Archivio Journal of Plant Pathology

Abstract:

During a survey carried out in 2013-14 on crops of Bacopa monnieri (L.) Pennell in Barasat, North Parganas district of West Bengal (India), many plants were found showing a foliar shot hole disease characterized by the presence of brown-coloured spots on the upper and lower leaf lamina. Generally, each affected leaf showed 1-2 spots with minute depressions which, under conducive environmental condi- tions, expanded to 2-3 mm in diameter that formed holes with a dark brown border. From affected leaves of symp- tomatic twigs, a fungus was isolated on potato dextrose agar (PDA), whose morphological features matched the de- scription of Phomopsis reported by Domsch et al. (1980). In pathogenecity tests, symptoms were reproduced after one week on 1-month-old plants of B. monnieri that had been sprayed with a conidial suspension of the fungus. Control plants sprayed with sterilized water remained healthy. The internal transcribed spacer region of the fungal isolate was amplified using primers ITS 1/ITS 4 (White et al., 1990) and sequenced (GenBank accession No. KJ451621.1). BLAST analysis of the sequence showed 100% homology with that of Diaporthe phaseolorum (Cooke et Ellis) Sacc. (anamorph:Phomopsis sp.) strain CBS113425 (accession No. KC343174.1). D. phaseolorum can infect sunflower and soy- bean, causing stem cankers and seedling blight (Muntaño- la-Cvetkovi et al., 1991). To our knowledge this is the first report of D. phaseolorum on Bacopa monnieri in India.