Dissection of environmental and physiological effects on the temperature difference between superior and inferior spikelets within a rice panicle

Temperature of a plant organ constitutes an integrative index to its eco-physiological properties and status. However, little attempt has been made dissect the combined effect ecological physiological factors on surface temperature such as rice spikelet. In this study, using deactivated reference, we developed novel comparison method environmental effects Three japonica cultivars with contrasting canopy features were used testing materials. Temperatures flag leaf, superior inferior spikelets their diurnal rhythm during grain filling stage precisely measured by hand-held infrared thermometer. The results showed that variation conditions within panicle was relatively minor, posing limited influence difference between On other hand, it intrinsic considerably affected spatial variations spikelet panicle. Chemical analysis sucrose starch in grains bracts indicated is more physiologically active at photosynthetic assimilation biosynthesis. Interestingly, sugar exhibited pattern changes similar source leaf but different from sink grain, confirming are organs for filling. Our findings yield penetrating insight into foundation temperature, thus being helpful application approaches crop breeding cooler canopy.