Response of bean micronutrient nutrition to arsenic and salinity

The effects of different levels of arsenic (As) and salinity on bean plant (Phaseolus vulgaris L., cv. Buenos Aires) nutrition were investigated. We studied the processes of absorption and accumulation of chloride (Cl) and micronutrient elements: boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn). The experiment was performed in soilless culture at two levels of As: 2 and 5 mg As L^‐1 [added as sodium arsenite (NaAsO₂)], and three saline levels [only sodium chloride (NaCl) was added]: 1, 2, and 4 dSm^‐1. Sodium arsenite and NaCl significantly affected micronutrients allocation within the bean plant at levels used in this study. Arsenite depressed Mn and Cl concentrations in the root, whereas root B, Cu, and Zn levels were increased. Boron, Cu, Fe, and Cl concentrations were significantly higher in As‐stressed plants compared with controls. The addition of NaCl increased the Cl and Mn concentrations in roots and Cl, Fe, and Mn in leaves.     

Differences in iron stress response and iron uptake in some sorghum varieties

Six sorghum (Sorghum vulqaris Pers.,) varieties representing male and female lines and hybrids were examined for their response to Fe‐stress, and their ability to absorb and transport Fe in the absence and presence of phosphate or CaCO,. It was found that the variety 2077‐A (male sterile female line) and the variety CSH‐5 (hybrid of 2077‐A r CS‐3541) showed distinct mechanism to tolerate and recover completely from chlorosis induced by Fe‐stress in 10 days. Furthermore, these 2 varieties were able to reduce the pH from 6.4 to 3.8 in about 9 days, and this was increased to about 6.2 in another 6 days, which period corresponded with the onset of chlorosis and subsequent recovery. The variety 2219‐A (male‐sterile female line) was also able to withstand Fe‐stress, although the chlorosis appeared only mild throughout. This variety also reduced pH from 6.4 to 4.5, but only after 14 days in the presence of CaCO₃ (8 mg/1), and this time corresponded to the period of complete recovery from chlorosis.

There appears to be no correlation between Fe uptake capacity and tolerance to Fe‐stress in these varieties. The presence of phosphate or CaCO₃ in the absorption medium was found to increase Fe absorption and transport in a few varieties.     

Lavandula multifida response to salinity: Growth,nutrient uptake,and physiological changes

Fern leaf lavender (Lavandula multifida L.) is a perennial shrub native to Almería with known medicinal properties, which grows in saline soils that are increasingly present in the Mediterranean region. However, the effects of salinity on the mineral nutrition and physiology of L. multifida are unknown. In the present study, we evaluated the salt resistance of this species and compared it with other members of the Lamiaceae . Plants of L. multifida were grown in pots in a mixture of sphagnum peat‐moss and Perlite, and treated with five different NaCl concentrations [10 (control), 30, 60, 100, and 200 mM NaCl] over a period of 60 d. The effects of different levels of salinity on mineral nutrient and osmolyte concentrations and on biomass were evaluated. Our results show that L. multifida plants were able to grow with 60 mM NaCl without significant biomass reduction. Na⁺ and Cl⁻ were the main contributors to the osmotic potential in both roots and leaves, whereas total soluble sugars (TSS) and proline made only a small contribution. The concentrations of TSS and proline showed different trends in the different organs: in roots, both showed the highest concentrations at 60 mM NaCl, whereas in leaves TSS increased and proline decreased with increasing salt stress. To survive salinity, L. multifida plants increased salt excretion (Na⁺ and Cl⁻) by leaves at 100 and 200 mM NaCl and leaf succulence at 60, 100, and 200 mM NaCl. Excessive accumulation of Na⁺ and Cl⁻ was avoided by shedding leaves. Our results indicate that L. multifida is better adapted to salinity compared to other members of the Lamiaceae ¸ a consideration that is particularly relevant for their growth in arid saline areas.     

Quantitation of polyphenols in different apple varieties

Forty-one apple samples, representing eight of the most widely cultivated varieties in western Europe, were collected in Trentino, Italy. Samples were extracted from fresh fruit with a mixture of acetone/water to achieve a good extraction of polyphenols, including proanthocyanidin oligomers which were analyzed by normal-phase HPLC. Up to 20 compounds including catechin, epicatechin, B2 procyanidin, hydroxycinnamates, flavonols, anthocyanins, and dihydrochalcones were analyzed by reversed-phase HPLC and LC-MS. Total polyphenol content was independently measured with an optimized Folin-Ciocalteu assay. The mean content of total polyphenols lay between 66.2 and 211.9 mg/100 g of FW depending on the variety. With chromatographic analysis, it was possible to explain the whole amount of total polyphenols measured by the FC assay. Flavanols (catechin and proanthocyanidins) are the major class of apple polyphenols (71-90%), followed by hydroxycinnamates (4-18%), flavonols (1-11%), dihydrochalcones (2-6%), and in red apples anthocyanins (1-3%).     

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.     

Volatile response of four apple varieties with different coatings during marketing at room temperature

Five experimental coatings with different resistance to gas exchange were used with freshly harvested and 20-week commercially stored apples of Delicious, Fuji, Braeburn, and Granny Smith varieties. The coated or noncoated apples were held at 20 degrees C for up to 4 weeks. The gas partial pressures inside the fruits with the various coatings ranged from 1 to 25 kPa CO(2) and from 20 to 1 kPa O(2). Volatile evaporation rates were measured, as also were the volatiles compositions in the fruit. The coatings with intermediate gas resistance (carnauba-shellac mixture and candelilla) gave intermediate values of CO(2) and O(2) in the internal atmosphere in Delicious, Fuji, and Braeburn apples and the highest concentrations of butyl acetate and 2-methylbutyl acetate in the fruits. The coatings with the highest gas resistance (shellac and shellac-protein) caused high internal CO(2) and low O(2), resulting in anaerobic fermentation in Braeburn and Granny Smith apples and relatively high amounts of low-molecular-weight ethyl esters trapped within the fruit. A small portion of the alcohols were evaporated from fruits compared to esters, this attributed to their high Henry's law coefficients.     

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.     

Growth,nutrient acquisition,and physiological responses of three olive cultivars to induced salt stress

Three olive (Olea europaea L.) cultivars Nabali Baladi (NB), Nabali Muhassan (NM), and Grossi Di'Espagna (GE) were evaluated under salt stress. Seedlings were treated with salinity induced by a 3:1 ratio of calcium chloride and sodium chloride to four concentration levels measured as electrical conductivity (EC) [1.2, 4.1, 7.0, and 14.0 dS/m] for 122 days. Olive seedlings varied in their response to salinity. In all treatments, NB had the highest root; stem and leaf dry weights had among the highest total plant dry weights, specific stem length (SSL) and relative water content (RWC). NB seedlings maintained the highest stomatal conductance at 7.0 dS/m and highest chlorophyll index at 14.0 dS/m. Olive seedlings that tolerated salt tolerance developed mechanisms of nutrient acquisition and distribution in the organs, by storing minimal amounts of sodium (Na⁺) and chloride (Cl^?) in the stems and loading the most in the leaves and roots.     

Wheat response to interactive effects of boron and salinity

Abstract

In semiarid regions with irrigated agriculture, excess boron (B) often occurs in association with moderate to high salinity. However, little information is available on plant uptake of B under saline conditions. This greenhouse study was conducted to determine the interactive effects of salinity and varying concentrations of boron on growth, yield and ion relations of wheat (Triticum aestivum L., cv. ‘Yecora Rojo'). Plants were grown in sand cultures that were irrigated four times daily with modified Hoagland's nutrient solution. Sixteen treatments were initiated 4 d after planting in a completely randomized factorial experiment with 4 salinity levels (electrical conductivities of the irrigation waters=1.5, 4, 8, and 12 dS m^?1) and 4 B concentrations (1, 5, 10, and 15 mg L^?1). Salinizing salts were NaCl and CaCl₂ (2:1 molar basis). Symptoms of B toxicity were closely correlated with B concentration in the leaves and injury became severe when leaf‐B exceeded 400 mg kg^?1. At each concentration of external B, shoot‐B was least under nonsaline conditions and increased significantly as salinity increased. Shoot‐calcium (Ca) concentration increased with increasing salinity, but was unaffected by applied B. Shoot‐magnesium (Mg), and potassium (‐K) decreased significantly in response to increases in salinity and substrate B. Salinity and B as well as their combined effects significantly reduced wheat biomass production, yield components, and final grain yield.     

Growth,mineral composition,leaf chlorophyll and water relationships of two cherry varieties under NaCl-induced salinity stress

Abstract

Growth, mineral nutrition, leaf chlorophyll and water relationships were studied in cherry plants (cv. ‘Bigarreau Burlat’[BB] and ‘Tragana Edessis’[TE]) grafted on ‘Mazzard’ rootstock and grown in modified Hoagland solutions containing 0, 25 or 50 mmol L^?1 NaCl, over a period of 55 days. Elongation of the main shoot of the plants treated with 25 or 50 mmol L^?1 NaCl was significantly reduced by approximately 29–36%, irrespective of the cultivar. However, both NaCl treatments caused a greater reduction in the dry weight of leaves and scion's stems in BB than in TE plants. Therefore, BB was more sensitive to salinity stress than TE. The reduction of leaf chlorophyll concentration was significant only when BB and TE plants were grown under 50 mmol L^?1 NaCl. Osmotic adjustment permitted the maintenance of leaf turgor in TE plants and induced an increase in leaf turgor of BB plants treated with 25 or 50 mmol L^?1 NaCl compared with 0 mmol L^?1 NaCl. Concerning the nutrient composition of various plant parts, Na concentrations in all plant parts of both cultivars were generally much lower than those of Cl. For both cultivars, leaf Cl concentrations were much higher than the concentrations in stems and roots, especially in the treatments containing NaCl. Finally, the distribution of Na within BB and TE plants treated with NaCl was relatively uniform.     

Physiological response of sunflower seedlings to salinity and potassium supply

Abstract

Sunflower seeds (Helianthus annutis L. cv. Dwarf) were grown only with increasing saline solutions [0, 50, and 100 mM sodium chloride (NaCl)] and potassium (K) supply to determine how salinity and K supply will affect plant germination and growth. Potassium supply under highly saline conditions (100 mM) or nonsaline conditions had a beneficial effect on sunflower seedlings germination which was not significantly altered with moderate salt concentrations (50 mM). During the stage studied, K supply in the absence of salinity increased significantly seedling biomass which reflects what is happening in the aerial part and root. This increase was proportionally higher in the stem than in the leaf with no variations in the foliar surface. In a saline environment, K supply did not markedly alter plant dry matter production, but increased foliar surface with moderate salt concentrations (50 mM) in the root environment.     

Polyphenolic compounds and antioxidant activity of new and old apple varieties

There is considerable evidence to show that a greater intake of apple contributes to improved health by reducing the risk of diseases, such as cardiovascular disease and some forms of cancer. Apple fruit is a major source of phenol compounds, because its consumption is widespread in many countries and it is available on the market for the whole year. The phenolic composition of 67 varieties of apple cultivars (new and old varieties) was examined for the concentration of some important phytochemicals and antioxidant activity. For the first time, we have looked at the correlation and compared polyphenolic coumpounds in Golden Delicious variety and new varieties grown from it. Up to 18 compounds, including catechin, procyanidin, hydroxycinnamates, flavonols, anthocyanins, and dihydrochalcones, were analyzed by high-performance liquid chromatography with diode array detection analysis of crude extracts and after thiolysis and LC-MS. The mean content of total polyphenols lay between 523.02 and 2723.96 mg/100 g dw and depending upon the apples variety. Flavanols (catechin and oligomeric procyanidins) are the major class of apple polyphenols, representing more than 80%, followed by hydroxycinnamic acids (1-31%), flavonols (2-10%), dihydrochalcones (0.5-5%), and in red apples, anthocyanins (1%). In this study, the best correlation was found for the total polyphenols and ABTS method, with a lower correlation for FRAP and DPPH methods ( r = 0.871, 0.839, and 0.804, respectively). The presented data clearly demonstrated that new varieties, i.e., Ozark Gold, Julyred, and Jester, of apple had the same or higher value of bioactive compounds in comparison to the old varieties, i.e., Golden Delicious, Idared, and Jonagold.     

Growth response and nitrogen metabolism of sunflower (Helianthus annuus L.) to vermicompost and biogas slurry under salinity stress

Sunflower was grown under saline media with or without vermicompost amendment and biogas slurry, the organic fertilizers. A randomized complete block design with five replications was used. Forty-five pots were divided in three sets comprising of 15 pots each. Out of 15 pots of each sets, five pots of each were subjected to different levels of saline water irrigation i.e. electrical conductivity (EC): 0.5, 4.8 8.6 dS/m). Amendments of vermicompost and biogas slurry have shown some reduction of sodium induced inhibitory effects. Analyses of fresh and dry weight of leaves, ions, amino acid, protein and nitrogen metabolism enzymes in leaves etc., have been undertaken with reference to above-mentioned treatments. Organic manure amendments improved growth yield, nitrate and protein content and decreased the amount of sodium (Na⁺), chloride (Cl^?), ammonium and total amino acid under saline or non-saline condition. Activities of nitrogen (N)-assimilating enzymes i.e. nitrate reducatse (NR, EC 1.6.6.1), nitrite reductase (NiR, EC 1.6.6.4), glutamine synthetase (GS, EC 6.3.1.2) and glutamate synthase (NADH-GOGAT, EC 1.4.1.14) were enhanced to some extent irrespective to non saline or saline condition. Under salinity NADH-glutamate dehydrogenase (GDH, EC 1.4.1.2) activity was stimulated concomitantly with the increasing ammonium contents and proteolysis activity in the leaves and organic manure did not show a significant difference as compared to their respective control. With respect to salt stress, among the two above-mentioned organic manure, vermicompost showed better result in the entire studied parameter as compared to the biogas slurry.     

Growth and ion accumulation responses of four grass species to salinity

Ion inclusion or ion exclusion are the two main strategies developed by plants to tolerate saline environments. Shoot sodium (Na⁺), potassium (K⁺), and calcium (Ca²⁺) in four perennial grass species (tall wheatgrass, Nuttall's alkaligrass, creeping foxtail, and switchgrass) treated with nutrient solution salinity levels ranging from 2 to 32 dS m^?1 were measured. As the nutrient solution salinity was increased from 2 to 10 dS m^?1, tall wheatgrass, creeping foxtail and Nuttall's alkali grass had increased shoot Na⁺ and decreased Ca²⁺ concentration while maintaining growth suggesting that these species tolerated these changes in shoot ion concentration. In contrast, switchgrass excluded Na⁺ from the shoot and maintained K⁺ and Ca²⁺ concentrations but suffered dramatic shoot dry weight reduction. Thus, the Na⁺ exclusion mechanisms present in switchgrass were less efficient in maintaining growth under the 10 dS m^?1 nutrient solution treatment than the Na⁺ inclusion mechanisms used by the other three species.     

Physiological,nutritional and growth responses of melon (Cucumis melo L.) to a gradual salinity built-up in recirculating nutrient solution

Minimizing salinity impacts on yield in melon crops cultivated in closed-loop hydroponic systems requires better understanding of the physiological impact of gradual salt accumulation in the recycled solution. To attain this objective, different sodium chloride (NaCl) concentrations in the irrigation water, i.e. 0.7, 2.5, and 5 mM, were applied in two cropping seasons (winter-spring;WS and spring-summer;SS). In both seasons plant biomass and yield were negatively affected only in high NaCl-treated plants, due to stomatal limitations, which restricted carbon dioxide (CO₂) diffusion into the leaf, osmotic and salt-specific effects. However, a progressive NaCl built-up to maximum concentrations in the root zone solution of 15 (WS) and 20 mM (SS), enabled plants to preserve several physiological mechanisms, thereby adjusting growth and yield without impairing fruit quality. Our results suggest that the use of irrigation water, containing up to 2.5 mM NaCl, is feasible in melon crops grown in closed-loop hydroponic systems, without yield and quality losses.     

Properties and available micronutrient status of some soils derived from Abeokuta formation in Nigeria

Available iron, zinc, copper and manganese were determined in six pedons located in upper slope, middle slope and valley bottom soils derived from Abeokuta geological materials in Nigeria. The soils had an average of 639.8 g kg^?1 sand, 241.8 g kg^?1 clay and 118.4 g kg^?1 silt. The fertility status of the soils was low–medium with a strongly acid–neutral reaction, 1.3–15.1 g kg^?1 organic carbon contents, moderate–high exchangeable bases and 1.38 mg kg^?1 available phosphorus. Both Fe (122.50 mg kg^?1) and Mn (111.40 mg kg^?1) occurred at toxic levels, whereas the mean Cu (1.27 mg kg^?1) and Zn (2.56 mg kg^?1) contents were found to be adequate for most crops grown in the region. There were significant positive correlations among the micronutrients and also between soil pH, organic carbon, particle size fractions and micronutrients. The high levels of Fe and Mn were probably due to the presence of oolitic ironstone in the parent material.     

Growth behavior of off-flavor-forming microorganisms in apple juice

Alicyclobacillus acidoterrestris and Streptomyces griseus griseus are two bacteria species that are frequently found in apple juice as spoilage bacteria. They both show thermoacidophilic behavior, adapting to the low pH of the juices and being able to survive high temperatures. They are able to regerminate in the shelf-stable product and spoil the juice by the formation of off-flavor compounds (i.e., guaiacol and 2,6-dibromophenol as metabolites of A. acidoterrestris and 2-isopropyl-3-methoxypyrazine, 2-methylisoborneol, 2-isobutyl-3-methoxypyrazine, and geosmin as important metabolites of S. griseus). In this study the growth behavior of the strains and the impact on apple juice were investigated under different conditions (i.e., temperature, oxygen supply, and mutual influence of the strains). The off-flavor formation was monitored by GC-MS after headspace SPME and subsequent calculation of the odor activity values. The results showed that S. griseus grows and consequently spoils the product even at 4 degrees C, whereas A. acidoterrestris needs at least room temperature to show significant growth. Limited oxygen supply did not significantly reduce off-flavor formation for any of the strains. The simultaneous presence of the strains in the juice reduced the growth of both species; nevertheless, off-flavor was detected.     

Organic carbon fractions and micronutrient status of soils under some plantation crops in southwestern Nigeria

The organic carbon (OC) fractions and micronutrient status of soil under cashew (Anacardium occidentale), plantain (Musa spp), oil-palm (Elaeis guineensis) and gmelina (Gmelina arborea) plantations were studied to determine their effectiveness for managing converted forest in the derived savanna ecology of southwestern Nigeria. The control secondary forest soil had statistically similar OC (2.11%) at 0–15 cm with gmelina but significantly higher than those of the remaining plantation crops. At deeper depths, however, the OC content of the control forest was lower than those of other plantation crops. Apart from gmelina, other plantation crops had carbon enrichment ratio (CER) <1 at 0–15 cm. Only gmelina sequestered as much non-hydrolysable carbon (NHC) as the control at 0–15 cm depth. Also it was observed that plantain plantation sequestered higher NHC than the control at 15–30 cm depth. At >30 cm depth, however, none of the plantation crops sequestered as much NHC as the control. Using the average NHC at all the soil depth as a quality index, gmelina has a better potential to sequester NHC than the other plantation crops used in this study.     

Influence of Ca concentration on micronutrient imbalances in in vitro propagated prunus rootstock

In vitro propagated plums of St. Julien GF 655–2 [Prunus insititia (L.)] (655–2), Damas GF 1869 [Prunus domestica (L.)] (D1869), and Clark Hill Redleaf [Prunus salicina (Until.) X Prunus cerasifera (Ehrh.)] (CHR), were grown in the greenhouse in nutrient solutions of 2, 6, 22, 66, 202, and 404 μM Ca for 96 days. 655–2 plants became severely chlorotic in Ca treatments of 66, 202, and 404 μM concentration after 86 days of growth. D1869 plants in 202 and 404 μM Ca exhibited slight interveinal chlorosis of new growth, while CHR exhibited no chlorosis at any Ca concentration. The best tissue nutrient indicator of chlorosis among rootstocks was foliar P/Fe and P/Zn ratios. 655–2 plants absorbed more P at higher Ca concentrations than did the other rootstock, resulting in the highest stem and leaf P/Fe, and P/Zn ratios. CHR plum may provide an easily propagated, chlorosis‐resistant rootstock for use on calcareous soils.