@article{oai:mie-u.repo.nii.ac.jp:00005826,
 author = {津田, 誠 and Tsuda, Makoto},
 journal = {三重大学生物資源学部紀要 = The bulletin of the Faculty of Bioresources, Mie University},
 month = {Aug},
 note = {application/pdf, The objective of this study was to examine whether there are genotypic differences in water stress susceptibility and panicle water potential in rice subjected to drought conditions at meiosis stage. The seedlings of paddy rice cultivar Guizhao 2 and upland rice cultivar IRAT 109 were grown in 1/1500a pots under a rain shelter. Plants were subjected to four drought treatments different in duration at meiosis stage and control plants were grown under submerged soil conditions during the whole growth period. Panicle water potential (PWP) decreased in proportion to leaf water potential (LWP) as water stress became severe. The decrease of PWP relative to LWP was greater in Guizhao 2. Number of total spikelets decreased and that of sterile spikelets increased in IRAT 109 under drought conditions, whereas the change in the parameters was small in Guizhao 2. As a result, a small change occurred in number of fertile spikelets in Guizhao 2. Since dry weight of one fertile spikelet changed little in the both cultivars, a decrease in panicle dry weight was smaller in Guizhao 2.  Water stress susceptibility was smaller in Guizhao 2 than in IRAT 109. It is concluded that a genotype which PWP decreases in harmony with a decrease in LWP under drought conditions is less susceptible to water stress at meiosis stage in rice., 本研究の目的は，減数分裂期のイネに干ばつを与えたとき，水ストレス感受性と穂の水ポテンシャルに品種間差が
あるかどうかを調べることであった。水稲品種桂朝2号および陸稲品種IRAT109の苗を雨よけの下で1/5000aポッ
トで栽培した。植物体には減数分裂期に期間の異なる4段階の水ストレスを与え，対照区の植物体は全生育期間湛水
状態を保った。穂の水ポテンシャル（PWP）の低下程度は，水ストレスが厳しくなるにつれ葉身の水ポテンシャル（LWP）に
比例的に低下した。LWPに対するPWPの低下程度は，桂朝2号の方が大きかった。IRAT109では籾数が低下す
るとともに不稔籾が増大したのに対して，桂朝2号では両者の変化は僅かであった。このため，稔実籾数の低下は，
桂朝2号の方が小さかった。1稔実籾重は水ストレスによって変わらなかったので，穂の乾物量の低下は桂朝の2号
の方が小さかった。水ストレス感受性は，IRATlO9より桂朝2号の方が小であった。以上より，イネでは減数分裂
期の干ばつ条件下でPWPがLWPと同程度低下する品種は，水ストレス感受性が小さいと結論した。},
 pages = {1--6},
 title = {イネ減数分裂期の水ストレス感受性と穂の水ポテンシャルの品種間差異},
 volume = {18},
 year = {1997}
}