Crop Biotech Update

Linkage Study on Resistance Genes for Common Bean Pathogens

December 17, 2010

Common bean (Phaseolus vulgaris L.) is the most important grain legume in the world in terms of its consumption value. However, production of common bean is limited by diseases anthractose (ANT) and angular leaf spot (ALS). In favorable conditions for the pathogens, ANT can reach yield losses up to 100%, while ALS can reach up to 70%. Based on previous studies, Co-14 gene gives resistance to ANT, while Phg-1 codes for resistance to ALS. These are both found in Andean common bean variety AND 277.

M.C. Goncalves-Vidigal of the State University of Maringá, Brazil, together with other researchers, conducted a study to evaluate the genetic linkage of the two resistance genes using the second offspring of AND 277 and susceptible varieties Ruda and Oura Negro.

Analysis showed that a single dominant gene confers resistance to three races of ANT, and one race of ALS. The two genes were also found to be tightly linked on a particular linkage group. Two effective markers were identified-CV542017 and TGA1.1. The use of such markers could be used to shorten the time and decrease the cost in studying the two resistance genes.

Read the original research article at