Effect of salinity on growth,mineral composition,and water relations of grafted tomato plants

A greenhouse experiment was designed in order to evaluate growth, water relations, and nutrient concentrations of grafted and ungrafted tomato plants grown under varying levels of salinity (0, 30, or 60 mM NaCl). Two cultivars, ‘Fanny’ and ‘Goldmar’, were grafted onto AR‐9704, using the cleft‐grafting method. Growth of grafted ‘Fanny’ plants was higher than that of ungrafted plants. Growth of ‘Goldmar’ plants was not affected by salinity treatments or grafting, but it was slower than for ‘Fanny’. Leaf turgor showed no significant differences between grafted and ungrafted plants or between salinity levels. The stomatal conductance (G_s) was higher for grafted than for ungrafted plants, and salinity decreased it significantly and progressively in both grafted and ungrafted plants and in both varieties. The concentrations of Na⁺ and Cl^– were significantly higher in ungrafted than in grafted ‘Fanny’ plants. ‘Fanny’ was more tolerant when grafted, probably due to reduced accumulation of Na⁺ and/or Cl^– in the shoot.     

Silicon-induced changes in growth,ionic composition,water relations,chlorophyll contents and membrane permeability in two salt-stressed wheat genotypes

We investigated the effect of exogenously applied silicon (Si) on the growth and physiological attributes of wheat grown under sodium chloride salinity stress in two independent experiments. In the first experiment, two wheat genotypes SARC-3 (salt tolerant) and Auqab 2000 (salt sensitive) were grown in nutrient solution containing 0 and 100 mM sodium chloride supplemented with 2 mM Si or not. Salinity stress substantially reduced shoot and root dry matter in both genotypes; nonetheless, reduction in shoot dry weight was (2.6-fold) lower in SARC-3 than in Auqab 2000 (5-fold). Application of Si increased shoot and root dry weight and plant water contents in both normal and saline conditions. Shoot Na⁺ and Na⁺:K⁺ ratio also decreased with Si application under stress conditions. In the second experiment, both genotypes were grown in normal nutrient solution with and without 2 mM Si. After 12 days, seedlings were transferred to 1-l plastic pots and 150 mM sodium chloride salinity stress was imposed for 10 days to all pots. Shoot growth, chlorophyll content and membrane permeability were improved by Si application. Improved growth of salt-stressed wheat by Si application was mainly attributed to improved plant water contents in shoots, chlorophyll content, decreased Na⁺ and increased K⁺ concentrations in shoots as well as maintained membrane permeability.     

Effects of NaCl salinity on some leaf nutrient concentrations,non-photochemical quenching and the efficiency of the PSII photochemistry of two Iranian pomegranate varieties under greenhouse and field conditions: Preliminary results

The present research was conducted to study the responses of ‘Malas–e–Saveh’ (M) and ‘Shishe–Kab’ (Sh) Iranian pomegranates to sodium chloride (NaCl) stress under greenhouse and field conditions. Treatments included waters electrical conductivity (EC = 1.5, 3, 6, 9 and 12 dS m^?1 for greenhouse) and (EC = 1.05 as control, 4.61 and 7.46 dS m^?1 for field studies). Interactive effects of salinity × variety indicated the highest chlorophyll and leaf potassium concentration, and the lowest leaf chloride and sodium in control under greenhouse study. Non-photochemical quenching, effective quantum yield of photochemical energy conversion in PSII reduced under the highest salinity level in field, however, basal quantum yield of non-photochemical processes in PSII increased in the highest salinity. Sodium and chloride increased with increased in salinity. Calcium, magnesium and iron significantly decreased with increased in salinity. It seems that there are differences between pomegranate cultivars and Malas-e-Saveh is more tolerant compared with Shishe Kab.     

Cell membrane stability and leaf water relations as affected by phosphorus nutrition under water stress in maize

Abstract

A field experiment was conducted to investigate the effect of P nutrition under water stress on the cell membrane stability measured by the polyethylene glycol test, plant growth, and internal plant water relations in maize (Zea mays L.). Adaptation to water deficits with improved P nutrition was observed. The cell membrane stability increased, leaf water potential and osmotic potential decreased, and turgor potential increased with improved P nutrition. Osmoregulation was evident with improved P nutrition. Sugar and K were the major osmotic contributors. Total plant dry weight and relative growth rate increased with improved P nutrition under water stress, suggesting that the supply of extra P to plants may be beneficial to increase the tolerance to drought.     

Barley growth,yield, antioxidant enzymes,and ion accumulation affected by PGRs under salinity stress conditions

Application of plant growth regulator (PGR) may alleviate some negative effects of environmental stresses such as salinity. A controlled environment experiment was conducted to study barley (Hordeum vulgare L. cv. Reyhane) growth, yield, antioxidant enzymes and ions accumulation affected by PGRs under salinity stress conditions at Shiraz University during 2012. The treatments were PGRs at four levels—water (as control), cycocel (CCC, 19 mM), salicylic acid (SA, 1 mM), and jasmonic acid (JA, 0.5 mM)—and four salinity levels—no stress (0.67 dS m^?1, as control), 5, 10, and 15 dS m^?1, which were arranged in a factorial experiment based on completely randomized design with four replicates. The results showed that salinity stress significantly decreased plant height, peduncle length, leaf area, ear length, grain number, dry weight, grain yield, harvest index, potassium (K⁺) accumulation, and potassium/sodium (K⁺/Na⁺) concentration ratio, which were closely associated with stress severity. However, PGRs compensated some of these negative effects, so that SA foliar application had the most ameliorative effect. Salt stress also increased Na⁺ accumulation as well as the activity of peroxidase, catalase, and superoxide dismutase (SOD). Since ion discrimination and enhanced antioxidant enzymes are associated with salt tolerance, in this experiment PGRs application might have enhanced K⁺ accumulation and antioxidant enzyme activity. The activity of SOD and K⁺/Na⁺ ratio were found to be useful in salt tolerance manipulation in barley plants.     

樱桃番茄叶片气孔特征和气体交换过程对NaCl胁迫的响应

为探讨樱桃番茄叶片气孔特征和气体交换过程对盐胁迫的响应机理,通过向营养液中添加NaCl盐,配制成0(对照)、0.05、0.10、0.15、0.20、0.25 mol/L浓度的Na Cl营养液,在人工气候箱条件下对樱桃番茄幼苗进行为期21 d的光照培养。结果表明,不同浓度NaCl溶液对气孔长度、气孔周长、气孔宽度和气孔形状指数均产生显著影响(P0.05),但其最大值均小于对照。随着Na Cl浓度的增加净光合反应速率(Pn)呈明显下降趋势,且在重度Na Cl胁迫(0.25 mol/L)下Pn同其他盐浓度处理的差异均为显著水平(P0.05)。同时,樱桃番茄叶片的蒸腾速率(T_r)、气孔导度(G_s)和细胞间CO_2浓度(C_i)随NaCl浓度的增加而降低,且与对照存在显著差异(P0.05)。另外,NaCl胁迫导致樱桃番茄叶片水平的水分利用效率(water use efficiency,WUE)降低,尤其是重度Na Cl胁迫(0.25 mol/L)的WUE比对照显著降低48%(P0.05)。此外,叶绿素含量随NaCl浓度增加先升高后降低。可见,NaCl胁迫条件下叶片通过调整单个气孔形态(气孔开度大小)和气孔分布特征(气孔密度和空间分布格局)优化气体交换效率,但其在重度盐胁迫下优化气体交换效率的能力却非常有限。研究结果可为樱桃番茄耐盐品种选育和盐碱地丰产增收提供依据。     

Adjustment of mineral ratio and composition in rice genotypes under varied salinity regimes

A study of the salinity effect on mineral content in rice genotypes differing in salt tolerance was conducted in a factorial Completely Randomized Design experiment. The results indicated that the genotypes developed differently by mutation conventional breeding. NS15 represented as salt-sensitive, Pokkali was included as an internationally salt-tolerant check and Iratom24 was moderately tolerant. The content of Na⁺, Ca²⁺, Mg²⁺ and Cl^? followed an increasing pattern in roots and shoots of all the rice genotypes due to increasing salinity levels except Ca²⁺ and Mg²⁺ in the root. However, the concentration of K⁺ showed more or less an increasing pattern in root and a decreasing pattern in shoot. The concentration of Na⁺ and Ca²⁺ sharply increased with increasing the salinity levels in both the roots and shoots of NS15. The concentration of K⁺ sharply decreased in shoot and increased in the root of susceptible genotype NS15 with increasing salinity over 6 dS m^?1 salinity levels, where the transformation of K⁺ from root to shoot was disrupted by Na⁺. The Cl^? content sharply increased with increasing salinity in the root of NS15 as compared to shoot. The effect of different salinity levels on Na⁺/K⁺ ratio in the shoots of the selected rice genotypes sharply increased in susceptible genotype NS15 as compared to the other genotypes.     

Effect of salinity on growth,photosynthesis and mineral composition in leguminous plant Alhagi pseudoalhagi (Bieb.)

Leguminous plant Alhagi pseudoalhagi was subjected to 0 (control), 50, 100, and 200 mM NaCI treatments during a 30 d period to examine the mechanism of tolerance to salinity. Plant dry weight, net CO₂ assimilation rate, leaf stomatal conductance, intercellular CO₂ concentration, and solute concentration in leaves, stems, and roots were determined. Total plant weight in the 50 mM treatment was 170% of that of the control after 10 d of treatment. Total plant weight was lower in the 100 and 200 mM treatments than in the control. The leaf CO₂ assimilation rate was approximately 150% of that of the control in the 50 mM treatment, but was not affected significantly by 100 mM of NaCI, while it was reduced to about 60% of that the control in the 200 mM treatment. Similarly stomatal conductance was consistent with the CO₂ assimilation rate regardless of the treatments. Intercellular CO₂ concentration was lower in the NaCI-treated plants than in the control. Changes in CO₂ assimilation rate due to salinity stress could be mainly associated with stomatal conductance and the carboxylation activity. Although the leaf Na⁺ concentration increased to 900 mmol kg^-1 dry weight in the 200 mM treatment compared to 20 mmol kg^-1 in the control, the plants did not die and continued to grow at such a high leaf Na⁺ concentration. Uptake and transportation rates of Na+, Ca²⁺, Mg²⁺, and K⁺, and the accumulation of N were promoted by 50 mM NaCI. Na⁺ uptake rate continued to increase in response to external NaCI concentration. However, the uptake and transportation rates of Ca²⁺, Mg²⁺, and K⁺ behaved differently under 100 and 200 mM salt stress. The results suggest that A. pseudoalhagi is markedly tolerant to salinity due mainly to its photosynthetic activity rather than to other physiological characteristics.     

Growth response and ion homeostasis in two bermudagrass (Cynodon dactylon) cultivars differing in salinity tolerance under salinity stress

Bermudagrass (Cynodon dactylon) is a salinity-tolerant turfgrass that has good use potential in the saline-alkali lands of warm regions. However, the systematic Na⁺ and K⁺ regulation mechanisms under salinity stress remain unclear at the whole plant level. Two bermudagrass cultivars differing in salinity tolerance were exposed to 0, 50, 100, 200, or 300 mM NaCl in a hydroponic system. Growth, absorption, transportation, and secretion of Na⁺ and K⁺, and gas exchange parameters were determined in both cultivars. K⁺ contents were decreased and Na⁺ contents and Na⁺/K⁺ ratios were increased in both bermudagrasses with increased salinity; however, lower Na⁺ content and Na⁺/K⁺ ratio and more stable K⁺ content were found in the leaves of the salinity-tolerant ‘Yangjiang’ than the salinity-sensitive ‘Nanjing’. Higher Na⁺ contents in root cortical cells were found than in the stele cells of ‘Yangjiang’, but the opposite was observed in ‘Nanjing’. Lower Na⁺ contents and higher K⁺ contents were found in vessels for ‘Yangjiang’ than for ‘Nanjing’. Salinity stress increased the selective transport of K⁺ over Na⁺ from roots to leaves and the Na⁺-selective secretion via salt glands, which were stronger in ‘Yangjiang’ than ‘Nanjing’. Net photosynthetic rate and stomatal conductance decreased in the two bermudagrasses with increased salinity; however, they were more stable in ‘Yangjiang’. The results suggested that bermudagrass could reduce Na⁺ accumulation and maintain K⁺ stability in leaves under salinity stress by restricting Na⁺ into vessels in roots, selectively transporting K⁺ over Na⁺ from roots to leaves, selectively secreting Na⁺ via leaf salt glands, and maintaining suitable stomatal conductance.     

水盐胁迫下番茄叶片对温度、湿度的光合反应

Greenhouse tomato plants (Lycopersicon esculentum Mill cv. Capello) were grown on peat-based substrate and treated with high (4.5 mS cm^-1) and low (2.3 mS cm^-1) nutrient solution electric conductivity (EC) under high and low substrate water contents. Four weeks after the beginning of the treatments, photosynthesis (P_N) was measured under different humidity and temperatures to examine the interactive effects with rhizosphere salinity and water deficit. A rectangular hyperbolic model fitted the light-photosynthesis curve. Photosynthetic capacity (P_C) was decreased but quantum yield (Y_Q) was increased by rhizosphere salinity caused by high EC. P_N was decreased by low humidity only in high EC- and/or water-stressed plants. Under high photosynthetic photon flux (PPF), low humidity induced P_C decline in water-stressed plants and P_N oscillation in high-EC-treated plants. P_N increased steadily as the leaf temperature changed from 18 ℃ to 23 ℃ and then decreased steadily from 23 ℃ to 38 ℃. At 34 ℃, P_N decreased significantly in water-stressed plants. Dark respiration (R_D) increased in an exponential manner as the leaf temperature changed from 18 ℃ to 38 ℃ to an extent about ten times higher under 38 ℃ than under 18 ℃. Our data suggested that P_N decrease under high temperature was attributed, at least in part, to the increased R_D. R_D in high EC- and/or water-stressed plants was higher than that in the plants of control under lower temperature but lower than that in the plants of control under high temperature. The analysis of stomatal and mesophyll conductance showed that low humidity effect was mainly through stomatal response while temperature effect was mainly through biochemical functions. The result showed that environmental stresses affected P_N in an additive or synergistic manner.     

Seed germination and seedling growth parameters in nine tall fescue varieties under salinity stress

ABSTRACT

To assess seed germination parameters and identifying tolerant varieties, seeds of nine tall fescue varieties (Festuca arundinacea Schreb.) were germinated under various salinity levels for 14 days. Tall fescue is considered ‘moderately tolerant’ to salinity stress, but our study revealed a remarkable diversity among the tested varieties. Armani, Essential, Fatcat, and Starlett were found to reach the same final germination (>90%), irrespective of NaCl concentration up to 15 ds m^?1 NaCl; Asterix and Meandre expressed lower germination under the highest salinity level (>75%); and final germination decreased in Eyecandy, Rhizing star, and Thomahawk gradually with increasing salinity (>55%). The main effect of increasing salinity was a delay in germination, and our study suggests that the recording of final germination, which is performed on day-14 in a standard germination test, should be postponed in order to understand the full effect of salinity on germination potential. Nonetheless, a delay in germination will affect turf quality negatively and hence there is good reason to test for salinity tolerance when choosing a variety for sowing on saline soil. Further, our findings indicate a future perspective for breeding for improved salinity tolerance in tall fescue by the identification of salinity-tolerant breeding lines or varieties.     

利用高光谱估测干旱胁迫下接菌根菌大豆叶绿素含量

该研究旨在利用高光谱遥感动态监测干旱胁迫下接种菌根植物生长状况,为菌根技术在旱区农业中的推广提供一定的理论基础。以盆栽大豆为对象,在不同接种丛枝菌根时期采用高光谱遥感技术监测不同干旱胁迫下接菌和不接菌处理大豆叶片的叶绿素含量变化,对比分析了3个水分梯度下及同一水分梯度下接菌和不接菌处理的大豆地上部分干质量、叶绿素含量和叶片光谱在可见光和近红外区域的响应特征差异,建立了大豆叶绿素含量与多个光谱变量的估测模型。研究结果表明:接菌第45天和第64天,同一水分梯度下接菌大豆地上部分干质量优于不接菌处理,且其叶绿素含量也高于不接菌,这些差异在叶片光谱曲线特征中同样得以反映,接种菌根在一定程度上可以缓解干旱胁迫对植物生长的影响;基于多元线性逐步回归方法建立的一阶微分模型能较准确地估测干旱胁迫下接菌大豆的叶绿素含量,其模型决定系数和预测检验决定系数分别为0.90和0.84,具有较高的精度和良好的预测能力。     

Growth,ion accumulation,and lipid composition of two olive genotypes under salinity 1

Olive (Olea europaea L cv. Leccino and cv. Frantoio) plants grown in aeroponic cultivation system were supplied with Hoagland solutions containing 0 and 150 mM NaCl for 4 weeks. Sodium (Na⁺), chloride (Cl^‐), and potassium (K⁺) concentration was measued on 15‐day‐old leaves and K⁺/Na⁺ selectivity ratio was calculated. Plant water relations were estimated on the same leaves by measuring leaf bulk water and osmotic potentials, and by calculating leaf turgor pressure. Root and leaf tissues were also analysed for lipid composition, estimating free sterol (FS), glycolipid (GL) and phospholipd (PL) content. The salt‐sensitive Leccino accumulated more Na⁺ and Cl^‐ in the leaves and showed a lower K⁺/Na⁺ selectivity ratio than the salt‐tolerant Frantoio. The FS/PL ratio and the content of GL (namely mono‐galactosyldiglyceride, MGDG) in the roots were related to the salt accumulation in the shoot. Salinity‐induced changes on root lipids were more important in Frantoio than in Leccino, indicating the specific role of the roots in salt exclusion mechanisms. Conversely the effect of salinity on leaf lipid composition was more important in the leaves of the salt‐sensitive Leccino.     

Amelioration of salinity stress in different basil (Ocimum basilicum L.) varieties by vesicular-arbuscular mycorrhizal fungi

Although the salt resistance mechanisms in plants have received much consideration for many years, varieties’ differences affecting salt resistance are still unsettled. Within the Ocimum genus there occur about 200 species in different varieties and forms. A pot experiment was performed to better understand salt stress responses in crop plants; we compared the impacts of salinity stress on growth and physio-biochemical characteristics in three varieties of basil (Ocimum basilicum) var. odoratus, O. b. var. alba and O. b. var. purpurascens) grown under four levels of salinity stress (0, 50, 100, and 150?mM NaCl) with mycorrhiza (Glomus clarum Nicol. &; Schenck) or without. Results showed significant differences within salinity treatments in all cultivars studied. In this study, the biomass production and physio-biochemical parameters of all cultivars reduced with raised salinity levels except concentration of reducing sugars, sodium, and proline at 150 mM of NaCl, only the variety ‘purpurascens’ didn't show reduction and observed resistant against severe salinity. The colonization of arbuscular mycorrhiza fungi enhanced the biomass production and accumulation of nutrients, reducing sugars, total soluble carbohydrates, photosynthetic pigments, proline, and protein by reducing Na. This study should help understand the function of AMF fungi in basil cultivars’ tolerance to salinity stress.     

Comparison of growth and mineral accumulation of two solanaceous species,Solanum scabrum Mill. (huckleberry) and S. melongena L. (eggplant), under salinity stress

Solanum scabrum Mill. (huckleberry) is widespread in West, East and Central Africa, where it constitutes one of the most important leafy vegetables. However, the salinity tolerance of this crop has not yet been assessed. The objective of this study was to assess the response of huckleberry to salinity stress in comparison with eggplant (S. melongena L.). Four-week-old seedlings of both species were subjected to two levels of salinity stress, 50 mM and 150 mM sodium chloride (NaCl), for 14 d. Leaf water potential of both species decreased with increasing salinity stress. This decrease was lower in huckleberry than in eggplant. Total dry weight and total leaf area were also decreased by salinity, and the reductions of total dry weight and total leaf area under the 50 mM treatment compared with the control were 25 and 18% in huckleberry, while they were 47 and 55% in eggplant, respectively. The increases in leaf sodium (Na) accumulation in the 50 and 150 mM treatments compared with the control were 65 and 66% for eggplant and 18 and 36% for huckleberry, respectively. Na accumulation in stem and root in huckleberry was higher than that of leaf, whereas it was the reverse in eggplant under both salinity treatments. Huckleberry accumulated less Na in the leaves than eggplant, suggesting that huckleberry might reduce the transport of Na to its leaves more effectively than eggplant. The decrease of potassium (K) accumulation and the increase of Na in leaves by salinity resulted in a higher Na/K ratio in leaves, but this trend was greater in eggplant than in huckleberry. The calcium (Ca) concentration in leaves of huckleberry was also increased by salinity, whereas that of eggplant was decreased. These results indicate that huckleberry is more tolerant to salinity than eggplant, and less decrease in leaf area associated with lower leaf Na and increased Ca concentrations may be important in enhancing quality and sustaining productivity of the crop under this stress.     

Growth and acquisition of Na,K and Ca in some elite sweetpotato [Ipomoea batatas (Lam.) L.] genotypes under salinity stress

Soil salinity is a concern in the wake of climate change challenges due to rising sea levels and coastal salinity in Papua New Guinea. A greenhouse experiment was conducted in Split Plot design, with five elite sweet potato genotypes (main-plot factors) and three levels of sodium chlroide (NaCl) concentrations (sub-plot factors) replicated six times. The vine cuttings of genotype RAB 45 showed very low mortality percentage (33%) at 600 mM NaCl concentration. At salinity level of 200 mM NaCl, aerial dry biomass of the genotypes was inversely but significantly (r = –0.40; p < 0.05) related to the accumulation of sodium (Na⁺) in the tissues. The Na⁺ accumulation in the tissues was antagonistic to the potassium (K⁺) and calcium (Ca²⁺) ions. Among the sweetpotato genotypes, Na⁺/K⁺ ratio decreased in the following order: RAB 45> KAV 11 > Northern Star > DOY 2 > L 46, which was more or less corroborated with the trend in the aerial dry matter.     

Characterization of salt tolerance in tomato plant in terms of photosynthesis and water relations

Three commercial tomato cultivars (UC-97, Momotaro, and Edkawi) were subjected to a gradual increase of NaCI concentrations and the effect on biomass production and its parameters was compared. The data indicated that salinity reduced plant growth and the reduction was more pronounced in UC-97 and less in Edkawi. The apparent photosynthetic rate (P _o) was also depressed by the salt treatment and the depression was more remarkable in UC-97 and less in Edkawi. Edkawi shoot showed a much higher concentration of sodium ion and proline compared with the other cultivars, which may result in the maintenance of a higher turgor potential. In all the cultivars examined the stem diameter decreased after the beginning of exposure to light and recovered after the light was turned off. The decrease in the stem diameter during day light was enhanced and the recovery at night decreased after 1 d of salt treatment and the changes in the stem diameter were less conspicuous in Edkawi than in the other cultivars. These results suggest that Edkawi is more tolerant to salinity than the other cultivars due to a higher ability of maintaining the root function for the uptake and supply of water to shoot under salinity conditions but not due to the adjustment of transpiration from stomata.     

Leaf photosynthesis,chlorophyll fluorescence and ion content of barley (Hordeum vulgare) in response to salinity

Eight barley genotypes contrasting in their salinity tolerance were assessed for their chlorophyll fluorescence, photosynthetic performance, lipid peroxidation level and ionic content. A pot experiment was conducted in Borj-Cedria (Tunisia), in a wire house with a glass roof to avoid rainfall. The assay consisted of three treatments (0, 100 and 200 mM NaCl) with eight barley genotypes following a completely randomized design. Each pot was considered as one replicate and nine replicates were used for each genotype and treatment. The salt-tolerant genotypes Kerkna and Tichedrett recorded the highest tolerance for photosynthesis and potassium accumulation, whereas the susceptible genotypes were mostly affected at severe salinity. Contrasting behavior was noted for fluorescence attributes, while PSII yield was unchanged reflecting good protection against photodamage. Photosynthetic performance, enhanced water use efficiency, maintained leaf K⁺ and oxidative defense remain the key components for tolerance mechanisms. Salt-tolerant barley could be suitable for management of salt-affected soils.     

被动荧光探测水分胁迫对玉米叶片影响的初步研究

利用叶绿素荧光被动探测方法初步探讨了水分胁迫对玉米叶片生理机能的影响。水分胁迫梯度通过将离体叶片放在干燥器时间不同而获得。室内采用积分球耦合ASD光谱仪，结合加/不加滤光片照明的方法得到反射率差值光谱，即代表叶绿素荧光光谱。结果表明随着叶片含水率的降低，叶绿素荧光发射峰的位置几乎没有变化，峰高在686 nm处有先上升后逐渐降低的趋势，在740 nm处则缓慢下降。双峰比值Dif₆₈₆/Dif₇₄₀与叶片含水率呈负相关关系(R²=0.3850，n=21)，不同水分胁迫程度下利用调制式荧光仪测定的荧光参数Fv/Fm与740 nm荧光光谱峰值线性正相关，与双峰比值有负相关趋势。表明该被动方法可以探测水分胁迫引起的叶片光系统受胁状况，为田间被动遥感探测植物叶绿素荧光和生理状态提供参考。