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.