La productividad del frijol en la región tropical del sureste de México está limitada principalmente por factores bióticos, entre los que destacan las enfermedades, y factores abióticos como sequía y suelos ácidos. Este trabajo se hizo para identificar genotipos de frijol con adaptación en la región, resistencia a enfermedades y tolerancia a suelos ácidos. Durante el ciclo primavera-verano 1999 y otoñoinvierno 1999-2000, se establecieron seis experimentos conformados por 16 genotipos entre los que se incluyeron a las variedades testigo Jamapa y Negro INIFAP, en un diseño de bloques al azar con tres repeticiones. Las características cuantificadas fueron: rendimiento de grano y reacción a enfermedades. Con la información obtenida en dos tratamientos de cal en un suelo ácido en Isla, Ver., se calculó el índice de susceptibilidad a suelos ácidos, la media geométrica y el índice de eficiencia relativa del rendimiento. Las líneas Icta Ju 97-1 y DOR-678 obtuvieron el mayor rendimiento a través de los ambientes de prueba. Algunas líneas mostraron resistencia a roya, mosaico dorado y mancha angular, pero no se encontró resistencia a la antracnosis. Las líneas de mejor respuesta en suelos ácidos fueron DOR-678, Icta Ju 93- 1 e Icta Ju 97-1. Las líneas DOR-667, Icta Ju 91-37 e Icta Ju 97-1 dieron los mayores índices de eficiencia relativa del rendimiento. Icta Ju 97-1 mostró amplia adaptación, resistencia a roya y mosaico dorado, y tolerancia a antracnosis, mancha angular y a suelos ácidos.

Charcoal rot (Macrophomina phaseolina) is a major disease of beans (Phaseolus vulgaris L.) in Mexico. The use of germplasm combining high-yield stability with resistance to drought and charcoal rot could reduce damage from this disease. In this study, we compared the Eberhart and Russell method and the Additive Main Effect and Multiplicative Interaction (AMMI) model plus biplot analysis for measuring grain yield (GY) and charcoal rot resistance (CHRR) stabilities in 98 F 8 : 10 recombinant inbred lines (RILs) derived from a cross between bean adapted to the tropics (BAT) 477 (resistant) · Pinto UI-114 (susceptible). Experiments were conducted from 2007 to 2009 in Isla, Cotaxtla, Rı´o Bravo and Dı´az Ordaz, Me´xico, under irrigated or terminal drought conditions. anova anova detected significant differences (P £ 0.05) in GY and CHRR among environments, genotypes and genotype · environment interactions (GEI). Most RILs showed good responses to unfavourable environments based on GY (48) and CHRR (40). AMMI anova anova s for both traits showed that all sources of variation in the model accounted for approximately 49% of the total squared sum. For the first principal component (PC1), we found 13 RILs that were stable for GY, and for the second (PC2), we found 9 that were stable for GI. For CHRR, we detected 14 stable RILs (PC1) and eight (PC2). Biplot analysis showed the largest vectors for Dı´az Ordaz (irrigated and drought, 2008), where the highest and most variable GYs were detected. The shortest vectors were found in Isla (drought, 2007) and Rı´o Bravo (irrigated and drought, 2008), where the lowest and least variable GY were found. We found differential responses of RILs to locations, years and soil humidity conditions as well as significant GEI based on GY and CHRR. The two methods were complementary, and both gave us information to select stable, high-yield germplasm associated with resistance to charcoal rot disease.