Seed viability of five wild Saudi Arabian species by germination and X-ray tests.

Our objective was to evaluate the usefulness of the germination vs. the X-ray test in determining the initial viability of seeds of five wild species (, , , and ) from Saudi Arabia. Usually several days were required to determine the viability of all five species via germination tests. However, X-ray test will give immediate results on filled/viable seeds. Seeds of all species, except and showed high viability in both germination (96-72% at 25/15 °C, 94-70% at 35/25 °C) and X-ray (100-80%) test. Furthermore, there was a general agreement between the germination (19%, 14% at 25/15 °C and 17% and 12% at 35/25 °C) and X-ray (8%, 4%) tests in which seed viability of and was very low due to insect damaged embryo as shown in X-ray analysis. Seeds of have physical dormancy, which was broken by scarification in concentrated sulfuric acid (10 min), and they exhibited high viability in both the germination (83% at 25/15 °C and 81% at 35/25 °C) and X-ray (96%) tests. Most of the nongerminated seeds of the five species except those of and , were alive as judged by the tetrazolium test (TZ). Thus, for the five species examined, the X-ray test was proved to be a good and rapid predictor of seed viability.