EFFECT OF X-IRRADIATION ON DATE PALM SEED GERMINATION AND SEEDLING GROWTH

Abstract

This study was conducted to examine the effect of low doses of X-rays on date palm (Phoenix dactylifera L., cv. Khalas) seed germination and seedling growth. A significant reduction in seed germination was observed in response to X-irradiation as compared to the non-irradiated control. A significant reduction in seed germination percentage (82.85%) began at 0.25 Gy of X-rays and persisted to decline to 61.42% at 15 Gy. Based on accumulative growth percent increase (AGPI), a significant enhancement of root growth was observed in response to increasing X-rays doses. The mean root length increase ranged between 3.7% at 0.05 Gy to 8.05% at 15 Gy after 1 week of X-rays exposure. Similarly after 2 weeks of exposure, a significant increase in root growth started at 0.1 Gy and root growth reaching the highest value (10.94%) at 15 Gy, while root growth reached 15.19% in week 4 at the same dose. A significant increase in leaf length of 0.05-0.25 Gy was observed but at higher doses reduced growth occurred. This study provides an insight into the potential use of X-rays in manipulating growth parameters of date palm and enhances understanding of the physiological responses inflicted by irradiation stress.