PREVENTION OF EFFECTS OF VICTORIN ON OAT SEED-GERMINATION

The germination of dormant oat seeds, sensitive to the pathotoxin victorin, was reduced from 99% for controls exposed only to water to 20% for seeds treated with 5000 units/ml of victorin for 1 h and then washed for 1 h in running tap water. However, when victorin-treated seeds were washed for 16 h or post-treated for 10 min with alkali, germination increased to 90%. The alkali post-treatment was equally effective in reducing lethal effects of victorin when applied to seeds that had been dried and stored for 2 to 3 weeks after treatment with the toxin. These results do not support the conclusion, reached in a previous study, that victorin acts on dormant, resting tissues as well as on those with an active metabolism. Instead they indicate that residual adsorbed victorin, acting only after germination has begun, is chiefly responsible for the lethal effects which have been observed. Seeds with visible signs of damage and those deliberately damaged were much more sensitive to victorin than undamaged seeds. Such damage may account for the failure of post-treatments to nullify completely the effects of victorin and also for apparent discrepancies between these results and those of a previous report. © 1978.