Strawberry Plants Research Articles

Impact of Soil-Applied Thyme Oil on Strawberry Yield and Disease Abundance

ABSTRACT Strawberry growers across the United States are looking for sustainable alternatives to conventional pesticides for management of soil-borne or crown-rot causing pathogens, such as plant-extracts like thyme oil. The objectives of this study were to determine the impact of soil-applied thyme oil fungicides on strawberry plant health, yield, sweetness, and foliar disease, and on the assemblage of soil microbial communities in strawberry plasticulture systems. In 2021 and 2022 the interaction of three soil-applied fungicides and three foliar fungicide programs were explored. Thyme oil was not found to improve strawberry plant growth or yield when compared to strawberries in the control. However, plants treated with mefenoxam exhibited an average winter crown weight of 2.11 g, significantly lower than control and thyme oil treatments at 3.14 g and 3.16 g, respectively. This translated into a significant yield loss where mefenoxam treated plants exhibited lowered yields at 416.04 g of fruit per plant compared to 523.57 g and 521.53 g per plant in the control and thyme oil treatments, respectively. A high incidence of foliar and fruit diseases was present; however, no interaction of soil and foliar fungicide treatments were observed for yield or fruit sweetness. Minimal root protection from pathogens was observed for all treatments and Fusarium, Pythium and Phytophthora fungi were regularly observed. Mefenoxam was observed to increase the recovery of oomycetes, which may cause Pythium and Phytophthora. No benefit from thyme oil was observed at our site and its addition as a soil fungicide would likely not benefit most growers.

The Influence of Container and Frigo Planting Material on the Vegetative Growth and Fertility of the Variety Clery

The quality of planting material plays a decisive role in the profitability of strawberry production. Of all categories of seedlings in commercial strawberry plantations in Bosnia and Herzegovina, frigo seedlings predominate. The goal of the research is to obtain relevant data on the reaction to external environmental conditions, vegetative growth, and reproductive potential of both types of seedlings by comparing frigo and container planting material. By researching the vegetative and generative growth of strawberries of the Clery variety with two different types of seedlings, it was concluded that green container seedlings are vegetatively more developed compared to frigo seedlings. The container seedlings produced a higher number of buds by 14.2% and leaf mass by 17.5% and entered the resting phase more readily. The percentage of unrooted container seedlings after planting is only 1.1% compared to frigo seedlings, where this percentage is 11.3%, due to the fact that container seedlings have less stress after transplanting, which is the result of the substrate around the roots of the seedling. On the other hand, green container seedlings form a higher percentage of stolons, which additionally burdens the work engagement when removing them in intensive strawberry production. Finally, the container seedlings had a higher and better yield, which amounted to an average of 10.34 grams per fruit, while the average fruit weight of the frigo seedlings was 9.84 grams. In the end, this difference in weight gave 80.29 grams more yield per plant in favor of container seedlings.

First Report of Strawberry Root Rot Caused by Fusarium falciforme in China.

Root rot caused by Fusarium spp. is a destructive disease affecting agricultural regions worldwide. Strawberries (Fragaria × ananassa Duch.) are an economically important crop in China. In March 2023, root rot was observed in strawberries grown in Jinan, Shandong Province, China. Symptoms included leaf wilt, necrotic roots, and plant death (Figure 1). Four strawberry samples (two symptomatic and two asymptomatic) were collected from ~2-acre fields where the disease incidence rate ranged from 2 to 3%. Tissue pieces (5 mm × 5 mm × 5 mm) from two healthy and two diseased strawberry root tissues were surface-disinfected with 75% ethanol for 3 min, treated with 10% sodium hypochlorite for 5 min, and washed three times with sterile water. These pieces were cultured for 5 days at 28°C on potato dextrose agar (PDA) containing 200 mg/L timentin. Typical Fusarium spp. like growth was observed on plates with the two symptomatic samples. Two representative fungal isolates (CM1 and CM2) with similar morphological characteristics were purified using the single-spore method (Figure 1). CM1 showed an average growth rate of 5 mm/d in PDA and comprised of several white-to-cream aerial mycelia after 5 d. After cultivation in carnation leaf agar medium for 7 d, falciform macroconidia, with blunt apical cells and slightly hooked basal cells comprising 3 to 4 septa of varying sizes (20 to 39)×(3.6 to 6.7 μm) were observed (n=50) (Figure 1). The chlamydospores were spherical, terminal or intercalary, solitary or chain-forming, and 3.1-10.5 μm in diameter (Figure 1). The microconidia on PDA were (5.8 to 13.6)× (2.5 to 3.3) μm in size (n=50). These morphological characteristics are consistent with previous descriptions of the Fusarium solani species complex (FSSC). DNA was extracted using the CTAB method (Stenglein and Balatti 2006). The internal transcribed spacer (ITS), translation elongation factor 1-α gene (tef1), RNA polymerase II largest subunit (rpb1), and RNA polymerase II second largest subunit (rpb2) were amplified and sequenced using specific primers (O'Donnell et al. 2010). The ITS (OR526528, OR526529), tef1 (OR536947, OR536948), rpb1 (OR536949, OR536950), and rpb2 (OR536951, OR536952) sequences of the CM1 and CM2 isolates were uploaded to the NCBI database. BLASTn analysis revealed that the ITS, tef1, rpb1, and rpb2 sequences were 99.1-100% identical to those of the Fusarium falciforme reference strains NRRL 54989 and NRRL 54978. A phylogenetic tree based on the ITS, tef1, rpb1, and rpb2 sequences was generated using MEGA v.11 via the maximum-likelihood method (Tamura et al. 2021). CM1 clustered with the Fusarium falciforme reference strains NRRL 54989 and NRRL 54978 and belonged to the FSSC based on its morphological and molecular characteristics (Figure 2). To test for pathogenicity, the roots of nine 3-month-old healthy strawberry (cv. Akihime) plants were exposed to conidial suspensions (1×108 spores/mL) of the CM1 isolate. Another nine root samples were treated with sterile water and used as controls. All strawberry plants were maintained in a growth chamber under a 12/12 h light/dark cycle at 28°C and 90% relative humidity and the experiment was repeated three times. After one month, the inoculated plants had withered and died, and the pith became dark red (similar to field plants) (Figure 1). The fungi isolated from the experimental plants were confirmed as F. falciforme using morphological and sequence analyses. F. falciforme causes root rot in several species including Nicotiana tabacum (Qiu et al. 2023) and Weigela florida (Shen et al. 2020); however, this study is the first to report root rot caused by F. falciforme in strawberries in China. Overall, F. falciforme infection poses a threat to strawberry production and breeding.

Efficacy of Using Chemical Inducers and Biological Agents to Control Strawberry Leaf Spot Disease on Chemical Components and Enzyme Activity

Strawberry plants are subjected to many pathogens. Fungal diseases of strawberries are important worldwide and occur in all parts of the plant, including leaves, crowns, and fruits. The results of the bio-agent experiment indicated that Trichoderma harzianum was the most effective in reducing the growth of Alternaria alternata and Botrytis cinerea in vitro, the main causes of leaf spots in strawberry plants. The inhibition zone was observed and mycelium of T. harzianum invaded the colony of the tested pathogens. The importance of the biochemical study of defense reaction in the physiology of disease resistance was accepted. The activity of total, free, and conjugated phenols as well as peroxidase, polyphenol oxidase, and catalase enzyme activities were determined in resistant and susceptible strawberry cultivars. All the total, free, and conjugated phenols increased in resistant cultivars (Fortuna and Winter Star) and decreased in susceptible cultivar (Festival). Oxidative enzymes, like the increased activity of enzymes that appear mince of new polypeptide protein, have become models in the study of plant disease resistance. The higher content of peroxidase, polyphenol oxidase, and catalase enzymes in resistant cultivars, were noticed compared with those in susceptible ones. It was found also that, the chemical inducers increased total phenols in resistant and susceptible cultivars i.e., potassium di-phosphate, ferrous sulphate, and oxalic acid. Inducer resistance also caused an increase of free phenols than the control. However, conjugated phenols accumulated faster after using chemical inducers in the leaves of the resistant cultivars, than the susceptible ones.

Effect of heat acclimation on thermotolerance of in vitro strawberry plantlets

ABSTRACT Strawberry production is facing a serious decline with the increase in global temperature as a result of climate change. Improving the heat tolerance is imperative for the strawberry plants to remain productive under high temperature conditions. The present work aimed to study the effect of heat acclimation on the thermotolerance of strawberry plants subjected to severe heat stress. Tissue cultured Fragaria ‘Taoyuan No. 1’ plantlets were subjected to four heat-acclimation treatments with gradual increase of temperatures from 30°C to 42°C for 1.25 hr to 10 hr before exposing them to the lethal temperature of 48°C for 4 hr. Survival, new leaf emergence and root growth, electrolyte leakage, chlorophyll and proline contents, as well as antioxidant enzyme activities were compared between the control, acclimated and non-acclimated plantlets. Results indicated that heat acclimation was required for the strawberry plantlets to survive under lethal temperature conditions. The acclimated plantlets registered a lower degree of electrolyte leakage and chlorophyll degradation, and a higher proline content compared to the non-acclimated plantlets. The activities of the antioxidant enzymes increased with the elevation of acclimation temperature and peaked at 42°C except for ascorbate peroxidase (APX) whose activity peaked at 39°C. Higher activities of superoxide dismutase (SOD), APX, glutathione reductase (GR), catalase (CAT) and peroxidase (POD) were observed in the acclimated plantlets compared to the non-acclimated plantlets. This study demonstrates that heat acclimation improved the thermotolerance of in vitro strawberry plantlets by reducing electrolyte leakage and chlorophyll degradation, as well as by enhancing proline content and antioxidant enzyme activities under severe heat stress.

Arbuscular Mycorrhizal Fungi, Ascophyllum nodosum, Trichoderma harzianum, and Their Combinations Influence the Phyllochron, Phenology, and Fruit Quality of Strawberry Plants

One biostrategy to boost the sustainability of strawberry cultivation is the application of biostimulants to the growing substrate. Here, we investigated whether the use of biostimulants and their combinations affects the strawberry plants’ phyllochron, phenology, and fruit quality. We tested the absence (control) and presence of biostimulants (arbuscular mycorrhizal fungi (AMF), Ascophyllum nodosum (AN), Trichoderma harzianum (TH), AMF + AN, AMF + TH, AN + TH, and AMF + AN + TH). The experimental design used was in completely randomized blocks (four replications). AMF was represented by a multi-species on-farm inoculant; A. nodosum was represented by the commercial product Acadian®; and T. harzianum was represented by the commercial product Trichodermil®. The leaf emission rate, the occurrence and duration of phenological stages, and fruit quality were assessed. The greatest precocity in terms of harvesting the first fruit was observed in plants grown with AMF + TH, which also had the lowest phyllochron (77.52 °C day·leaf−1). Those treated only with AMF were the latest (144.93 °C day·leaf−1). More flavorful fruits were produced by plants grown with AMF + TH. Plants inoculated with the AMF community, whether or not associated with A. nodosum and T. harzianum, had more than 94% mycorrhizal colonization. We conclude that AMF, A. nodosum, T. harzianum, and their combinations influence the phenology, phyllochron, and fruit quality of strawberry plants. In the growing conditions of the Brazilian subtropics, the AMF and T. harzianum combination shortens the strawberry cycle, from transplanting the daughter plants to harvesting the first fruit, and improves the fruit flavor.

Response of Mulching and Organic Fertilizers on the Growth Performance of Strawberry (Fragaria ananassa L.) in Southern Philippines

Strawberry is a hybrid species of the genus Fragaria that is widely grown worldwide, especially in cool climate areas and are widely cultivated for their fruit. It is one of the important horticultural crops grown in many parts of the world. Strawberries can be grown using organic fertilizers under different mulching technique. This study investigated the growth and yield performance of strawberries to various application of organic fertilizers (vermicast, vermicompost and vermitea) and mulching materials (rice hull and plastic mulch). Planting materials were taken from a healthy, disease-free strawberry (Shoga) and carried out in Split Plot Factorial Design replicated four times. Strawberry plants applied with vermicompost resulted in significantly high percentage survival (99.16%), plant height (21.61 cm) and number of runners (3.93) compared to plants applied with vermicast and vermitea. Moreover, strawberry plants under plastic mulch condition had the highest growth and yield performance in terms of plant height (21.07 cm), number of runners (4.19), number of leaves (6.57) and total number of marketable fruits (48.10). Based on these results, strawberry applied with vermicompost under plastic mulch condition are recommended. Moreover, results can serve as basis for strawberry growers to use effective yet less expensive fertilizer particularly in tropical Philippines.

Neem (Azadirachta indica) seed extract formulation for managing anthracnose and gray mold diseases in strawberry

Anthracnose caused by Colletotrichum nymphaeae and gray mold caused by Botrytis cinerea are the most epidemic fungal diseases causing significantly losses in strawberry plantings. The objective of the study is to determine the antifungal activity of neem (Azadirachta indica A. Juss.) seed extracts and preparing new formulated antifungal agent. Plant extracts including alcoholic, aqueous and oil were extracted from neem seeds and used in concentrations of 1000, 2000, 4000, 8000 and 10,000 µl/l to control the vegetative mycelial growth of pathogens. The results showed that alcoholic extract had highest antifungal effect and used for the formulation. The concentration of 10,000 microliters of alcoholic extract showed 91.6 % inhibition of gray mold disease, while it inhibited 80.66 % in anthracnose disease and a significant difference was observed between them. For encapsulation of alcoholic neem extract with plant biopolymers with new changes, the separation method of water-miscible solvent through precipitation with salt was used. The results showed that the best effect of the formulation was observed at a dose of four per thousand. Inhibition at this concentration as the best option in terms of controlling gray mold and anthracnose disease was 86.3 % and 79.38 %, respectively, and they were placed in the same statistical group (d). This formulation is designed to determine the minimum concentration threshold and reduce the consumption of alcoholic extract. Based on the results, the use of formulated alcoholic extract of neem seed as an alternative to chemical fungicides can help control anthracnose and gray mold in strawberries.

LIQUID MANURE AS A POTENTIAL ALTERNATIVE NUTRIENT SOLUTION FOR ORGANIC STRAWBERRY PRODUCTION

The experiment was conducted at Horticultural Farm, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, during the period of November 2023 to February 2024. The single-factor experiment was laid out in a randomized complete block design (RCBD) with three replications to study organic strawberry production. The experiment consisted of five treatments, namely: T1: Recommended Fertilizer Dose (RFD); T2: Vermi Tea (VT); T3: SAU-MLM; T4: SAU-NLM; and T5: SAU-PLM. Treatments were applied to plants four times every 10 days, starting 7 days after plant transplantation. The effects on vegetative growth, yield attributes, and fruit quality (Brix%) were investigated, and they showed significant variation. The results showed that RFD (T1) and SAU-PLM (T5) treatments more prominently enhanced vegetative growth SPAD value and yield attributes; maximum flower number (19.3), fruit number (17.0), diameter of fruit (41.5 mm), fruit weight (39.1 g), leaf area (153.0 sq. cm), Brix value (8.6) recorded in T5 treatment, and similar yield per plant are found in T1 (632.3 g) and T5 (636.3 g). Hence, it can be affirmed that SAU-PLM constitutes a potent liquid fertilizer capable of enhancing the growth and yield of strawberry plants.

Host Range of Phytophthora spp. from Berry Crops in Huelva, Spain.

Crop declines have been observed in raspberry and blueberry farms in the southwest region of Spain, which is the most important berry-producing area in the country. This study aimed to identify and characterize the pathogens associated with these diseases using molecular and morphological methods. Additionally, pathogenicity tests were performed on different raspberry, blueberry, and strawberry cultivars to determine possible susceptible hosts in the area. An isolate of Phytophthora cactorum was obtained from a symptomatic strawberry plant, an isolate of P. cinnamomi was obtained from a symptomatic blueberry plant, and isolates identified as P. rosacearum, P. rubi, and a previously unknown species named P. balkanensis were recovered from symptomatic raspberry plants. Results from the pathogenicity tests reported, for the first time, P. rubi causing root rot and wilting complex in Spanish raspberry crops. Additionally, P. cinnamomi was found to affect highbush blueberry production in Spain. Thus, this study provides valuable insights into the identification and characterization of Phytophthora spp. associated with the decline of blueberry and raspberry crops in Huelva. It also provides essential recommendations regarding the potential risks associated with the use of other types of berries as rotational crops and emphasizes the necessity for effective management strategies to mitigate crop losses. This is particularly critical given the limited soil disinfection alternatives available in Spain.

Study of a genetic collection of strawberry (Fragaria L.) for resistance to powdery mildew.

Powdery mildew (Sphaerotheca macularis Mag. (syn. Podosphaera aphanis Wallr.)) is a dangerous disease of strawberry (Fragaria L.). The resistance of strawberry to powdery mildew is controlled polygenically. Several genetic loci with a large contribution to disease resistance have been identified in various strawberry varieties. Diagnostic DNA markers have been developed for QTL 08 To-f. They showed a high level of reliable gene detection in mapping populations. The purpose of this study was assessment of a strawberry genetic collection for resistance to powdery mildew and identification of promising strawberry forms for breeding for resistance to S. macularis. The objects of the study were wild species of the genus Fragaria L., varieties and selected seedlings of strawberry (Fragaria × ananassa Duch.) created in the I.V. Michurin Federal Scientific Center, and strawberry varieties introduced from various ecological and geographical regions. To identify QTL 08 To-f, DNA markers IB535110 and IB533828 were used. Locus 08 To-f was detected in 23.2 % of the analyzed strawberry genotypes, including wild species F. moschata and F. orientalis, strawberry varieties of Russian breeding (Bylinnaya and Sudarushka) and foreign breeding (Florence, Korona, Malwina, Ostara, Polka and Red Gauntlet). The correlation between the presence of markers IB535110 and IB533828 and phenotypic resistance (powdery mildew effect on strawberry plants is absent) was 0.649. The determination coefficient (R2 ) showing the contribution of the studied locus to the manifestation of the trait was 0.421, that is, in 42.1 % of cases resistance was explained by the presence of QTL 08 To-f, and in 57.9 % of cases, by other genetic factors. All strawberry genotypes with locus 08 To-f were characterized by high field resistance to S. macularis in the conditions of Michurinsk, Tambov region. Thus, locus 08 To-f is promising for conferring resistance on local powdery mildew races, and markers IB535110 and IB533828 can be used in marker-assisted breeding programs to create powdery mildewresistant strawberry genotypes.

Improving strawberry plant resilience to salinity and alkalinity through the use of diverse spectra of supplemental lighting

BackgroundThis study explores the impact of various light spectra on the photosynthetic performance of strawberry plants subjected to salinity, alkalinity, and combined salinity/alkalinity stress. We employed supplemental lighting through Light-emitting Diodes (LEDs) with specific wavelengths: monochromatic blue (460 nm), monochromatic red (660 nm), dichromatic blue/red (1:3 ratio), and white/yellow (400–700 nm), all at an intensity of 200 µmol m-2 S-1. Additionally, a control group (ambient light) without LED treatment was included in the study. The tested experimental variants were: optimal growth conditions (control), alkalinity (40 mM NaHCO3), salinity (80 mM NaCl), and a combination of salinity/alkalinity.ResultsThe results revealed a notable decrease in photosynthetic efficiency under both salinity and alkalinity stresses, especially when these stresses were combined, in comparison to the no-stress condition. However, the application of supplemental lighting, particularly with the red and blue/red spectra, mitigated the adverse effects of stress. The imposed stress conditions had a detrimental impact on both gas exchange parameters and photosynthetic efficiency of the plants. In contrast, treatments involving blue, red, and blue/red light exhibited a beneficial effect on photosynthetic efficiency compared to other lighting conditions. Further analysis of JIP-test parameters confirmed that these specific light treatments significantly ameliorated the stress impacts.ConclusionsIn summary, the utilization of blue, red, and blue/red light spectra has the potential to enhance plant resilience in the face of salinity and alkalinity stresses. This discovery presents a promising strategy for cultivating plants in anticipation of future challenging environmental conditions.

Assisting the Planning of Harvesting Plans for Large Strawberry Fields through Image-Processing Method Based on Deep Learning

Reasonably formulating the strawberry harvesting sequence can improve the quality of harvested strawberries and reduce strawberry decay. Growth information based on drone image processing can assist the strawberry harvesting, however, it is still a challenge to develop a reliable method for object identification in drone images. This study proposed a deep learning method, including an improved YOLOv8 model and a new image-processing framework, which could accurately and comprehensively identify mature strawberries, immature strawberries, and strawberry flowers in drone images. The improved YOLOv8 model used the shuffle attention block and the VoV–GSCSP block to enhance identification accuracy and detection speed. The environmental stability-based region segmentation was used to extract the strawberry plant area (including fruits, stems, and leaves). Edge extraction and peak detection were used to estimate the number of strawberry plants. Based on the number of strawberry plants and the distribution of mature strawberries, we draw a growth chart of strawberries (reflecting the urgency of picking in different regions). The experiment showed that the improved YOLOv8 model demonstrated an average accuracy of 82.50% in identifying immature strawberries, 87.40% for mature ones, and 82.90% for strawberry flowers in drone images. The model exhibited an average detection speed of 6.2 ms and a model size of 20.1 MB. The proposed new image-processing technique estimated the number of strawberry plants in a total of 100 images. The bias of the error for images captured at a height of 2 m is 1.1200, and the rmse is 1.3565; The bias of the error for the images captured at a height of 3 m is 2.8400, and the rmse is 3.0199. The assessment of picking priorities for various regions of the strawberry field in this study yielded an average accuracy of 80.53%, based on those provided by 10 experts. By capturing images throughout the entire growth cycle, we can calculate the harvest index for different regions. This means farmers can not only obtain overall ripeness information of strawberries in different regions but also adjust agricultural strategies based on the harvest index to improve both the quantity and quality of fruit set on strawberry plants, as well as plan the harvesting sequence for high-quality strawberry yields.

New Genotypes of Phytophthora nicotianae Found on Strawberry in Florida.

Phytophthora cactorum is the most common causal agent of Phytophthora crown rot and leather rot of strawberry, but P. nicotianae is also responsible for the disease in Florida. Studies of P. nicotianae populations have suggested that different groups of genotypes are associated with different hosts; however, it is not yet clear how many lineages exist globally and how they are related to different production systems. The aim of this study was to determine the genetic relationships of P. nicotianae isolates from Florida strawberry with genotypes reported from other hosts, quantify the genetic variation on strawberry, and test for an association with nursery source. A total of 49 isolates of P. nicotianae were collected from strawberry plants originating from multiple nursery sources during six seasons of commercial fruit production in Florida. Microsatellite genotyping identified 28 multilocus genotypes on strawberry that were distinct among 208 isolates originating from various hosts and locations. Based on STRUCTURE analysis, two genetic groups were identified: one consisting of isolates from strawberry, and the other comprising samples from different hosts. Multilocus genotypes were shared among nursery sources, and populations defined by nursery were not differentiated. Both mating types were found among the isolates from North Carolina- and California-origin plants and in most strawberry seasons; however, a predominance of A1 was observed, and regular sexual reproduction was not supported by the data. This study reveals a unique genetic population of P. nicotianae associated with strawberry and emphasizes the vital role of nursery monitoring in mitigating disease spread.

Differences on the modifying inheritance between the species; Fragaria vesca L. and Fragaria ananassa

By modifying variability, let’s mean that a certain feature of the organism undergoes changes and does not maintain uniformity during its appearance (ie during the transfer of information from the genetic structure to the phenotypic one). In this paper, it is shown how the modifying inheritance is presented in the two types of the strawberry plant, in the one that grows in nature, Fragaria vesca L., and in the one cultivated in greenhouses, Fragaria ananassa. The number of leaf teeth, of these species, has served as the analyzed feature, on which our search for this type of inheritance is based. The paper sheds light on the great role of the environment in elaborating the inheritance of organisms by causing modifying changes in their phenotype in function of the status of the environmental factors in which this organism grows and develops. When these phenotypic modifications manage to become heritable, then it is possible to deal with the action of the epigenetic effect in inheritance. For this reason, studies of modifying inheritance in the phenotype of organisms are necessary. From the comparison of the results obtained, in terms of the modification changes observed between these two species, the null Hypothesis (Ho) is rejected; so, the observed changes have a real basis and are not a random finding. Thus it becomes clear to us that the modifying changes in the inheritance of the plant grown in the natural environment (with significant changes in environmental factors) are greater than those of the species grown in strict conditions – in greenhouses (without large variations in environmental factors). Of course, these changes have an impact on the nutritional and taste values of their fruits, as they affect the nutrient processing laboratory, the leaves

First report of strawberry polerovirus 1 in strawberry in Italy.

Strawberry (Fragaria × ananassa Duch.) was introduced in Sicily (Italy) in the 1930s in the small town of Maletto, on the slopes of Etna volcan, where it's currently cultivated in a total area of 30 ha. The French cv. 'Madame Moutot', appreciated for its unique flavor and intense fragrance, was there propagated vegetatively and after decades, the distinctive 'Etna ecotype' originated by adaptation to the peculiar environmental conditions of the area (Milella et al., 2006). In May 2023, in a 0.5 ha "Etna ecotype" strawberry field, virus-like symptoms were observed in approximately 50% of the plants. Symptoms included severe dwarfing, leaf cupping and chlorotic spotting which lead to decline of infected plants. To investigate the etiology of the disease, leaf samples were collected from eight symptomatic plants for analysis by High-Throughput Sequencing (HTS). To this aim, total RNAs were extracted by using the RNeasy PowerPlant Kit (Qiagen, Germany). The RNAs were pooled, depleted of ribosomal RNA (QIAseq FastSelect; Qiagen), and a library was prepared according to the Illumina DNA Prep Kit. Sequencing on a NextSeq2000 instrument at Leibniz Institute DSMZ (Braunschweig, Germany) generated 31,149,784 of paired-end reads (150 nt), which were further analyzed in Geneious Prime version 2023.2 (Biomatters) using a custom workflow for virus discovery and genome assembly. Analysis of the assembled contigs by local BLASTn and BLASTp alignments against a custom plant virus database of NCBI nuclear-core (NC) reference sequences assigned a number of contigs to accession NC_025435, strawberry polerovirus 1 (SPV-1). Reconstruction of the virus genome by assembly of contigs and reads alignment resulted in a nearly complete genome sequence of SPV-1 (GenBank Acc. No. OR989958) showing by BLASTn 98.69% identity to the SPV-1 NC reference sequence, and 98.99 % identity with an isolate from the Czech Republic (GenBank Acc. OL421571). To confirm the presence of SPV-1 in each sample, RT-PCR using specific primers designed in this study SPV-1-CP-1F (5'-TCGAGATACGTCTAGAACTGCAA-3') and SPV-1-CP-1R (5'-GAGAGGCCCCTTCTACCTATTTG-3') targeting the entire 623 bp coat protein (CP) gene was performed. Amplicons of the expected size were obtained in five samples and Sanger-sequenced. The resulting sequences shared 99.85% - 100% of identity to the HTS - derived sequence (GenBank Acc. No. OR989958) through BLASTn analysis. Strawberry mottle virus (SMoV), strawberry mild yellow edge virus (SMYEV) and strawberry crinkle virus (SCV) were detected in the same library in addition to SPV-1 and then confirmed by RT-PCR using specific primers (Martin & Tzanetakis 2013). Strawberry polerovirus 1, related to the genus Polerovirus in the family Solemoviridae, was first reported in strawberries in Canada (Xiang et al. 2015) and was thereafter detected in the United States (Thekke-Veetil & Tzanetakis 2016), Argentina (Luciani et al. 2016), and Nepal (Kuwak et al. 2022). To date, the virus has been reported in Europe only in the Czech Republic (Franova et al. 2021). To our knowledge, this is the first report of SPV-1 in strawberry plants in Italy. Although the correlation between SPV-1 and strawberry decline (SD) is still uncertain (Xiang et al. 2015) transmission of the virus via aphids has recently been demonstrated (Franova et al. 2021). Our report let to hypothesize that its dissemination in Europe can be considered as increasing.

On the etymology of strawberry

ABSTRACT The word strawberry (Old English streawberige) is peculiar to English among the Germanic languages. There is no consensus on the etymology of the word. Several theories have been suggested: 1) the appearance of the achenes of the berry, supposedly looking like straw (= motes): 2) the runners of strawberry plants compared to straws; 3) strawberries supposedly growing where there is much straw (= grass or hay); 4) strawberries growing at ground level as straw spread as litter; 5) the practice of putting straw under strawberry plants to prevent the berries from rotting; 6) the custom of children to string wild strawberries on a straw of grass. This article favors the last of these explanations. This custom is still well known in Scandinavia and can, through various sources, be shown to have been practiced earlier in a large part of Europe, including Britain.

A histone deacetylase, FaSRT1-2, plays multiple roles in regulating fruit ripening, plant growth and stresses resistance of cultivated strawberry.

Sirtuins (SRTs) are a group of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that target both histone and nonhistone proteins. The biological function of SRT in horticultural plants has been rarely studied. In this study, FaSRT1-2 was identified as a key member of the 8 FaSRTs encoded in cultivated strawberry genome. Transient overexpression of FaSRT1-2 in strawberry fruit accelerated ripening, increased the content of anthocyanins and sugars, enhanced ripening-related gene expression. Moreover, stable transformation of FaSRT1-2 in strawberry plants resulted in enhanced vegetative growth, increased sensitivity to heat stress and increased susceptibility to Botrytis cinerea infection. Interestingly, knocking out the homologous gene in woodland strawberry had the opposite effects. Additionally, we found the content of stress-related hormone abscisic acid (ABA) was decreased, while the growth-related gibberellin (GA) concentration was increased in FaSRT1-2 overexpression lines. Gene expression analysis revealed induction of heat shock proteins, transcription factors, stress-related and antioxidant genes in the FaSRT1-2-overexpressed plants while knocked-out of the gene had the opposite impact. In conclusion, our findings demonstrated that FaSRT1-2 could positively promote strawberry plant vegetative growth and fruit ripening by affecting ABA and GA pathways. However, it negatively regulates the resistance to heat stress and B. cinerea infection by influencing the related gene expression.

Growth and Physiological Characteristics of Strawberry Plants Cultivated under Greenhouse-Integrated Semi-Transparent Photovoltaics.

The integration of semi-transparent photovoltaics into the roof of greenhouses is an emerging technique used in recent years, due to the simultaneous energy and food production from the same piece of land. Although shading in many cases is a solution to maintain the desired microclimate, in the case of photovoltaic installations, the permanent shading of the crop is a challenge, due to the importance of light to the growth, morphogenesis, and other critical physiological processes. In this study, the effect of shade from semi-transparent photovoltaics on a strawberry crop (Fragaria x ananassa Duch.) was examined, in terms of growth and quality (phenolic and flavonoid concentration of fruits). According to the results, in non-shaded plants, there was a trend of larger plants, but without a significant change in leaf number, while the total number of flowers was slightly higher at the end of the cultivation period. Moreover, it was found that the percentage change between the number of ripe fruits was smaller than that of the corresponding change in fruit weight, implying the increased size of the fruits in non-shaded plants. Finally, regarding the antioxidant capacity, it was clearly demonstrated that shading increased the total phenolic content, as well as the free-radical-scavenging activity of the harvested fruits. Although the shading from the semi-transparent photovoltaics did not assist the production of large fruits, it did not affect their number and increased some of their quality characteristics. In addition, the advantageous impact of the semi-transparent photovoltaics in the energy part must not be neglected.

The growth, nutrient uptake and fruit quality in four strawberry cultivars under different Spectra of LED supplemental light

An experiment was conducted in a greenhouse to determine the effects of different supplemental light spectra on the growth, nutrient uptake, and fruit quality of four strawberry cultivars. The plants were grown under natural light and treated with blue (460 nm), red (660 nm), and red/blue (3:1) lights. Results showed that the “Parous” and “Camarosa” had higher fresh and dry mass of leaves, roots, and crowns compared to the “Sabrina” and “Albion”. The use of artificial LED lights improved the vegetative growth of strawberry plants. All three supplemental light spectra significantly increased the early fruit yield of cultivars except for “Parous”. The red/blue supplemental light spectrum also increased the fruit mass and length of the “Albion”. Supplemental light increased the total chlorophyll in “Camarosa” and “Albion”, as well as the total soluble solids in fruits. The “Albion” had the highest concentration of fruit anthocyanin, while the “Sabrina” had the lowest. The use of supplemental light spectra significantly increased the fruit anthocyanin concentration in all cultivars. Without supplemental light, the “Camarosa” had the lowest concentration of K and Mg, which increased to the highest concentration with the use of supplemental light spectra. All three spectra increased Fe concentration to the highest value in the “Sabrina”, while only the red/blue light spectrum was effective on the “Camarosa”. In conclusion, the use of supplemental light can increase the yield and fruit quality of strawberries by elevating nutrients, chlorophyll, and anthocyanin concentrations in plants.