, but poorly studied tropical legume species, such as Discolobium spp., may considerably improve their usage and preservation.