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ARS Home » Southeast Area » Mayaguez, Puerto Rico » Tropical Crops and Germplasm Research » Research » Publications at this Location » Publication #341722
Title: Evaluation of common bean (Phaseolus vulgaris) response to charcoal rot

Author
item ESTEVEZ DE JENSEN, CONSUELO - University Of Puerto Rico
item COLLEY, J. - University Of Puerto Rico
item Porch, Timothy - Tim
item BEAVER, JAMES - University Of Puerto Rico
item FUENTES, J. - Agricultural Experiment Station, Puerto Rico

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary: Charcoal rot in common beans is an endemic disease in the prevailing hot and dry conditions in southern Puerto Rico. This study evaluated the 120 bean genotypes that compose the BASE 120 panel under screenhouse conditions. After the panel was artificially inoculated with a colonized rice inoculum collected in common bean tissue grown in Juana Diaz, PR, disease severity (DS) was assessed using the CIAT scale 1 – 9, 1 = no visible disease symptoms and 9 = approximately 50% or more of the hypocotyl and stem tissues were covered with lesions fifteen days after the inoculation. The experiment was repeated twice, and the evaluations were conducted two and three weeks after inoculation. The stem tissue was then isolated on media to assess pathogen colonization. There were contrasting reactions between the different genotypes of the BASE 120 panel. In the first and second experiments, the genotypes that exhibited intermediate reactions (DS <5) to Mph-JD2 were: BAT 477, MER 2212-28, PR 1147-3, TARS-LFR1 and TARS-MST1. Based on disease severity and on the colonization of the pathogen in the stem tissue, no resistant genotypes were identified for the isolate Mph-JD2 used in the study. Charcoal rot in common beans is an endemic disease in the prevailing hot and dry conditions in southern Puerto Rico. This study evaluated the 120 bean genotypes that compose the BASE 120 panel under screenhouse conditions. After the panel was artificially inoculated with a colonized rice inoculum collected in common bean tissue grown in Juana Diaz, PR, disease severity (DS) was assessed using the CIAT scale 1 – 9, 1 = no visible disease symptoms and 9 = approximately 50% or more of the hypocotyl and stem tissues were covered with lesions fifteen days after the inoculation. The experiment was repeated twice, and the evaluations were conducted two and three weeks after inoculation. The stem tissue was then isolated on media to assess pathogen colonization. There were contrasting reactions between the different genotypes of the BASE 120 panel. In the first and second experiments, the genotypes that exhibited intermediate reactions (DS <5) to Mph-JD2 were: BAT 477, MER 2212-28, PR 1147-3, TARS-LFR1 and TARS-MST1. Based on disease severity and on the colonization of the pathogen in the stem tissue, no resistant genotypes were identified for the isolate Mph-JD2 used in the study.

Technical Abstract: Charcoal rot in common beans (Phaseolus vulgaris L.), caused by Macrophomina phaseolina (Tassi) Gold. (Mph), is an endemic disease in the prevailing hot and dry conditions in southern Puerto Rico. This study evaluated the 120 bean genotypes that compose the BASE 120 panel under screenhouse conditions, grown in a PROMIX substrate. After the panel was artificially inoculated with a colonized rice inoculum using the virulent Mph-JD2 isolate collected in common bean tissue grown in Juana Diaz, PR, disease severity (DS) was assessed using the CIAT scale 1 – 9, 1 = no visible disease symptoms and 9 = approximately 50% or more of the hypocotyl and stem tissues were covered with lesions and with pycnidia fifteen days after the inoculation. The experiment was repeated twice, and the evaluations were conducted two and three weeks after inoculation. The stem tissue was then isolated on potato dextrose agar media to assess pathogen colonization. There were contrasting reactions between the different genotypes of the BASE 120 panel. In the first and second experiments, the genotypes that exhibited intermediate reactions (DS <5) to Mph-JD2 were: BAT 477, MER 2212-28, PR 1147-3, TARS-LFR1 and TARS-MST1. Based on disease severity and on the colonization of the pathogen in the stem tissue, no resistant genotypes were identified for the isolate Mph-JD2 used in the study.