The effect of gamma radiation on seed germination and seedling growth of Lathyrus chrysanthus Boiss. under in vitro conditions

Abstract

The effects of radiation at different doses (0, 50, 100, 150, 200 and 250 Gy) of radioactive cobalt (60Co)grays on seed germination and seedling growth ofLathyrus chrysanthuswere investigated underin vitroconditions. The results showed that irradiated seeds had increased seed germination percentage, seed-ling and root lengths, seedling fresh weight, seedling dry matter content and total chlorophyll content inthe leaves of seedlings. However, at higher doses stress was evident and significant decreases in allparameters were observed. The highest seed germination percentage was recorded as 62.4%, 7 days afterstudy initiation when seeds were irradiated with 150 Gy gamma dose, while 100 Gy gamma dose wasranked in second order. Fourteen days after culture initiation, the best shoot growth initiation was againobtained from 150 Gy gamma dose as 75.7% and this was followed by 100 Gy gamma radiation as 74.6%.Gamma doses over 150 Gy resulted in sharp decreases in all parameters examined. On the 14th day, thehighest shoot and root lengths were recorded from 150 Gy gamma dose as 1.2 and 2.9 cm, respectively.Twenty eight days after study initiation, the highest values of seedling and root lengths, seedling freshweight, seedling dry matter content and total chlorophyll content were noted from 50 Gy gamma ra-diation as 9.7 and 6.3 cm, 0.39, 0.09 g (23.08%) and 471.6mg/g fresh tissue, respectively. This study isimportant from the aspect of showing that stimulatory effect of low gamma doses for germination andseedling growth may not be the same.