The Relationship between Environmental Factors and Behaviour of Stomata in the Rice Plant : 1. On the measurement of the stomatal aperture

[摘要] In the first place of this work the present study was conducted to settle a measurement method of the stomatal aperture in the leaves of the rice plant under the paddy field. The measurement methods used here were the infiltration and the micro-relief impression methods. The aperture of the stomata in the infiltration method was expressed in terms of the numbers of solutions penetrating the leaf and this was referred to as the infiltration score. A score of 1 represented injection by l0 per cent iso-butanol+90 per cent ethylene glycol solution (No.1 solution) only which penetrated the stomata with small aperture. A score of 5 represented injection by all solutions containing less than 50 per cent ethylene glycol which penetrated the stomata with wide aperture. In the micro-relief impression method the transparent negative celluloid micro-relief impressions of epidermis were prepared and the pore width of the stomata were measured microscopically. The aperture of the stomata, distributed even in the small portion of the epidermis in the leaf, showed much variation from each other; for example, the range of the pore width was from 0.5μ to 1.2μ, but these variations did not depend on the position where the stomata were situated along the large or small veins, and near the edge or the midrib of the leaf. A linear relationship was obtained between the infiltration score and average pore width of a large number of the stomata in the leaves of the various developmental stages of the rice plant under various weather condition. Almost same score was obtained for the stomatal perture in the upper and lower epidermis of the leaf. The aperture of the stomata in the middle part of the leaf were a little larger than those in the base or top part, but sometimes these differences could not be found. From these results it is concluded that the infiltration method using iso-butanol ethylene glycol mixture solution is suitable for measuring the aperture of the stomata of the leaf in the rice plant under the paddy field.

[学科分类] 农业科学（综合）