Identification of SSR and RAPD markers linked to a resistance allele for angular leaf spot in the common bean (Phaseolus vulgaris) line ESAL 550

Abstract

The objective of this study was to identify RAPD and SSR markers associated with a resistant allele for angular leaf spot (Phaeoisariopsis griseola) from the line 'ESAL 550', derived from the Andean 'Jalo EEP 558' cultivar, to assist selection of resistant genotypes. The resistant line 'ESAL 550' and the susceptible cultivar 'Carioca MG' were crossed to generate F 1 and F 2 populations. One hundred and twenty F 2:3 families were evaluated. The DNA of the 12 most resistant families was bulked and the same was done with the DNA of the 10 most susceptible, generating two contrasting bulks. One RAPD and one SSR marker was found to be linked in coupling phase to the resistant allele. The SSR marker was amplified by the primer PV-atct001 282C , and its distance from the resistant allele was 7.6 cM. This is the most useful marker for indirect selection of resistant plants in segregating populations. The RAPD marker was amplified by the primer OPP07 857C linked in coupling phase to the resistant allele, and distant 24.4 cM. Therefore, this RAPD marker is not so useful in assisting selection because it is too far from the resistant allele.

Seleção assistida com uso de marcador molecular para resistência a potyvírus em pimentão

“…Muitos marcadores moleculares associados a genes de resistência a viroses têm sido desenvolvidos, porém sua utilização não é frequente, pois, na maioria das vezes, não estão ligados muito próximos aos genes de interesse (Silva et al, 2003;Santos, 2004). Este não é o caso do alelo Pvr4 (Caranta et al, 1999).…”

Effect of natural selection on common bean (Phaseolus vulgaris) microsatellite alleles

“…As no band was observed in the Carioca MG parent or in the segregant families, it might be a dominant marker (Liu et al, 2001;Silva et al, 2003). Furthermore in the majority of the cases the absence of the marker in the F 24 generation means that the presence of the DNA fragment amplified in the ESAL 686 line is associated with less adaptation than its absence in the Carioca MG parent.…”

Selection of Carioca type common bean lines with anthracnose and angular leaf spot-resistance

“…For this purpose, approximately 2g of young leaves were collected from every ten plants per line for DNA extraction, using a procedure modified by Rogers and Bendich (1988). The SCAR marker analyses were performed in a similar procedure to the one used by Silva et al (2003).…”