Abstract:
Gamma irradiation has a great potential to develop new crop varieties quantitatively and
qualitatively. An experiment was conducted to identify the optimal gamma-ray dose for
mutational breeding of eggplants at the Department of Agricultural Biology, University of
Ruhuna, in 2019. Seeds of eggplants (variety SM 164) were subjected to five different gamma
irradiation doses (100, 200, 300, 400 and 500 Gy). The irradiated and untreated seeds (0 Gy)
were sown in tray nurseries and the experiment was carried out using completely randomized
design (CRD) with 50 replications. The germination percentage (GP), shoot length (SL), and
leaves per plant (LPP) were recorded. The data were analyzed using analysis of variance
(ANOVA) followed by Tukey post hoc test using SPSS (Version 22). The results revealed that 100
% germination in controls while showing a declining trend with increasing dose level. The SL
and LPP were significantly (p<0.05) affected by the irradiation dose. Similarly, the highest SL
was observed in the control group (5.26±0.16 cm) 2 weeks after seed sowing, while the highest
LPP observed in 100 Gy dose level (3.20±0.10) and (4.06±0.06) in two and three weeks after
seed sowing respectively. In addition, characters (GP, SL and LPP) of each seedling in the control,
100 Gy and 200 Gy doses had significantly higher values compared to rest of the doses.
Therefore, the present study concluded that high gamma irradiation doses 300, 400 and 500 Gy
could be used for future studies for the successful induction of genetic diversity in eggplants to
enhance suitable mutants for breeding purposes.
