Growth Analysis of Tillering Stage in Phytochrome-deficient Rice Mutant Using Auto Digital Imaging System

Abstract

We have been developing a plant growth imaging system for recording visible phenotypes over a long term in high-throughput performance. Using this system, we cultivated phytochrome-deficient rice mutants grown in a long-day condition(14h light 30°C/10h dark 25°C). Standard material plants (Nipponbare,WT) showed that the 5th to 11th new leaves of main culm emerged in an average interval of 84±4.5 h. The appearance cycle of new leaves in a phytochrome A-deficient(phyA)mutant, was 12 h shorter than that in WT. On the other hand, the cycle in a phytochorome B-deficent(phyB)mutant was evidently longer (8th-11th leves:127.2±19.2h) than that in WT. The rate of a new leaf elongation in the phyB mutant was also affected. These results suggest that phyA delayed the appearance cycle of a leaf and phyB promoted leaf appearance and leaf elongation.