Vol. 12, Issue 10 (2023)

Author(s):
R Livitha and D John Christopher

Abstract:
Rice brown spot is one of the most destructive diseases of rice, caused Bengal famine in 1942-43. In the present study, twenty isolates of Bipolaris oryzae were collected from five rice-growing districts of Tamil Nadu in the Cauvery delta region to identified the virulence under pot culture condition. Among these, the isolate of Bo₃, Bo₂, Bo₅, Bo₁ and Bo₄ were found to be the most virulent in the decreasing order of merits. Molecular characterization of the virulent five isolates was done with two ITS primers. Molecular confirmation through ITS region sequencing and confirmed to be Bipolaris oryzae. In phylogenetic analysis, the brown spot isolates were grouped into two major clusters. This study showed high degree of genetic and morphological variability among the isolates collected from the Cauvery Delta region of Tamil Nadu.