The Brazilian lima bean landraces: conservation and breeding

Abstract

\n Brazil is one of the countries with the greatest genetic diversity in lima beans ( Phaseolus lunatus L.), which has been maintained both on farm and in germplasm banks. The knowledge of this diversity in the country is extremely important for developing a strategy for use and conservation. The objective of this study was characterizing landraces lima bean accessions from different regions in Brazil . Twenty two accessions conserved in the Phaseolus Germplasm Bank from UFPI (Piauí-Brazil) were characterized with 37 agro-morphological descriptors and 15 microsatellite markers. In the agro-morphological characterization, the maximum value of genetic divergence was obtained for the pair UFPI-262 and UFPI-252 (D = 88.74). The UPGMA grouping made it possible to form four groups. Tocher s optimization method enabled the formation of 10 groups. Regarding molecular characterization, 10 loci presented polymorphism, and the number of alleles per locus varied from two to seven. The Polymorphic Information Content (PIC) varied from 0.0767 to 0.7240. The loci GATS91 and PVat001 were highly informative and can be indicate for further studies involving the lima bean. The genetic diversity found (He = 0.316) was higher than that reported in the Yucatán Peninsula, a region indicated as a center of diversity for lima bean. Thus, the agro-morphological and molecular characterization were efficient in quantifying the genetic divergence between the studied accessions. The data found in this research provide a valuable resource for geneticists to subsidize breeding programs involving the lima bean.