Influence of Incubation Temperature on Variation in Physiology of Growth and Sporulation of Colletotrichum Gloeosporioides Isolates Infecting Tropical Fruits
M. S. Joshi
Department of Plant pathology, Dr. B. S. Konkan Krishi Vidyapeeth, Dapoli, Dist. Ratnagiri, India
D.M. Sawant
Mahatma Phule Krishi Vidyapeeth, Rahuri, India
J.S. Dhekale
Department of Agril. economics, Dr. B. S. Konkan Krishi Vidyapeeth, Dapoli, Dist. Ratnagiri, India
P. G. Borkar
Department of Plant pathology, Dr. B. S. Konkan Krishi Vidyapeeth, Dapoli, Dist. Ratnagiri, India
Keywords: Temperature, Colletitrichum gloeosporioides, Isolates, Growth, Sporulation.
Abstract
There was profound effect of temperature on isolate variability of C. gloeosporioides isolates infecting tropical fruits. Maximum average growth was attended by Cg 91
( 9.34 cm day-1) infecting jamun and the lowest average growth rate was attended by Cg 61 ( 5.02) infecting mango. Isolates Cg 51, Cg 54, and Cg 63 also showed considerable retarded growth. In general, isolates from sweet orange and pomegranate showed moderate to poor growth at temperature range of 18 – 36 0 C. It was observed that the optimum temperature for the growth of C. gloeosporioides isolates was 27 – 300C. The effect of temperature on isolate variability was highly significant. Maximum sporulation irrespective of isolates was attended at 240C. and was followed by at 27 and 300 C. The difference in temperature by 30C. from 24 to 27 reduced the average sporulation ability considerably. However, with further increase in temperature from 27 to 300C the amount of sporulation ability was almost constant but declined sharply at 330C. Few isolates were found to be distinct for the temperature requirements. Isolates, Cg 42 and Cg 62 sporulated at 300C and isolates Cg 63 Cg 83 and Cg 84 sporulated at 330C These isolates failed to sporulate at lower temperature levels.