PHYTOPHTHORA FOLIAR BLIGHT MULTI-RACE SCREENING TECHNIQUE IN Capsicum Annuum L

Phytophthora blight is a major disease threat to production and long-term viability of chile pepper (Capsicum annuum L. ), caused by the oomycete Phytophthora capsici. Separate and independent resistant genetic systems for root rot, foliar blight, and stem blight syndromes have evolved for each disease syndrome (Sy et al., 2005). In addition, several races of the pathogen have been identified (xxxx, ssss).  Therefore, a reliable and accurate screening technique to detect resistance to each race for foliar blight would be helpful.  A new technique is described that allows for multiple races to be evaluated on a single plant.  The P. capsici resistant line Criollo de Morelos (CM-334), the susceptible lines Jalapeno Espinalteco (NMCA10399), Camelot; and three New Mexico Recombinant Inbred Lines (NMRILs), were used to evaluate a new technique for Phytophthora blight multi-race screening. Three different P. capsici races were used.  The resistant control CM-334 was always resistant, and the susceptible controls (NMCA10399 and Camelot) were always susceptible against the races tested. The NMRILs displayed race-specific resistance against the different races, as they did with single inoculations. This technique is reliable and accurate in evaluating the foliar blight disease syndrome using different races simultaneously on a given plant.