Pathogenic Variability of Fusarium fujikuroi Causing Bakanae Disease of Rice (Oryza sativa L.)

Bakanae or foot rot disease is one of the newly emerged diseases of rice in Kashmir. An extensive survey conducted during 2014 in two districts of south Kashmir viz., Anantnag and Kulgam, revealed the prevalence of the disease in all the surveyed areas with varied levels of incidence which ranged from 0.6 per cent to 19.3 per cent. The fungus inciting the disease was identified as Fusarium fujikuroi Nirenberg [teleomorph: Gibberella fujikuroi (Sawada) Ito] on the basis of its morphological and pathological characteristics. Pathogenic variability study of 20 F.fujikuroi isolates collected from 17 diverse locations, on a set of seven putative rice differential lines, revealed the existence of variability in terms of pathogenicity of the isolates. The twenty test isolates discern into six pathogenic groups on the basis of similarity in reaction pattern of the differential lines against the test isolates. Two isolates from Block Larkipora (Ff13 and Ff15) shared a single group i.e, Group I and 5 isolates (Ff1, Ff2, Ff3, Ff4 and Ff5) from Larnoo block accommodated in Group II, Similarly, three isolates (Ff10, Ff12 and Ff17) from Block Qaimoh and three isolates (Ff6, Ff7 and Ff8) from block D.H. Pora shared group V and VI, respectively. Group III accommodated three isolates, 2 from Achabal block (Ff9 and Ff11) and 1 from Pahloo block (Ff16) and Group IV accommodated 4 isolates, 2 (Ff14 and Ff20) from Pahloo block, 1 (Ff18) from Achabal block and 1(Ff19) from Qaimoh block.