Cultural, morphological and molecular variability in Fusarium moniliformeisolates causing bakanae disease of aromatic rice in Haryana, India

Bakanae disease caused by Fusarium moniliforme has become a serious problem in the successful cultivation of aromatic rice under north-west plain zone of India. The present study was carried out during rainy (kharif) season of 2020 and 2021 at Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana to assess cultural, morphological and molecular variability among 26 selected isolates of Fusarium moniliforme collected from different locations and 11 districts of Haryana from roving survey conducted which includes bakanae infected plants of aromatic rice varieties namely PB 1121, PB 1718, PB 1401, PB 1509 and Basmati 521. On potato dextrose agar (PDA) media, colony colour of different isolates varied from white, milky white to creamy white. The microscopic observations showed that only three isolates showed macro-conidia, whereas the others 23 had micro-conidia. The macro and micro conidia size ranged between (22.36–28.09) × (3.01–4.71) and (4.80–9.92) × (1.42–2.71) μm in length and breadth, respectively. The isolates were divided into 3 groups based on cultural characteristics, macro and micro conidial size range. The precision molecular characterization of different isolates was done using specific primers, viz. β-tubulin, Vertf and (rp 32 and rp 33) primers which were found positive for 20, 22 and 9 isolates, respectively. The present investigations confirm that, there is variability among 26 isolates on the basis of morphological characteristics and further precision technique molecular markers confirm the same in Fusarium moniliforme causing bakanae disease and they may be useful in breeding programme for bakanae resistant genotypes.