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1.
C. A. Braue R. L. Wample P. E. Kolattukudy B. B. Dean 《American Journal of Potato Research》1983,60(11):827-837
Potato (Solanum tuberosum L. cv. Russet Burbank) tuber periderm resistance to water loss was monitored during the harvest season. Periderm resistance of tubers from water-stressed plants was compared with tubers from unstressed plants throughout a six-week harvest period, in order to determine the effect of plant condition on tuber resistance to water loss. Tubers stored for ten days at 4°C immediately following harvest were also monitored to determine if storage enhanced periderm resistance and if any difference occurred between tubers from stressed vines compared with those from unstressed vines. During the harvest season, tuber resistance to water loss was positively correlated with plant water stress, as measured by leaf water potential and leaf diffusive resistance. Storage of tubers after harvest also caused an increase in periderm resistance. The commercial practice of vine killing, therefore, may have a positive effect on reducing weight loss in storage by enhancing the resistance of tuber periderm to water loss. 相似文献
2.
C. D. van Loon 《American Journal of Potato Research》1981,58(1):51-69
The effect of water stress on plant morphology, production rate and marketable yield is discussed based on the literature. Compared to other species the potato is a drought sensitive plant. The reduction of yield as a result of water stress can be caused by reduced leaf area and/or reduced photosynthesis per unit of leaf area. Water shortage during the tuber bulking period decreases yield to a larger extent than drought during other growth stages. The relationship between the stress parameters relative water content (RWC), leaf water potential (LWP) and stomatal diffusion resistance on the one hand and photosynthesis on the other is discussed. Further it is shown how the amount of water needed by the potato crop depends on climate, soil and plant characters. Finally the effect of water stress on marketable yield and varietal differences to shortage of moisture are discussed. 相似文献
3.
不同形态氮素营养和水分条件对苗期水稻生长及渗透调节能力的影响 总被引：1，自引：0，他引：1
为比较不同形态氮素营养下籼稻与粳稻对水分胁迫的响应,采用室内营养液培养,通过供应不同形态氮素及100 g/L PEG6000模拟水分胁迫的方法,对4种不同基因型水稻的生长状况及渗透调节能力进行了分析。结果表明：1）与铵态氮营养相比,水分胁迫明显抑制了硝态氮营养籼稻和粳稻的地上部生长,降低了叶片净光合速率,且对粳稻的抑制效果更加显著;2）水分胁迫条件下,铵态氮营养籼稻和粳稻植株内的游离氨基酸和K+可以更有效地积累、转运和穿梭,以致伤流液和韧皮部汁液拥有更强的渗透调节能力;3）铵态氮营养籼稻和粳稻在通过渗透调节降低叶片渗透势的同时,能够提高或维持叶片含水量。由此可见,铵态氮营养下,籼稻和粳稻均可通过渗透调节促使叶片在渗透势下降和维持含水量之间达到合理的平衡,保证叶片在水分胁迫下维持正常的光合速率,提高了水稻的抗旱能力。 相似文献
4.
Gas-exchange characteristics of potato (Solanum tuberosum L.) canopies were determined with crop enclosures under condition of optimal water supply, during soil water depletion, and during recovery from drought-stress. The plants were grown under a rainshelter in large containers with 2-m2 surface area. Control plants received water throughout the growth period. In Expt. 1, transient drought was imposed by interrupting water supply completely for 22 days. During the 33-day period of drought treatment in Expt. 2, the stressed plants received half the amount of water that was given to the control plants (irrigations 2–3 times per week).
During soil water depletion, stomatal conductance of the canopy was reduced earlier and more than photosynthesis. This resulted in a lower internal carbon dioxide concentration in the leaves of stressed plants and a higher ratio between photosynthesis and stomatal conductance. The value of that ratio increased as soil water potential dropped.
Water-use efficiency ( ) increased during drought stress. The cultivar Bintje showed a larger ratio between photosynthesis and stomatal conductance of the canopy and a higher than cv. Saturna, both for optimal water supply and during drought stress.
Photosynthesis and conductance of the canopy started to recover immediately upon rewatering, even when relative values had declined to 20–30% during the preceding stress period. After release from stress, the leaves in the top layer of the canopy had a higher stomatal conductance in treated plants than in control plants. 相似文献
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以盆栽大豆为材料,设置不同程度的土壤盐分(NaCl)、干旱及旱盐组合处理,然后测定各处理大豆植株的株高、生物量、光合作用指标以及植株的水分状况和Na~+、K~+含量,探索干旱条件下土壤盐分对大豆生长的影响及可能机制。结果表明:干旱和盐胁迫均可导致大豆叶片的净光合速率降低和生长量的减少,干旱还导致光合机构的严重损伤。但是,干旱和适量土壤盐分(100~150 mmol·L~(-1)NaCl)组合处理的大豆植株,其生长量、净光合速率和PSⅡ最大光化学效率都显著高于单一干旱处理。同时,旱盐组合处理的大豆叶片RWC、Na~+含量也高于单一干旱处理,水势和渗透势低于后者,且叶片Na~+含量与其渗透势降低显著相关。综合分析表明,在干旱条件下,土壤适量NaCl的存在使大豆能够吸收和积累更多Na~+等盐离子作为渗透调节物质,来降低渗透势、提高吸水能力,以改善植株的水分状况和光合性能,保持植株较高的生长速率,即土壤中适量盐分(NaCl)的存在可减轻干旱对大豆的负效应。 相似文献
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《Plant Production Science》2013,16(1):53-57
AbstractThe photosynthetic rate in the fl ag leaf of rice at the full heading stage was examined in three japonica varieties, Koshihikari, Aikoku and Asanohikari, and the indica high-yielding variety Takanari at the same level of leaf nitrogen. At an ambient CO2 concentration of 350 µL L-1, Takanari had a higher photosynthetic rate and stomatal conductance than the japonica varieties when plants were compared at a leaf nitrogen content of approximately 1.5 g m-2. Stomatal conductance increased considerably with increases in leaf nitrogen content in the japonica varieties. As a result, at a leaf nitrogen content of approximately 2.0 g m-2, differences in terms of the photosynthetic rate among varieties were small. By contrast, there were no clear varietal differences in Rubisco content at any identical nitrogen content of leaves. We conclude that stomatal conductance is responsible for the varietal differences in photosynthetic rate examined at the same leaf nitrogen content. 相似文献
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向日葵耐盐性比较及耐盐生理指标选择 ) 总被引：19，自引：1，他引：19
植于蛭石中的3个向日葵品种用0% (CK) 、0. 3%和0. 9% NaCl Hoagland溶液胁迫处理, 20d和40d分别 测定各种指标。结果表明,DK119较以色列H1和陇葵杂1号具有较强的耐盐性; 0. 3% NaCl和短时间(20d)处理, 向日葵的叶面积和膜透性相对值可作为评价植株耐盐性的指标,处理时间延长至40d,膜透性相对值失去对植株耐 盐性评价的意义;脯氨酸含量、叶绿素含量和光合速率亦不能作为评价植株耐盐性指标;当NaCl浓度为0. 9%时, 任何指标都失去评价意义。 相似文献
9.
旱涝急转对不同花生品种生理生化指标的影响 总被引：2，自引：0，他引：2
为探讨旱涝急转对花生生理生化的影响,以不同旱涝耐性的3个花生品种中花8号（抗旱）、豫花15（耐涝）和湘花2008（旱涝兼耐）为材料,进行不同梯度的先旱、后涝连续处理,比较不同花生品种的叶片相对含水量,过氧化物酶（POD）、过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、谷胱甘肽还原酶（GR）活性,以及丙二醛（MDA）含量的变化情况。结果表明,在旱、涝急转的胁迫过程中,干旱对叶片相对含水量的影响甚于湿涝。一定强度的旱或涝胁迫总体上均可使花生叶片的4种抗氧化酶POD、SOD、CAT、GR活性提高,随着胁迫的加深活性降低,复水后活性回落至对照水平,且旱甚于涝。MDA含量总体变化趋势是干旱胁迫下各品种花生叶片中MDA含量有所升高,并于复水解除干旱胁迫后恢复至对照水平;而湿涝处理阶段,MDA含量呈直线上升趋势,在胁迫解除后有所降低。中花8号、豫花15、湘花2008等3个花生品种具有显著不同的水分适应性,中花8号抗旱性更强而耐涝性较弱,豫花15抗旱性较弱而耐涝性强,湘花2008抗旱性中等而耐涝性更强,为水分广适性品种。 相似文献
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The influence of submergence on photosynthesis and antioxidant capacities in rice varieties Swarna and Swarna-Sub1 with or without Sub1 QTL were evaluated under control,simulated complete submergence and subsequent re-aeration.The leaf photosynthetic rate and stomatal conductance decreased in the both varieties during the progression of submergence as compared to the control plants,but significant varietal differences were observed after 1 d of submergence.Submergence also altered the PSII activity,as reflected in a decrease in the values of Fo,Fm and Fv/Fm and degradation of chlorophyll,more in Swarna than in Swarna-Sub1.During early submergence period,the activities of superoxide dismutase(SOD),ascorbate peroxidase(APX),dehydroascorbate reductase(DHAR),glutathione reductase(GR) against reactive oxygen species were increased in the both varieties.However,with the progress of submergence period(after 7 d),the activities of SOD,catalase(CAT),APX,guaiacol peroxidase(GPX),GR and DHAR declined,more in Swarna than in Swarna-Sub1.During re-aeration,Swarna-Sub1 showed significant increase of above antioxidant enzymes but not in Swarna.Swarna-Sub1 improves photosynthetic activity,showing higher photosynthetic rate compared to Swarna under submergence and subsequent re-aeration because of less degradation of chlorophyll,higher stomatal conductance,and efficient PSII activity along with better antioxidant protection from oxidative damage. 相似文献
11.
Jadwiga W. Płodowska Peter H. J. Jongebloed Pieter A. C. M. Van De Sanden Paul C. Struik 《Potato Research》1989,32(3):255-266
Summary Single-stemmed potato plants, cv. Bintje, were grown on a nutrient solution under controlled conditions. They were exposed
to a short drought stress, or remained untreated. Short-term changes in tuber volume and in specific leaf weight were measured
non-destructively.
Tubers from control plants increased rapidly in volume during the night and did not grow, or even shrivelled during the day.
Tubers of stressed plants did not show a uniform response; some tubers markedly declined in volume during the day. The patterns
of volume increase of stressed plants became erratic after the stress, mainly because some plants never fully recovered.
Patterns of diurnal fluctuation in tuber volume were similar to diurnal changes in specific leaf weight; tubers within the
same stressed plant sometimes reacted differently. In these cases the effects on the diurnal fluctuation partly reflected
the long-term effects, reported in an earlier paper. 相似文献
12.
ABSTRACTRice (Oryza sativa L.) is one of the most important staple foods in the world, however most improved rice varieties are susceptible to drought stress. A two-year study was conducted to explore the effects of various drought stresses and subsequent recovery on the accumulation and degradation of proline, total soluble sugar and starch in different rice varieties at vegetative stage. The results showed that relative water content in the leaves and sheaths of rice varieties significantly decreased under drought stresses, but not at the same rate. Under control and drought conditions, the water content in sheaths was higher than that in leaves. Interestingly, under severe drought stress in 2015, the leaf water content was higher than the sheath water content. The water distribution between leaves and sheaths might be a response of plants to protect leaf system from devastation by drought. Proline was highly accumulated under drought stress but rapidly decreased after re-watering. The drought tolerant variety DA8 expressed higher ability in accumulation of proline than susceptible varieties. In general, total soluble sugar and starch contents in leaves and sheaths of varieties decreased under drought stress conditions. Total soluble sugar and starch content of DA8 were less affected than other varieties under drought conditions. Our study indicated that metabolisms of total soluble sugar and starch in rice were affected by both environmental conditions and characteristics of varieties. Proline accumulation ability of varieties can be used as a useful indicator for drought tolerant potential in rice breeding for water-limited environments. 相似文献
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《水稻科学》2017,(5)
Drought is the major abiotic stress factor that limits rice production worldwide.To evaluate the osmotic stress responses in rice varieties under drought condition,a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India.The experimental setup comprises of initial hydroponic treatments at different osmotic potentials,artificially induced by desired strengths of polyethylene glycol(PEG6000),and followed by the pot planted experiments in the rain-out-zone.The activities of antioxidant enzymes,relative water content,cell membrane stability,photosynthetic pigments,proline content,along with plant growth parameters of the varieties under drought condition were evaluated.Moreover,the standard scores of these rice varieties were assessed under stress and recovery conditions based on the scoring scale of the Standard Evaluation System for rice.Among the 42 rice varieties,we identified 2 rice varieties,Swarnaprabha and Kattamodan,with less leaf rolling,better drought recovery ability as well as relative water content,increased membrane stability index,osmolyte accumulation,and antioxidant enzyme activities pointed towards their degree of tolerance to drought stress.The positive adaptive responses of these rice varieties towards drought stress can be used in the genetic improvement of rice drought resistance breeding program. 相似文献
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Frost resistance of interspecific and varietal potato crosses was evaluated at Bogotá, Colombia using intact plants in a programmed low temperature growth cabinet. Plants were exposed to a 2 hour frost during the dark period and the minimum test temperature was successively lowered 1 C on subsequent nights. The foliage was visually scored for damage 10–12 hours after each frost. While most commercial varieties were killed at—2 to—3 C (28 to 26 F), 101 of 121 clones which have been bred specifically for frost resistance survived to at least—5 C (23 F) and some crosses resisted—9 C (16 F) without observable foliar damage. This suggests the possibility of obtaining cultivated varieties from varietal parents of cultivated species such as G. Andigena, G. Phureja, G. Stenotomum,S. ajanhuiri, and others, which are reasonably frost resistant. 相似文献
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以3个海滨雀稗(Paspalum vaginatum)品种(Sea Isle2000、Platinum、Supreme)及其经辐射诱变筛选出的7个突变体为试验材料,在干旱胁迫条件下通过测定叶片相对含水量(RWC)、叶片相对电导率(REC)、脯氨酸(Pro)含量、可溶性总糖含量(TSC)及叶片萎蔫系数等5个生理指标,综合评价其抗旱性。结果表明:干旱胁迫导致试验材料的RWC下降,叶片萎蔫系数、Pro、TSC、REC上升,但不同品种材料的变化幅度不同。突变体"PL-40-1"、"PL-40-2"、"SP-40-2"在干旱胁迫下,其RWC下降幅度显著低于对照,叶片萎蔫系数、Pro、TSC、REC的上升幅度均明显低于对照,说明突变体"PL-40-1"、"PL-40-2"、"SP-40-2"叶片的保水能力较强,抗旱性优于其亲本;而突变体"SI-50-1"、"SI-50-5"、"SI-60-6"、"PL-40-8"抗旱性不及其亲本。 相似文献
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《Industrial Crops and Products》2007,25(2):123-128
Aloe vera (Sábila) is used in folklore medicine and commercial cosmetology products in many countries. Little is known about the plant's physiological, growth, and yield responses under different irrigation regimes. The plant has a crassulacean acid metabolism (CAM) that allows water conservation within the tissue, and therefore, resistance to high water stress. A. vera plants were submitted to different irrigation regimes in a greenhouse experiment to evaluate the response of the physiologic processes such as stomatal resistance and transpiration as well as leaf growth and yield. The experiment consisted of three irrigation regimes under a completely randomized design. No initial effect on stomatal resistance or transpiration was exhibited, but as time elapsed changes in these variables were noted. We suggest that the high water content in the parenchyma maintains stomatal opening despite water stress. In a subsequent period, the leaves that were submitted to water stress at the beginning, showed stomatal opening reduction related to low soil water potential. The low soil water potential reduced leaf weight, plant growth rate, and leaf number, mainly in leaf growth during the experiment confirming the sensitivity of new leaves to water stress. The results suggest that the low leaf temperature increases stomatal resistance, decreases plant and leaf growth rates. This behavior is opposite to other CAM species in semiarid condition. 相似文献