Growth characteristics and phytochemical responses of Iranian fenugreek (Trigonella foenum-graecum L.) exposed to gamma irradiation.

• Gamma irradiation improved the growth characteristics of fenugreek plants. • The seed yield was increased by low dose (100 Gy) gamma rays. • Trigonelline content increased in the plants raised from low dose irradiated seeds. • Low dose gamma rays application can be a useful seed pre-sowing technique. Fenugreek (Trigonella foenum-graecum L.), an aromatic and spice herb, is extensively used to treat a wide range of diseases such as paralysis and diabetes. In order to improve fenugreek growth and pro-health potential, seeds of fenugreek were exposed to gamma rays (including 0, 100, 200, 300 and 400 g) from cobalt 60 gamma radiation source. This experiment was arranged in a randomized complete block design (RCBD) with three replications. Results showed that, number of leaves per plants, shoot diameter, stems dry weight, leaf dry weight, shoot dry weight, number of pods per plant, 1000-seeds weight and biological yield in plants exposed to different doses of gamma radiation were significantly higher than those of the non-irradiated control. In addition, low-dose gamma irradiation especially 100 Gy had stimulatory effects on the number of branches per plant, pod length, seed yield, seed trigonelline and nicotinic acid content, while high-dose gamma irradiation (400 Gy) exhibited inhibitory effects. Furthermore, the maximum amounts of seeds diosgenin and mucilage were recorded in the control samples, while those of the samples exposed to gamma irradiation were gradually decreased by increment of gamma dose. These results indicate that the irradiation of low dose gamma rays (100 Gy) can be useful for improving the growth characteristics and accumulation of some valuable compounds in fenugreek seeds. [ABSTRACT FROM AUTHOR]