Search Results (490)

Apple breeding programs focus on enhancing yield, quality, and disease resistance, with a strong emphasis on evaluating phenological traits like flowering time and pomological traits such as fruit size and flavour, which are crucial for commercial success and consumer preference. Twenty-four families were obtained by crossing six apple varieties selected as pollen receptors and four apple genotypes resistant to scab selected as pollen donors. Data related to bud burst date, flowering date, harvest date, lengths of the periods between bud burst and flowering and from flowering to harvest (developmental period), fruit equatorial and polar diameter, fruit polar/diameter ratio, soluble solid content (SSC) and flesh firmness were analysed as a genetic partial diallel design. The study’s ANOVA on 24 fruit families across two years revealed significant genotype–environment interactions affecting flowering date, harvest date, and developmental periods, with some variables like fruit weight and soluble solids showing consistent variation. During each year, temperature influenced phenological phases, with earlier budbreak and flowering in warmer, less variable conditions in 2019. Analysis of genetic effects indicated high heritability for phenological traits and moderate heritability for fruit morphology and quality, with parental genetic contributions varying over years. Principal component and Procrustes analyses identified key variable groupings and parent profiles, highlighting genotypes such as ‘Granny Smith’, ‘McIntosh’, and ‘HM100’ with consistent additive effects, and certain families with notable heterotic performance. Overall, genetic and environmental interactions significantly shape phenological and fruit quality traits, guiding breeding strategies. Full article

This study included the nectar of nine standard apple (Malus × domestica) cultivars (‘Red Aroma’, ‘Discovery’, ‘Summerred’, ‘Rubinstep’, ‘Elstar’, ‘Asfari’, ‘Eden’, ‘Fryd’, and ‘Katja’) and two crab apple (Malus sylvestris) cultivars (‘Dolgo’ and ‘Professor Sprenger’). The aim was to determine the diversity of chemical compounds in the floral nectar of the two different apple species and their cultivars. Chemical analysis identified five sugars, two sugar alcohols, two organic acids, forty phenolic compounds, and five phenylamides. The crab apples ‘Dolgo’ and ‘Professor Sprenger’, along with the commercial cultivar ‘Rubinstep’, had the highest levels of all three main sugars (glucose, sucrose, and fructose). The cultivar’s ‘Katja’ nectar had the highest level of total phenolic content (60.7 mg/100 g GAE), the nectar sample from ‘Dolgo’ exhibited the greatest ability to neutralise DPPH radicals (83.4 mg/100 g TE), and the ‘Dolgo’ (100.6 mg/100 g TE FW) and ‘Katja’ (72.1 mg/100 g TE FW) nectars proved to be the best reducing agents. Floral nectar from ‘Eden’ and ‘Fryd’ showed very high levels of isorhamnetin, 49.04 mg/kg and 50.83 mg/kg, respectively, while nectar from ‘Katja’ had the highest level of gentisic acid at 39.06 mg/kg. Besides being vital for insects, apple floral nectar is a significant reservoir of phenolic compounds and can be considered a “superfood” for the human diet. Full article

This study is Part II of a five-year (2018–2022) field trial in western Portugal evaluating the effects of three microbial biofertilizers—Mycoshell^® (Glomus spp. + humic/fulvic acids), Kiplant iNmass^® (Azospirillum brasilense, Bacillus megaterium, Saccharomyces cerevisiae), and Kiplant All-Grip^® (Bacillus megaterium, Pseudomonas spp.)—applied at different dosages alongside two mineral fertilizer regimes, T100 (full dose) and T70 (70% of T100, alone or combined with biofertilizers), on the physiological performance of ‘Gala Redlum’ apple trees. Part I had shown that Myc4 (Mycoshell^®, 4 tablets/tree), iNM6, and iNM12 (Kiplant iNmass^®, 6 and L ha⁻¹, respectively) consistently enhanced fruit growth, yield, and selected quality traits. While Part I showed clear agronomic gains, Part II demonstrates that these improvements occurred without significant alterations in seasonal photosynthetic performance, canopy reflectance, or chlorophyll fluorescence parameters over five years, highlighting the contrast between observed yield improvements and physiological stability. Seasonal monitoring of physiological traits—including specific leaf area (SLA), chlorophyll content index (CCI), gas exchange (A_n, g_s, E, C_i), spectral indices (NDVI, OSAVI, SIPI, GM2), and chlorophyll fluorescence (OJIP). It is clear that physiological values remained largely stable across biofertilizer treatments and years. Importantly, this stability was maintained even under a 30% reduction in mineral fertilizer (T70), indicating that specific microbial biofertilizers can sustain physiological resilience under reduced nutrient inputs, thereby providing a physiological basis for the yield-enhancing effects observed and supporting their integration into fertilizer reduction strategies in Mediterranean orchards. Full article

Thidiazuron, 6-benzylaminopurine riboside, and meta-topolin are cytokinins often used in apple tissue cultures. Three different CK-containing Murashige and Skoog media were used during the experiments: medium without CK or media containing 4.5 μM thidiazuron, 4.5 μM 6-benzylaminopurine riboside, or 4.5 μM meta-topolin, respectively. Comparative ultrastructural studies across cytokinin types and apple cultivars were lacking. We studied the changes in photosynthetic pigment content of the leaves with absorption spectroscopy and chloroplast structure with light and transmission electron microscopy. At the light microscopy level, large changes were detected in the length and length-to-width ratios of the chloroplasts in the spongy and palisade mesophyll cell sections in 6-benzylaminopurine riboside- and meta-topolin-treated leaves of the McIntosh scion. In the chloroplasts of the McIntosh plants treated with 6-benzylaminopurine riboside and meta-topolin, and Húsvéti rozmaring leaves treated with meta-topolin, the diameter of grana increased. In both cultivars, thidiazuron caused the height of grana to increase. Thidiazuron and 6-benzylaminopurine riboside influenced leaf anatomy both in the Húsvéti rozmaring and McIntosh cultivars. 6-benzylaminopurine riboside and thidiazuron treatments reduced the content of photosynthetic pigments in the in vitro leaves of both cultivars. In contrast, meta-topolin treatment had no significant effect on the chlorophyll content as compared to the control. Differences were observed not only among the effects of cytokinins, but even between the two apple scions examined. In in vitro apple shoot cultures, TOP maintained chloroplast integrity and pigment content, whereas TDZ exerted stress-like effects. Full article

One significant trend in the research of plant treatment methods is that regarding the use of natural-based methods in plant protection. In this study, antimicrobial activity and changes in MdPR10 gene expression were tested for a total of five plant pathogens in a model of apple fruits, where strawberry and ivy EOs were used. The vapor-phase chemical composition of both EOs was profiled using HS-GC-MS. qRT-PCR was applied for a bacterial response analysis, together with disk diffusion assays, and minimum inhibitory concentrations were determined. To elucidate the molecular basis of the antibacterial potential of essential oils (EOs), docking analyses were performed. For Xanthomonas arboricola and Pectobacterium carotovorum, the presence of EOs resulted in the downregulation of MdPR10. Strawberry EO was more effective against weakly virulent strains of bacteria; ivy EO had greater inhibitory effects. HS-GC-MS detected 13 volatiles in strawberry EO—dominated by ethyl butyrate, ethyl 2-methylbutanoate, ethyl hexanoate, and ethyl 3-methylbutanoate—and 16 in ivy EO, characterized by monoterpenes and monoterpenoids with 1,8-cineole as the principal component. P-cymene showed the most potent binding activity against D-alanine–D-alanine ligase. Ivy EO has the potential to be effective as a natural preservative alternative mainly in postharvest technology. Full article

The aim of this study was to investigate the effect of gibberellins on the setting and quality of parthenocarpic apples (Malus × domestica Borkh.). The experiment was conducted in 2021 on the ‘Golden Delicious’ cultivar in the Warsaw University of Life Sciences experimental orchard. During the trial, we compared the effect of various gibberellins, such as GA₃, GA₄₊₇, and a mixture of GA₃ + GA₄₊₇. These gibberellins were administered to both intact and mechanically injured flowers (damaged by emasculation and style removal) at the pink bud stage. The results clearly demonstrate that gibberellins applied during blooming supported the induction of parthenocarpic fruit setting in Golden Delicious apples; however, fruitlet retention remained significantly lower than in natural pollinated flowers. The most efficient treatment among emasculated flowers was the mixture of GAs, resulting in a final fruit retention of 23.6%. Fruit size and morphology differed across treatments: GA₃ applied on intact flowers resulted in the largest parthenocarpic fruits, while the GA₄₊₇ and GAs mixture promoted a more elongated fruit shape. Moreover, gibberellin treatment affected other fruit quality traits. Almost all GA treatments led to a higher soluble solids content in fruits. In addition, apples derived from intact flowers treated with GA₃ showed reduced firmness. Overall, our findings indicate that gibberellins can support fruit set, even when flowers are injured, and to lower extent modify fruit quality, but the results depend on flower condi-tions and the type of GA used. Full article

This study aimed to select Metschnikowia pulcherrima strains with antimicrobial potential and high biomass content, optimize their cultivation conditions, evaluate growth characteristics at different scales, and assess antimicrobial activity on apple plants (Malus domestica cv. Golden Delicious) infected with phytopathogens. Of the nine tested strains, M. pulcherrima D2 was selected for its strong inhibitory activity against all tested phytopathogenic molds: Venturia inaequalis, Botrytis cinerea, Phoma exigua, Colletotrichum coccodes, Monilia laxa, Alternaria alternata, Alternaria tenuissima, Fusarium sambucinum, and Fusarium oxysporum, both in vitro on laboratory media (inhibition zones from 13.5 to 35.0 mm) and in vivo on stems, leaves, flowers, and fruits of apple. Morphological observations of treated plants showed the complete absence or significant delays of disease symptoms for up to 10 days. Disease symptoms for several pathogens (V. inaequalis, A. alternata, A. tenuissima, B. cinerea, F. sambucinum) remained reduced by ≥50% for up to 31 days post-treatment compared to the untreated control. Optimal cultivation conditions for M. pulcherrima D2 were established: a complex medium containing yeast extract (5.0 g/L), soy peptone (5.0 g/L), and glucose (2.6 g/L), at pH 5 and 25 °C, with shaking at 180 rpm, resulted in high biomass contents (10⁷–10⁸ CFU/mL). Scale-up in 5 L bioreactors confirmed efficient biomass production (10⁸ CFU/mL and from 3.1 to 3.9 g/L of dry biomass). These findings highlight the strong biotechnological potential of M. pulcherrima D2 for the development of a biocontrol agent to protect apple fruits and trees against fungal phytopathogens. Full article

Irrigated agriculture in Mediterranean semi-arid regions is increasingly constrained by aquifer depletion and climate change. Enhancing water use efficiency in the irrigation of perennial crops is essential for long-term agricultural sustainability. This study introduces a Spatial Irrigation Adequacy Index (SIAI), a normalized index expressing the deviation between actual evapotranspiration (ET_a) and Crop Water Requirements (CWR). The framework was applied to assess irrigation performance in grapevine (Vitis vinifera), apple orchards (Malus domestica) and citrus tress (Citrus sinensis) across three groundwater-dependent systems: Requena-Utiel (Spain), Ain Timguenai (Morocco), and Campina de Faro (Portugal). ET_a was estimated using Landsat 8 and 9 imageries processed with the SSEBop model, while crop water demand was calculated with the FAO-56 dual crop coefficient method incorporating site-specific agroclimatic data. Results revealed distinct crop-specific irrigation patterns: grapevines achieved near-optimal water use, apple orchards were generally over-irrigated, and citrus groves experienced persistent deficits. The framework enables scalable, transferable assessments of irrigation performance, supporting sustainable water management and adaptive irrigation under climate variability, with potential applications in digital farm management systems, water authority decision-making, and corporate ESG reporting frameworks. Full article

Fire blight, caused by Erwinia amylovora, is one of the most damaging bacterial diseases affecting apple production and the safety of wild Malus sieversii populations in Central Asia. Effective monitoring relies on accurate molecular diagnostics; however, comparative data on commonly used detection methods remain limited for the region. In this study, we evaluated the performance of three molecular assays—LAMP, real-time PCR, and targeted nanopore sequencing of a 16S rRNA gene fragment—using 124 plant samples exhibiting fire blight symptoms collected from 30 sites across Southern Kazakhstan and Kyrgyzstan. The results of LAMP, real-time PCR, and the amplification of 16S sequences were highly consistent with each other. Targeted 16S nanopore sequencing reliably identified E. amylovora in all PCR-positive samples, yielding high read counts and consistent species-level classification, although the analyzed 16S region provided limited resolution for intraspecies variation. Across sampling locations, abandoned orchards represented major reservoirs of infection compared to maintained orchards and wild populations. Our results confirm that all three approaches are robust tools for detecting E. amylovora. These findings support the importance of different molecular diagnostic methods to assist fire blight surveillance in the region. Full article

In the present study, extracts from the fragrant agrimony (Agrimonia procera Wallr.) herb and the pseudo-fruits of rose (Rosa rugosa) were incorporated into a 50% sucrose solution used for the osmotic dehydration of Champion apples (Malus domestica Borkh.). This approach enabled the investigation of the migration of fragrant agrimony and rose polyphenols—both total polyphenols and their main representatives—during the dehydration process of apples, which are among the most popular fruits due to their health-promoting and nutritional properties. The total polyphenol content was determined using spectrophotometric methods, while the major individual compounds were quantified by UHPLC-DAD-MS. At a polyphenol content of 4 g/L in the solution, a more intensive water migration (water loss of about 3 g/g DM) from the fruit tissue was achieved for both extracts compared to the pure sucrose solution. However, no relationship between the polyphenol level in the hypertonic solution and the migration of sucrose into the apple tissue was observed. With regard to polyphenolic compounds, the level of polyphenols in apples dehydrated in the presence of extracts, compared to those dehydrated in pure sucrose solution, increased with the extract dose. The maximum value—approximately 825 mg/100 g DM of total polyphenols—was obtained at an extract concentration of 6 g/L, derived from both fragrant agrimony herb and rose pseudo-fruit. In the apples dehydrated using the extracts, the presence of phenolic compounds not found in fresh apples, characteristic of the applied extracts, such as ellagitannins, ellagic acid, flavonols including quercetin and kaempferol glycosides, as well as flavones, including derivatives of apigenin and luteolin, was observed. These findings indicate that the use of fragrant agrimony and rose extracts in osmotic dehydration may serve as an effective strategy for enhancing the polyphenolic profile and functional value of dehydrated apple products. Full article

Apple (Malus domestica) is a deciduous perennial tree that belongs to the family “Rosaceae”. Due to the highly suitable agro-climatic conditions for apple cultivation, it is among the widely cultivated fruits in Gilgit-Baltistan (GB). This study aims to evaluate elite apple genotypes in GB based on morphological and biochemical traits. Five- to six-year-old plants were selected for this study. The research employed a completely randomized design (CRD) with three replications, and mean differences were analyzed using the LSD test. In this study, five genotypes were assessed based on morphological (fruit weight, fruit length, fruit width, and firmness) and biochemical attributes (TSS, TA, ascorbic acid, total phenolic content, and flavonoid content). The results revealed significant variation among apple cultivars in both phytochemical and fruit quality attributes. The cultivar ‘Red Delicious’ exhibited the highest fruit weight (146.18 g), total soluble solids (TSS) (15.4 °Brix), and flavonoid content (105.75 mg 100 g⁻¹ FW). In contrast, ‘Red Full Star’ demonstrated superior firmness (7.19 kg cm⁻²), along with the highest total phenolic content (TPC) (4.00 mg GAE g⁻¹ FW) and ascorbic acid content (26.45 mg 100 g⁻¹ FW). Although the indigenous variety ‘Nus Khushu’ exhibited lower values in commercial traits, it holds substantial potential for conservation due to its unique local adaptation. The findings indicate that the “Red Delicious” and “Red Full Star” cultivars cultivated in GB are enriched with a variety of bioactive compounds that offer notable health benefits and may be utilized for future crop enhancement and breeding initiatives. Full article

Exogenous cytokinin supply is a crucial factor during the in vitro shoot multiplication of apples. Meta-topolin has been shown to cause improved multiplication rate, higher quality in vitro shoots with better rooting, and acclimatization ability than the widely used benzyl adenine. The effects of benzyl adenine and meta-topolin on mRNA transcription in in vitro shoots were analyzed by using mRNA-seq, bioinformatics analysis, GO annotation, and KEGG mapping. The present investigations revealed that there were about 6-fold more significantly up-, or down-regulated genes (DEGs) in shoots grown on the benzyl adenine-containing medium than in those grown on the meta-topolin-containing medium. DEG analyses showed that WRKYs, bHLH, and MYB were the most affected transcription factors after both cytokinin treatments, while the expression of MIKC-type MADS-box, ERF, and AP2 transcription factors changed only after benzyl adenine treatment. DEGs related to auxin transport and signaling, as well as auxin synthesis, were differently affected by the two cytokinins. The DEG encoding cytokinin hydroxylase-like protein and related to trans-zeatin biosynthesis was up-regulated only after benzyl adenine treatment. The DEG encoding gibberellin 20 oxidase 2-like was down-regulated after a benzyl adenine supply while it was up-regulated after a meta-topolin supply. Changes in the cytokinin–auxin balance and gibberellin biosynthesis in in vitro shoots may contribute to the morphological differences previously observed for the two cytokinins. Full article

Apple scab, caused by the fungus Venturia inaequalis, is one of the most widespread and economically significant diseases of apple orchards, leading to reduced photosynthesis, fruit damage, and yield losses of up to 70%. In this study, a survey of 30 wild and cultivated apple populations in Kazakhstan and Kyrgyzstan was conducted, encompassing 302 samples. The pathogen was detected in 8 populations (48 samples), corresponding to an infection rate of 16%. Molecular identification using the EF-1α marker and ITS region sequencing definitively confirmed the presence of V. inaequalis in all positive samples. Phylogenetic analysis showed clear population structuring: isolates from Kyrgyzstan formed a distinct clade close to international lineages, while Kazakh isolates showed high genetic variation. These findings highlight the ongoing presence of V. inaequalis in Central Asia and emphasize the importance of combining morphological, molecular, and phylogenetic methods for effective pathogen monitoring and control. Full article

Biochar has gained attention as a promising soil amendment capable of improving soil structure, nutrient retention and plant resilience to stress. However, its performance in perennial horticultural systems, particularly during the early stages of orchard establishment, remains insufficiently documented. This study, conducted in 2021 in a newly established apple orchard (‘Gala Brookfield Baigent’/P 60) in Wieluń, Central Poland, aimed to evaluate the effectiveness of three methods of using cattle-manure-derived biochar at a dose of 10 t ha⁻¹ (application before ploughing prior to orchard establishment, application to planting holes and surface spreading). Neither tree growth nor fruiting potential were affected by biochar, which made the comparison of its application methods inconclusive. According to the principal component analysis performed, mineral nitrogen showed a tendency to promote the formation of mixed-type buds on short shoots, a propitious growing pattern for intensive orchard management. In contrast, compost fertilisation favoured vegetative growth over generative development, as reflected by the significantly negative coefficient in regression analysis (b = −0.12; 95% CI: −0.25 to –0.00 for the Box-Cox-scaled fruiting-to-growth potential ratio). Nonetheless, the overall growth response of apple trees in the first year after planting to the applied soil-enriching practices was rather modest, with this observation validating the strategy of reducing fertiliser doses during orchard establishment on productive soils maintained in good agricultural condition. Long-term studies under abiotic or nutrient-limiting constraints, as well as the combined use of biochar with microbial inoculants, are recommended to fully elucidate its potential in apple production. Full article

Apple (Malus domestica) is a very important crop grown in Kazakhstan. Cytospora species are capable of causing destructive stem cankers on a wide range of woody plants, including apples, and can lead to twig and branch dieback. This study aimed to identify the Cytospora species responsible for canker disease of apple in Kazakhstan and to assess the susceptibility of major apple cultivars to these pathogens. Investigations were conducted in Almaty, Kazakhstan, during 2023 and 2024. Samples from symptomatic trees were collected, and nine Cytospora isolates were obtained from diseased apple trees. Multigene phylogenetic analysis based on combined sequence data of ITS, tef1-α, tub2, and LSU loci, together with morphological characteristics and pathogenicity assays, revealed two Cytospora species: C. leucostoma and C. sorbicola. The reactions of six apple cultivars (Gala, Golden Delicious, Red Delicious, Granny Smith, Fuji, and Jonaprince) to these species were evaluated, and statistically significant differences were found among cultivars (p < 0.05). The largest lesions occurred on Red Delicious and Fuji, indicating that these cultivars are the most susceptible. In contrast, lesion lengths on Jonaprince were significantly smaller than on all other cultivars, suggesting that Jonaprince is resistant to Cytospora species in Kazakhstan. This is the first report of C. leucostoma and C. sorbicola causing apple canker disease in Kazakhstan. Full article