Growth Retardation at Different Stages of Bean Seedlings Developed from Seeds Exposed to Synchrotron X-Ray Beam

Irradiated seeds of Phaseolus vulgaris cv. Rajmah using Synchroton X-Ray Beam (BL-07) at RRCAT, Indore at various doses in the range of 0.5 - 10 Gy were used to raise the seedling and the growth status at different stages was evaluated. Prior to germination, in the seeds soaked for 24 hours, the water regain remained unaffected by seed irradiation at 1 - 10 Gy doses, while the acid phosphatase activity was significantly reduced. Strong correlation (R2 = 0.685) between irradiation dose and enzyme activity also resulted. Analysing seed irradiation effect on seed development up to 4 days, % germination, germination index (GI), seedling wt, and seedling vigour were non significantly decreased at 5.0 Gy dose. The overall growth of 10 days old seedlings raised from irradiated seeds was substantially reduced at irradiation doses of 2 and 5 Gy exerting strong -ve correlation. Also % germination and seed vigour index (SVI) were prominently decreased due to seed irradiation. The nitrogen status of the seedlings, reflected by nitrate reductase activity (NRA) was significantly reduced in response to irradiation exerting strong correlation. The results demonstrate decreased phosphate mobilization in soaked seeds, time dependent decreased growth being more substantial with longer duration and reduced nitrate assimilation due to seed irradiation with Synchroton X-Ray Beam.