@article{oai:niigata-u.repo.nii.ac.jp:00028441,
 author = {Tsukaguchi, Tadashi and Egawa, Yoshinobu},
 issue = {2},
 journal = {新潟大学農学部研究報告, 新潟大学農学部研究報告},
 month = {Mar},
 note = {Snap bean (Phaseolus vulgaris L.) is a heat-sensitive crop. A snap bean cultivar Haibushi, which was developed from an accession collected in Southeast Asia, shows higher heat tolerance than other cultivars or lines. For an effective breeding program, elucidation of the mechanism controlling the heat tolerance in Haibushi is necessary. A high temperature often coincides with intensive solar radiation, which causes excessive transpiration and temporal water deficit in plants in the daytime, even when soil moisture content is adequate. In snap bean cultivars, leaf water status declined at mid-day and there was a cultivar difference in mid-day depression of leaf water status. In heat-tolerant cultivars including Haibushi, mid-day depression in leaf water status was smaller and stomatal conductance was higher than those in heat-sensitive cultivars. Higher stability in leaf water status of Haibushi was due to higher water uptake rate in the morning. Under high temperature conditions leaf temperature of heat tolerant cultivars was lower than that of heat-sensitive cultivars, well reflecting stomatal conductance and growth. However technical hurdles should be cleared to use cool leaf as a selection criterion. We conclude that daily stability in leaf water status could be a reliable characteristic to estimate heat tolerance in Phaseolus vulgaris.インゲンマメは高温に弱い作物である。東南アジアで採集された系統から育成されたインゲンマメ品種ハイブシは他の品種あるいは系統よりも高い耐暑性を示す。効率的な育種のためにハイブシの耐暑性の支配機構を明らかにする必要がある。高温はしばしば強日射を伴うが、高温と強日射が相まって植物体の過剰な蒸散を招き、たとえ土壌の水分状態が良好であっても植物体は日中しばしば一時的な水分欠乏状態となる。インゲンマメ品種においても日中の葉の水分状態は低下し、その低下の度合いには品種間差異が認められた。ハイブシを含む耐暑性品種においては感受性品種よりも葉内水分状態の日中の低下は小さく、気孔コンダクタンスも高く保たれた。ハイブシにおいて日中の葉の水状態が安定に保たれたのは午前中の水吸収速度が高かったためと考えられた。高温条件下で成長速度の大きい耐暑性品種では高い気孔コンダクタンスを反映し葉温が低かったが、葉温を耐暑性の評価に用いるには技術的な問題がある。これらのことから、日中の葉の水分維持はインゲンマメの耐暑性を評価する指標となりうると考えられた。},
 pages = {79--84},
 title = {Higher Stability in Leaf Water Status in Heat-Tolerant Cultivars of Snap Bean (Phaseolus vulgaris L.)},
 volume = {58},
 year = {2006}
}