Resumo

SANCHEZ-GARCIA, Bertha María et al. Colletotrichum lindemuthianum pathotypes in Oaxaca and San Luis Potosi, Mexico, and resistance in common bean. Agric. Téc. Méx [online]. 2009, vol.35, n.1, pp.49-60. ISSN 0568-2517.

Anthracnose, a disease of common bean caused by Colletotrichum lindemuthianum (Sacc. et Magn.) Scrib., is worldwide distributed. C. lindemuthianum displays a significant pathogenic diversity which is important to know for the development of resistant cultivars. In Mexico 54 pathotypes are known; however, some of the important bean producing states have not been thoroughly sampled. In this research 23 strains of C. lindemuthianum from Oaxaca (15) and San Luis Potosí (8) were pathotypically characterized using twelve differential cultivars, during 2005-2007. In addition, 24 bean landraces from San Luis Potosí, 115 from Guanajuato, as well as 55 bread cultivars, were challenged with the pathotypes 64 and 320 (which occur in both states) that infect differential cultivars from Mesoamerican origin, in the search for sources of resistance. Twelve and five pathotypes were identified in Oaxaca and San Luis Potosí, respectively, with seven of them (69, 100, 260, 324, 325, 356 and 485) reported for the first time in Mexico. Results indicate higher pathogenic diversity than previously reported and that newly form or undetected combinations of avirulence genes are pre sent in Mexico. From the 24 bean landraces from San Luis Potosí, 115 from Guanajuato, and the 55 bred cultivars challenged, 12, 76 and 28, respectively, were resistant to both races; these genotypes could be used as sources of resistance against C. lindemuthianum.

Palavras-chave : Glomerella lindemuthiana(Sacc. et Magn.) Scrib.; frequency and distribution of pathotypes; sources of resistance.

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