First report of leaf spot disease on ridge gourd caused by Fusarium solani

Abstract

Ridge gourd (Luffa acutangula Roxb.) is a widely cultivated vegetable crop of sub-Himalayan West Bengal. During June to August 2022, a disease looking like leaf spot disease was found in Coochbehar district. The disease incidence was 25%. The leaves of ridge gourd showed symptoms of large brown necrotic lesions that appear on leaves, especially on the tip of basal leaves. In PDA medium profuse white aerial mycelium was seen. Macroconidia having 3 to 4 septa were 15-20 μm long. To confirm the identity of this fungus, the internal transcribed spacer, 28S rRNA regions and TEF (Translation Elongation Factor) gene of RG/DE/F were amplified and sequenced. GenBank accession numbers are OR026030, OR782923 and OR800599 respectively. All the sequences showed 99%, 97% and 100% resemblance with sequences of Fusarium solani in GenBank. Pathogenicity tests showed positive results with disease symptoms similar to those of natural symptoms. Thus, the pathogen has been identified as Fusarium solani. The isolate RG/DE/F (F. solani) is being reported as a pathogen of ridge gourd for the first time.