Abstract

ANAYA-LOPEZ, José Luis et al. Challenges and opportunities in assisted selection of resistant bean to BCMV and BCMNV in Mexico: II. Opportunities for assisted selection. Rev. Mex. Cienc. Agríc [online]. 2015, vol.6, n.3, pp.495-507. ISSN 2007-0934.

Considering recent information, the objective was to review the knowledge on the mechanisms of resistance to BCMV and BCMNV, describe the use of DNA markers for assisted selection of bean varieties resistant to both viruses and point out the need to design and generate more efficient molecular markers. The most economical and efficient way to prevent damage caused by both viruses is to plant resistant varieties obtained by gene pyramiding, in which a broad-spectrum resistance against pathogroups of BCMV and BCMNV are combined. For over 30 years the role of the dominant I gene are known, which confers resistance to non-necrotic strains, and bc recessive genes, including c-u, bc-1, bc-1², bc-2, bc-2², and bc-3, which confer resistance to some specific pathogroups of BCMV and BCMNV. However, except for bc-3 gene which corresponds to PveIF4E gene, their identity is unknown. Regarding to bc3 gene has been identified at least three alleles, bc3¹, bc3² and bc3³, of which only the bc3² allele in combination with I gene, confers immunity to strain of NL3 from BCMNV. To date, the two most used molecular markers to monitor BCMV resistance: ROC11 and SW13 have not been consistent through diverse germplasm. It is therefore necessary to develop new or additional resistance markers based on knowledge of the biological function of the corresponding genes.

Keywords : BCMV; BCMNV; molecular markers; SAMM; bc3; eIF4E.