Effects of gamma radiation on fungi infected rice (in vitro).

Purpose: This work focuses on the effect of gamma radiation on seed born fungi (in vitro) on Oryza sativa (Swarna, Initial Evaluation Trial-5656).

Materials And Methods: The responses of fungi to gamma radiation (0-4.2 kGy; 0.12 kGy/h) were studied in individual cultures of major seed-borne fungi including Alternaria alternata, Aspergillus flavus, Trichoderma viride and Curvularia geniculata.

Results: The inactivation of individual fungal-viability was noted between 1.0-2.0 kGy for A. alternata and A. flavus and 0.5-1.0 kGy for T. viride and C. geniculata. Complete inhibition was observed at <2.5 kGy. Formations of multiple germ tubes were noted in A. alternata and A. flavus at 2 kGy and 2.5 kGy, respectively. A. flavus required a higher dose to reduce viability to 10% (D(10)) value in comparison to other selected fungi.

Conclusions: Different fungi exhibited different radiosensitivity. The dose range of 2-2.5 kGy was effective in killing all selected fungi. The fungi showing a higher D(10) value exhibited multiple germ tubes.