Physiological Mechanisms on Severe Water Deficits Called "Acute Wilt Diseases" in Crop Plants

它被观察到，向日葵的叶子在植物（自然光）中生长了很多，叶子的颜色仍然是绿色的，在土壤水潜力的地方叶子生长的户外没有很多。在Such phenomenon observed in sunflower grown in the phytotron is thoug\to be one of so-called "acute severe wilting" phenomena in many crop plants.It was clariified that such "acute severe wilting" of sunflower occurred in the plants grown under the conditions with high air humidity by comparing the degrees of wilting and death of leaves among the plants grown under various conditions.Leaf water potential decreased considerably in the plants生长在植物生长的植物中，生长在土壤生长的室外，生长在土壤湿度下。在叶子运动潜力和植物生长的户外环境中，没有什么不同，在植物生长和植物生长的户外环境中。植物生长的户外装饰的叶子的差异性行为 ... More sed markedly as leaf water potential decreased from about-6 bars and became very small at leaf water potential of about - 15 bars。On the other hand， leaf diffusive conductance of the plants grown in the phytotron did not decrease markedly until leaf water potential decreased to about - 15 bars。植物在植物生长的叶子行为仍然高于植物生长的室外条件，因为植物生长在叶子水的潜力低于大约16个酒吧。When ABA solution was sprayed on the leaf of the plants grown in the phytotron， diffusive conductance of the leaf of which water potential高于about - 14 bars decreased markedly。From the results mented above，这是澄清的，因为在高空气湿度下生长的向日葵的叶子仍在继续，以便通过低叶子水潜在的转化流失水，因为它们的磁带抵抗力相对而言低矮和潮湿不能接近低叶子的水潜力，这可能是为什么向日葵生长在空气湿度下的条件下的空气湿度会迅速消失到严重不足的水的原因。Less（低）

It was observed that leaves of sunflower plants grown in a phytotron (natural light) wilted severely and died leaving the leaf color still green at the soil water potential where leaves of the plants grown outdoors did not wilt severely. Such phenomenon observed in sunflower grown in the phytotron is thought to be one of so-called "acute severe wilting" phenomena in many crop plants.It was clarified that such "acute severe wilting" of sunflower occurred in the plants grown under the conditions with high air humidity by comparing the degrees of wilting and death of leaves among the plants grown under various conditions.Leaf water potential decreased considerably in the plants grown in the phytotron compared with the plants grown outdoors under deficient soil moisture. There were no differences in leaf osmotic potential and the bulk modulus of elasticity between the plants grown in the phytotron and the plants grown outdoors. Leaf diffusive conductance of the plants grown outdoors decrea … More sed markedly as leaf water potential decreased from about ー 6 bars and became very small at leaf water potential of about - 15 bars. On the other hand, leaf diffusive conductance of the plants grown in the phytotron did not decrease markedly until leaf water potential decreased to about - 15 bars. Leaf conductance of the plants grown in the phytotron was still higher than that of the plants grown outdoors at leaf water potential lower than about ー 16 bars. When ABA solusion was sprayed on the leaf of the plants grown in the phytotron, diffusive conductance of the leaf of which water potential was higher than about - 14 bars decreased markedly.From the results mentioned above, it was clarified that the leaves of sunflower grown under the conditions with high air humidity still continue to lose water through transpiration at low leaf water potential since their cuticle resistance is relatively low and stomata do not close much at the low leaf water potential, which might be the reason why the leaves of sunflower grown under the conditions with high air humidity die rapidly due to severe water deficits under deficient soil moisture. Less