SURVEILLANCE OF SEED BORNE PATHOGENS AND EVALUATION OF HEALTH STATUS OF HYV SEEDS OF RICE GROWN IN BADC FARMS OF BANGLADESH

Abstract

Experiments were conducted to evaluate the health status of eleven selected HYV seeds grown in different BADC farms of Bangladesh. Experiments were performed during the period July 2021 to June 2022 at Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh. The rice variety were BRRI dhan48, BRRI dhan82, BRRI dhan83, BRRI dhan85, BRRI dhan98, BRRI dhan49, BRRI dhan75, BRRI dhan87, BRRI dhan28, BRRI dhan29, BRRI dhan89. Seed health study was conducted following dry inspection and blotter method of ISTA. In inspection of dry seed method the highest purity percentage was found in BRRI dhan49 (99.98%) whereas the highest inert matter percentage (0.37%) was found in BRRI dhan28.10 fungal pathogen, bacterial ooze and unidentified mycelial growth observed on seeds of HYV rice in blotter seed health test method. The identified fungi were Bipolaris oryzae, Aspergillus flavus, Aspergillus niger, Aspergillus sp, Curvularia lunata, Fusarium oxysporum, Fusarium moniliforme, Nigrospora oryzae, Chaetomium sp, Pyricularia oryzae and Rhizopus stolonifer. Pathogen incidence of identified fungi, Bacterial ooze and unidentified mycelial growth of fungi were recorded. Among Aus varieties, BRRI dhan48 and BRRI dhan98 showed the highest (49.25%) and the lowest (28.8%) of seed borne pathogenic infection, respectively. In case of Aman varieties, the highest (58.8%) pathogenic infection was found in BRRI dhan75. However, BRRI dhan49 and BRRI dhan87 showed the same (50.25%) seed borne pathogenic infection. On the other hand, among Boro varieties, BRRI dhan29 and BRRI dhan89 showed the highest (35.5%) and the lowest (17.75%) seed borne pathogenic infection respectively. Considering the frequency and occurrence of seed borne pathogen, Fusarium sp., Aspergillus flavus, Bipolaris oryzae and unidentified white mycelial growth were found predominant seed borne pathogens.