Effects of Panicle Water Potential on Water Stress Susceptibility in Rice

Japanese Journal of Crop Science

Makoto TSUDA¹  Shinichi TAKAMI¹  Katsuhiko IKEDA¹  Haruhide YAMAGUCHI¹ 

关键词: Development;    イネ;    Panicle;    精籾;    Rice;    発育段階;    Water potential;    ç©‚;    Water stress susceptibility;    水ストレス感受性;    Winnowed paddy number;    水ポテンシャル;   

DOI  :  10.1626/jcs.63.200

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

The effects of drought on the rice yield differ depending on the time when plants are subjected to the drought. It is therefore probable that water stress susceptibility, the degree of yield reduction due to drought, is also a function of plant development. Water stress susceptibility is defined as the fractional decrease of panicle weight per unit change of cumulative water stress (an integrated water stress with time). The objective of this study was to determine whether water stress susceptibility is correlated with the yield responses to drought. Wetland rice plants (cultivars Koshinishiki and Somewake) were grown in pots containing soil under polyethylene rain shelters. Water potentials of leaves and panicles, and grain yield were measured in plants subjected to short-term water deficit imposed at various stages of panicle development. Water stress susceptibility increased with panicle development prior to heading but decreased as reproduction progressed. A similar trend was also seen in the data of winnowed paddy number. Prior to heading panicle water potential under drought increased with panicle development, whereas the water potentials of panicles and leaves were similar after heading. These results indicate that changes in water stress susceptibility reflect the variability, of grain yield under drought at least partly. The greater water stress susceptibility, was due to a smaller number of winnowed paddies. In addition, the susceptibility before heading was related to the maintenance of a higher panicle water potential under drought.

【 授权许可】

Unknown