•A single foliar spray with relatively low amounts of B or Zn nano-fertilizers (34mgBtree−1 or 636mgZntree−1, respectively) led to increases in pomegranate fruit yield.•Fertilization with the highest ...of the two doses led to significant improvements in fruit quality, including TSS, decreases in TA, and increases in maturity index and pH in juice.•Physical fruit characteristics were unaffected. Changes in total sugars and total phenolic compounds were only minor, whereas the antioxidant activity and total anthocyanin were unaffected.
This study was carried out to assess the effects of the foliar application of nano-fertilizers of zinc (Zn) and boron (B) on pomegranate (Punica granatum cv. Ardestani) fruit yield and quality. A factorial experiment was conducted based on a completely randomized block design, with nine treatments and four replications per treatment. Foliar sprays of nano-Zn chelate fertiliser at three concentrations (0, 60 and 120mgZnL−1) and nano-B chelate fertiliser (0, 3.25 and 6.5mgBL−1) were applied as a single spray before full bloom at a rate of 5.3Ltree−1. The application of Zn and B increased the leaf concentrations of both microelements in August, reflecting the improvements in tree nutrient status. A single foliar spray with relatively low amounts of B or Zn nano-fertilizers (34mgBtree−1 or 636mgZntree−1, respectively) led to increases in pomegranate fruit yield, and this was mainly due to increases in the number of fruits per tree. The effect was not as large with Zn as with B. Fertilization with the highest of the two doses led to significant improvements in fruit quality, including 4.4–7.6% increases in TSS, 9.5–29.1% decreases in TA, 20.6–46.1% increases in maturity index and 0.28–0.62pH unit increases in juice pH, whereas physical fruit characteristics were unaffected. Changes in total sugars and total phenolic compounds were only minor, whereas the antioxidant activity and total anthocyanins were unaffected.
Due to global climate changes, the growth of ornamental plants will be influenced by warming episodes in winter. The purpose of this examination was to estimate the effect of three levels of ...irrigation regimes on the freezing tolerance of acclimated viola (
Viola × wittrockiana
‘Iona Gold with Blotch’). This experiments included three irrigation regimes (80, 60 and 40% FC) with different temperatures (20, 0, − 3, − 6, − 9, − 12, − 15, − 18, − 21 and − 24 °C). After irrigation regimes, proline and carbohydrate contents were recorded. Then, plants were moved to the thermo-gradient freezer and electrolyte leakage percentage (EL %), survival percentage (SU %), lethal temperature resulting in 50% mortality according to the electrolyte leakage percentage and survival percentage (LT50el and LT50su) were evaluated. The carbohydrate and proline content increased when plants were under drought stress conditions. Electrolyte leakage percentage across three levels of irrigation treatment increased by lowering the temperature; this increase at − 24 °C was fivefold more than the control. Survival percentage in all treatments was not affected in the thermal ranges of 0 to − 9 °C, but decreasing the temperature to − 24 °C resulted in the full loss in all treatments. Vegetative growth and reproductive components were significantly affected by drought and freezing temperature treatments. Dry weights of different parts of plants reached peak values when plants were under 60% FC at 0 °C condition. A negative correlation between LT50el with carbohydrate and proline levels was found and drought treatment significantly increased freezing tolerance (lower LT
50
) in plants grown under 60% FC compared to other treatments.
Ornamental plants can usually encounter various types of environmental stress, which reduce plant productivity. A proper application of fertilizers can improve plantsʼ tolerance to drought stress. ...Nutrients such as potassium and silicon are known to have beneficial effects. This study aimed to evaluate the growth of Bellis perennis under drought stress (80, 70, and 60% FC) and with the application of potassium silicate (0, 2, and 4 mM). The results showed that potassium silicate (2 and 4 mM) increased K and Si accumulation in plants under drought stress. Plants treated with potassium silicate under drought stress exhibited a lower degree of electrolyte leakage and less MDA accumulation in the following order: 2 and 4 mM potassium silicate. An increase in relative water content and chlorophyll was observed with application of potassium silicate under drought stress. Regardless of potassium silicate, the plant enzymatic defense system was significantly improved compared to non-stressed plants. Potassium silicate enhanced the amount of osmotic regulators (carbohydrate and proline) and secondary metabolites (flavonoids and phenols) compared to control plants regardless of drought stress. The anthocyanin content in the flowers significantly decreased by 32.2% when the plants were treated with 4 mM potassium silicate at 60% FC, compared to 80% FC. In conclusion, potassium silicate mitigated the effects of drought stress, enhanced plant tolerance to drought stress, increased the activity of antioxidant enzymes, and improved the amounts of osmotic regulators and secondary metabolites.
Iranian seedless barberry is a very recalcitrant species in in vitro culture which does not show appropriate growth on standard culture media. Response surface methodology was employed to evaluate ...the effects of changing macronutrients concentrations on establishment and proliferation phases. KNO
3
and NH
4
NO
3
macronutrients at 0.3 to 1.5 × MS medium levels and CaCl
2
, MgSO
4
and KH
2
PO
4
macronutrients in a range of 0.5 to 1.5 × MS medium concentrations were tested in a response surface design with 30 treatments. Many significant interactions were found among the macronutrients. High concentrations of KNO
3
, NH
4
NO
3
and CaCl
2
improved the growth rate in the establishment phase. The growth rate in media containing high KNO
3
and low CaCl
2
was high. Reduced concentrations of CaCl
2
and KNO
3
decreased hyperhydricity. The greatest hyperhydricity was induced when both NH
4
NO
3
and CaCl
2
were used at 1.5 × MS level. The number of hooked leaves decreased as KH
2
PO
4
increased and MgSO
4
reduced. In the proliferation phase, there were many significant interactions among the macronutrients. Increased concentration of NH
4
NO
3
and reduced concentration of KH
2
PO
4
improved the growth rate. Proliferation rate increased in media containing high concentration of KNO
3
and low to moderate concentrations of NH
4
NO
3
. The greatest production of new tissues and organs was seen in media with high KNO
3
and moderate to high CaCl
2
. High concentration of NH
4
NO
3
and low concentration of KH
2
PO
4
also increased production of new tissues and organs. No shoot apical meristem was seen when CaCl
2
level was high and KNO
3
level was low. Formation of shoot apical meristem required high KH
2
PO
4
concentration and low CaCl
2
concentration. Finally, low concentration of KNO
3
and low to moderate concentrations of NH
4
NO
3
increased phenol exudation.
Key message
Establishment and proliferation phases of Iranian seedless barberry were improved, for the first time, by manipulation of five macronutrients of MS basal medium using Response Surface Methodology.
The current study was aimed to solve the problem of browning in Iranian seedless barberry
in vitro
culture by using a variety of different approaches. As such, several experiments were carried out. ...The results revealed that addition of 225 mg/l citric acid + 50 mg/l ascorbic acid could alleviate phenol browning compared to control. Presoaking of explants in 300 mg/l citric acid solution for 30 min and culturing them in media containing 225 mg/l citric acid could further reduce browning rate. Results related to the effect of sampling time indicated that explants cut off in April showed the lowest browning rate and those cut off in January, February and March showed the highest browning rate. Effects of conditions related to stock plant were also investigated, and the results displayed that explants harvested from upper position of current-year shoot and sucker showed the lowest browning rates, respectively, while those collected from lower position of one- and two-year old shoots exhibited the highest browning rate, respectively. Data obtained from shoot color and diameter also demonstrated that explants taken from pinkish-colored shoots with small diameter showed the lowest browning rate and those collected from dark brown-colored shoots with large and very large diameter contained the highest browning rates. Use of 8‑hydroxyquinoline and Fe-EDDHA for reduction of browning was investigated for the first time, and interestingly the results showed that both compounds, in particular 8‑hydroxyquinoline, caused a significant reduction in phenol exudation. More interestingly, they could cause a significant increase in bud break rate. Furthermore, phenol exudation and peroxidase activity in treatments supplemented with 8‑hydroxyquinoline and Fe-EDDHA were lower than those in treatments containing antioxidants.
Water scarcity and dwindling natural resources due to global warming are negatively impacting ornamental plant survival. Soil fertility remains a problem in arid and semiarid regions. In this study, ...the effects of four media (arable soil, arable soil + cow manure, arable soil + rice hull, arable soil + wheat straw) on macronutrient content and quantitative characteristics of Alcea rosea L. under drought stress were investigated. Application of organic amendments mitigated the negative effects of drought in the soil and increased the available organic macronutrients. The application of organic amendments increased the total N, P, and K content in the soil and leaves of hollyhock. Total soluble sugars (by 11.9%), RWC (by 8.75%) and phenolics (by 36.4%) of hollyhock were significantly improved by the application of organic amendments at 80% FC. The amended soil (soil + cow manure) increased the activities of superoxide dismutase and ascorbate peroxidase at 80% FC. Moreover, the soil + cow manure proved to be the best supplement to improve leaf area and dry weight. In conclusion, the application of organic amendments can be successfully used as a cost-effective management method to improve soil fertility and crop production in arid and semi-arid areas.
Carbon source plays an important role in the induction of embryogenic callus (EC). Therefore it is necessary to determine the effective carbohydrate for improving this process. In this study, ...different carbohydrates as sucrose, maltose, and sorbitol with different levels (0–30 g/L) were tested in the callus induction of
Pyrus communis
. At first, in solid culture, calli were divided in relation to their morphological appearance in EC and non-EC. EC was white or yellow with the granular aspect. The morphological study revealed the highest frequency of EC (28.5%) obtained at 30 g/L sucrose. Biochemical analyses showed EC exhibited both soluble sugar and protein high contents, while the starch was at the lowest level. As well as flow cytometry showed EC were genetically similar to donor explants. With transferring the EC into the liquid culture, then, subculturing calli along with 2 ml cell suspension on solid medium led to the globular embryo.
Background
Rosa canina
is one of the most popular rose species which is widely used as the rootstock for the propagation of rose cultivars. The purpose of the present study is to improve the in vitro ...propagation efficiency of this valuable plant species using various growth stimulants in a proliferation medium. In this study, in vitro-derived axillary buds of
R. canina
were inoculated in Vander Salm (VS) medium supplemented with varying levels of organic or inorganic elicitors including casein hydrolysate (200, 400, and 600 mg/l), glutamic acid (2, 4, 8, and 12 mg/l), proline (500, 1000, 1500, and 2000 mg/l), and silver nitrate (25, 50, 75, and 100 mg/l), separately. Benzyl amino purine (BAP) as well as naphthalin acetic acid (NAA) were added to all media at a constant rate to promote shoot proliferation.
Results
The results indicated that the supplementation of casein hydrolysate to the VS medium markedly stimulated shoot regeneration by 173% in comparison to control. Shoot proliferation was also positively influenced by glutamic acid at all levels, however, at a lesser extent compared to casein hydrolysate. Silver nitrate at 100 mg/l induced the longest shoots (2.52 ± 0.248 cm) and maximum leaf number (8.90 ± 0.276) among all treatments. Although it did not encourage efficient shoot regeneration, the highest quality shoots with maximum growth vigor were observed in this treatment.
Conclusion
In this study, the promising role of casein hydrolysate in combination with plant growth regulators has been emphasized for the improved efficiency of
R. canina
regeneration protocol. Moreover, the addition of silver nitrate to the culture medium seems vital for enhancing the quality of regenerated shoots. The results of this study could be beneficial either for the further pharmaceutical or biochemical investigations of
R. canina
or commercial purposes for mass propagation of this specimen.
•Active osmotic adjustment operated contributing to the maintenance of leaf relative water contents.•The increase of antioxidant enzyme activities could improve drought tolerance of pansy plants.•The ...effect of moderate water stress on physiological indexes was higher than severe water stress in the same growth period.•The plants ability to maintain physiological functions during drought and recover after re-watering are important for determining final productivity of pansy.•The final dry matter of pansy was affected by drought stress, and its extent was depend on the drought intensity and its duration.
Drought is one of the major factors limiting ornamental plant production. Exposure to long-term drought conditions inhibits plants growth and leads to their yield loss. In this study, various responses of pansy plants to drought stress and recovery period were comparatively studied at physiological and biochemical levels, after one, two and three week period of exposure to drought stress and one week of recovery period. This study results showed that prolonged drought stress dramatically decreased relative water content (RWC), chlorophyll a, b and total chlorophyll and antioxidants including ascorbate peroxidase (APX), superoxide dismutase (SOD) and dehydroascorbate reductase (DHAR) activities of plants while increased the accumulation of proline, sucrose, glucose, and fructose content, hydrogen peroxide (H2O2), malondialdehyde (MDA), and glutathione peroxidase (GPX) activity. Under well-watered condition, plants exhibited an increase in electrolyte leakage after three weeks period of exposure to drought stress, followed by rapid recovery. Under moderate and severe drought stress, plants displayed relatively less adaptability to drought, with a slower recovery after re-watering and a greater increase in electrolyte leakage. This study findings highlighted that enhanced antioxidative protection and osmotic adjustment plays an important role in pansy tolerance against drought. It was concluded that even though plants recovered after re-watering, the final dry matter was affected by drought stress, and its extent was depend on the drought intensity and its duration.
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