Radiation sensitivity of sesame (Sesamum indicum L.) genotypes in M1 generation

Abstract

The present study investigated the gamma ray sensitivity of two sesame (Sesamum indicum L.) varieties viz., SVPR1 and TMV7 irradiated with five different doses from 250 Gy to 450 Gy at 50 Gy intervals. Germination percentage, root and shoot length, pollen fertility (%) decreased gradually and observed a dose dependent relationship with an increase in dosage of gamma rays. Survival percentage recorded irregular decreasing trend with upsurge in survival rate at certain doses. SVPR1 showed a pronounced maximum reduction in germination percentage (37.5%) than TMV7 (40.05) at 450 Gy, whereas survival percentage of TMV7 (20.02%) and SVPR1 (19.5%) was drastically reduced at 250 Gy itself. At a higher dose of 450 Gy, root (3.08) and shoot (3.03) length of seedlings of SVPR1 were greatly inhibited. Pollen fertility percentage showed a linear reduction irrespective of the genotypes, and maximum reduction was rear at 450 Gy in SVPR1 (62.76%) was recorded. LD 50 values that showed 50% reduction in biological parameters differed between TMV7 and SVPR1. Based on all the biological parameters studied, the mutagen sensitivity of SVPR1 is higher than TMV7. The overall considerations on M1 generation effects showed that SVPR1 were highly sensitive to gamma rays.