Vol. 7, Issue 6 (2019)

A lab experiment was conducted during 2015-16 at Department of Seed Science and Technology, Professor Jayashankar Telangana State Agricultural University, Rajendranagar, Hyderabad to study the influence of gamma radiation doses generated from 60Cosource of Gamma chamber 5000 on seed quality parameters of sorghum varieties. The experiment was laid out in completely randomised design (CRD) with factorial concept with eighteen treatments in combination of three sorghum cultivars (CSH14- Kharif hybrid, C43- Kharif parental line and CSV29R- Rabi variety) and six gamma dose (T0- Control, T1- 250 Gy, T2- 500 Gy, T3- 750 Gy, T4- 1000 Gy and T5- 2000 Gy) with four replications. Seed quality parameters viz., germination percentage, field emergence, speed of germination, root length, shoot length and seed vigour index were evaluated immediately after irradiation and up to nine months under storage at ambient conditions.

Marked significance of interaction effects was recorded for various seed quality parameters studied immediately after exposing the seed to selected doses of gamma rays. The results indicated that gamma doses up to 750 Gy were found to exercise positive influence in enhancing all the germination, seedling and biochemical parameters. However, this gamma radiation differed significantly in their response and registered variable values for seed quality parameters. The doses beyond 750 Gy had detrimental effect by interfering with various seed quality attributes.

The analysis of bimonthly data at four intervals on seed storage potential up to nine months indicated significant influence of storage period on all the seed quality parameters including seed health. Marked decline in germination percentage, seedling dimensions and corresponding vigour index was noticed over a period of nine months. Among germination and seedling traits studied, vigour index and root and shoot length were the most sensitive seed quality parameters affected by ageing due to storage under ambient conditions, which registered higher reduction at the end of nine months. These traits can serve as reliable parameters for assessing seed quality under the influence of gamma radiation.