Effects of Water Deficit on Photosynthesis in Wheat Plants : VI. Capacitance and resistance of transpiratory water flux in different plant parts

[摘要] In order to explore the physiological basis for the difference among plant parts in photosynthetic depression by soil water dieficit, the tissue water status was examined by using an electric circuit analogue. It was found that the tissue water storage capacity per unit volume was larger in the leaf blades than in the ear, and larger in the lower leaves than in the upper ones. In reverse, the tissue water storage resistance was larger in the ear than in the leaf blades, and in the upper leaves than in the lower ones. This suggests that the water loss is easier in the lower parts of a plant than in the upper ones. Furthermore, the percentage change of stomatal resistance per unit leaf water potential decrease was larger in the lower leaves than in the upper ones, and larger in the leaf blades than in the ear, suggesting that stomata close earlier in the lower plant parts as water stress develops. These results account for the difference among plant parts in photosynthetic depression by soil water deficit.

[学科分类] 农业科学（综合）

[关键词] Electric analogue;æ°—å­”;Leaf water potential;光合成;Photosynthesis;コムギ;Soil water deficit;Stomata;電気回路アナログ;Triticum aestivum L.;土壌水分欠乏;Water stress;水ストレス;Wheat;水ポテンシャル