We developed an automatic digital imaging system to acquire sequential growth images of rice in tillering stage. In this system, we cultivated 24 plants and acquired images of each individual plant at one-hour intervals. We measured leaf height using this system for 36 days from these sequential images. These sequential leaf height measurements made it possible to quantify the precise growth of rice plants, showing the timing of leaf elongation, leaf emergence interval and leaf elongation rate. We applied this method to evaluate the effect of photoperiod and tem-perature on rice growth. The timing of leaf emergence and the leaf emergence interval were affected by temperature and day length. On the other hand, the maximum leaf elongation rate was not significantly different under the temperature and day length examined. These results suggest that temperature and day length have different effects on leaf emergence and leaf elongation in rice. This method and instrument could be applied to phenotypic profiling studies for comprehensive growth of various plants species and cultivars.
Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists