How precisely can x-ray predict the viability of wild flower plant seeds?

Abstract

The detection of seed viability is an important step in seed production, as well as in conservation and restoration practice. Due to random natural events, the quality and viability of seeds of wild flowering species vary substantially, and hence a quick and reliable method for seed viability assessment is desirable. X-rays provide information about the internal structures of a seed and therefore show promise for detection of viability and even germination capacity. Seeds of 207 accessions of 176 wild flowering plant species were x-rayed and the viability results were compared with combined germination-TZ test results. Of special interest was whether there are certain plant families for which x-ray is an appropriate method for viability detection, considering correlations with seed internal morphology, seed mass and/or shape. The comparison revealed a strong correspondence between viability determination by combined germination-TZ tests and by x-ray analysis. According to taxonomy and seed type, two main groups could be distinguished, that differed significantly in viability detection by x-ray and combined germination-TZ test. Whereas the evaluation of little/non-endospermic seeds gave approximately identical results, there was greater discrepancy for of endospermic seeds. Seeds of different sizes and shapes were evaluated similarly with both methods. Especially for little/non-endospermic seeds, x-ray can provide a useful and quick tool for viability detection, whereas for endospermic seeds, further research is needed. For the commercial seed industry, viability detection via x-ray should be the first step before further vigour testing is performed.