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To better understand the influence of altitude on fruit characteristics of bog bilberry (Vaccinium uliginosum L.), here we investigated the adaptation of its fruit morphological and chemical traits to the environment at six growing positions along an altitudinal gradient (706, 957, 1 226, 1 315, 2 000 and 2 190 m) on the northern slope of Changbai Mountain, China. Fruit longitudinal diameter, fruit transverse diameter and fruit weight decreased significantly with increasing altitude. Vitamin B1 content reached its highest at 2 190 m, while both vitamin B2 and vitamin C contents reached their highest and lowest at 1 226 and 706 m, respectively. Anthocyanin content and DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging ability initially decreased and then improved with increasing altitude. We observed a highly significant (P < 0.001) negative correlation between external fruit quality traits (fruit length, diameter and weight) and internal fruit quality traits (vitamins B1, B2, C and anthocyanin), and found that environmental factors significantly influenced fruit characteristics. Taken together, we concluded that on the northern slope of Changbai Mountain, bog bilberry fruits were larger at low altitudes, fruits at mid altitudes contained higher vitamins B2 and C, while high altitude (especially at 2 190 m) was beneficial for vitamin B1, anthocyanin, and DPPH free radical scavenging ability.

This study tested the impact of priming peanut seeds from the VD01-2 cultivar with either 6 mg/L of abscisic acid or 20 mg/L of sodium nitroprusside to prevent damage from drought stress. Throughout the development of peanuts under drought-stress conditions, various morphological, physiological, and biochemical changes were analyzed. According to the study, it was determined that priming with SNP had a more significant effect than priming with ABA. The use of sodium nitroprusside priming resulted in an improvement in both the yield and quality of peanuts when grown under drought conditions. Furthermore, the findings indicate that the use of sodium nitroprusside priming showed an increase in chlorophyll content, gas exchange capacity, and antioxidant activities while reducing lipid peroxidation.

Plant growth regulators (PGRs) are artificially synthesized substances that control growth, development, and other various physiological processes in plants. Synthesized auxins, ethylene, abscisic acid, cytokinin, and gibberellins are only a few of the key PGRs that have been studied and used for quite a long period of time. brassinosteroids, salicylic acid, jasmonic acid, CPPU (N-(2-chloro-4-pyridyl)-N’-phenylurea), putrescine, hexanal, triacontanol, melatonin, and other chemicals have been added to the list of PGRs. These PGRs can be considered the new generation of plant growth regulators. These relatively novel hormones are critical for a plant’s growth and development. They aid in the increase of not only the quantity (fruit set, length, weight, yield, volume, pulp percentage, and so on) but also the quality of fruit crops (fruit colour, firmness, total soluble solids, total sugar, ascorbic acid content, etc). They also help to prolong the shelf life of certain fruits and minimize the losses after harvesting. As a result, these new-generation PGRs can be used to boost an orchard’s productivity and income while minimizing pre and post-harvest losses to the greatest extent possible. Hence, this extensive review discusses the impact of these new-generation PGRs on fruit crops.

Choerospondias axillaries (CA) is an important fast-growing afforestation tree species in southern China, and its fruit has medicinal and edible value. High performance liquid chromatography was used to determine the composition and content of sugar and acid in CA fruits from different provenances, and cluster analysis was conducted on different provenances. The results showed that the total sugar content of CA fruit ranged from 49.31 to 139.41 mg/g, with sucrose accounting for the highest proportion of total sugar, followed by glucose, and fructose was the lowest. The total acid content of CA fruit ranged from 47.97 to 82.81 mg/g, with citric acid accounting for 67.09% of the total acid, followed by ascorbic acid, quinic acid, tartaric acid, and malic acid. Cluster analysis was conducted on 20 CA fruits, which were divided into 4 categories. It was recommended to develop N19 fruit had the highest content of sucrose and glucose, and the highest sweetness value, sugar-acid ratio and sweet-acid ratio. It can be suggested to be developed as a high-sugar fresh food source. N02 fruit with high sugar and high acid content can be used as a raw material for fruit cake processing. This result provides an important reference for the quality evaluation and rational development and utilization of CA.

In recent years, grafting has emerged as an efficient and alternative tool to the relatively slow conventional breeding methods, aiming to increase tolerance to abiotic stresses and soil pathogens while improving yield and quality attributes in fruit vegetables. In the present investigation, six inter-specific cucurbitaceous rootstocks, viz. sponge gourd (SG), ridge gourd (RG), ash gourd (AG), bottle gourd (BG), and Summerfit (SF), an inter-specific hybrid of snap melon × acidulus melon, were evaluated for cucumber (C) cv. ‘Kashi Nutan’. Experimental findings revealed that cucumber grafted onto inter-specific SF exhibited a 14.63%, 57.5%, and 20.05% increase in vine length, number of branches, and dry matter production, respectively, compared to the self-rooted control. Photosynthetic parameters such as photosynthetic rate (P_n), stomatal conductance (g_s), and maximum quantum efficiency of photosystem II (PS II) (Fv/Fm) were also higher in cucumber leaves grafted onto the SF rootstock. Compared to self-rooted plants, cucumber grafted onto SF recorded 72.3% more fruits, a 36.9% increase in fruit weight, and an 80.9% higher fruit yield. The SF rootstock also showed a 44.54% increase in total root length (TRL), a 77.11% increase in root volume, and a 27.25% increase in average root diameter over self-rooted cucumber.

The clonal propagation of guava (Psidium guajava L.) is essential to avoid segregation, and its multiplication through cuttings is the easiest and cheapest way to raise a nursery, as other propagation techniques are laborious and need expertise. The current study was planned to evaluate the best rooting stimulators and rooting substrates for guava nursery propagation. In this experiment, the guava-prepared cuttings were treated with rooting stimulators, indole butyric acid (IBA) and paclobutrazol (PB) with concentrations (0, 200, 400, and 600 ppm) and were planted in independent rooting substrates (sand, silt and topsoil) under polytunnels. The results revealed that the highest number of roots, root length and root weight were achieved in cuttings planted in the sand with IBA 400 ppm concentration. In contrast, the highest survival percentage (50%) was obtained in silt substrate with a similar concentration of IBA. However, sand’s lowest and highest concentrations of both rooting hormones produced zero plants. In shooting capacity, maximum leaves (13.6) and sprouts (3.76) were obtained using IBA 400 ppm in silt substrate. The highest sprouting length (6.80 cm) and cutting height (26.2 cm) were attained with sand using PB 200 ppm. In the overall comparison, rooting stimulator IBA 400 ppm and rooting substrate silt performed better than other rooting stimulators and rooting substrates.

The choice of variety, sowing time and optimum nutrition are important management options to optimise the seed yield. Accordingly, an experiment comprising of 18 treatments was conducted during the winter 2017–2018 and 2018–2019 in a factorial randomized block design, replicated three times to assess the response of pea genotypes (DPP-SP-6, Him Palam Matar-1 and Pb-89) to the seeding time (26th October and 10th November) and nutrient levels (0, 100 and 125% of the recommended NPK). The individual treatment effects revealed that early sowing, application of 125% NPK and DPP-SP-6 were significantly superior for the seed yield and related traits. The interaction effects indicated a significant response of the 125% NPK on the early sown crop for the seed yield, harvest index and NPK uptake. Significantly highest soil available NPK were obtained at 125% NPK with a respective increase of 41.54, 5.90 and 30.82 kg/ha, respectively, over the initial status. Early sowing of DPP-SP-6 with an application of 125% NPK is a better preposition for enhancing the productivity of peas.

Metabolomics analysis based on UPLC-MS/MS was used to investigate the influence of rain shelter (RS) conditions on metabolites of sweet cherry leaves. It was found that there were 134 differential metabolites. These differential metabolites were enriched in 40 metabolic pathways. Studies on the biosynthetic pathways and regulatory mechanisms of metabolites in sweet cherry leaves showed that low-light and drought stresses in RS plants were related to the amino acid biosynthesis metabolic pathway and that of flavone and flavonol biosynthesis. Sweet cherry trees exhibited improved tolerance to drought stress by regulating the increase in the content of metabolites, such as proline in the amino acid metabolic pathway and the content of flavonoids in the phenylpropane metabolic pathway. To cope with low-light stress, sweet cherry leaves can increase their photosynthetic efficiency by regulating the flavonol content in the flavone and flavonol biosynthetic pathway under the catalysis of a series of enzymes.

Ornamental cabbages are cultivars of cabbages grown for decorative purposes due to the varied shape and colour of their internal leaves. The aim of the study was to determine the course of growth and to assess the decorative and nutritional value of two cultivars of ornamental cabbage ('Pigeon Red', 'Coral Prince') grown in a flowerbed along with annual plants: the French marigold (Tagetes patula nana L.) and flossflower (Ageratum houstonianum Mill.), using a pine bark mulch. The impact of the marigold and flossflower on the cabbage height and foliage changed with the plant growth. Cabbages growing without the proximity to the other species had the smallest diameter and formed the least leaves; and the plant's height was lower in September. The cabbage height, foliage and leaf colour were modified by the weather in the subsequent years of research. The proximity of the marigold or flossflower and mulching of the soil with bark did not affect the colour of the leaves. The nutritional value of the ornamental cabbage was high, and the content of the mineral components in the leaves depended largely on their colour. The coloured leaves were more abundant in nitrogen, phosphorus, potassium and magnesium, while the green leaves contained more calcium and sulfur, and slightly more dry matter.

This study evaluated the influence of the arbuscular mycorrhizal fungi (AMF) inoculation of leek (Allium porrum L.) on the leaching of ammonia and nitrate nitrogen from the experimental pots filled with either sterile or non-sterile soil mix, consisting equally of the arable soil and horticultural substrate. Leek plants were inoculated by Funneliformis mosseae, Claroideoglomus claroideum, Rhizophagus intraradices and by their combinations. Based on the obtained data, it can be concluded that: (a) the influence of AMF on nitrate leaching does not follow some simple rules, (b) the amounts of percolating nitrates can be affected also by sterilization and by the combination of AMF inocula, (c) AMF can, in general, reduce the nitrate leaching from soil even though mycorrhizal colonization of roots did not achieve extremely high rates. These conclusions may be useful in the horticultural practice and ecological sustainability of the soil quality.

Phenolic content of apples from an integrated and organic apple tree orchard was analysed at the Institute of Horticulture of Lithuanian Research Centre for Agriculture and Forestry in 2012-2013. Apples of 'Lodel' and 'Aldas' cultivars on rootstock B.396 in 8-9th leaf were tested. Nitrogen and potassium fertilizers were applied annually at the rates of 50 kg/ha N and 66.4 kg/ha K in an integrated fruit orchard. A mixture of perennial grasses with 25% of white clover was sown in interrows in the second year after tree establishment in the organic production system. Every two years sward in alternate interrows was tilled for natural organic matter mineralization. Fertilizers were not used in the organic apple orchard. Organic apples of both cultivars had a higher content of procyanidins B1 and B2, phloridzin, chlorogenic acid, (+)-catechin, and (-)-epicatechin. Organic 'Aldas' apples also contained more hyperoside, avicularin and quercitrin than non-organic apples. On average, the total phenolic content of organic apples of both cultivars was 43% higher than that of apples from the integrated orchard. These differences could be explained by nitrogen nutrition: the N content in organically grown apple leaves was significantly lower than that in leaves from the integrated production system. Tree trunk diameter and yield of organic apple were less, and fruits were better coloured.

Our study comparative analyzed the morphological and physiological performance of Juglans regia L. cv. ‘Xiangling’ (JRX) grafted onto five rootstock species originated from China. A wide range of coefficient of variation (CV), 1.155–39.848%, was detected for fourteen indexes among the studied seedlings. CV of plant height, total dry biomass, total leaf area, root/shoot ratio, chlorophyll index, and stomatal conductance was higher than 15.00%, suggesting higher variation. Principal component analysis, hierarchical cluster analysis and subordinate function analysis were used to screen engrafted seedlings for their quality. All three methods produced the same result that seedling quality of ‘Xiangling’ engrafted with the five rootstock species from high to low were – Juglans regia L. cv. ‘Jizhaomian’ (JRJ), JRX, Juglans regia L. cv. ‘Lvxiang’ (JRL), Juglans mandshurica, Maxim., and Juglans hopeiensis Hu.. The evaluation results were highly consistent with the actual growth performance of the engrafted seedlings, it verified the reliability of our results and the evaluation methods. The results demonstrated that JRJ, JRX, and JRL are potential rootstock candidates in the studied walnut planting regions. It would provide important implication for the selection of proper rootstock species for a certain particular walnut variety.

Weed control and replenishing soil moisture and fertility are important areas in fruit production. The number of studies focused to determine whether living mulches in tree rows can fulfil these tasks increases recently. In the paper the results of an 11-year experiment on the effect of two such mulches (Trifolium repens L. and Agrostis capillaris L.) on the growth, yield, and fruit quality of three pear cultivars (‘Alfa’, ‘Dolores’, ‘Amfora’) in relation to herbicide fallow are presented. In the experiment, a single sowing of covering plants without additional treatments was used. A statistically significant reduction in yield (20–22%) was found for both mulches used, which was related to weakening the vegetative growth of trees. The average fruit mass did not change significantly, but the percent share of large fruits increased significantly (about 17%) in the A. capillaris mulch. Fruits from trees growing in T. repens contained significantly more soluble solids and Ca. However, that mulch became heavily infested with weeds after a few years. The obtained results allow us to recommend the use of the living mulch A. capillaris in the tree rows of a commercial pear orchard. The ‘Dolores’ and ‘Amfora’ cvs are particularly recommended.

Botrytis cinerea is one of the main pathogens that harm the tomato yield and cause huge economic losses worldwide. Studies of circRNAs in response to the stress caused by pathogens have received more and more attention in tomato and other model crops. In this study, four groups were treated with ZaoFen (ZF), CuiLi (CL) (susceptible and tolerant genotypes to B. cinerea, respectively), ZFBc, CLBc (48 hour response to a B. cinerea infection). A total of 918 circRNAs were identified, among which exonic circRNAs (70.70%) accounted for the majority of them, and 118 circRNAs (12.85%) were located in chr1. A total of 18 (1.96%) circRNAs were shared among the four libraries. A total of 6 circRNAs showed fold changes in the differential expression analysis between the time and cultivar control groups, and circRNA115, circRNA145 and circRNA223 repeatedly appeared in the different control treatments. Notably, the gene targeted by circRNA115 was an ethylene-forming enzyme. At the same time, we predicted the target genes of the six circRNAs obtained in the study, and a total of 319 miRNAs were predicted. This study contributes to the mechanism in response to B. cinerea stress in the tomato, and paves the way for the further study of circRNAs under tomato pathogen stress.

To date, ‘Japansche Citroen’ (JC) has only been used commercially as a rootstock in Indonesia; however, the use of suitable rootstock remains challenging because of water limits in different places. The morphological, physiological, and gene expression changes of one-and-a-half-year-old mandarin cv. ‘Keprok Batu 55’  (KB) and sweet orange cv. ‘Manis Pacitan’  (MP) budded onto ‘Japansche citroen’ (JC), ‘Rough Lemon’ (RL), ‘Salam’ (S), ‘Volkameriana’ (V), and ‘Cleopatra Mandarin’ (C) rootstocks, subjected to six-week drought-stress conditions, were examined under a shade house. The experiment was conducted in Junrejo Subdistrict ( ± 990 m a.s.l.), Batu City, East Java Province, Indonesia, from January 2022 to May 2023. The experimental design was a factorial randomized block design with two factors: rootstocks as factor I and two citrus species as factor II, with three replications. A low shoot/root (S/R) ratio indicates much more root development than shoots observed in KB/C (0.89) and MP/RL (0.87) plants under drought conditions; the MP/RL plant had the greatest stomatal density (16.0/0.015 mm2) and percentage of stomatal closure (58.8%). In this condition, it had lower leaf relative water content (RWC) than the control, with comparatively high RWC ranging from 45–55% in KB/JC, KB/S, MP/C, and MP/RL. The drought did not affect cell membrane damage, although this did slightly increase the quantity of chlorophyll a, b, and carotenoids (P < 0.05). Aside from that, leaf proline and total soluble sugar levels were higher in the dryness than in the control, with the combination of KB/C (331.6 μ mol proline/g fresh weight), MP/JC, and MP/RL plants having the highest (347.9 and 337.1 μmol proline/g fresh weight). Meanwhile, the plants with the greatest quantities of soluble sugar were KB/C (35.9 mg/g dry weight) and MP/V (75.3 mg/g dry weight). Regardless of scion-rootstock interaction, KB enhanced the relative quantity of several genes such as 1-Aminocyclopropane-1-carboxylate (ACC) synthase, Chlase, ethylene receptors (ETR1), osmotin, plasma membrane instrinsic proteins (PIP1), and PIP2 allowing it to respond more effectively to drought stress conditions. In contrast, MP only increased Chlase and ETR1 ones. Under drought conditions, the KB/C and MP/RL combinations are assumed to be more adaptable than others.

Raspberry has acquired great interest in human health due to its content of bioactive compounds that provide protection against diseases caused by non-communicable diseases. Bioactive compounds are mainly represented by secondary metabolites such as phenols, anthocyanins, and flavonoids. Biostimulants and elicitors are substances or microorganisms that provide protection and defence to the physiological processes of plants. The present study evaluated the effect of two elicitors (hydrogen peroxide, salicylic acid) and three biostimulants (humic and fulvic acids, glutamic acid, seaweed extracts) on the content of bioactive compounds in raspberry fruits, agronomic and fruit yield parameters in plants. Hydrogen peroxide increased the content of bioactive compounds such as flavonoids, anthocyanins, omega 3 and oleic acid. Salicylic acid increased the content of flavonoids, anthocyanins, and citric acid in raspberry fruits; the number of fruit loaders and fruits per plant was also increased. Humic and fulvic acids, glutamic acid, and glutamic acid combined with seaweed extracts increased the content of flavonoids and anthocyanins, without affecting growth parameters and fruit yield. Glutamic acid and seaweed extracts were the only treatments that increased the content of palmitic acid, while seaweed extracts increased °Brix content in fruits.

The present study aimed to use a non-parametric data envelopment analysis (DEA) to estimate the energy efficiency and greenhouse gas (GHG) emissions in off-season cucumber-producing greenhouses in different farm level management systems in Iran. Data were collected using a questionnaire completed by 83 cucumber producers through face-to-face interviews. The results showed that the energy use rate was 75.1%, 82.6%, and 86.2% in small (0.5–0.9 ha), medium (0.9–2 ha), and large farms (≥ 2 ha), respectively. In all the farm levels, the greatest energy use shares belonged to electricity, chemical fertilisers, and human labour, respectively. The results of the DEA revealed that the technical, pure technical, and scale efficiencies of the large farms were 87.3%, 92.8%, and 97.1%, respectively, which were higher compared to other farm level management systems. The ratio of energy savings was estimated at 5.62% and 2.97% for small and large farms, respectively. The results also showed that electricity, chemical fertilisers, and diesel fuel were the most responsible for the GHG emissions. By optimising the energy use, pollution per one/ha one of off-season cucumbers can be mitigated by 1 614.5 and 1 315.0 kg of CO2/ha in small and large greenhouses; indicating more attention is required in managing the energy inputs in small-sized agro-ecosystems, especially for electricity.

The impact of rhizosphere aeration on the composition of xylem sap in cucumber grown in soil was studied to determine its effects on (i) water and nutrient uptake, (ii) xylem transport, and (iii) amino acid synthesis in the roots. Plants grown under three different aeration conditions were subjected to progressive gas stress throughout the whole growth period. The shoot and root growth, xylem nitrate (NO₃^–) concentration, potassium (K⁺) concentration, xylem sap flow rate, and amino acid concentrations were higher in the Z1 treatment plants than in the control (CK) plants, and the former also showed a lower CO₂ (0.25–0.84%) and a higher O₂ (18.22–20.02%). However, the Z3 treatment plants exhibited decreased xylem loading of amino acids, NO₃^– concentrations, and K+ concentrations and a lower flow rate of xylem sap, which restricted shoot and root growth due to poor aeration caused by a higher CO₂ (0.75–3.68%) and a lower O₂ (11.51–18.6%). Furthermore, the xylem pH in these plants was lower by approximately 0.17 units, and the conductivity was decreased by approximately 0.31 mS/cm. Based on the observed results, the CO₂ and O₂ in the soil can potentially regulate root and shoot growth and the xylem sap composition in cucumber. Therefore, rhizosphere aeration is important for the vigorous growth of plants.

The physiological regulation of Welsh onion seedlings was explored under short- and long-term drought stress. The Welsh onion cultivar ‘Neicong 3’ was grown in pots under drought stress (22.5–25% soil water content) or controlled watering conditions (65–67.5% soil water content). Different lengths of drought stress (7, 14, 21, and 28 days) were studied to determine the effects of the drought on the levels of the osmoregulatory substances, including proline (Pro), free amino acids (FAAs), soluble sugar (SS), and soluble protein (SP); the membrane-damage indicator malondialdehyde (MDA); the endogenous hormones indoleacetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA), and jasmonic acid (JA); and the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). The soil water content was restored to the control level after the drought stress to analyse the physiological responses of the Welsh onion with regards to rehydration. The results showed that the Welsh onion responded to drought stress primarily by increasing the levels of the osmoregulatory substances and the activities of the protective enzymes. The drought stress resulted in the accumulation of Pro, FAA, SS, MDA, and ABA in the pseudostems, while the IAA and GA levels decreased. Short-term drought stress led to a decrease in the SOD activity and an increase in the CAT activity, whereas the long-term drought stress led to a decrease in the POD activity. The effects of the drought stress on the SP and JA contents were negligible. The rehydration demonstrated that the short-term drought stress (7 or 14 days) did not exceed the tolerance of the Welsh onion; the substances regulating the drought tolerance were restored to normal levels after the stress conditions were relieved. In contrast, after the severe drought stress (28 days), the substances regulating the drought tolerance in the seedlings could not return to normal levels. This study provides a theoretical basis for the cultivation of the Welsh onion under early drought conditions and for breeding of drought-resistant varieties.

The aim of this study was to determine the effects of elevated CO₂ (eCO₂) on the quality and cadmium (Cd) accumulation of vegetables grown in soil with a background Cd level or in Cd-contaminated soil. We used four types of vegetable: pak choi (Brassica rapa L.), water spinach (Ipomoea aquatica Forssk.), cherry radish (Raphanus raphanistrum subsp. sativus (L.) Domin) and pepper (Capsicum annuum L.). Cd stress significantly reduced vegetable vitamin C and reducing sugar content; however, under eCO₂, vitamin C and reducing sugar content levels were significantly higher than they were under ambient CO₂ (aCO₂) levels. The nitrate content of pak choi, cherry radish and pepper was reduced under eCO₂, and the effect was more pronounced among plants grown under Cd stress. The Cd content of cherry radish and pepper roots grown under eCO₂ and Cd stress was significantly reduced (29.2% and 18.5%, respectively) compared with plants grown under aCO₂ conditions and Cd stress. The Cd transfer coefficient of pak choi and water spinach grown under eCO₂ and Cd stress was significantly lower (22.7% and 25.2%, respectively) than under aCO₂ conditions. Our data suggest that growing vegetables under eCO₂ is beneficial, especially when grown in Cd-contaminated soil, because Cd accumulation is reduced and vegetable quality is improved.

Watermelon (Citrullus lanatus L.) is grown in tropical and temperate regions and an economically important crop. Characterization studies of watermelon may provide valuable information for breeding and research programs. The objectives of this study were to determined of morphological, phytochemical, genetic diversity and population structure among the watermelons. Morphological and phytochemical variations including sugar contents were determined in 96 watermelon genotypes grown in the field. The average number of fruits per plant was determined as 2.52 ± 0.06, and the average yield was determined as 6.2 ± 0.11 kg/m2. The mean total sugar was determined as 6.27 ± 0.12 %, and the lowest value was measured in genotype 234 (1.1%); the highest value was measured in genotype number 184 (8.66%). A total of 62 SSR (Simple Sequence Repeat) primers were used in the molecular characterization study. The similarity coefficients among the 96 genotypes varied between 0.23 and 0.99. This study indicates that there is a wide morphological and sugar parameters variation among watermelon genotypes but narrow molecular genetic diversity. It also provides useful information for watermelon breeding studies.

In an environment where fruit production is increasingly affected by unpredictable weather patterns, it is important to look for ways to minimise the impact of climate change on production. Under Central European conditions, a limiting factor for apricot (P. armeniaca L.) and Asian plum (P. salicina Lindley) growing in certain years is the occurrence of late spring frosts. One measure to eliminate their impact is to delay the actual flowering of the trees. This can be done by breeding or just by applying various plant growth regulators (PGRs). In our experiment, the effect of a total of 6 active substances in 16 different concentrations was evaluated. The results show that the application of Ethrel-based mixtures (concentrations of 0.05 and 0.5%) had the greatest influence, delaying flowering by up to 3-5 days, but also had the most destructive effect on tree health. The application of the commercial product Rhodofix (NAA - 0.3%) and the application of a proprietary mixture based on NAA 1.0% did not have a very significant effect, with a delay in flowering of just 2 to 3 days. One interesting finding was that the application of the above products had a statistically significant effect on the ripening date of apricot fruit, with a difference of up to 4 days.

Many studies have demonstrated that brassinolide improves the drought tolerance of plants. This study aims to test whether the drought tolerance of chrysanthemums can be improved by brassinolide and to clarify the underlying physiological mechanism. An own-root chrysanthemum and a corresponding grafted-root line (Artemisia annua rootstock) were treated with brassinolide under three water levels in a randomised complete block design with five replications. The results showed that brassinolide increased the relative water content, net photosynthetic rate, chlorophyll (Chl) fluorescence parameters, Rubisco, ascorbate peroxidase, glutathione reductase, dehydroascorbate reductase and monodehydroascorbate reductase activities, ascorbate/dehydroascorbate, glutathione/oxidised glutathione and dry mass, and reduced the H2O2 content in the own-root and grafted-root chrysanthemums, especially under drought stresses. The magnitude of the changes to the parameters was greater in the own-root line than in the corresponding grafted-root line under brassinolide treatment. The above parameters showed significant differences (P < 0.05) between the brassinolide chrysanthemums and the corresponding non-brassinolide chrysanthemums under drought stresses. This might be the physiological mechanism of improved drought tolerance by brassinolide in chrysanthemums.

Rosa damascena is one of the oldest valuable rose flower varieties that is almost drough tolerant. However, selecting and identifying landraces that are more tolerant to drought conditions will be effective in developing the cultivation of the plant under stress. The most important step in developing drought-tolerant plants is the evaluation and identification of resistant and susceptible genotypes. In this case, an experiment was performed under in vitro conditions using five levels (0, 25, 50, 75, and 100 g/L) of polyethylene glycol (PEG) on four landraces of the Damask rose (Maragheh, Urmia, Pakdasht, and Kashan). Based on the findings, the resistance of the different landraces to a water deficit was measured by the Design-Expert software using the response level (RSM) method. The results showed that Maragheh, with the highest fresh and dry weight, total chlorophyll, chlorophyll a, chlorophyll b, proline and an increase in the superoxide dismutase activity, had a high tolerance to drought stress. Moreover, Maragheh with a decreasing leaf number, height, malondialdehyde, hydrogen peroxide and having a higher membrane stability index, showed a better defence mechanism against oxidative stress than the other landraces. Also, after Maragheh, Pakdasht had the best performance compared to the other two landraces up to 75g/L of PEG, but not as well as Maragheh at the highest level of the tested PEG. Urmia and especially Kashan probably do not have much tolerance to drought stress regarding all the results and levels of desirability.

Apples and pears are the main temperate fruit tree species, and metabolic disorders may occur during their development and post-harvest storage periods, leading to physiological diseases. In this study, we detected the phenylalanine ammonia-lyase (PAL) enzyme and related metabolites involved in phenylpropanoid metabolism in the pulp of pear with hard-end or cork spot and in the pulp of apple with bitter pit. These three physiological disorders differed in phenylpropanoid metabolism and had similar PAL activity, but their polyphenol, flavonoid, and lignin contents changes were completely. For fruits with the three types of physiological metabolic disorders, the auxin content in the tissues with metabolic disorder symptoms was higher than that in the healthy tissues. In summary, the three physiological disorders showed similar changes in the activities of key enzymes (i.e., PAL) involved in phenylpropane metabolism, but their metabolites significantly differed.

Exogenous polyamines can elevate postharvest fruit cold resistance and alleviate cold injury. However, the mechanism, by which polyamines mediate cold tolerance, is still to be explored. So in this paper, the conjugated polyamines in tonoplast and vacuole conformation were illuminated in the flesh cells of peach fruit subjected to cold stress, which were pretreated with exogenous putrescine. The results showed that under cold condition, fruit firmness decreased and flesh browning area increased, and vacuole conformation changed. The cold injury could be alleviated by pretreatment with exogenous putrescine, as judged by stabilization of the vacuole conformation, increased fruit firmness and reduced flesh browning area. Furthermore, the cold alleviation was coupled with the increases in the levels of covalently conjugated putrescine and non-covalently conjugated spermidine and spermine in the tonoplast. The results suggested that these conjugated polyamines in tonoplast and vacuole conformation might be involved in putrescine-mediated cold tolerance. The suggestion was further verified by applications with inhibitors, phenanthroline and methylglyoxal-bis (guanylhydrazone) (MGBG). Phenanthroline and MGBG could restrain the putrescine-induced increases in covalently and non-covalently conjugated polyamines mentioned above in the tonoplast, respectively, and increase flesh browning area, decrease fruit firmness and vacuole conformation stabilization. So, we can conclude that exogenous putrescine alleviates cold injury in peach fruit via elevating the contents of the polyamines conjugated to the tonoplast and thereby maintaining vacuole conformation.

The aim of the study was to assess the impact of the use of biofertilizers on the degree of colonization of cucumber and tomato plant roots by arbuscular mycorrhizal fungi and the number of AMF spores in the rhizosphere soil. Two experiments were carried out in containers on cucumber and tomato plants under field conditions. The plants were fertilized with standard NPK fertilizer, mineral fertilizers: POLIFOSKA 6, Super FOS DAR 40 and urea in the full recommended dose and reduced by 40%, microbiologically enriched, and only with strains of beneficial microorganisms (Bacillus spp., Bacillus amyloliquefaciens, Paenibacillus Polymyxa, Aspergillus niger, Purpureocillium lilacinum). The experimental results showed a beneficial effect of the POLIFOSKA 6 mineral fertilizer enriched with beneficial bacteria of the Bacillus genus on increasing the colonization of the roots of tomato and cucumber plants by arbuscular mycorrhizal fungi. Compared to the control, fertilization with microbiologically enriched urea at doses of 100% and 60% reduced the frequency of mycorrhizas in the roots of tomato and cucumber plants. The use of POLIFOSKA 6 100% and Super FOS DAR 40 at a dose of 60% resulted in an increase in the number of spores in the rhizosphere soil. The experimental results will allow the development of new biofertilizers as alternative methods of fertilizing plants and improving soil quality compared to standard mineral fertilization.

This study was conducted to determine the effect of traffic stress by soil compaction on zoysiagrass by analyzing the aerial and underground parts and hyperspectral analysis. Zoysiagrass plants were subjected to a compaction strength gradient from 35 to 80 kgf/cm² to confirm the compaction resistance and recoverable limit and measure the physiological change during stress. Changes in leaf color, photosynthesis, and hyperspectral reflectance due to continuous weak and strong traffic stress were measured, and vegetation indices were evaluated for the critical traffic stress injury assessment. As a result, the stem of the zoysiagrass was severely damaged up to 70 kgf/cm² based on soil hardness. The recoverable limit strength of soil compaction was 55 kgf/cm² under weak response pressure conditions. Collectively, our results show that the damage of weak compaction strength on the zoysiagrass was quickly recovered after the stop of traffic stress, especially since the growth of the underground part was increased by weak traffic stress. However, if the compaction strength above 65 kgf/cm2 lasted for a long time, the growth of the underground part is limited by lowering the energy supply for the recovery occurred, in turn, the recovery occurred slowly after the compaction was stopped. Among the vegetation indices obtained from hyperspectral data, pigment specific simple ratio for chlorophyll a (PSSRa), pigment specific simple ratio for chlorophyll b (PSSRb), and pigment specific simple ratio for carotenoids (PSSRc) were effective in evaluating the damage of traffic stress.

To investigate the regulation mechanism of exogenous plant growth regulators on the sugar accumulation of ‘Fengtang’ plum fruits, and to provide theoretical support for improving the sugar content of ‘Fengtang’ plum fruits. The expression of fruit sugar fractions and related genes was determined by spraying different concentrations of exogenous  abscisic acid (ABA) and Gibberellic acid 3 (GA3) during the critical period of sugar accumulation in ‘Fengtang’ plum. The results showed that exogenous ABA treatment increased fruit soluble solids content, delayed the decline in fruit firmness, increased fruit sucrose and sorbitol content and decreased glucose and fructose content at 90 and 100 days after flowering, while exogenous GA3 treatment decreased fruit sorbitol and sucrose content and increased glucose and fructose content at 110 days after flowering; Exogenous ABA treatment significantly increased the expression of the fruit sugar transporter protein genes PsSWEET4 and PsSTP1 as well as the sucrose phosphate synthase genes PsSUS4 and PsSPS2 at 90 and 100 days after flowering, whereas exogenous GA3 treatment increased the expression of the neutral converting enzyme genes PsNINV1/3/4 at 90, 100, and 110 days after flowering to convert sucrose to fructose and glucose. The conclusion is that ABA increases fruit sugar content by increasing the expression of the fruit sugar transporter protein genes PsSWEET4 and PsSTP1 as well as the sucrose synthase genes PsSUS4 and PsSPS2, whereas GA3 decreases sugar accumulation and delays fruit ripening by decreasing the accumulation of sugar during ripening by increasing the expression of the neutral transforming enzyme genes PsNINV1/3/4 to break down sucrose into fructose and glucose.

To study the effects of long-term and short-term high temperature stress and recovery on the physiological functions and appearance quality of chrysanthemums, a controlled experiment with chrysanthemums was conducted. The treatments were 25 °C for 3 days (T1D3), 25 °C for 9 days (T1D9), 41 °C for 3 days (T2D3) and 41°C for 9 days (T2D9). The results indicated that there is no significant difference between the T1D3 and T1D9 groups. Conversely, the total chlorophyll content (Chl), net photosynthetic rate (PN), and maximum quantum yield of Photosystem II (PSII) (FV/FM) under T2D3 and T2D9 decreased by 27.07%, 43.30%, 5.62%, and 44.85%, 68.22%, 8.29%, respectively. The JIP-test results showed that the T2D9-stressed plants had a lower efficiency and functional antenna size, and a higher activity of the reaction centre than T2D3. The contents of malondialdehyde, soluble protein and proline increased by 3.67 nmol/g FM, 298.75 μg/g, and 192.99 μg/g, and the antioxidant enzymes activities were inhibited significantly under T2D9. After the stress was relieved, Chl, PN, and FV/FM under T2D3 recovered to the same level as T1D3, while T2D9 did not. Furthermore, the diameter of the flowers in T2D3 showed no significant difference with the chrysanthemums under T1D3. However, the plants in T2D9 recovered poorly. Both the diameter of the flowers and the anthocyanin under T2D9 reduced significantly comparing with T1D9, indicating that the damage in the chrysanthemum seedlings caused by long-term high temperature was irreversible.