Effect of Ustilaginoidea virens Infection on Seed Germination and Vigour in Tolerant and Susceptible Rice Genotypes

Aims: To evaluate the seed infection of U. virens and its relationship to seed germination and vigour quality of false smut tolerant and susceptible rice genotypes Study Design: CRD. Place and Duration of Study: Indian Institute of Rice Research, Hyderabad and Seed Research and Technology Centre, PJTAU, Hyderabad. Methodology: The moderately tolerant lines identified at ICAR- IIRR, viz., RL-479 (DL-27), RL-1516 (DL-28), RL-2453 (DL-29), RL-4609 (DL-31) and Vary Lava IRGC 386-1 (PAU2) under artificial screening were selected for the current studies. The susceptible genotype includes RL-263 (DL-25), CO51, BPT-5204, and GSR123 (PAU3).U. virens chlamydospores and conidia were used for artificial inoculation and seed quality parameters were documented. Results: Upon chlamydospore treatment, the tolerant genotypes, recorded mean reduction of 0.53% of germination percentage as against 5.83% in the susceptible genotypes. Similarly, the germination percentage of conidia treated susceptible genotypes recorded reduction of 9.5% as against 1.6% in tolerant genotypes. The mean Vigor Index 1 across the tolerant genotypes upon chlamydospore treatment was reduced by 230 units and in case of conidial treatment it was 359. However, in the seeds of susceptible genotypes, the reduction of mean Vigor Index was 829 in the chlamydospore treatment and 595 in the conidial treatment. Conclusion: The identified tolerant genotypes maintained significantly better seed quality traits (germination %, root/shoot length, vigour indices, and biomass) against U. virens chlamydospore and conidial infection compared to the susceptible genotypes. This suggests enhanced physiological resilience of tolerant lines, making them suitable candidates for further breeding programs targeting disease resistance and seed quality.