Relationship between Panicle Weight per Plant and Cumulative Water Stress in Rice

Japanese Journal of Crop Science

Makoto TSUDA¹  Shinichi TAKAMI¹  Yuji YAMANE¹ 

关键词: Cumulative water stress;    イネ;    Heading and anthesis;    出穂開花期;    Leaf water potential;    積算水ストレス;    Panicle weight per plant;    個体当り穂重;    Rice;    水ストレス感受性;    Water stress susceptibility.;    葉身水ポテンシャル.;   

DOI  :  10.1626/jcs.62.60

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

Decrease of panicle weight per plant in rice in proportion to cumulative water stress (an integrated estimate of the degree and duration of water stress) has been demonstrated in rice subjected to increasing water stress imposed at the early stages of panicle development. Since yield decrease under drought is proportional to yield without drought, it was expected that the decrease of panicle weight per plant by a unit change of cumulative water stress might be proportional to panicle weight per plant under submerged soil condition. To prove this hypothesis, we conducted an experiment in which the relationship between panicle weight per plant and cumulative water stress was examined. Two rice cultivars, one wetland (Koshihikari) and another dryland (Sensyou), were grown in pots differing in their size and fertilizer level. The plants were subjected to different water treatments started either at the stage of the secondary-branch primordia differentiation or at heading and anthesis. Control plants were kept continuously submerged. The decrease in panicle weight per plant under drought was proportionally related to the cumulative water stress in plants subjected to water stress during heading and anthesis as was during early stages of panicle development. The linear regression coefficient between the panicle weight per plant and cumulative water stress was also proportional to the panicle weight per plant under submerged condition. In other words, the panicle weight per plant under water stress G (g plant-1) can be related to the cumulative water stress CWS (MPa·day) by : G=Go (1-K·CWS), where Go is the panicle weight per plant under submerged condition (g plant-1) and K is the constant defined as water stress susceptibility (MPa-1day-1).

【 授权许可】

Unknown