K. Furusawa et al., ANALYSIS OF GRAVITY-INDUCED GROWTH-RESPON SE OF SHOOT IN RICE (ORYZA-SATIVA L) - RESPONSE OF LEAF PULVINUS, LAMINA JOINT AND TORSION OF LEAF SHEATH, Nippon Sakumotsu Gakkai Kiji, 65(1), 1996, pp. 44-50
Plants were grown in pots containing soil. Every tiller was cut off wh
en it emerged and only the main shoots were allowed to grow. Exp. 1. P
lants in pots were artificially placed horizontally and the bending de
gree of lamina joints and pulvini was investigated. The artificial pla
cement in the horizontal direction increased the bending degree of lam
ina joint and pulvini. In the treatment in which pots were placed hori
zontally and then turned upright, the bending degree of pulvini was de
creased, but that of lamina joint was not changed. Exp, 2, The respons
e direction of the torsion in the leaf sheath of rice placed horizonta
lly was downward at a portion from the top to the center, while it was
upward from the center to the bottom. Exp. 3. The leaf blade was part
ly removed or added weight. The results suggested that the leaf blade
weight influenced the degree of torsion. When the weight of the leaf b
lade which was set sideways was released, the degree of torsion decrea
sed. Exp, 4, In the temperature treatment, the low temperature decreas
ed the torsion of the leaf sheath. This result suggested that the tors
ion of leaf sheath physiologically influenced by the temperature. It s
eems that the unit of ''pulvinus = leaf sheath = lamina joint'' was a
response to gravity.