Evaluation of Relative Resistance of Rice against Sheath Rot through Combined Screening Techniques

The wild rice species (Oryza rufipogon, O. latifolia), thermogenic male sterile lines (TGMS) and Cuddalore rice accessions were evaluated for their reaction to the sheath rot pathogen (Sarocladium oryzae) under field conditions. The resistant TGMS line TS 47, Jeragasala 1, 2 and 3 (Cuddalore accessions) exhibited reduced disease symptoms. These field-screened cultivars were further confirmed for their resistance under in vitro conditions. The efficiency to grow in the toxin-containing medium was appraised. The medium was supplemented with toxin as crude, diluted preparation and culture filtrate. All the field identified genotypes except TS 47 showed better callus proliferation in vitro. Indeed they produced plantlets in toxin free medium further confirm their resistance. The germination test conducted in toxin containing culture tube also endorsed the suitability of Jeragasala 1, 2 and 3 as resistance donor. In addition, the difference in the protein profile of disease susceptible and resistant cultivars ...