Dynamic Changes of DNA Methylation During Wild Strawberry (Fragaria nilgerrensis) Tissue Culture

Tissue culture is an important tool for asexual propagation and genetic transformation of strawberry plants. In plant tissue culture, variation of DNA methylation is a potential source of phenotypic variation in regenerated plants. However, the genome wide dynamic methylation patterns of strawberry tissue culture remain unclear. In this study, we used whole-genome bisulfite sequencing (WGBS) to study genomic DNA methylation changes of a wild strawberry Fragaria nilgerrensis at six stages: from explants of shoot tips to outplanting and acclimation. Global methylation levels showed that CG sites exhibited the highest methylation level in all stages with an average of 49.5%, followed by CHG (33.2%) and CHH (12.4%). Although CHH accounted for the lowest proportion of total cytosine methylation, it showed the most obvious methylation change and the most of these changes occurred in the transposable element regions. The overall methylation levels alternately decreased and increased during the entire tissue culture process and the distribution of DNA methylation was non-uniform among different genetic regions. Furthermore, much more differentially methylated regions (DMRs) were detected in dedifferentiation and redifferentiation stages and most of them were transposable elements, suggesting these processes involved activating or silencing of amounts of transposons. The functional enrichment of the DMR-related genes indicated that genes involved in hormone metabolic processes, plant development and the stress response changed methylation throughout the tissue culture process. Finally, the quantitative real-time PCR (qRT-PCR) was conducted to examine the association of methylation and gene expression of a set of different methylated genes. Our findings give deeper insight into the epigenetic regulation of gene expression during the plant tissue cultures process, which will be useful in the efficient control of somaclonal variations and in crop improvement.

Evolutionary pattern of the presence and absence genes in Fragaria species

Presence and absence polymorphisms (PAPs) exist extensively and have been investigated in different organisms. However, PAPs have rarely been detected between strawberry species at the genome level. This study identified the presence and absence genes (P/A genes) between wild strawberry species (Fragaria vesca) and octoploid cultivated species (F. × ananassa) under a relatively strict criterion. In total, 333 P/A genes present in the wild strawberry but absent in the cultivated strawberry were detected. Of the P/A genes, 91.89% (306/333) were single genes, and only 8.11% were confirmed as multi-genes. The majority of the identified P/A genes in Fragaria were generated by tandem duplications. The P/A genes were unevenly distributed on the seven chromosomes of woodland strawberry, and they clustered preferentially near the telomeric regions of the chromosomes. The P/A genes tended to encode proteins with domains closely associated with responses to varying ecological factors, such as PPR, Protein kinases (PKs), NB-ARC, F-box and EF-hand domains. This indicated that the P/A genes were associated with coping with biotic and abiotic stresses to improve the adaptability of plants to changing environments.

Assessment of the adaptive potential of strawberry genotypes based on the development of endophytic microbiota and identified R-genes

The paper presents the results of a study of the strawberry genotypes (Fragaria L.) by characteristics of endophytic microbiota and genetic determinants of resistance to fungal pathogens. Highly adaptive genotypes were identified: F. virginiana Duch. ssp. platypetala, F. orientalis Los., F. ovalis Rydb., F. moschata Duch., 298-19-9-43, Urozhaynaya CGL, Flora, Privlekatelnaya and Troitskaya. These strawberry forms are characterized by a high frequency of testing of bacterial microbiota, which suppresses endophytic fungal pathogens. The wild strawberry F. virginiana Duch. ssp. platypetala is characterized by red stele root rot resistance (Rpf1 gene). Strawberry varieties Borovitskaya and Elianny are characterized by anthracnose resistance (Rca2gene).

An Evolutionary Analysis of B-Box Transcription Factors in Strawberry Reveals the Role of FaBBx28c1 in the Regulation of Flowering Time

Flowering connects vegetative and generative developmental phases and plays a significant role in strawberry production. The mechanisms that regulate strawberry flowering time are unclear. B-box transcription factors (BBXs) play important roles in the flowering time regulation of plants. Nevertheless, BBXs in octoploid cultivated strawberry (Fragaria ananassa) and their functions in flowering time regulation have not been identified. Here, we identified 51 FaBBXs from cultivated strawberry and 16 FvBBXs from diploid wild strawberry (Fragaria vesca), which were classified into five groups according to phylogenetic analysis. Further evolutionary analysis showed that whole-genome duplication or segmental duplication is a crucial factor that leads to the expansion of the BBX gene family in two strawberry species. Moreover, some loss and acquisition events of FaBBX genes were identified in the genome of cultivated strawberry that could have affected traits of agronomic interest, such as fruit quality. The promoters of FaBBX genes showed an enrichment in light-responsive, cis-regulatory elements, with 16 of these genes showing changes in their transcriptional activity in response to blue light treatment. On the other hand, FaBBX28c1, whose transcriptional activity is reduced in response to blue light, showed a delay in flowering time in Arabidopsis transgenic lines, suggesting its role in the regulation of flowering time in cultivated strawberry. Our results provide new evolutionary insight into the BBX gene family in cultivated strawberry and clues regarding their function in flowering time regulation in plants.

Genetic Variability and Structure of Fragaria nilgerrensis Schlecht. Germplasm in Sichuan Province

Fragaria nilgerrensis Schlecht. (wild strawberry) is widely distributed in Southwest China, characterized by stress tolerance and the fruits of a notable peach aroma. So far there is only limited knowledge of variability and genetic structure in this species. Using AFLP markers, we investigated the genetic variability of 37 plants of F. nilgerrensis sampled in six main mountain areas of Sichuan Province and analyzed their genetic structure. Genetic similarity according to Nei and Li was used for cluster analysis based on UPGMA method and Agglomerative Hierarchical Clustering. Stratification of plants into more distinctive genetic groups was determined using Bayesian structure analysis. Six primer combinations produced a total of 1302 fragments of which 818 (62.8%) were polymorphic. Bayesian analysis showed the 37 plants of F. nilgerrensis grouped into five distinctive genetic groups. Most of the plants from the same mountain area clustered into the same genetic group, indicating each area as an area with the unique genetic profile. The genetic parameters analyzed here indicate a huge genetic variability of F. nilgerrensis in Sichuan Province. Our results provide reference data for surveying and protecting the germplasm resources of F. nilgerrensis that could be used in strawberry breeding programs.

Physiological, Biochemical, and Biometrical Response of Cultivated Strawberry and Wild Strawberry in Greenhouse Gutter Cultivation in the Autumn-Winter Season in Poland—Preliminary Study

Strawberry and wild strawberry are among the most popular horticultural crops. Due to the development of soilless cultivation systems, the whole-year production of these economically important fruit crops is achievable even in countries with temperate climate. However, the responses of strawberry (Fragaria × ananassa Duch.) and wild strawberry (Fragaria vesca L.) to microclimate conditions in greenhouse gutter cultivation in the autumn–winter season in Poland have not been yet determined. The aim of this study was to analyze the physiological, biochemical, and biometrical responses of two cultivars of strawberry ‘Ostara’ and ‘San Andreas’ and two cultivars of wild strawberry ‘Baron von Solemacher’ and ‘Regina’ grown for 20 weeks, starting from September 17th, in controlled greenhouse conditions on coconut mats in gutters in the autumn–winter season and irradiated with sodium lamps. Strawberry ‘San Andreas’ produced 30% larger leaves and almost three-fold higher fresh and dry weight of biomass than ‘Ostara’. The strawberry plants ‘San Andreas’ had a higher content (20%) of chlorophyll a and 30% of chlorophyll b than ‘Ostara’ plants. Generally, ‘San Andreas’ displayed an overall higher concentration of intercellular CO2 (about 14%) than ‘Ostara’ plants providing higher gas exchange processes. Photosynthetic rate amounted to 13.0 μmol·m−2·s−1 for ‘San Andreas’ that was almost two-fold higher than for ‘Ostara’. ‘San Andreas’ flower and fruit productions were uniform and the six-fold higher individual fruit yield proved the excellent attributes of this cultivar to the greenhouse cultivation. Even though the productivity of the two studied wild strawberry cultivars was similar, ‘Regina’ showed higher values of some parameters than ‘Baron von Solemacher’ (40% larger leaves, 25% higher photosynthetic rate, 10% higher concentration of intercellular CO2). A high nutritional value of fruits is maintained compared to traditional open-air cultivation.

Rosaceae Rubus Rosifolius Smith: Nutritional, Bioactive And Antioxidant Potential Of Unconventional Fruits

Porpuse: Rubus are economically important fruits, being highly valued for their taste and medicinal properties, for which it is estimated that there are between 400 to 700 species but many of them are still unknown by the population. Methods: The literature does not present much information regarding the physicochemical, bioactive composition and antioxidant activity of Rosaceae Rubus rosifolius Smith and for this reason this research was carried out. Results: The fruits presented low content of lipids (7.42%) and ash (0.27%), intermediate values of protein (11.54%), and with considerable content fiber (23.72%) and carbohydrates (59.18%), low acidity, and interesting values of soluble solids. Regarding bioactive compounds, good concentrations of phenolic compounds (289.4 (mg. g− 1 EAG), flavonoids (155 mg100g− 1), anthocyanins (120.11 mg cyanidin-3-glucoside 100g− 1) and phytoene (517.3 mg100g− 1). Conclusion: The wild strawberry showed good antioxidant capacity verified by different methods of analysis. Given the findings of this research, it is observed that this fruit has nutritional and phytochemical potential to be inserted in the human diet and therefore its consumption should be encouraged.

Genetic diversity in wild species and cultivars of strawberry for the FanAAMT gene controlling fruit flavor volatiles

Background. An important consumer trait of strawberry fruits is their aroma. Methyl anthranilate makes a considerable contribution to the fruit flavor. The methyl anthranilate content in strawberry fruits is controlled by the FanAAMT (аnthranilic acid methyltransferase) gene. Identification of genetic determinants for this trait facilitates targeted selection of promising forms based on diagnostic DNA markers. The purpose of this study was to study the allelic diversity of the FanAAMT fruit flavor gene in wild strawberry species and strawberry cultivars for identification of promising genotypes.Materials and methods. The objects of this study were wild species of Fragaria L. as well as F. × anaschata Kantor. and F. × ananassa Duch. cultivars of different ecogeographic origin. The FanAAMT gene was identified with the dominant marker FanAAMT.Results and conclusion. In the analyzed collection of strawberry genotypes, the FanAAMT gene was identified in 36.4% of the forms, including the wild species F. vesca L., F. moschata Duch. and F. virginiana subsp. platypetala (Rydb.) Staudt, and cv. ‘Kupchikha’ (F. × anaschata). Among the analyzed F. × ananassa cultivars, the FanAAMT gene was found in 31.6% of the tested forms, specifically in 27.3% of the 22 Russian cultivars, and 37.5% of the analyzed foreign ones. Promising sources of high methyl anthranilate content in fruits were identified: wild spp. F. moschata, F. vesca, and F. virginiana subsp. platypetala; cv. ‘Kupchikha’ (F. × anaschata); Russian garden strawberry cvs. ‘Bylinnaya’, ‘Zenit’, ‘Lastochka’, ‘Neznakomka’, ‘Feyerverk’ and ‘Tsarskoselskaya’; and foreign garden strawberry cvs. ‘Karmen’, ‘Ostara’, ‘Samson’, ‘Symphony’, ‘Troubadour’ and ‘Vima Tarda’, in which the functional allele of the FanAAMT gene was found. In the remaining studied strawberry genotypes the marker FanAAMT was not detected, which presumably indicates that the FanAAMT gene is absent. cells (R9.4.1).