Desmanthus is a legume native to northern, Central and South America and the Caribbean that provides high quality feed for cattle and sheep in tropical perennial pastures. A core collection was developed from the former Australian Tropical Forages Genetic Resources Centre (CSIRO, Brisbane Australia) from a diversity analysis of 284 accessions, representing 11 species, using RAPD markers.

There was considerable polymorphism in D. virgatus, D. leptophyllus and D. pernambucanus but this was not always uniform across the geographical range of these species. There was little polymorphism in D. pubescens. Few accessions of D. acuminatus, D. paspalaceus and D. tatuhyensis were represented in the collection, but these species, which have an almost sympatric distribution in Paraguay / Uruguay / Argentina / Brazil, showed affinities to D. leptophyllus and to each other.

Desmanthus pernambucanus was the only species with representatives from regions other than the Americas, suggesting that at least this species has the capacity to colonize new regions. The core collection was based on manual RAPD marker assessment, but includes geographical and morphological information contributed by the creators. Whilst modern techniques for creating subsets based on molecular biology are now available, the subset is still the best available at this time.

Two lines selected for pre-release by Harry Bishop – AC 10 (APG 48486) and AC 11 (APG 48487) were added to the core to form a group of 77 accessions. A further accession, APG 48329, was added retrospectively to provide representation of D. fruticosus. The aim of this core is to enhance the efficiency of germplasm selection for evaluation and to identify regions of the world that hold most promise for providing new germplasm.

Reference: Pengelly, B.C. and Liu, C.J. (2001) Genetic relationships and variation in the tropical mimosoid legume Desmanthus assessed by random amplified polymorphic DNA, Genetic Resources and Crop Evolution 48: 91–99, 2001