HOST SELECTIVE VIRULENCE, TEMPERATURE RESPONSE AND GENETIC DIVERSITY IN MACROPHOMINA PHASEOLINA ISOLATES FROM SESAME AND PEANUT IN SOUTHERN TURKEY

Abstract

In this work, host specificity (comparing virulence levels on diverse hosts), temperature response as a physico-morphological characteristic, and genetic diversity of 40 M. phaseolina isolates from sesame and peanut plants with different geographic origins were evaluated. Sesame and peanut isolates of M. phaseolina performed different levels of virulence on maize, watermelon, melon, peanut, and soybean. The temperatures between 25 and 30 degrees C were the optimum temperatures for colony size of isolates from sesame and peanut. A temperature of 25 degrees C was optimal for only 26 isolates (65%), but 30 degrees C was optimal for 39 isolates (97.5%). UPGMA clustering of data indicated that the Sesame and peanut isolates displayed various levels of genetic similarity within a range of 0.79 to 1.0 similarity coefficient index in three major cluster groups. With a few exceptions, isolates from the same or close locations tended to group together.