Study of the simultaneous effect of gamma and salicylic acid irradiation on the biochemical and physiological characteristics of fenugreek

with nitrogen fixing bacteria and produce most of its required nitrogen. The purpose of this study was to investigate the simultaneous effect of gamma radiation and salicylic acid on the morphological, biochemical and genetic characteristics of fenugreek. In this study, fenugreek seeds were subjected to doses of ۰, ۱۰, ۱۵ and ۲۰ Gy of gamma rays. After plants reached the ۴-leaf stage, they were sprayed with ۱- and ۳-mM salicylic acid solution for two weeks. The leaves were harvested before reaching the flowering stage. Methanolic extract was used to investigate the biochemical properties of the plants. The phenolic content of the extracts was measured using Folin-Ciocalteu method and using ELISA. Free radical scavenging activity of ۲,۲-diphenyl-۱-pericylhydrazyl (DPPH) as well as total flavonoid content, total chlorophyll, total soluble protein and morphological characteristics of the plants (rate and percentage of germination, number of leaves per plant, stem length, RWC) were measured. Data were analyzed using SPSS ۲۵ software according to the factorial experiment based on a completely randomized design. The results showed that the interaction of gamma radiation and salicylic acid was negative on plant height, stem diameter and the number of leaves and the highest values were observed in the control plants. Also, this interaction did not have a significant effect on the relative moisture content and total chlorophyll content, and the highest values were observed in the plant height and the main effect, when the ۲۰ Gy dose of gamma radiation was applied. In dry weight, the amount of salicylic acid had the opposite effect, but with increasing dose to ۱۵ Gy, an increase in the amount of dry matter was observed. The highest weight of plants was observed when the highest amount of salicylic acid was applied with the lowest dose of gamma radiation. The highest percentage and germination rate of fenugreek seeds was related to the control plants and ۲۰ Gy Gamma dose, respectively. The amount of DPPH increased with increasing gamma and decreased with increasing salicylic acid, so that the highest amount was observed in the ۲۰ Gy of gamma radiation and ۰ mM of salicylic acid. The interaction of the treatments had a positive effect on the amount of flavonoids and the highest value was observed at ۲۰ Gy of gamma radiation and ۳ mM of salicylic acid. However, this interaction had an adverse effect on the amount of total phenol and the decrease in total phenol was observed with increasing gamma radiation dose. The highest amount of catalase enzyme was related to the interaction of the ۱۵ Gy of Gamma and zero mM of salicylic

Keywords:

fenugreek , gamma ray , silicic acid , biochemistry , phenol , flavonoids