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ARS Home » Southeast Area » Mayaguez, Puerto Rico » Tropical Crops and Germplasm Research » Research » Publications at this Location » Publication #319799

Title: Response of different common bean lines to Phaeoisariopsis griseola in Puerto Rico

item ESTEVEZ DE JENSEN, C. - University Of Puerto Rico
item Porch, Timothy - Tim
item BEAVER, JAMES - University Of Puerto Rico

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/6/2015
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Angular leaf spot (ALS), caused by Phaeoisariopsis griseola (Sacc.) Ferraris sin. Pseudocercospora griseola (Sacc.) Crous & U. Braun., is an important disease in common bean Phaseolus vulgaris L. in the Caribbean and Central America. The wide pathogen variability makes it necessary to continuously monitor virulence patterns when breeding common bean for resistance. An isolate from Phaeoisariopsis griseola was inoculated on 63 advanced black and white lines and parental cultivars “Verano” and “Beniquez”. The lines were derived from crosses with ALS 9951-101, BMD RMR 12 and PR0443-151. The standard differential series for determination of the ALS pathotype, consisting of 12 lines were also included in the study. The experiment was arranged in a completely randomized design replicated three times and inoculated twice with isolate ALS-9029 JD2 (105 conidia ml-1) from Juana Diaz. The evaluation was carried out 21 days after inoculation (18 and 25 days after planting) using the CIAT scale where: 1 = no visible disease symptoms and 9 = 25% of the leaf area covered with sporulating lesions. Based on the reaction of the ALS differentials, the ALS-9029 JD2 isolate was classified as pathotype 61:11 and this pathotype was pathogenic to the Andean (Don Timoteo, Amendoin, Bolon Bayo and Montcalm) and Mesoamerican (Pan 72, G02858 and Mexico 54) genotypes. Parental lines Verano and Beniquez were similar in their disease reaction showing susceptibility to the pathogen by producing lesions that covered approximately 5 - 10% of the leaf area. Three lines exhibited a susceptible reaction and 14 lines an intermediate reaction to the pathotype evaluated. Fifteen lines were resistant to isolate ALS-9029 JD2 with no sporulating lesions. Additional isolates of the pathogen from Puerto Rico should be evaluated to provide more information about ALS variability on the island.