Vol. 11, Issue 7 (2022)

Author(s):
Sanjog Chhetri and Srabani Debnath

Abstract:
The Southern corn rust (SCR), caused by the fungus Puccinia polysora, has been one of the major foliar diseases of Maize. In plant disease development, temperature and incubation time is the critical factor. In vitro experiments were conducted to assess the effects of temperature and time of exposure on P. polysora uredospore germination. The development of the germ tube was assessed for 12 hours. The 0.6g of fresh urediniospores were added to 10ml sterilized distilled water and plated in a 0.1 ml aliquot in water – agar (1.5%), placed in BOD, and regulated at temperatures of 5oc, 10oc, 15oc, 20oc, 25oc, 30oc, 35oc and 40oc. Readings were performed after 1, 3, 6, 12, 18 and 24 hours. The studies on the effect of temperature and incubation time on germination of urediniospores revealed that maximum percent spore germination was found at 25oc (25%, 33%, 57.67%, 67.67% and 78% at 2hrs, 3hrs, 6 hrs, 9hrs and 12hrs respectively). The minimum and maximum temperatures where germination percentage were found to be nil at different incubation times are 5oc and 40oc respectively.