IMPACT OF DIFFERENT RANGE OF pH AND TEMPERATURE ON GROWTH AND SPORULATION OF Alternaria solani ISOLATED FROM INFECTED TOMATO PLANTS
Tomato is considered to be the most widely used vegetables in the world in general and India in particular. However, the crop is damaged by different pathogens in which Alternaria solani is most important. From the infected fruits the fungus was isolated, and pure culture was maintained on Potato Dextrose Agar medium. From these cultures inoculum was taken and cultured in liquid culture medium adjusted with ten different pH (3.0-8.0) and incubated atten different temperatures (10 0-44 0 C) to
... (10 0-44 0 C) to observe the effect on growth and sporulation in Alternaria solani. Mycelial growth was measured on the solid medium as radial growth, while the dry mycelial weight was considered as the growth rate in the liquid medium. Maximum radial growth in the solid medium was noted in the culture adjusted at pH 7.0 which was 86.28 mm and at 7.5 it was 85.24 mm. Similarly at 28 0 C the radial growth was 82.76 mm followed by 32 0 C which was 81.18 mm. The dry mycelial weight at 7.0 pH was 1620 mg/ l of culture, while at 7.5 it was 1540 mg respectively. The dry mycelial weight at 28 0 C was 1686 mg/l of culture, while it was 1570 mg at 32 0 C. Neither the lowest pH nor the lowest temperature, similarly neither the highest pH nor the highest temperature could promote better mycelial growth. Sporulation was better in the conditions where the mycelial growth was noted better.