USING SEQUENTIAL IMAGERY TO EVALUATE ASPECTS OF SEED VIGOR AND GERMINATION

A sequential imaging system using a flat bed scanner interfaced to a personal computer was developed to study seed germination and vigor. The utility of the system was demonstrated in studies relating aspects of seed vigor in impatiens seed lots and for dormancy release in two woody perennials. Impatiens seed lots were kept in storage for 6 months to obtain a range in vigor levels. The ability to see differences at the individual seed level was possible because of the development of the sequential imaging system. It was observed that seeds deteriorated both under optimum 4OC as well as 25OC storage conditions. It was determined that both germination rate and seedling growth rate were appropriate measures of seed vigor. As untreated and primed seed lots were aged, germination percentage was negatively correlated with germination rate and positively correlated with seedling growth. However, there was a lack of correlation between germination rate and seedling growth on an individual seed basis. The data suggests that germination rate and seedling growth rate appear to be measuring different aspects of vigor. Sequential imagery also showed subtle changes in seed and seedling growth as seeds came out of dormancy that would not be detectable otherwise. This technique revealed changes in seed morphology that were previously not documented for seeds with physical dormancy. The current study furthered the utility of the imaging system by the development of sequential imaging that allows for samples to be collected hourly without technician input. This permitted very accurate determinations of germination rate and seedling growth on a single seed basis