Vol. 10, Issue 5 (2021)

Author(s):
P Ramanjineyulu, K Viswanath, N Kiran Kumar and P Nagamani

Abstract:
Fusarium spp, Rhizoctonia bataticola and Sclerotium rolfsii were isolated from the pod rot affected samples. Cultural and morphological traits were recorded for the ten isolates of Fusarium spp. The colony morphology of the isolates varied with zonation, aerial mycelia with zonation and appressed mycelia with irregular zonation. The colour of the mycelia varied with the isolates, white thread like, yellow, white cottony and creamy cottony. While the substrate colour was found to be dark brown greyish, yellowish, whit, light brown and light pink. With regard to conidial production, all the isolates produced both macroconidia and microconidia. The growth rate of the pathogen varied from 13 days to 17 days. With regard to the chlamydospore formation and position, chlamydospores were found to be abundant with terminal and intercalary, scanty and intercalary, scanty and terminal. The ten isolates of R. bataticola showed difference in the colony morphology as regular, regular zonation, concentric zonation, regular fluffy and irregular appressed. The mycelia colour of the isolates varied from white to greyish white and the aerial mycelium was present, while it was absent in some isolates. The growth rate of the pathogen was varied from 102 h to 216 h. The ten isolates of Sclerotium rolfsii showed difference in the colony morphology as thread like with upright growth habit, thread like mycelia strands and woven, white thread like aggregated mycelium and slight upright, thread like mycelia strands, slightly upright mycelium with slow growth habit, aggregated cottony mycelium and white thread like mycelium. The time taken for full spreading of the plate varied from 120 to 216 h. While the pattern of sclerotial distribution varied among the isolates as aerial, scattered, peripheral and aerial and scattered.