Morphological and pathogenic variability in Alternaria alternata causing leaf spot of Aloe vera (Aloe barbadensis Mill.)

摘要

Among five different isolates collected 2006-07, isolates from Ramjipura (AL_2) and Boraj (AL_3) exhibited excellent sporulation with a mean colony diameter 48.90 mm and 46.50 mm, respectively. Ramgarh (AL_5) isolate showed poor sporulation with 43.50mm colony diameter. Isolate collected from Renwal (AL_1) showed maximum length of spore (48.80 um) followed by Boraj (ALJ and Ramjipura (AL_2). The maximum width of spores (17.95 um) was observed in Renwal (AL_1 followed by Ramjipura (AL_2) and Boraj (AL_3) isolates. The pathogen also showed pathogenic variability, mean infection percentage was highest (70.0%) in Ramjipura (AL_2) followed by Boraj (AL_3), and Renwal (AL_1) isolates.