Assessment of tolerance to NaCl salinity of five olive cultivars,based on growth characteristics and Na and Cl exclusion mechanisms     

Haifa Kchaou  Ajmi Larbi  Kamel Gargouri  Mohamed Chaieb  Fermín Morales  Monji Msallem 《Scientia Horticulturae》2010

Changes caused by NaCl-induced salinity on several growth parameters and ions accumulation have been measured in five olive (Olea europaea L.) cultivars (‘Chemlali’, ‘Chetoui’, ‘Koroneiki’, ‘Arbequina I18’, and ‘Arbosana I43’) growing in a greenhouse in nutrient solution pot experiment. One-year-old plants were transplanted to sand–perlite (1:1) culture, and were irrigated with half-strength Hoagland nutrient solution containing NaCl at various levels (0.5, 50, 100 and 200 mM). Salinity induced significant decrease in growth parameters, but to a different extent in each cultivar. Leaf growth and total leaf area per plant were significantly affected by all salinity treatments in all studied cultivars, being ‘Arbequina I18’ the most sensitive cultivar. Leaf drop phenomenon was observed from 60 days after salt application at high salinity treatments, mainly in Arbequina I18. Contrary to leaf area, leaf thickness increased progressively during the experiment. ‘Chemlali’ developed thicker leaves at the two highest salinity treatments when compared to the other cultivars. Na⁺ and Cl⁻ concentrations were higher in roots than in shoots and leaves in most of the cultivars investigated. The effectiveness of Na⁺ exclusion mechanism in the roots differed significantly among studied cultivars, working effectively in ‘Chemlali’ (by inhibiting translocation of Na⁺ to the aerial part) and being much less efficient in ‘Arbequina I18’. Furthermore, leaf abscission can be considered as an additional tolerance mechanism of olive cultivars allowing the elimination of leaves that had accumulated Na⁺ and Cl⁻ ions. Tolerance to salinity stress was as follows: ‘Chemlali’ > ‘Chetoui’ > ‘Arbosana I43’ > ‘Koroneiki’ > ‘Arbequina I18’. This order of salt tolerance was indicated by lower reduction in plant growth parameters (shoot elongation, trunk diameter, total plant dry weight, internodes length, and total leaf area), the increase of leaf thickness, and by the effectiveness of the exclusion mechanism of Na⁺ and Cl⁻ in the root system.  相似文献   

Alleviation of salt-induced adverse effects in eggplant (Solanum melongena L.) by glycinebetaine and sugarbeet extracts     

Wasim Abbas  Muhammad Ashraf  Nudrat Aisha Akram 《Scientia Horticulturae》2010

Two eggplant cultivars, Dilnasheen and Bemisal, were selected to assess whether pure GB and sugarbeet extract could effectively ameliorate the harmful effects of salt stress on eggplant (Solanum melongena L.), under saline conditions. Salt stress markedly suppressed the growth, yield, photosynthetic capacity, internal CO₂ level, transpiration, and stomatal conductance in both cultivars. Potassium (K⁺) and Ca²⁺ contents and K⁺/Na⁺ ratios of both root and leaf were also reduced, while GB and proline in leaves, and Na⁺ and Cl⁻ contents in roots and leaves were significantly enhanced. Exogenously applied glycinebetaine and sugarbeet extracts significantly counteracted the salt-induced adverse effects on growth, yield, various gas exchange characteristics, GB and leaf K⁺, Ca⁺, Cl⁻ and Na⁺. However, GB and sugarbeet extract showed differential effects on photosynthetic rate, stomatal conductance and transpiration, internal CO₂ level, C_i/C_a ratio, leaf K⁺, Ca²⁺, and Cl⁻ contents, and K⁺/Na⁺ ratio. Sugarbeet extract proved better than the GB in improving growth, photosynthetic rate, transpiration, stomatal conductance, yield and GB accumulation. Since, sugarbeet extract contains a substantial amount of GB along with a variety of other important nutrients so it was found as effective as pure GB in improving growth and some key physiological processes in eggplant under salt stress. Thus, it can be used as an alternative cheaper source of GB for its use as an ameliorative agent for protecting plants against the hazardous effects of salt stress.  相似文献   

Additional nitrogen fertilization affects salt tolerance of lemon trees on different rootstocks     

V. Gimeno  J.P. Syvertsen  M. Nieves  I. Simón  V. Martínez  F. García-Sánchez 《Scientia Horticulturae》2009

Irrigation with saline water is one of the major problems in citrus crop in arid and semi-arid regions. Because rootstock and fertilization play an important role in citrus salt tolerance, we investigated the influence of the nitrogen fertilization and rootstock on salt tolerance of 2-year-old potted Fino 49 lemon trees. For that, trees grafted on Citrus macrophylla (M) or Sour orange (SO) rootstocks were watered for 12 weeks with complete nutrient solution containing either 0 mM NaCl (control, C), 50 mM NaCl (S), 50 mM NaCl with an additional 10 mM potassium nitrate (S + N), or 50 mM NaCl with a 1% KNO₃ (S + Nf) foliar spray application. Trees on M were more vigorous than trees on SO and saline treatments reduced leaf growth similarly in trees on both rootstocks. Trees on SO had a lower leaf Cl⁻ and Na⁺ concentration than those on M. Additional soil nitrogen (S + N) decreased leaf Cl⁻ concentration and increased leaf K⁺ concentration in salinized trees on both rootstocks. However, the salinity-induced reduction leaf growth was similar in S + N and S trees. This was due to osmotic effect, beside leaf Cl⁻ and Na⁺ toxicity, played an important role in the growth response of Fino 49 lemon to the salt stress. Additional foliar nitrogen in the S + Nf treatment also reduced leaf Cl⁻ concentration relative to the S treatment but trees from S + Nf treatment had the lowest leaf growth. Net assimilation of CO₂ (ACO₂$A_{\text{C}{\text{O}}_2}$), stomatal conductance (g_s) and plant transpiration were reduced similarly in all three salt treatments, regardless rootstock. Salinity reduced leaf water and osmotic potential such that leaf turgor was increased. Thus, the salinity-induced ACO₂$A_{\text{C}{\text{O}}_2}$ reductions were not due to loss of turgor but rather due to high salt ion accumulation in leaves.  相似文献   

Responses of eight chile peppers to saline water irrigation     

Genhua Niu  Denise S. Rodriguez  Evan Call  Paul W. Bosland  April Ulery  Erik Acosta 《Scientia Horticulturae》2010

Salt tolerance of five cultivars of Capsicum annuum L. Early Jalapeno, Golden Treasure, NuMex Sweet, NuMex Joe E. Parker, and Santa Fe Grande, two cultivars of C. chinense Jacq. Habanero and Pimienta De Chiera, and one accession of C. annuum, NMCA 10652, were evaluated in a field study. Seedlings were transplanted in late May to field raised beds containing loamy sand soils in a semi-arid environment. Plants were well irrigated throughout the experiment. Three saline solution treatments, prepared by adding NaCl, MgSO₄, and CaCl₂ to tap water at different amounts to create three salinity levels of 0.82 dS m⁻¹ (control, tap water), 2.5 dS m⁻¹, and 4.1 dS m⁻¹ electrical conductivity (EC), were initiated on 15th June and ended in late August. Among the eight varieties, NMCA 10652 had the highest survival percentage at 100% in the 4.1 dS m⁻¹ treatment, followed by ‘Early Jalapeno’, ‘NuMex Sweet’, ‘Pimienta De Chiera’, ‘Santa Fe Grande’, ‘Golden Treasure’, and ‘NuMex Joe E. Parker’. ‘Habanero’ had the lowest survival at 28%. Compared to control, final shoot dry weight of the plants irrigated with saline solution at 4.1 dS m⁻¹ was reduced by 92% in ‘Habanero’, followed by ‘Golden Treasure’ at 80%. For fruit fresh weight in 4.1 dS m⁻¹ vs. control, ‘Habanero’ had the highest reduction at 86%, followed by ‘Golden Treasure’ at 74%, while NMCA 10652 and ‘Santa Fe Grande’ had the least at 26% and 19%, respectively. NMCA 10652, the most tolerant to salinity, had the lowest leaf Na⁺ accumulation, while ‘Habanero’, the most sensitive to salinity, had the highest Na⁺ in the leaves. For leaf Cl⁻, ‘Early Jalapeno’ had the highest, while ‘Habanero’ had the lowest Cl⁻ accumulation in the leaves. Generally, sensitive varieties accumulated more Na⁺ and/or Cl⁻ in leaves, except for ‘Early Jalapeno’, which was relatively tolerant to salinity but had high Na⁺ and Cl⁻ accumulation in leaves.  相似文献   

Improving the fruit yield and quality of cucumber by grafting onto the salt tolerant rootstock under NaCl stress     

Yuan Huang  Rui TangQiuliang Cao  Zhilong Bie 《Scientia Horticulturae》2009

To investigate the feasibility of using salt tolerant rootstock to increase fruit yield and quality of cucumber under NaCl stress, a greenhouse experiment was carried out to determine fruit yield, leaf relative water content, fruit quality, and mineral composition of cucumber plants (Cucumis sativus L. cv. Jinchun No. 2), either self-grafted or grafted onto the commercial salt tolerant rootstock Figleaf Gourd (Cucurbita ficifolia Bouche) and Chaofeng Kangshengwang (Lagenaria siceraria Standl). Plants were grown in a substrate culture (peat:vermiculite:perlite = 1:1:1, v/v) and irrigated with half-strength Hoagland solutions containing 0, 30, or 60 mM NaCl. The results showed that salinity significantly reduced fruit yield of cucumber owing to a decrease both in mean fruit weight and fruit number. Rootstock had no significant effect on leaf relative water content. Plants grafted onto Figleaf Gourd and Chaofeng Kangshengwang had higher fruit number, marketable and total fruit yield than those of self-grafted plants under 0, 30, and 60 mM NaCl, which could be attributed to, at least in part, the higher K⁺ but lower Na⁺ and/or Cl⁻ contents in the leaves. Salinity improved fruit quality by increasing fruit dry matter, soluble sugar, and titratable acidity contents of all the plants, but had no significant effect on vitamin C content. In comparison to the self-grafted plants, plants grafted onto Figleaf Gourd and Chaofeng Kangshengwang had an overall improved fruit quality under NaCl stress owing to an increase in contents of soluble sugar, titratable acidity, and vitamin C, and a decrease in the percentage of non-marketable fruit and Na⁺ and/or Cl⁻ contents of fruits in comparison to the self-grafted plants, mainly under 60 mM NaCl. Overall, it is suggested that the use of salt tolerant rootstock could provide a useful tool to improve fruit yield and quality of cucumber under NaCl stress.  相似文献   

The effects of sodium chloride on ornamental shrubs     

Carla Cassaniti  Cherubino Leonardi  Timothy J. Flowers 《Scientia Horticulturae》2009,122(4):586-593

The use of saline waters is an option for the irrigation of salt tolerant ornamentals as competition for high quality water increases. However, despite the importance of ornamental shrubs in Mediterranean areas, salt tolerance of such species has received little attention. The aims of our investigation were to quantify the growth response and any injury symptom of 12 widely cultivated ornamental shrubs to irrigation with saline water and to investigate any possible relation with the concentration of Na⁺ and Cl⁻ in the plants. Species were irrigated with different salinities (10, 40, and 70 mM NaCl) for a 120-day period. At the end of salt treatment, plants were sampled and dry biomass recorded; the relative growth rate (RGR) was also calculated. Root and leaf samples from each species were used to evaluate Na⁺, K⁺ and Cl⁻ concentrations. Growth rates were significantly reduced in Cotoneaster lacteus, Grevillea juniperina and Pyracantha ‘Harlequin’, which also showed the highest percentage of necrotic leaves. The increasing external NaCl lead to an increase of Na⁺ and Cl⁻ in roots and leaves of the different species, although less Na⁺ was accumulated than Cl⁻: growth reduction well correlated with the concentration of Cl⁻ and/or Na⁺ in the leaves. The most sensitive species (i.e. C. lacteus, G. juniperina and Pyracantha ‘Harlequin’) had high concentrations of Na⁺ and/or Cl⁻ in their leaves and also showed a decrease in their leaf K⁺/Na⁺ ratios. Even though other species (i.e. Bougainvillea glabra, Ceanothus thyrsiflorus, Leptospermum scoparium, Leucophyllum frutescens and Ruttya fruticosa) demonstrated a high ion concentration in their leaves, they could be considered relatively salt tolerant as there was little growth reduction and few symptoms of injury in the leaves. In some other cases (i.e. Cestrum fasciculatum, Escallonia rubra and Viburnum lucidum) the observed tolerance was related to higher ion concentration in the roots compared to the leaves, probably indicative of a limited transport to the shoots. Only in Eugenia myrtifolia was the absence of symptoms associated with a limited Na⁺ and Cl⁻ uptake from the rhizosphere.  相似文献   

Physiological responses and adaptive strategies of tomato plants to salt and alkali stresses     

Xiaoping Wang  Shujuan Geng  Yong-Jun Ri  Donghui Cao  Jie Liu  Decheng Shi  Chunwu Yang 《Scientia Horticulturae》2011

In this study, seedlings of tomato were treated with salt stress or alkali stress. The growth, photosynthesis and concentrations of solutes and inorganic ions in tissue sap of stressed seedlings were measured to investigate the physiological adaptive mechanisms by which tomato tolerates alkali stress. The alkali stress clearly inhibited growth and photosynthesis. With increasing salinity, the Na⁺ concentration and Na⁺/K⁺ ratio in leaves increased, with greater degrees of increase under alkali than under salt stress. This indicated that high-pH caused by alkali stress might affect the control of roots on Na⁺ uptake and increased the intracellular Na⁺ to a toxic level, which might be the main cause of reductions of stomatal conductance and net photosynthetic rates under alkali stress. Under salt stress, organic acids (OAs), Na⁺, K⁺ and Cl⁻ were the main osmolytes in both roots and leaves. Under alkali stress, roots and leaves revealed different mechanisms of ion balance and osmotic regulation. Under alkali stress, in roots, OAs and Na⁺ were the main osmolytes, and the osmotic role of K⁺ was small; however, in leaves, OAs, Na⁺ and K⁺ all played important osmotic roles. The mechanisms governing ionic balance under both stresses were different. Under salt stress, the contribution of inorganic ions to keep ion balance was greater than that of OAs. However, under alkali stress, Cl⁻, H₂PO₄⁻ and SO₄²⁻ concentrations decreased, and tomato might have enhanced OA synthesis to compensate for the shortage of inorganic anions.  相似文献   

Effects of Stockosorb and Luquasorb polymers on salt and drought tolerance of Populus popularis     

Yong Shi  Jing Li  Jie Shao  Shurong Deng  Ruigang Wang  Niya Li  Jian Sun  Hua Zhang  Huijuan Zhu  Yunxia Zhang  Xiaojiang Zheng  Dazhai Zhou  Aloys Hüttermann  Shaoliang Chen 《Scientia Horticulturae》2010

The effects of two types of hydrophilic polymers on drought and salt resistance of 1-year-old cuttings of Populus popularis 35–44 were investigated in this study. The polymers used in the experiments were Stockosorb 500 XL (Stockosorb) (a granular type, cross-linked poly potassium-co-(acrylic resin polymer)-co-polyacrylamide hydrogel) and Luquasorb^® product (a powder type of potassium polyacrylate), which were manufactured by Stockhausen GmbH Krefeld and BASF Corporation in Germany, respectively. Drought or salt stress significantly decreased leaf photosynthesis and transpiration, as well as plant water-consumption and dry weight. A significant reduction occurred in Drought + NaCl-stressed plants. Soils treated by 0.5% Stockosorb or Luquasorb markedly alleviated the inhibition of plant growth and leaf gas-exchange that were caused by drought and/or salt stress treatments, and the occurrence of stress-induced leaf injury was delayed for 31 and 51 days, respectively. Experimental results showed that hydrophilic polymers in root media assisted P. popularis plants to tolerate the drought and salt stresses, due to the following reasons: (1) roots took up the retained water from hydrophilic polymers when water was deficient in the soil (Stockosorb-treated plants exhibited a higher rate of water uptake); (2) under saline conditions, Stockosorb and Luquasorb held Na⁺ and Cl⁻ in the soil solution due to their high water-holding capacity, thus limiting an excessive accumulation of toxic ions in the plant organs; furthermore, the exchangeable K⁺ that contained in Stockosorb and Luquasorb resulted in an improved K⁺/Na⁺ homeostasis in salinized plants; (3) hydrophilic polymers aided the plants to tolerate an interactive impacts of drought and salt stresses, which was mainly accounted for their water- and salt-holding capacities. In comparison, the growth and survival enhancement effects of the hydrophilic polymers on Drought + NaCl-treated plants was more evident by Luquasorb application, because it supplied water to plants at a lower rate during soil drying, thus prolonging the duration of water supply and allowed roots to grow in an environment of lower salinity for a long period of salt and drought stresses.  相似文献   

Mechanisms of salt stress tolerance in two rose rootstocks: Rosa chinensis ‘Major’ and R. rubiginosa     

《Scientia Horticulturae》2001,87(3):207-216

The responses of two rose rootstocks Rosa chinensis ‘Major’ and R. rubiginosa were investigated under salt stress. The distribution of chloride and sodium ions in all plant parts was determined. The salt treatments were applied through irrigation water containing 0, 5, 10, 20 and 30 mM NaCl. Necrosis on the leaves as a result of the NaCl treatments was observed with in rootstocks after two months. Leaf injury was more pronounced in R. chinensis ‘Major’ than R. rubiginosa. The rootstock R. rubiginosa showed a higher tolerance to the NaCl stress than R. chinensis ‘Major’. The survival of the plants under increased NaCl stress as well as the extent of leaf injury could be used in the determination of tolerance of the rose genotypes. The lower older leaves contained higher concentrations of Cl⁻ than the young upper leaves. Leaf samples had higher concentrations of Cl⁻ than stem samples taken from the same positions. The roots contained higher amounts of Cl⁻ than the stem samples. The plants accumulated higher amounts of Cl⁻ in comparison with Na⁺. The lower leaves of R. chinensis ‘Major’ had higher amounts of Na⁺ than in all other parts whereas R. rubiginosa had higher concentrations of Na⁺ in the roots than in all other parts.  相似文献   

Growth,biomass allocation and leaf ion concentration of seven olive (Olea europaea L.) cultivars under increased salinity     

Slavko Perica  Smiljana GoretaGabriela Vuletin Selak 《Scientia Horticulturae》2008

Olive (Olea europaea L.) is the major fruit tree in the Mediterranean region, often grown in locations where plants are exposed to increased salinity. To determine the effect of NaCl on shoot and root growth, dry matter allocation, leaf Na⁺ and K⁺ concentration, electrolyte (EL) and K⁺ leakage (KL), seven olive cultivars of different origins were grown in nutrient solution containing 0, 33, 66, 100 or 166 mM NaCl for three months. The general effect of salinity was linear and quadratic decrease of observed plant growth parameters. Different responses of tested cultivars to applied levels of salinity were found for stem dry weight, shoot length and number of leaves. As salinity increased, growth of ‘Manzanillo’ declined sharply, whereas ‘Frantoio’ was the most tolerant to growth reduction in most of the observed growth parameters. Allometric analysis showed that biomass allocation under salinity stress was similar in all cultivars, but the slope between shoot weight and total plant weight decreased as salinity increased. Since the higher allocation in roots was not found, it seems that salinity only slowed the above ground plant canopy growth. Sodium concentration in leaves of all cultivars increased as salinity increased with the highest increment reached when the salinity of nutrient solution was raised from 100 to 166 mM NaCl. Significant differences among genotypes were found in leaf Na⁺ and K⁺ concentration and K⁺:Na⁺ ratio, but they were not related to the growth rate. Generally, ‘Frantoio’ and ‘Oblica’ accumulated less Na⁺ and were able to maintain higher K⁺:Na⁺ ratios as compared to other genotypes. Electrolyte leakage and KL linearly increased with increasing salinity and the magnitude of the response depended upon the olive cultivar.  相似文献   

Regeneration and characterization of plants derived from leaf in vitro culture of two sweet orange (Citrus sinensis (L.) Osbeck) cultivars     

Ehsan Ullah Khan  Xing-Zheng Fu  Jing Wang  Qi-Jun FanXiao-San Huang  Ge-Ning ZhangJie Shi  Ji-Hong Liu 《Scientia Horticulturae》2009

In the current work attempts were made to investigate culture of leaf explants derived from in vitro seedlings of two sweet orange (Citrus sinensis (L.) Osbeck) cultivars, Bingtangcheng and Valencia. Effects of several factors, including culture medium, lighting condition, explant age and genotype on regeneration response were examined based on three parameters, percentage of explants producing shoots, mean number of shoots per explant and shoot forming capacity. Culture of the explants on shoot-inducing media (SIM) composed of MT salts supplemented with different growth regulators gave rise to disparate shoot regeneration, in which SIM₁ (MT + 0.5 mg L⁻¹ BA + 0.5 mg L⁻¹ Kinetin + 0.1 mg L⁻¹ NAA + 3% sucrose + 0.8% agar, pH 5.8) was shown to be the most effective medium for direct induction of shoots from leaf explants. Highly significant difference in the response of shoot bud regeneration was noted between the two cultivars, with Bingtangcheng being more responsive than Valencia. Culture of explants from fully developed leaves led to better shoot regeneration capacity in comparison to undeveloped ones. However, the two lighting conditions used herein did not cause significant difference in shoot regeneration. Phenotypic observation and randomly amplified polymorphic DNA (RAPD) analysis confirmed that all the regenerated plants from both genotypes were genetically identical to their donor plants, suggesting absence of detectable genetic variation in the regenerated plants. The data presented here demonstrated that direct initiation of plants from leaf explants has been successfully accomplished. To our knowledge, this is the first report on direct regeneration of shoots from leaf explants in Citrus, which will provide an alternative source for citrus genetic manipulation in the future.  相似文献   

Response to drought and salt stress of lemon ‘Fino 49’ under field conditions: Water relations,osmotic adjustment and gas exchange     

J.G. Pérez-Pérez  J.M. RoblesJ.C. Tovar  P. Botía. 《Scientia Horticulturae》2009

Drought and salinity are two of the most important factors limiting the lemon yield in south-eastern Spain. The effects of drought and salt stress, applied independently, on water relations, osmotic adjustment and gas exchange in the highest evapotranspiration period were studied to compare the tolerance and adaptive mechanisms of 13-year-old ‘Fino 49’ lemon trees, in immature and mature leaves. The study was carried out in an experimental orchard located in Torre Pacheco (Murcia). Three treatments were applied: Control, well-irrigated; drought-stress (DS), non-irrigated from 15th May to 7th July and salinity, irrigated with 30 mM NaCl from 1st March to 7th July. At the end of the experiment, only DS trees showed a decreased leaf stem water potential (Ψ_md). Under DS conditions, both types of leaf lost turgor and did not show any osmotic or elastic mechanism to maintain leaf turgor. Osmotic adjustment was the main tolerance mechanism for maintenance of turgor under salt stress, and was achieved by the uptake of Cl⁻ ions. Gas-exchange parameters were reduced by DS but not by salinity, stomatal closure being the main adaptive mechanism for avoidance of water loss and maintenance of leaf turgor. Salinity gave rise to greater Cl⁻ accumulation in mature than in immature leaves. The increase of proline in immature leaves due to DS indicates greater damage than in mature leaves.  相似文献   

Fruits are more sensitive to salinity than leaves and stems in pepper plants (Capsicum annuum L.)     

Reona Azuma  Naoko Ito  Nobuhiro Nakayama  Ryuichi Suwa  Nguyen Tran Nguyen  Juan Á. Larrinaga-Mayoral  Muneraru Esaka  Hideyasu Fujiyama  Hirofumi Saneoka 《Scientia Horticulturae》2010

The effects of NaCl stress on plant growth, gas-exchange, activity of superoxide dismutase (SOD), rate of lipid peroxidation, and accumulation of Na⁺ ion and sugar were investigated in leaves and fruits of pepper plants (Capsicum annuum L.). Especially, the gene expression of l-galactono-1,4-lactone dehydrogenase (GalLDH), which is the last enzyme of ascorbic acid (AsA) biosynthesis, and the relationships between AsA level and Na⁺ concentration in plant tissue were investigated with increasing salinity. Plants were treated with three treatments: the control (0 mM NaCl) and two salinity levels (50 and 100 mM NaCl) for 21 days under greenhouse conditions. Plant growth was markedly restricted due to the reduction of photosynthetic rate and the increase of Na⁺ accumulation in leaves with the increasing intensity of NaCl stress. Salinity had more effect on fruit growth comparing to leaf growth, suggesting that fruits could be more sensitive to salinity than leaves. In comparison with the control, salt stress significantly increased lipid peroxidation (as measured as malondialdehyde content) but decreased SOD activity in both fruits and leaves although the effect was larger in fruits; and the rate of the decrease in SOD activity was greater than that of the increase in lipid peroxidation. The AsA concentration transiently increased first 7 days but it slightly decreased from the initial level in the end of treatment day 21. The change in GalLDH gene expression was similar to AsA concentration. The accumulation of Na⁺, the reduction of AsA level at severe salinity stress were greater in fruits than in leaves; and AsA level had a negative relationship with Na⁺ concentration in both leaves and fruits. These results suggest that the difference in salt sensitivity between fruits and leaves in pepper plants can be related to the difference in inhibition of AsA synthesis, which in turn is probably due to the toxicity of extreme accumulation of Na⁺.  相似文献   

Salinity stress in tomatoes can be alleviated by grafting and potassium depending on the rootstock and K-concentration employed     

Molin Fan  Zhilong Bie  Angelika Krumbein  Dietmar Schwarz 《Scientia Horticulturae》2011

Plant production under salinity requires increased capacity for K⁺ homeostasis. For this purpose, supplementary K₂SO₄ in the nutrient solution and grafting on a tolerant rootstock were employed in two experiments to test whether grafting, potassium and their interactions can alleviate salinity stress in tomato (Solanum lycopersicum L.). In Exp-ion, plants were cultivated for 122 days to compare different ionic compositions: EC 9 dS m⁻¹ in EC_all (by macro-nutrients) and in EC_NaCl (by 64.2 mM NaCl), EC 12 dS m⁻¹ in EC_K (EC_NaCl + 25.8 mM K⁺). Exp-K⁺ was established to compare K⁺ concentrations of 6, 16 and 36 mM at 150 mM NaCl. In both Experiments, ‘ZS-5’, selected as a salt sensitive cultivar, was either self-grafted or grafted onto the cultivar ‘Edkawi’, reported as salt tolerant. Yield and growth, minerals, gas exchange, soluble sugars, and proline were analyzed. Different ionic treatments affected almost all characteristics considered while differences between rootstocks were rarely observed. No pronounced differences were found in shoot growth, yield and gas exchange between EC_all and EC_NaCl. EC_K did not show any salinity alleviative effects but inhibited even growth compared with the other treatments. In Exp-K⁺, 16 mM K⁺ increased plant growth, leaf soluble sugars and proline concentrations. 36 mM K⁺ did not further reduce upper leaf Na⁺ although leaf K⁺ concentration increased significantly. The results indicated that the response of tomato plant to NaCl stress was principally attributed to the osmotic component in Exp-ion, excessive K⁺ showed no mitigating effect on fruit yield and shoot growth. However, 16 mM K⁺ in the root environment enhanced the salt adaptive capacity of plants stressed at 150 mM NaCl. The use of the tolerant rootstock resulted in no ameliorative effects, owing to its susceptibility to blossom-end rot, failure in enhancing photosynthesis, and ineffectiveness of restraining the long-distance transport of Na⁺.  相似文献   

Effect of nitrogen form and radiation on growth and mineral concentration of two Brassica species     

C. Fallovo  G. Colla  M. Schreiner  A. Krumbein  D. Schwarz 《Scientia Horticulturae》2009

Three greenhouse experiments were carried out to determine the growth, yield, nitrate, total N and S concentration in shoots, and water uptake of hydroponically grown Brassica rapa L. subsp. nipposinica var. chinoleifera and Brassica juncea L. In each experiment, daily photosynthetically active radiation (PAR) level was 5.0 mol m⁻² (low), 6.8 mol m⁻² (medium) or 9.0 mol m⁻² (high). Plants were supplied with nutrient solutions having equal N concentrations of 11 mM in different forms: 100% NH₄, 50% NH₄ + 50% NO₃, and 100% NO₃. Nitrogen supplied as 100% NH₄ reduced fresh and dry shoot biomass, leaf area, and leaf number in both Brassica species, especially at low and medium PAR levels. In both Brassica species, S concentrations were highest, while nitrate concentrations were lowest in leaves of plants grown at N supplied as 100% NH₄. No differences in leaf nitrate concentrations were observed between 50% NH₄ + 50% NO₃ and 100% NO₃ treatments. Low and high PAR levels increased the nitrate concentrations and decreased the N/S ratio in leaves of both crops compared to medium PAR level. Fresh shoot biomass was maximized in Brassica rapa when PAR level was above the medium value and nitrate was supplied in the nutrient solution as NO₃ or as a mixture of 50% NO₃ and 50% NH₄. The highest fresh shoot biomass of Brassica juncea was observed in all nutrient solution treatments at high PAR level.  相似文献   

Comparison of three pea cultivars (Pisum sativum) regarding their responses to direct and bicarbonate-induced iron deficiency     

Nahida Jelali  Imen Ben Salah  Wissal M'sehli  Silvia Donnini  Graziano Zocchi  Mohamed Gharsalli 《Scientia Horticulturae》2011

The aim of this work was to explore leaf characteristics underlining the difference in the sensitivity of pea cultivars (cv. Kelvedon, Douce and Lincoln) to Fe deficiency. Plants were grown in a greenhouse under controlled conditions in continuously aerated solution. Three treatments were used: 30 μM Fe (+Fe), 0 μM Fe (−Fe); direct deficiency and 30 μM Fe + 10 mM NaHCO₃ (+Fe+Bic); indirect deficiency for 12 days. Growth parameters, iron status, potassium content, chlorophyll fluorescence and photosynthetic capacity were studied. Our results showed that Fe deficiency led to a significant decrease of chlorophyll index (SPAD readings) and bivalent iron content in all Pisum sativum cultivars. The lower reduction was observed in Fe-deficient plants of Kelvedon and Douce. In addition, shoot length and whole plant dry weight were not affected by Fe deficiency in the latter cultivars. Both tolerant cultivars showed higher accumulation of potassium content in their leaves compared with the sensitive one. Moreover, both chlorophyll fluorescence ratios (F_v/F_m and F_v/F₀) were significantly decreased in all cultivars under both Fe deficiency treatments. The photosynthetic electron transport activity was reduced in the sensitive cultivar, especially in the absence of iron. The adverse effect of bicarbonate-induced Fe deficiency on the above mentioned parameters were more pronounced than that of the direct one. The capacity of both tolerant cultivars to preserve adequate chlorophyll synthesis, photosynthetic capacity and plant growth under iron-limiting conditions is related to the suitable nutrition of their leaves in ferrous iron, due to (at least partially) their higher potassium content.  相似文献   

Growth, photosynthesis and antioxidant metabolism in mustard (Brassica juncea L.) cultivars differing in ATP-sulfurylase activity under salinity stress     

N.A. Khan  R. Nazar  N.A. Anjum 《Scientia Horticulturae》2009,122(3):455-460

Salinity is one of the major environmental factors limiting crop productivity. The effect of increasing salinity levels (0, 50, 100 mM NaCl) on growth, photosynthetic traits, leaf water potential, oxidative stress, enzymatic and non-enzymatic antioxidants was studied in Pusa Jai Kisan and SS2 cultivars of mustard (Brassica juncea L. Czern & Coss.) differing in ATP-sulfurylase activity at 30 days after sowing (DAS). The cultivar SS2 (low ATP-sulfurylase activity) accumulated higher content of Na⁺ and Cl⁻ in leaf than root. SS2 also showed greater content of thiobarbituric acid reactive substances (TBARS) and H₂O₂ and higher decrease in growth, photosynthetic traits and leaf water potential than Pusa Jai Kisan with increasing salinity levels. Contrarily, Pusa Jai Kisan (high ATP-sulfurylase activity) exhibited higher Na⁺ and Cl⁻ content in root than leaf, lower TBARS and H₂O₂ content and higher activity of catalase, ascorbate peroxidase and glutathione reductase. However, the activity of superoxide dismutase was greater in SS2 than Pusa Jai Kisan. Higher activity of ATP-sulfurylase in Pusa Jai Kisan resulted in increased content of glutathione, a reduced form of inorganic sulfur and an essential component of cellular antioxidant defense system. The lesser decrease in growth and photosynthesis in Pusa Jai Kisan was the result of lesser Na⁺ and Cl⁻ in leaf, higher turgidity and increased activity of antioxidant enzymes and glutathione content.  相似文献   

Chromosome doubling of Lychnis spp. by in vitro spindle toxin treatment of nodal segments     

Takahiro Nonaka  Eriko Oka  Megumi Asano  Sachiko Kuwayama  Hiromu Tasaki  Dong-Sheng Han  Toshinari Godo  Masaru Nakano 《Scientia Horticulturae》2011

Lychnis (Caryophyllaceae) consists of about 30 species distributed throughout the temperate regions of the Northern Hemisphere, from East Asia to Europe. Many Lychnis spp. have high ornamental value and cultivated as pot or garden plants. In the present study, in vitro chromosome doubling of several Lychnis spp. was examined in order to widen their variability in horticultural traits. Initially effect of various spindle toxin treatments [100, 500 or 1000 mg l⁻¹ colchicine (COL), 10, 20 or 50 mg l⁻¹ oryzalin (ORY), or 1, 5, 10 mg l⁻¹ amiprophos-methyl (APM)] of nodal segments of a triploid genotype of L. senno (3x) was investigated on survival of nodal segments and chromosome doubling in nodal segment-derived plantlets. Significantly higher percentage (75.0%) of surviving segments after spindle toxin treatment was obtained in 10 mg l⁻¹ ORY treatment. Flow cytometry (FCM) analysis of leaf tissues showed that 9.4–13.8% of plantlets, which were derived from 10 to 20 mg l⁻¹ ORY, or 5 mg l⁻¹ APM treatments, were hexaploid (6x) or ploidy chimera (3x + 6x, 4x + 6x, 5x + 6x, 3x + 4x + 6x). The results obtained by FCM analysis were confirmed by chromosome observation in root tip cells. Thus 10 mg l⁻¹ ORY treatment of nodal segments is suitable for in vitro chromosome doubling of triploid L. senno. Efficient chromosome doubling was also achieved in diploid L. fulgens (2x) and L. sieboldii (2x) by treating nodal segments with 10 mg l⁻¹ ORY: 68.9–88.7% of nodal segments survived after ORY treatment, and 24.7–26.5% of plantlets derived from ORY-treated nodal segments were tetraploid (4x) or ploidy chimera (2x + 4x) in both species. These results indicate that the in vitro chromosome doubling method established for triploid L. senno may be applicable to a wide range of Lychnis spp. Tetraploid L. fulgens and L. sieboldii showed a compact plant form, and had thick stems and deep green leaves compared with the diploid mother plants. On the other hand, hexaploid L. senno showed very poor growth and died before flowering.  相似文献   

Factors affecting mango (Mangifera indica L.) protoplast isolation and culture     

Ramezan Rezazadeh  Richard R. Williams  Dion K. Harrison 《Scientia Horticulturae》2011

The major factors influencing protoplast isolation and culture of mango (Mangifera indica L.) cv. Kensington Pride were investigated. The resultant protocol was used to compare plating efficiency among 4 mango cultivars. Most responses differed between proembryonic masses (PEMs) and leaf sources. Protoplast yields of 15.22 × 10⁶ g⁻¹ from PEMs and 8.68 × 10⁶ g⁻¹ from greenhouse-derived leaves were obtained in a solution of 0.7 M mannitol CPW plus 1.5% cellulase, 1% hemicellulase and 0.75% macerozyme for PEMs or 0.5 M mannitol CPW plus 1.5% cellulose, 1% hemicellulase and 1.5% macerozyme for leaves. Culture in Ca-alginate beads with initial plating densities (IPD) of 2.5 × 10⁴ Pp mL⁻¹ for PEMs and 2.5 × 10⁵ for leaves gave the highest plating efficiencies (FPE). For PEMs 1 mg L⁻¹ 2,4-d and 3.5 mg L⁻¹ kinetin gave an FPE of 2.85% whereas lower kinetin (2 mg L⁻¹) plus 0.5 mg L⁻¹ 6-BAP was most effective for leaves (FPE of 2.12%). Most protoplast mortality occurred during the first week of culture and was more severe in liquid culture. In Ca-alginate beads, protoplast survival at 14 days was higher for PEMs (30%) than leaf (21%) as was the frequency of cell division (17.6% compared to 13.6%). PEMs protoplasts continued development through embryogenesis to in vitro plantlet regeneration whereas leaf protoplasts underwent cell division up to 40-cell colonies but failed to proceed further. For PEMs, polyembryonic cvs. Kensington Pride and Keow Savoey produced higher FPE (1.95%) than monoembryonic cvs. Tommy Atkins and Keitt (1.75%). There was no effect of cultivar for leaf protoplasts.  相似文献   

Spectral effects on embryogenesis and plantlet growth of Oncidium ‘Gower Ramsey’     

Jen-Ping Chung  Chia-Ying Huang  Ting-En Dai 《Scientia Horticulturae》2010

Embryogenic calli of Oncidium were grown under tubular fluorescent lamp (FL) or light-emitting diode (LED) arrays with different spectra to determine the effects of light quality on protocorm-like body (PLB) formation and plantlet growth from the callus. The effect of light is generated by monochromatic blue, red or mixed far-red LEDs on the photomixotrophic radiation. The light sources induced higher number of PLB formation compared with the darkness. The best condition for PLB formation was to culture on MS half salt medium supplemented with 0.1 mg l⁻¹ NAA and 0.4 mg l⁻¹ BA under red + blue + far-red (RBFr) LEDs and FL radiation for 8 weeks. Roughly 3000 embryos were induced in an initial culture of 1 g of fresh weight of calluses. During subculturing, PLBs had the ability to convert into plantlets. In this study also indicated the far-red LED radiation was a noticeable factor. It showed that using Fr combined with R and B (RBFr) or RFr radiation significantly enhanced leaf expansion, numbers of leave and root, chl contents, fresh and dry weight of Oncidium plantlets. Therefore, the wavelength specificity of RBFr LEDs comprising a novel illumination system is advantageous over FLs for PLB formation, resulting in higher efficiencies of plant regeneration and growth in Oncidium cultures.  相似文献