Detection and identification of seed borne pathogens from some cultivated hybrid rice varieties in Bangladesh

Seed health testing to detect seed borne pathogens is an important step in the management of crop diseases. This study was carried out to assess seeds of cultivated hybrid rice varieties (13 imported, two local hybrid rice varieties and two local varieties as check) for seed borne pathogens. Blotter method, paper towel method and agar plate method were used to identify seed borne pathogens and a total of 12 pathogens (Xanthomonas oryzae, Rhizopus stolonifer, Aspergillus spp. Fusarium moniliforme, Phoma sp. Bipolaris oryzae, Curvularia lunata, Penicillium sp. Alternaria tenuissima, Nigrospora oryzae, Chaetomium globosum and Tilletia barclyana.) were identified. Among these pathogens, Xanthomonas spp. Rhizopus stolonifer, Aspergillus sp. Bipolaris oryzae and Fusarium moniliforme are pre-dominent on all tested hybrid rice varieties. The lowest pathogenic incidence recording varieties showed lowest rotten seed, dead seed and highest seed germination and seedling vigour index. Hira-1 and Hira-2 showed the better performance in terms of lowest pathogenic incidence, rotten seed, dead seed seed germination and seedling vigour index.