SSR MARKERS LINKED TO META-QTLS FOR WHITE MOLD RESISTANCE IN COMMON BEAN

INTRODUCTION Several studies have been conducted to identify QTLs for resistance to white mold in Phaseolus vulgaris. SSR markers have the advantages of being codominant and distributed throughout the genome, being considered one of the best genetic markers for mapping purposes and efficient to identify QTLs (Soule et al. 2011). In the meta-QTL analysis, SSR markers can be used to identify stable genomic regions in populations, and therefore, be more promising in marker-assisted selection programs. The objective of the study was to identify SSR markers nearby and/or within the meta-QTL intervals described by Vasconcellos et al. (2017), in order to evaluate the possibility of using these markers for resistance to Sclerotinia sclerotiorum in common bean. MATERIAL AND METHODS Two progenies derived of a recurrent selection program for resistance to white mold were used one from Cycle X (CX 53/3) and one from Cycle XII (CX 11/185) and two checks: Cornell 605 (resistant) and Beryl (susceptible). The Cornell 605 line is derived from the cross between the Redkote (Cornell University, NY, USA) and the Cornell line 6603 (Griffiths et al., 2012). The Beryl line is highly susceptible to white mold and is used as a negative control in several studies involving this pathosystem (Griffiths et al. 2012; Lehner et al., 2015). The plants had its DNA extracted and were evaluated for the reaction to S. sclerotiorum by the Straw test method, described by (Petzoldt and Dickson, 1996) and modified by (Terán et al., 2006). SSR primers located within or very close to the meta-QTLs (Vasconcellos et al. 2017) and, that had polymorphism between check lines were selected thus, marking it possible to identify more stable QTLs of resistance and/or susceptibility (Table 1).