Revista Facultad Nacional de Agronomía, Medellín
Print version ISSN 0304-2847
CUELLAR QUINTERO, Alejandra; ALVAREZ CABRERA, Elizabeth and CASTANO ZAPATA, Jairo. EVALUATION OF RESISTANCE OF PLANTAIN AND BANANA GENOTYPES TO BLACK SIGATOKA (MYSCOSPHAERELLA FIJIENSIS MORELET.). Rev.Fac.Nal.Agr.Medellín [online]. 2011, vol.64, n.1, pp. 5853-5865. ISSN 0304-2847.
A study was conducted to evaluate plantain and banana genotypes with Mycosphaerella fijiensis Morelet isolates of different virulence and geographic origin. The pathogenicity test and morphological characterization of the M. fijiensis populations were performed with a group of fifty monosporic isolates representative of the geographic growing areas in Colombia. For the pathogenicity and resistance assays an aqueous spore suspension of 5.000 conidias mL-1 was used to inoculate seedlings of plantain and banana genotypes, disease response of genotypes was rated by measuring the variables incubation period (IP), time of evolution of symptoms (TES), area under disease progress curve (AUDPC) and rate of disease development (r).The inoculation of fifty isolates on Dominico Harton cultivar allowed to establish five levels of virulence (very high, high, medium, low and very low), which were not related to their geographic origin nor to genotype of the isolates. Isolates with different virulence level were present in the same zone and in the same genotype. The resistance assay showed that plantain and banana genotypes can present a differential behavior to the M. fijiensis isolates. The disease severity measured in the genotypes allowed to classify the in three disease reactions levels, resistance, intermediate and susceptible genotypes The plantain genotypes Topocho, Maqueno, FHIA 20 and FHIA 21, and the banana genotype Sedita and FHIA 23 were characterized for having a higher level of resistance, that was expressed as a lower disease severity and slower disease progress as compared with the other genotypes.
Keywords : Musaceous; pathogenicity; virulence; resistance.