Differential Reactions to Colletotrichum Leaf Spot and Genetic Variability in Some Cultivars of Turmeric

Twenty-seven cultivars of tumeric were tested against leaf spot disease incited by Colletotrichum capsici. Low disease severities were recorded in CLS 20, Ranga, Roma, BSRI, Armoor, Kasturi, PTS 43, ranged from 2.4 to 11.3%. In the divergence analysis, the selection index in respect of disease showed that the cultivar CLS 20 was superior in resistance reaction and had a moderately high yield, The cultivar Alshiguda 25 showed very high susceptibility to this disease, which directly reflected the yield also. The trend of clustering in the dendrogram based on morphological and yield parameter with disease incidence severity revealed that high degree of similarity was observed between cvs. PTS 8 and Kamalganj local, PTS 62 and Kasturi and Surama and Kalimpong local. Two broad groups showed highest genetic distance. With a few exceptions, genetic relationships derived from divergence analysis data appeared to be consistent in respect of the phenotypic characters and leaf spot disease reaction of the turmeric cultivars.