Genetic diversity in Carioca and Pérola cultivars of common bean based on RAPD markers
Marcus Vanner Carvalho de Oliveira de Menezes, João Bosco dos Santos and Mariney de Menezes
Abstract: Common bean is a self-pollinated species and as such has a low cross-pollination rate (around 0.5%). Besides the low crossing rate, mixtures of cultivars and lines and mutations on large planted areas contribute to the variabili ty within cultivars, which is selectable in common bean breeding. Then, the objective of this study was a preliminary evaluation of variability by means of the genetic similarity based on RAPD (Random Amplified Polimorphic DNA) markers. Ninety-eight common bean lines of Carioca and Pérola cultivars were sampled on farms in Sete Lagoas, State of Minas Gerais. The genetic
similarity based on eighty-one polymorphic RAPD bands were estimated by Nei Li’s method, and grouped by the UPGMA procedure to generate a dendrogram. The lines presented wide genetic variability, mainly those selected from the Carioca cultivar. The Carioca cultivar farmers use is therefore substantially different from the original one. A smaller variability was observed among Pérola cultivar lines, which was approved for sale more recently than “Carioca”.