Effect of activated charcoal and ascorbic acid on in vitro morphogenesis and o-dihydroxyphenols content in Paphiopedilum insigne

Phenolic compounds limit micropropagation of many orchids in vitro. The aim of the study was to estimate the effect of activated charcoal (AC);1, 2 or 4 g/L) or ascorbic acid (AA; 10, 20 or 30 mg/L) added to the half strength MS medium on the growth and o-dihydroxyphenols content in Paphiopedilum insigne in vitro. A positive effect of AC on the shoot and root formation has been found. The highest multiplication rate (5.6 shoots/explant) and rooting frequency were obtained on medium containing 2 g/L of AC. However, AC reduced the leaf number as compared to the control. The lowest content of o-dihydroxyphenols was marked in Paphiopedilum insigne leaves when the shoots were grown on medium with 10 mg/L AA, followed by AC at 1 or 2 g/L.

Effect of growing location on anthocyanin content and total antioxidant capacity of haskap (Lonicera caerulea L.) berry: A preliminary investigation

The haskap has been successfully cultivated in many geographical zones in Canada. We investigated whether the latitude has any impact on the anthocyanin accumulation and total antioxidant capacity in the haskap berry. The measured quality attributes were compared with that of the blueberry. Haskap ‘Aurora’ berries were collected from Yukon, British Columbia, Saskatchewan, and Nova Scotia in Canada, and blueberries were collected from Nova Scotia. Cyanidin-3-O-glucoside (C3G), the most abundant anthocyanin of haskap berry, the total anthocyanins, the total polyphenols, the soluble solids (°Brix), the pH value, the total antioxidant capacity, and the moisture content were determined. The results revealed that the total anthocyanin, total phenolic content, and antioxidant capacity of the haskap range between 88 to 273 mg C3GE/100 g fresh weight (FW), 256 to 442 mg GAE/100 g of FW, and 27 to 52 µmol TE/g FW, respectively. The liquid chromatography-mass spectrometry (UPLC/MS) analysis revealed that the C3G contained in the haskap berry is highly dependent on the harvest stage. Among the samples, the haskap berry harvested on July 19, 2019, from the Yukon had the highest C3G content. Interestingly, the total anthocyanin content of the haskap berry is comparable to that of the lowbush blueberry, but higher than the highbush blueberry. A systematic multi-year experiment employing many cultivars and growing locations is recommended to better understand the latitude effect.

The effect of weather conditions in southern Russia on the frost resistance of apricot generative buds

One of the reasons limiting the apricot expansion in the world is the short period of winter dormancy in the plants and the rapid development of generative buds in the spring. Apricot flower buds often die even after small spring return frosts that limit the commercial culture of this fruit crop. The aim of this investigation was to study collection-breeding plantations and select frost-resistant genotypes that have promise for commercial and breeding use. To solve this problem, the frost resistance of generative buds in 50 apricot cultivars and the breeding forms of various origins were studied by freezing treatments of the branches in a climatic chamber. The Czech cultivar ‘Leala’ was selected due to its best frost resistance. In late winter 2020–2021, six cultivars and breeding forms, which kept 41.8 to 65.9% of the generative buds alive, were identified. These genotypes are characterised by a slow development that prevents any negative freezing temperature effects. Thus, the results of the study confirmed the dependence of the adaptation mechanisms in apricot plants on the rates of their morphogenesis and abiotic factor pressures.

Response of sweet cherry buds and twigs to temperature changes – evaluated by the determination of the degradation and synthesis of sucrose

This study was undertaken to determine the degradation and synthesis of sucrose (Suc) in sweet cherry buds and the twig tissue response to a sequence of environmental temperature changes (cold (orchard) – warm (controlled temperature of ∼22 °C) – cold (orchard)). The results of two years’ (2016, 2017) findings were compared with the buds of trees and the buds of twigs in November/December in northeast Germany. The Suc content in the buds of trees and the buds of twigs under natural conditions was stable. Temperatures of ∼22 °C resulted in a significant (Suc) degradation (62%, from 39 to 15 mg/g DW) in the buds of twigs after 21 days (day of the year (DOY) 340). The significant re-synthesis (66%, to 25 mg/g DW after 21 days, DOY 361) in the orchard is noteworthy, and highlights the Suc value as a cryoprotective saccharide. The marked changes in the Suc, glucose, and fructose contents of the twigs exposed to a cold-warm-cold sequence (< DOY 319, DOY 319–340, DOY 340–361), lead to the conclusion that this adaptation is the result of tissue- and cold-specific sucrose invertases/synthases. The effect of low-temperature-active enzymes explains the role of Suc in the buds of trees during the winter rest. When using twigs for plant physiological examinations during the winter rest, results on a metabolite level should be considered when drawing conclusions concerning the overall tree physiology.

The difference in temperature between day and night affects the strawberry soluble sugar content by influencing the photosynthesis, respiration and sucrose phosphatase synthase

Plenty of studies have demonstrated that DIF has an effect on the fruit growth. To study the effects of day and night temperature differences on the strawberry sugar quality, an experiment using climate chambers was conducted. Five different differences between the day and night temperatures (DIF) were set, which were 6 °C (28 °C/22 °C, day/night temperature), 8 °C (29 °C/21 °C), 10 °C (30 °C/20 °C), 12 °C (31 °C/19 °C), 14 °C (32 °C/18 °C). The results showed the following indices peaked with a DIF of 12 °C, including the photosynthesis rate, glucose content, fructose content, sucrose content, soluble sugar content and sugar metabolic enzyme activity. The respiration rate increased with the DIF during the day and decreased with the DIF at night. The root dry weight peaked at a DIF of 10 °C, the stolon dry weight peaked at a DIF of 8 °C and the leaf dry weight peaked at a DIF of 6 °C; however, the fruit dry weight reached maximum values at a DIF of 12 °C. The Grey correlation analysis showed that the most important factor in our experiment affecting the fructose content was the sucrose phosphate synthase; however, for the sucrose, glucose, and soluble sugars, the most important factor was the photosynthesis. We found that a DIF of 12 °C (31 °C/19 °C, day/night temperature) was the most suitable for strawberry growth, especially for the sugar content accumulation.

Impact of fertilisers on five turfgrass mixtures for football pitches under natural conditions

For 2 years (2019–2020), a field experiment to test the activities of different fertilisation schemes on the yield, colour and health status of five different grass mixtures for football pitches was conducted. Two grass mixtures were composed of different varieties of perennial ryegrass, one mixture was composed of varieties of perennial ryegrass and Kentucky bluegrass, one mixture consisted of the species Lolium perenne, Festuca rubra, Festuca arundinacea and Poa pratensis, and the seeds of only one variety of perennial ryegrass were sowed in one plot. Three different fertilisation schemes were included in the experiment. The first scheme (A) contained an inorganic fertiliser with added soil improvers, the second scheme (B) included an organic fertiliser with added soil improvers and the third scheme (C) was composed of an inorganic fertiliser. According to this study, the grass yield largely depends on the soil temperature, amount of precipitation and soil water content, and the occurrence of the fungus Laetisaria fuciformis is influenced by the fertilisation scheme, as the % infection with the fungus was highest when organic fertilisers with low % nitrogen was used. The selection of fertilisers is seen as an important factor for the turfgrass colour.

The effect of a magnetic field on the phenolic composition and virus sanitation of raspberry plants

A magnetic pulse treatment led to an increase in the Raspberry bushy dwarf Idaeovirus-free microplants’ output and their phenolic composition change. The greatest output of the virus-free raspberries microplants (80–82%) was marked after complex treatment with pulsed and rotating magnetic fields with a time-changing frequency from 3.2 to 51 Hz, as well as with a pulsed magnetic field with a frequency from 1 to 10 Hz. The pulsed and rotating magnetic fields’ complex effect resulted in the gallic and salicylic acid content increase by 14 % and 71%, respectively, compared to the untreated variant. The chlorogenic, salicylic and gallic acids’ active synthesis was observed 72 hours after the magnetic treatment with a frequency from 3.2 to 51 Hz. There was a tendency for the amount of the phenolcarbonic acid to decrease 14 days after the magnetic treatment, except for the variant with the pulsed and rotating field treatment.

Scots roses in Northern Ukraine

The article presents the results of the evaluation of eleven Scots rose cultivars in the northern part of Ukraine due to its severe winter conditions. A range of variations regarding the bloom colour, bloom size, bloom type, flowering incidence, plant size was noticed. The evaluation showed the decorative value and considerable frost resistance of the varieties ‘Double White’, ‘Dunwich Rose’, ‘Frühlingsduft’, ‘Frühlingsgold’, ‘Frühlingsmorgen’, ‘Karl Forster’, ‘Mon Amie Claire’, ‘Red Nelly’, ‘Stanwell Perpetual’, ‘Suzanne’, and ‘William III’. The varieties studied can be used for decorative purposes in urban landscapes in the northern part of Ukraine.

Storage of proliferating gooseberry cultures under slow growth conditions

Short storage of in vitro cultures under slow-growth conditions is included in the commercial large-scale micropropagation process. It is dictated by the organizational scheme that provides temporary stop multiplication of shoots for some months. To avoid subculturing to fresh media every 4 weeks, which is obligatory for gooseberry, they can be kept in conditions that protect them from ageing, by slowing down their metabolism. To develop a rational schedule of gooseberry micropropagation, two experiments were used to adopt a temperature and length of time for storage. The best results were obtained with storage conditions at 2 °C for two or four months for proliferating cultures. Under these conditions, the percentage of necrotic shoots was low (< 10%), and shoot proliferation in the subsequent passages was at a level similar to proliferation cultures incubated in the growth room and sub-cultured monthly. The rate of shoots > 1 cm was higher than in the control in the growth room. Storage at 4 °C increased the probability of necrotic shoots up to 80% and decreased the number of all shoots and shoots > 1 cm in subsequent passages.

A modification in an open centre training system for increasing the crotch angles of peach scaffold branches

One-year-old ‘Florida Prince’ cultivar (cv) peach trees grafted on a ‘Nemaguard’ rootstock were planted in the early spring of 2018 at the Centre of Agricultural Research and Experiments, Minia University, located in southwest Egypt. The trees were planted 5 × 5 m in a randomised complete block design with four replicates, with ten trees in each replicate. In the late spring, two different pruning systems were applied; traditional open centre (OC) and de-branched top trees (DBT). The OC trees were headed at 80 cm above the ground. DBT is a modification of the OC, but no heading was undertaken and the new shoot growth arising from the 20 cm at the top of the plant were removed. Before the winter pruning took place, measurements were taken on the upper two opposite branches. The average length and diameter values of the upper two opposite branches at the top of the trees trained to the OC were higher than those trained with the DBT. In contrast, the distance between the upper two branches (25 cm) at the top of the DBT trees was significantly higher. Likewise, the values of the crotch angles (48°) and the number of branches (81 of 100 branches) that showed desired crotch angles (more than 40°) were remarkably higher in the trees trained with the DBT. After the winter pruning took place, the DBT trees were higher than the OC trees. Additionally, the trees trained with the DBT had low pruning costs and took less time. Moreover, the pruning wood weight of the DBT trees was about half of the pruning wood weight of the OC trees. In conclusion, the DBT training system showed the desired impact on the crotch angles and the tested pruning characteristics.