Solar UVB response of bioactives in strawberry (Fragaria × ananassa Duch. L.): a comparison of protected and open-field cultivation

Strawberries (Fragaria × ananassa Duch. cvs. Everest, Elsanta) were grown in a tunnel covered with two films, which were distinguished in their ultraviolet transparency, as well as under open-field conditions. One applied film was not transparent for UVB radiation, and the second film transmitted 70% of UVB radiation. During the present study, the nutritional value and quality parameters of the fruits were evaluated. Strawberries were UV-unresponsive in view of the content of ascorbic acid and sum parameters like total anthocyanins and antioxidant capacity measured with TEAC (trolox equivalent antioxidant capacity), ORAC (oxygen radical absorbance capacity) and total phenols. These parameters were mainly affected by sampling date and cultivar. However, HPLC analysis showed that individual phenolics were affected in the absence of UV radiation. The content of the anthocyanin cyanidin 3-glucoside and the flavonols quercetin 3-glucuronide and kaempferol 3-glucoside was decreased in the fruits grown under UV blocking film compared to open-field grown strawberries. By means of the UV transparent film the content of the mentioned flavonoids could be enhanced up to similar amounts like in open-field grown strawberries. All other phenolics were not consistently affected by UV radiation. This result was independent of cultivar.     

Composition of soilless substrates affect the physiology and fruit quality of two strawberry (Fragaria × ananassa Duch.) cultivars

Abstract

Leaf-level physiology, yield, and fruit quality of two strawberry (Fragaria?×?ananassa Duch.) cultivars, “BG4.370” and “Splendor” grown in five growing substrates were assessed. Substrate ratios were T1: tuff (0–4?mm), T2: cocopeat?+?perlite 4:1, T3: peatmoss?+?perlite 4:1, T4: tuff?+?cocopeat 4:1, and T5: tuff?+?peatmoss 4:1. Strawberry parameters were greatly affected by substrate composition but not cultivars. Plants grown in cocopeat?+?perlite 4:1 had the highest photosynthesis, transpiration, radical scavenging activity, and fruit firmness while those grown in peatmoss?+?perlite 4:1 had the highest yield, total phenolics and nitrate concentration compared to other substrates. Given that peat-based growing substrate has raised concerns over the environmental impacts such as, a reduction of wet-lands and loss of soil organic carbon, the lower environmental impact and higher fruit quality grown on cocopeat justifies the use of cocopeat as an alternative substrate to peatmoss.     

Photoprotective potential of strawberry (Fragaria × ananassa) extract against UV-A irradiation damage on human fibroblasts

Exposure to UV-A radiation is known to induce discrete lesions in DNA and the generation of free radicals that lead to a wide array of skin diseases. Strawberry (Fragaria × ananassa) contains several polyphenols with strong antioxidant and anti-inflammatory activities. Because the major representative components of strawberry are anthocyanins, these may significantly contribute to its properties. To test this hypothesis, methanolic extracts from the Sveva cultivar were analyzed for anthocyanin content and for their ability to protect human dermal fibroblasts against UV-A radiation, as assayed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenytetrazolium bromide and Comet assays. Five anthocyanin pigments were identified using high-performance liquid chromatography-diode array detection-electrospray ionization/mass spectrometry. Moreover, the strawberry extract showed a photoprotective activity in fibroblasts exposed to UV-A radiation, increasing cellular viability, and diminishing DNA damage, as compared to control cells. Overall, our data show that strawberry contains compounds that confer photoprotective activity in human cell lines and may protect skin against the adverse effects of UV-A radiation.     

Fruit development in artificially self- and cross-pollinated strawberries (Fragaria × ananassa) and raspberries (Rubus idaeus)

Tunnel cultivation of berries is increasing on a global basis, and suitable management techniques are being studied for growing berry crops in a protected environment. Soil mulching and irrigation are among the techniques that significantly affect plant growth and yield. Tunnel cultivation is often limited to growing single cultivars, and little attention has been paid to the effects of growing several cultivars in the same tunnel. There are indications that crop yield and quality might benefit from cross-pollination. In this study, the effects of artificial self- and cross-pollination were studied in 15 strawberry and 6 red raspberry cultivars grown in a protected environment in a greenhouse. Four strawberry cultivars benefited from cross-pollination and one required it. In the case of raspberries, self- and cross-pollination had no effect on yield and fruit quality. In conclusion, particular berry cultivars are better suited to tunnel cultivation.     

Interactive effects of Si and NaCl on growth,yield, photosynthesis,and ions content in strawberry (Fragaria × ananassa var Camarosa)

The effects of silicon (Si) (0, 1, and 2 mM) and sodium chloride (NaCl) salinity (0, 20, and 40 mM) on the yield, photosynthesis, and ion content in strawberry grown in hydroponics were investigated. Salinity caused a reduction in leaf area and plant biomass, regardless of Si supplement. Leaf area in Si₁Na₂₀ treatment was 37% higher than that of Si₀Na₂₀ treatment. Salinity at 20 mM concentration had a 25% yield reduction in absence of Si, corresponding to no reduction in the yield in the presence of Si compared with the Si treatment without salinity. The highest reduction of photosynthetic rate (Pn) was observed in Si₁Na₄₀ treatment; however, in the presence of Si, there was no reduction in the Pn rate at 20 mM NaCl concentration. An obvious positive relationship was found between potassium/sodium (K/Na) and Pn rate. Within each Si concentration, the increased salinity increased Na concentration in the leaf tissue. However, when Si was supplied to the salinity treatments Na concentration was significantly lower than that of the similar treatments without Si. Supplement of Si to the nutrient solution increased the Si concentration in the roots, and old and young leaves. A clear negative relationship (r² = 0.71) was found between Si and Na concentration in the leaves. Salinity (NaCl₄₀) increased the proline level 2.5-fold in the absence of Si, corresponding to no changes the proline level in the presence of 1 mM Si concentration compared with the Si treatment without salinity. The salinity (40 mM) increased the electroleakage by 50% compared with 0 mM NaCl treatment in the absence of Si supplement. Findings from this study lead to the conclusion that Si supplement to the nutrient solution ameliorated the deleterious effect of salinity on the strawberry growth; these effects were attributed to an enhanced K/Na ratio and the reduction in Na content and electroleakage ability in the leaf tissue.     

Substitution of mineral fertilizers with biofertilizer: an alternate to improve the growth,yield and functional biochemical properties of strawberry (Fragaria × ananassa Duch.) cv. Camarosa

Abstract

An experiment was conducted to substitute mineral fertilizers with biofertilizers in strawberry to work out the yield, quality of strawberry and soil fertility. A 25% substitution of mineral fertilizer with biofertilizer increased the number of fruits/plant along with improving Juice content (89.55%), Total soluble solids (10.35°B), total sugar (6.69%), ascorbic acid (43.80?mg 100?g^?1), anthocyanin content (81.05?mg 100?g^?1), total phenol (5.97?mg Gallic acid equiv. g^?1), flavonoids (0.12?mg g^?1) and antioxidant capacity (2.13?µmol. Trolox equiv. 100?g^?1). The available N and K content in post-harvest soils were improved significantly with 75% RDF + Azospirillium @ 2?g plant^?1 + PSB @ 2?g plant^?1 + topdressing of 25% K treatments (200.10 and 211.70?kg ha^?1, respectively). Viable count of soil microorganisms (Bacteria, actinomycetes and fungi) was also estimated maximum (4066, 190 and 11.33?×?10⁴ cfu g^?1?dry soil, respectively) with substitution of 25% of mineral fertilizer either with Azotobacter or Azospirillum.     

Variation in the amounts of selected volatiles in a model population of fragaria × ananassa Duch. As influenced by harvest year

Volatile metabolites are a basis for sensory and resistance traits of Fragaria × ananassa . Stability of expression is important for the selection of cultivars. For the first time, the stability of volatiles in a strawberry population after cross-combination of two distinct cultivars ('Mieze Schindler' × 'Elsanta') has been investigated. In this work, environmentally caused variations in the synthesis of 18 volatiles were studied over two years using a model population of 158 clones. The stability varied throughout the F1 seedling population between the two years, defining stable and unstable genotypes with respect to volatile synthesis. Most of the stable genotypes exhibited low values in relative volatile concentration. Merely 6 stable volatiles were detected in the parental cultivars, whereas about 40% of the F1 progeny had up to 11 stable volatiles. Consequently, a higher stability in volatile synthesis can be achieved by breeding.     

Effect of sodium‐vinasse application on seed germination and growth of three species differing in salt tolerance

Abstract

The produced vinasse from molasses of sugar beets contains high amounts of nitrogen, potassium, and sodium (Na‐vinasse). In a pot experiment involving plant species of different tolerance to soil salts (cotton, corn, and beans), applications up to 10 t vinasse ha^‐1 did not significantly affect the seed germination, and had a positive effect on plant growth of all species. Increasing the vinasse application to 20 t ha^‐1 had no effect on seed germination of cotton and increased its growth. In contrast, a 20 t ha^‐1 application delayed the time of germination and inhibited corn and bean growth up to one month. Subsequently, plant growth increased and plant height 52 days after sowing was similar to that with the 10 t ha^‐1 treatment. For the bean plants, the negative effect of the 20 t ha^‐1 application continued and resulted in a higher dry matter in leaves, but lower dry matter in stems and fruits compared to the untreated soil. A replacement of potassium by sodium in cotton and corn plants was also observed at this vinasse application. Very high application of vinasse (100 t ha^‐1) resulted in a damage of cotton and bean seeds, while a higher portion of corn seeds germinated (64%). However, corn seeds that germinated collapsed after a few days. Among the three species studied, cotton plants absorbed the highest amount of sodium, corn plants the highest amount of potassium and those of bean the highest amount of nitrogen.     

Effects of potassium silicate and nanosilica on quantitative and qualitative characteristics of a commercial strawberry (fragaria × ananassa cv. ‘camarosa’)

Silicon (Si) is considered as a beneficial element to higher plants especially under stress conditions. A factorial experiment, in a completely randomized design with four replications, was used to investigate the effects of two application methods (spraying and soil drenching) and eight levels of Si compounds including 0, 5, 10 and 15 mM of potassium silicate (K₂SiO₃) and 0, 5, 10 and 15 mM of nanosilica (SiO₂). The results indicated that Si application (all or some treatments) decreased transpiration, specific leaf area, petiole length, and promoted the flowering, fruit firmness, leaf/crown number, fresh and dry weight of shoot and root, water use efficiency. They also showed it did not affect the fruit set percentage, yield, chlorophyll index, total soluble solid, leaf area, fresh and dry weight of crown, photosynthesis, stomatal conductance, internal carbon dioxide (CO₂) concentration and mesophyll efficiency of strawberry. The results suggest the beneficial effects of Si on growth and development of strawberry.     

Mechanisms of aluminum tolerance in triticum aestivum L. (wheat) III. Long‐term pH changes induced in nutrient solutions by winter cultivars differing in tolerance to aluminum

Five winter cultivars of Triticum aestivum L., representing a known range of tolerance to aluminum (Al), were grown in nutrient solutions with and without Al for 41 days to determine long‐term changes in solution pH. Plant‐induced pH of the nutrient solutions declined for 16 to 17 days. Subsequently, the pH induced by Al‐sensitive plants grown without Al and Al‐tolerant plants grown with Al and without Al increased rapidly, presumably reflecting depletion of NH₄ ⁺ from the nutrient solutions. Aluminum‐sensitive plants grown with Al showed a less pronounced pH rise after 16 to 17 days of treatment.

After nutrient solutions were renewed on days 26 and 34, plant‐induced pH patterns were similar to those during days 1 to 26. However, the time required for the onset of the rapid rise in pH decreased. In these subsequent pH cycles, the pH patterns induced by Al‐tolerant plants grown with Al progressively approximated those induced by plants grown without Al. Aluminum‐sensitive plants grown with Al did not induce a rapid rise In pH of nutrient solutions.

Differential tolerance to Al was apparent visually after three to five days growth. Cultivar tolerance to Al was correlated with the initial rate of the pH decline (days 1 to 26) as well as final pH of solutions discarded on days 26, 34, and 41. These results support the hypothesis that differential uptake of NH₄ ⁺ and NO₃ ^‐ causes cultivar differences in plant‐induced pH of nutrient solutions and affects the relative growth of cultivars in Al‐toxic nutrient solutions.     

Metabolic profiling of strawberry grape ( Vitis × labruscana cv. 'Isabella') components by nuclear magnetic resonance (NMR) and evaluation of their antioxidant and antiproliferative properties

In the assessment of the antioxidant properties of edible plants, the widely consumed Vitis × labruscana cv. 'Isabella', known in Italy as "fragola" (strawberry) grape, was of interest. Phenol and flavonoid contents of the methanolic extracts of peel, pulp, seed, leaf, and stalk components of the plant were determined. The metabolic profile of the extracts was performed by 1D and 2D NMR. Quantitative analysis, obtained in the presence of 0.01% of internal standard trimethylsilyl propionate, evidenced the presence of catechins in both stalk and seed extracts, whereas caffeic acid and quercetin were the main metabolites of the leaf extract. Furthermore, the extracts were tested for their radical scavenging and reducing capacities by measuring their capacity to scavenge DPPH(?) and ABTS(?+) and to reduce Fe(III) and Mo(VI) salts. The antioxidant efficacy of the extracts in cell-free systems and their antiproliferative activity toward HepG2 and A549 cells were also evaluated. Seed and stalk components are able to reduce by 39.6 and 40.6%, respectively, the amount of the metabolically active HepG2 cells after only 24 h of exposure.     

Influence of humic acid and salicylic acid on yield,fruit quality,and leaf mineral elements of strawberry (Fragaria × Ananassa duch.) cv. Camarosa

A greenhouse experiment was conducted to evaluate the effects of foliarly-applied Humic Acid (HA) and Salicylic Acid (SA) on strawberry (Fragaria × Ananassa cv. Camarosa). On average, HA applications, regardless of concentration, increased overall yield, Soluble Solids Concentrations (SSC), Titratable Acidity (TA), vitamin C, red tone (a*), leaf potassium (K), phosphorus (P), calcium (Ca) and magnesium (Mg) while had no effect on pH and fruit luminosity (L*). In contrast, fruit from the untreated control tended to have higher Total Antioxidant Capacity (TAC) and SSC: TA ratio than HA-treated plants. Application of SA significantly increased yield, vitamin C, SSC, SSC: TA ratio, TAC, a*, leaf P and Ca while had no effect on TA, fruit size, L* and pH. In general, application of either HA at 25 mg L¹ or SA at 2 mM resulted in better strawberry performance than did other rates of these compounds.     

Nutritional (Fe-Mn) interactions in ‘Big Top’ peach plants as influenced by the rootstock and by the soil CaCO3 concentration

Manganese (Mn) toxicity in plants is often not a clearly identifiable disorder and it can interfere with the absorption, translocation, and utilization of other elements such as Ca, Mg, Fe, and P. Soil conditions, management factors, and the use of different genotypes of rootstock can determine the degree of Mn toxicity and of interaction with other elements in the orchard. Five plants of the cultivar ‘Big Top’® grafted onto itself, onto plum rootstock ‘Mr.S.2/5’ and onto hybrid peach x almond rootstock ‘GF677’ were grown in 25-L containers under three treatments, 0, 20, 30% concentration of total lime, obtained by mixing powdered CaCO₃ to a sandy soil. Plants were fertilized with manure and a solid fertilizer early in April and irrigated in summer periodically with water rich in manganese. After just 28 d, active lime caused a decrease of chlorophyll SPAD index especially in plants grafted on itself, while those grafted on the tolerant ‘GF677’ rootstock behaved better than those grafted on ‘Mr.S.2/5.’ From June to September, irrigation caused increases in soil Mn concentration and Mn concentration in control plants. This caused first a serious defoliation in Big Top / Big Top plants and then a re-greening of cultivar grafted onto ‘Mr.S.2/5’ and ‘GF677,’ probably due to the interaction between iron and manganese at high pH. In particular the 20% CaCO₃ addition to the soil preserved the plants of cultivar grafted onto ‘Mr.S.2/5’ from Mn toxicity, as shown by their high chlorophyll content and growth and lower Mn leaf concentrations. Plants grafted onto ‘GF677’ rootstock showed the best behaviour under 30% CaCO₃ treatment associated to higher Fe(III)-reducing capacity and photosynthetic activity. Rootstocks and soil conditions (lime and waterlogging) influenced mineral status and growth of the peach cultivar ‘Big Top,’ particularly by interacting together and modifying Fe-Mn availability.     

Vegetative Growth,Yield and Leaf Mineral Composition in Strawberry (Fragaria × Ananassa DUCH. CV. Pajaro) as Influenced using Nickel Sulfate and Urea Sprays

In this study, interactions of nickel sulfate and urea sprays on vegetative growth, yield and leaf mineral contents in strawberry were investigated. Rooted Pajaro strawberry plants were potted in 3 liter pots filled with soil, leaf mold and sand (1:1:1, v/v/v). Established plants were foliar sprayed with nickel sulfate at 0, 150, 300 and 450 mg L^?1 and urea 0 and 2 g L^?1 concentrations. Results indicated that nickel (Ni; 300 mg L^?1) plus urea (2 g L^?1) significantly increased the yield and runner numbers. Nickel sulfate at the rate of 300 and 150 mg L^?1and urea (2 g L^?1) significantly increased the crown numbers. The greatest root fresh and dry weights were obtained from untreated plants. Urea at 2 g L^?1 without nickel significantly increased shoot fresh and dry weights. Nickel at 450 mg L^?1 without urea significantly increased Ni concentration in leaves. Overall, nickel sulfate at 150 and 300 mg L^?1 along with urea at 2 g L^?1 were the best treatments.     

Intra‐specific variation for salt tolerance in a potential oil‐seed crop,brown mustard (Brassica juncea (l.) Czern. and Coss.)

Thirty eight accessions of brown mustard (Brassica juncea (L.) Czern. and Coss.) were screened after two weeks growth in solution culture containing 120 mol m‐³ NaCl. Considerable variation for salt tolerance was observed in this set of germplasm, since some accessions showed relatively vigorous growth in saline medium.

In order to determine the consistency of degree of salt tolerance at different growth stages of crop life cycle two salt tolerant accessions, P‐15 and KS‐51 and two salt sensitive 85362 and 85605 were tested at the adult stage in 0(control), 100 and 200 mol m^‐3 NaCl. Both the tolerant accessions produced significantly greater fresh and dry biomass and had considerably higher seed yield than those of the salt sensitive accessions. Analysis of different ions in the leaves showed that salt tolerant accessions contained greater amounts of Na⁺, K⁺ and Ca²⁺ than the salt sensitive accessions, although they did not differ significantly for leaf Cl^‐. Only one salt tolerant accession P‐15 had greater leaf K/Na ratio and K⁺ versus Na⁺ selectivity compared with the tolerant KS‐51 and the two salt sensitive accessions.

From this study it was established that there is a considerable variation for salt tolerance in B.juncea which can be exploited by selection and breeding for improvement of its salt tolerance. Since the degree of salt tolerance in B.juncea does not change at different growth stages of the crop life cycle, selection for salt tolerance at the initial growth stages could provide individuals that would be tolerant at all other growth stages. Accumulation of Na⁺, K⁺ and Ca²⁺ in the leaves are important components of salt tolerance in B.juncea.     

Optimizing Adsorption of Co(II) and Ni(II) by 13× Molecular Sieves Using Response Surface Methodology

Batch experiments were carried out to investigate the adsorption characteristics of Co(II) and Ni(II) by 13× molecular sieves which are hydrothermally synthetic byproducts accompanied with preparation of potassium carbonate from insoluble potash ores. The response surface methodology technique was utilized to optimize the process conditions. The combined effects of the major parameters including pH, initial concentration of metal ions, and temperature on the adsorption were investigated using central composite design. The analysis of variance of the quadratic model suggested that the predicted values were in good agreement with experimental data. The optimum conditions were found to be: initial concentration of metal ions, 20?mg/L; temperature 40?°C for both the metals; and pH, 6.29 and 8.0 for Co(II) and Ni(II), respectively. Scanning electron microscope and X-ray diffraction analyses testified to the obvious change of the surface morphology and the presence of metal on the sorbent after adsorption. The results from the sequential adsorption?Cdesorption cycles showed that 13× molecular sieves adsorbent held good desorption and reusability.     

Is salt stress of faba bean (Vicia faba) caused by Na+ or Cl– toxicity?

The effect of sodium chloride (NaCl), sodium sulfate (Na₂SO₄), and potassium chloride (KCl) on growth and ion concentrations of faba bean (Vicia faba L. cv. Troy) was studied. After 14 or 15 d of isoosmotic treatment with 100 mM NaCl or 75 mM Na₂SO₄, respectively, plants developed toxicity symptoms. These symptoms were characterized by local and nonchlorotic wilting spots, which later turned to black, necrotic spots. In contrast to NaCl or Na₂SO₄ treatment, plants treated with 100 mM KCl did not show these symptoms. The symptoms occurred on those leaves that accumulated highest concentrations of Na⁺ and showed highest Na⁺ : K⁺ ratios. Our results indicate that Na⁺ toxicity inducing K⁺ deficiency is responsible for the spot necrosis of faba bean. Additionally, chlorotic symptoms occurred. The concentrations of Na⁺ and Cl^– were determined in chlorotic leaves and in isolated chloroplasts. The reduction of chlorophyll in leaves after NaCl exposure may be explained in terms of high Cl^– concentrations in the chloroplasts and appears to depend on high Na⁺ concentrations. Chlorotic toxicity symptoms can be avoided by additional Mg²⁺ application.     

Isolation and Analysis of Genes Induced by Rehydration after SeriousDrought in Broomcorn Millet (Panicum miliaceum) by Using SSH

利用抑制消减杂交(suppression subtraction hybridization，SSH)技术构建了糜子(Panicum miliaceum)干旱后复水条件与正常浇水条件下基因差异表达的SSH-cDNA文库。对其中的60个阳性克隆进行了测序，在去除冗余的cDNA后，利用NCBI的BLAST软件在GenBank 中进行核酸和蛋白质同源性的比较和功能分析。核酸比对结果表明,有32个cDNA片段与已知cDNA片段具有较高的同源性，且多数与植物受到生物或非生物胁迫时的反应机制相关，同时有11条序列与小鼠肝被手术切除后再生时产生的EST有一定同源性。蛋白分析结果显示，有28个序列与已知功能蛋白序列同源性较高，这些功能蛋白涉及植物体内的信号转导、转录调控及蛋白加工等。实验结果表明糜子在干旱复水条件下可诱导一系列特异基因的表达。     

Priming effect of bamboo (Phyllostanchys edulis Carrière) biochar application in a soil amended with legume

Abstract

Biochar application to soils can mitigate carbon dioxide (CO₂) by increasing soil carbon (C) sink, but also causes increased CO₂ released from soils through priming effects of soil organic carbon (SOC). However, priming effects of biochar application on SOC are complex, showing inconsistent results, and further complicated when applied with other substrates such as organic amendment (OA). Incubation experiments were conducted using Typic Durudand with bamboo (Phyllostanchys edulis Carrière) biochar (400°C) and OA (crotalaria) applied individually, simultaneously or with biochar applied 5 weeks prior to OA application. After 56 d of incubation, cumulative CO₂ released from soils with no amendments (control), biochar only (BC), OA only (OA), simultaneous (BC+OA), and differently timed (BCP+OA) applications reached 313, 326, 1270, 1535 and 1311 mg CO₂ kg^?1, respectively. The OA application distinctly increased CO₂ released from the soils due to its decomposition. The OA decomposition rates were comparable with OA and BC+OA, while those with BCP+OA were lower than those with other treatments during early incubation. Net CO₂ (CO_{2-(treatment)} ? CO_2-control) from soils with BC, OA, BC+OA and BCP+OA yielded 13, 957, 1222 and 998 mg CO₂ kg^?1, respectively. Primed CO_2-BC of 13 mg CO₂ kg^?1 was equivalent to 4.2% of priming effect relative to CO_2-control. Primed CO_2-BC+OA [net CO_2-BC+OA ? (net CO_2-BC + net CO_2-OA)] and primed CO_2-BCP+OA were 252 and 28 mg CO₂ kg^?1, equivalent to 26% and 2.9% of priming effects relative to sum of net CO_2-BC + net CO_2-OA, respectively. The priming effect with BC was negligible likely because of limited amounts of biochar labile C to induce co-metabolism, while BC+OA showed a modest priming effect most likely as a result of co-metabolism induced by additional mineralization of presumably SOC and/or biochar, because the OA decomposition rates were not affected by biochar application. The priming effect with BCP+OA was comparable to that with BC likely due to changes in soil properties caused by biochar application prior to OA, likely from slowed decomposition rates of OA.