Isolation and Characterization of the Incitant of Leaf Spot of Turmeric and in-vitro Efficacy of Native Isolate of Endophytic Bacteria

Abstract

Turmeric, Curcuma longa L. is an important commercial spice crop cultivated in Meghalaya covering 2,649 ha area with 16,497 MT productions. However, the turmeric cultivation is severely affected by leaf spot disease limiting its yield. So, the present study was conducted to identify the pathogen associated with leaf spot disease of turmeric as well as to check the efficiency of bacterial endophytes in managing the disease. Based on the morphological and cultural studies, six isolates of Colletotrichum gloeosporioides were identified as the causal organism of leaf spot disease of turmeric. The isolates on PDA medium produced white to grey fluffy (raised/ flat) cottony culture with serrated margin. All the isolates produced dark brown acervuli and globular conidia with oil globules inside. Five bacterial endophytes viz., BE 1, BE 222, M1W1, NGB21 and SVC 11 were tested against C. gloeosporioides by using dual culture assay. They were able to inhibit the mycelial growth of C. gloeosporioides in the range of 35.82-68.11%. The highest percent inhibition in dual culture assay was recorded in the isolate NGB 21 (68.11%) followed by isolate BE1 (59.89%).