Fruit Traits Research Articles

A framework for the restoration of seed dispersal and pollination

Species reintroduction is a management strategy to restore ecosystem functioning through the reestablishment of ecological interactions and related ecological processes, like pollination and seed dispersal. Selecting the best species to achieve this goal remains challenging. We present a trait‐based framework to estimate the effects of species reintroductions on seed dispersal and pollination. Our framework assesses the potential contribution of a consumer species (e.g. seed disperser) by considering both the originality of its interactions and the availability of resources it consumes. Originality refers to the degree of uniqueness versus redundancy of a species' interactions compared with the interactions of the current consumer community. Resource availability, defined by the distribution of trait values in the resource community that enable interactions (like fruit size), determines the potential magnitude of a species' effect. The framework also allows assigning different weights to unique interactions, thereby facilitating decisions on whether to prioritize species that potentially add unique interactions if selected for reintroduction. Using our framework, we compared the potential effects of two reintroduced frugivores (agoutis and howler monkeys) on seed dispersal in an Atlantic Forest site. While both species have similar potential effects when not accounting for interaction originality, howlers interact with more common fruit's trait values, whereas agoutis have more unique interactions and with a broader variety of trait values. We also provide ways of generalizing our approach to include other factors, e.g. species abundances, to assess the consequences of other scenarios affecting community composition, such as species extinctions and invasions.

Transcriptome differential expression analysis of defoliation of two different lemon varieties.

'Allen Eureka' is a bud variety of Eureka lemon with excellent fruiting traits. However, it suffers from severe winter defoliation that leads to a large loss of organic nutrients and seriously affects the tree's growth and development as well as the yield of the following year, and the mechanism of its response to defoliation is still unclear. In order to investigate the molecular regulatory mechanisms of different leaf abscission periods in lemon, two lemon cultivars ('Allen Eureka' and 'Yunning No. 1') with different defoliation traits were used as materials. The petiole abscission zone (AZ) was collected at three different defoliation stages, namely, the pre-defoliation stage (CQ), the mid-defoliation stage (CZ), and the post-defoliation stage (CH). Transcriptome sequencing was performed to analyze the gene expression differences between these two cultivars. A total of 898, 4,856, and 3,126 differentially expressed genes (DEGs) were obtained in CQ, CZ, and CH, respectively, and the number of DEGs in CZ was the largest. GO analysis revealed that the DEGs between the two cultivars were mainly enriched in processes related to oxidoreductase, hydrolase, DNA binding transcription factor, and transcription regulator activity in the defoliation stages. KEGG analysis showed that the DEGs were concentrated in CZ and involved plant hormone signal transduction, phenylpropanoid biosynthesis, glutathione metabolism, and alpha-linolenic acid metabolism. The expression trends of some DEGs suggested their roles in regulating defoliation in lemon. Eight gene families were obtained by combining DEG clustering analysis and weighted gene co-expression network analysis (WGCNA), including β-glucosidase, AUX/IAA, SAUR, GH3, POD, and WRKY, suggesting that these genes may be involved in the regulation of lemon leaf abscission. The above conclusions enrich the research related to lemon leaf abscission and provide reliable data for the screening of lemon defoliation candidate genes and analysis of defoliation pathways.

MelastomaTRAITs 1.0: A database of functional traits in Melastomataceae, a large pantropical angiosperm family.

The recent availability of open-access repositories of functional traits has revolutionized trait-based approaches in ecology and evolution. Nevertheless, the underrepresentation of tropical regions and lineages remains a pervasive bias in plant functional trait databases, which constrains large-scale assessments of plant ecology, evolution, and biogeography. Here, we present MelastomaTRAITs 1.0, a comprehensive and updatable database of functional traits for the pantropical Melastomataceae, the ninth-largest angiosperm family with 177 genera and more than 5800 species. Melastomataceae encompass species with a wide diversity of growth forms (herbs, shrubs, trees, epiphytes, and woody climbers), habitats (including tropical forests, savannas, grasslands, and wetlands from sea level to montane areas above the treeline), ecological strategies (from pioneer, edge-adapted and invasive species to shade-tolerant understory species), geographic distribution (from microendemic to continental-wide distribution), reproductive, pollination, and seed dispersal systems. MelastomaTRAITs builds on 581 references, such as taxonomic monographs, ecological research, and unpublished data, and includes four whole-plant traits, six leaf traits, 11 flower traits, 18 fruit traits, and 27 seed traits for 2520 species distributed in 144 genera across all 21 tribes. Most data come from the Neotropics where the family is most species-rich. Miconieae (the largest tribe) contains the highest number of trait records (49.6%) and species (41.1%) records. The trait types with the most information in the database were whole-plant traits, flowers, and leaf traits. With the breadth of functional traits recorded, our database helps to fill a gap in information for tropical plants and will significantly improve our capacity for large-scale trait-based syntheses across levels of organization, plant-animal interactions, regeneration ecology, and thereby support conservation and restoration programs. There are no copyright restrictions on the dataset; please cite this data paper when reusing the data.

Genetic Variability for Mulberry Fruit Traits in Different Mulberry Accessions (Morus spp.)

Genetic Variability for Mulberry Fruit Traits in Different Mulberry Accessions (Morus spp.)

Screening candidate genes for fruit size based on QTL-seq in Chinese jujube.

Fruit size is an important economic trait affecting jujube fruit quality, which has always been the focus of marker-assisted breeding of jujube traits. However, despite a large number of studies have been carried out, the mechanism and key genes regulating jujube fruit size are mostly unknown. In this study, we used a new analysis method Quantitative Trait Loci sequencing (QTL-seq) (bulked segregant analysis) to screen the parents 'Yuhong' and 'Jiaocheng 5' with significant phenotypic differences and mixed offspring group with extreme traits of large fruit and small fruit, respectively, and, then, DNA mixed pool sequencing was carried out to further shortening the QTL candidate interval for fruit size trait and excavated candidate genes for controlling fruit size. The candidate intervals related to jujube fruit size were mainly located on chromosomes 1, 5, and 10, and the frequency of chromosome 1 was the highest. Based on the QTL-seq results, the annotation results of ANNOVAR were extracted from 424 SNPs (single-nucleotide polymorphisms) and 164 InDels (insertion-deletion), from which 40 candidate genes were selected, and 37 annotated candidate genes were found in the jujube genome. Four genes (LOC107428904, LOC107415626, LOC125420708, and LOC107418290) that are associated with fruit size growth and development were identified by functional annotation of the genes in NCBI (National Center for Biotechnology Information). The genes can provide a basis for further exploration and identification on genes regulating jujube fruit size. In summary, the data obtained in this study revealed that QTL intervals and candidate genes for fruit size at the genomic level provide valuable resources for future functional studies and jujube breeding.

Multi-nutrient fertilization-based analysis of fruit quality and mineral element composition during fruit development in Merlot wine grapevine1

Mineral elements play a crucial role in plant growth and development. Ensuring the proper supply of these elements in soil and maintaining an optimum range within plants is necessary for achieving optimal fruit yield and quality. Unfortunately, the application of NPKCaMg fertilizers to fruit trees is often either insufficient or excessive, leading to both environmental degradation and reduced fruit yield and quality. To assess the impact of different fertilizers on the biological-related traits of grape fruit and its response to nutritional elements, Merlot grapevines were subjected to multi-nutrient fertilization over four consecutive growing seasons from 2018 to 2021 in Penglai District, Yantai, China. Principal component analysis revealed that T11 treatment, consisting of N3P3K1Ca2Mg4, was the most suitable fertilizer type and application design for this experiment. The application of T11 resulted in a significant decrease (24.29%–35.20%) in fertilizer usage, and it resulted in an increase in several important traits such as 100 grain weight (HGW), number of seeds (SN), total soluble solids (TSS), total seed phenols (SP), seed flavanols (SFI), and seed tannins (ST) by 3.28%–12.84%, 3.76%–20.03%, 1.11%–14.95%, 2.16%–23.69%, 11.00%–32.78%, 1.07%–23.35%, respectively, compared to T14 (N4P2K3Ca1Mg4), T16 (N4P4K1Ca3Mg2), T13 (N4P1K4Ca2Mg3), and T15 (N4P3K2Ca4Mg1) treatments. Flowering and fruiting behavior exhibited a considerable demand for NPK, with a higher requirement for K and B during fruit growth and development compared to the other mineral elements. Excessive K in soil was found to enhance the competitive inhibition of Ca uptake by Merlot grapevines. The optimum ranges of mineral element content for total peel phenols (PP), peel flavanols (PFI), total peel flavonoids (PFD), total seed phenols (SP), and seed tannins (ST) were primarily influenced by grape variety and nutritional analysis method. In conclusion, the careful selection of NPKCaMg fertilizer and its meticulous application to soil at an optimum range of mineral elements are critical for grapevine growth and development.

Evaluation of Morphological Characteristics in Some Apple Varieties (Malus Pumila Mill.) from Northeastern Algeria

Abstract The current investigation is centered on the characterization of specific apple cultivars in the Garza region, within the Teniet El Abed municipality, situated 55 km east of Batna (NE-Algeria). Utilizing descriptors outlined by UPOV 2015 pertaining to apples, the study focuses on morphological parameters of leaves, fruits, and terminal shoots across three varieties: Golden Delicious, Royal Gala, and Starkrimson. Additionally, soil analysis was conducted to ascertain its suitability for apple cultivation. The examination revealed limited morphological diversity among the investigated apple cultivars, with some descriptors, particularly those related to fruit traits, showing insignificant differences between cultivar types. Overall, the studied varieties - Golden Delicious, Royal Gala, and Starkrimson - exhibit distinct physiological and morphological characteristics. Variations in size, shape, skin color, flesh attributes, as well as sugar and acid content, contribute to the uniqueness of each variety. Whether one prefers sweet or tart apples, or favors larger or smaller fruits, there exists an apple variety to cater to individual tastes. Our findings complement molecular analyses and underscore the need for further exploration of apple germplasm, alongside sustained conservation efforts.

A new Angolan species from the Triaspis hypericoides complex (Malpighiaceae) based on macromorphology and palynology

Triaspis hypericoides currently comprises three accepted subspecies endemic to woodland savannas of southern continental Africa. After an unusual population belonging to this complex was collected in southwestern Angola, we re‐evaluated the classification of this group. This study was based on the analysis of type specimens, protologues, field photographs and herbarium sheets of all subspecies within T. hypericoides. We reinstate T. canescens, T. hypericoides and T. nelsonii based on differences in leaf, flower and fruit traits. Additionally, the Angolan population is proposed here as a new species of Triapis endemic to the dry miombo woodlands of Bicuar National Park, Huíla Province, southwestern Angola. Triaspis bicuarensis sp. nov. is easily distinguished from T. nelsonii by its alternate (versus opposite) leaves, ovate to widely ovate (versus widely ovate to very widely ovate) leaf laminas, rounded (versus sagittate) leaf base, flat (versus undulate) margins, sparsely white‐tomentose (versus glabrous to glabrescent) abaxial leaf surface, petiole 4–8 mm long (versus 2–3 mm long), compound inflorescences in thyrses (versus corymbs) and bracteoles inserted below apex of peduncles (versus in the middle of peduncles). An identification key to all species belonging to this species complex is presented alongside a complete morphological description for the new species, photographic plates and comments on the distribution, ecology, palynology and taxonomy. These results underline the need for continued revisions of the taxonomy of the neglected African genera of Malpighiaceae.

Multi-omics analysis provides new insights into the changes of important nutrients and fructose metabolism in loquat bud sport mutant.

Bud sport is a common and stable somatic variation in perennial fruit trees, and often leads to significant modification of fruit traits and affects the breeding value. To investigate the impact of bud sport on the main metabolites in the fruit of white-fleshed loquat, we conducted a multi-omics analysis of loquat fruits at different developmental stages of a white-fleshed bud sport mutant of Dongting loquat (TBW) and its wild type (TBY). The findings from the detection of main fruit quality indices and metabolites suggested that bud sport resulted in a reduction in the accumulation of carotenoids, fructose, titratable acid and terpenoids at the mature stage of TBW, while leading to the accumulation of flavonoids, phenolic acids, amino acids and lipids. The comparably low content of titratable acid further enhances the balanced and pleasent taste profile of TBW. Expression patterns of differentially expressed genes involved in fructose metabolism exhibited a significant increase in the expression level of S6PDH (EVM0006243, EVM0044405) prior to fruit maturation. The comparison of protein sequences and promoter region of S6PDH between TBY and TBW revealed no structural variations that would impact gene function or expression, indicating that transcription factors may be responsible for the rapid up-regulation of S6PDH before maturation. Furthermore, correlation analysis helped to construct a comprehensive regulatory network of fructose metabolism in loquat, including 23 transcription factors, six structural genes, and nine saccharides. Based on the regulatory network and existing studies, it could be inferred that transcription factors such as ERF, NAC, MYB, GRAS, and bZIP may promote fructose accumulation in loquat flesh by positively regulating S6PDH. These findings improve our understanding of the nutritional value and breeding potential of white-fleshed loquat bud sport mutant, as well as serve as a foundation for exploring the genes and transcription factors that regulate fructose metabolism in loquat.

Prediction accuracy of genomic estimated breeding values for fruit traits in cultivated tomato (Solanum lycopersicum L.)

BackgroundGenomic selection (GS) is an efficient breeding strategy to improve quantitative traits. It is necessary to calculate genomic estimated breeding values (GEBVs) for GS. This study investigated the prediction accuracy of GEBVs for five fruit traits including fruit weight, fruit width, fruit height, pericarp thickness, and Brix. Two tomato germplasm collections (TGC1 and TGC2) were used as training populations, consisting of 162 and 191 accessions, respectively.ResultsLarge phenotypic variations for the fruit traits were found in these collections and the 51K Axiom™ SNP array generated confident 31,142 SNPs. Prediction accuracy was evaluated using different cross-validation methods, GS models, and marker sets in three training populations (TGC1, TGC2, and combined). For cross-validation, LOOCV was effective as k-fold across traits and training populations. The parametric (RR-BLUP, Bayes A, and Bayesian LASSO) and non-parametric (RKHS, SVM, and random forest) models showed different prediction accuracies (0.594–0.870) between traits and training populations. Of these, random forest was the best model for fruit weight (0.780–0.835), fruit width (0.791–0.865), and pericarp thickness (0.643–0.866). The effect of marker density was trait-dependent and reached a plateau for each trait with 768−12,288 SNPs. Two additional sets of 192 and 96 SNPs from GWAS revealed higher prediction accuracies for the fruit traits compared to the 31,142 SNPs and eight subsets.ConclusionOur study explored several factors to increase the prediction accuracy of GEBVs for fruit traits in tomato. The results can facilitate development of advanced GS strategies with cost-effective marker sets for improving fruit traits as well as other traits. Consequently, GS will be successfully applied to accelerate the tomato breeding process for developing elite cultivars.

MORPHO-YIELD RESPONSE AND QUALITY CHARACTERIZATION OF BOTTLE GOURD (LAGENARIA SICERARIA) VARIETIES TO NITROGEN FERTILIZATION

The morpho-yield and quality traits of bottle gourd varieties were tested in response to nitrogen (N) nutrition during the year 2020 at the horticulture research area of Sindh Agriculture University Tandojam. The study was performed by applying Randomized complete block design (RCBD) with three replications. The two varieties Anmol and Long green were tested by applying six N rates that included (0 Kg N, (control), 50, 75 ,100, 125 and 150 Kg N ha-1). Both the varieties exhibited positive response to nitrogen fertilization. The maximum vine length, branches vine-1 were noted in plants, fertilized with increasing N rates (150 and 125 kg ha-1). In contrast shorter plants with less branches were noted when they were not fertilized with N nutrition.). The N nutrition also had a positive effect on fruit traits. The maximum fruit number with greater length and weight was recorded in plants supplied with increasing N fertilization. The N fertilization had beneficial influence on plant quality characteristics. The maximum pH, TSS, moisture and ash content in plants were observed, nourished with increasing N supply. The varietal comparison indicates that fruits of "Long green" had lower pH (5.88 vs. 6.0), higher in TSS (5.39 vs. 4.28%), moisture (67.74 vs. 55.52%), ash contents (19.96 vs. 19.01%), fruit yield (18178 vs. 17123 kg ha-1) than variety “Anmol”. In general, vines fertilized at 150 kg ha-1 N performed better than those fertilized at lower N levels for entire studied attributes, and "Long green" did better than "Anmol" among the evaluated varieties. The data clearly indicated severe soil N deficiency; and with each increment in applied N, the crop response was positive and significant (p<0.05). Hence, the farmers are suggested that “Long Green” bottle gourd variety may preferably be adapted with N at 150 kg ha-1 due to intense performance under agro-ecological conditions of Tandojam Sindh, Pakistan

Importance of plant and fruit traits on the structure of bird seed dispersal networks in different disturbed habitats.

Species functional traits can influence seed dispersal processes and consequently affect species' role in the mutualistic network. Although the effect of animal traits on the structure of the seed dispersal network is well explored, it remains poorly understood how plant and fruit traits contribute to the structure. We here studied the effects of plant and fruit traits on the structure of bird seed dispersal networks across different disturbed habitats in the Meihua Mountain National Nature Reserve, Southeastern China. During the study period, 16, 20, 13, and 15 bird species were recorded foraging on 10, 11, 12, and 8 plant species, resulting in 511, 312, 265, and 201 foraging events in the protected forest, natural forest, village, and bamboo forest, respectively. The composition of these seed dispersal networks is not primarily influenced by a specific group of bulbul species, but rather by the presence of an endangered plant species, Taxus chinensis. As we expected, the structure of the four networks was different among the four disturbed habitats. Furthermore, our results also showed tree height and canopy density were the most important plant traits for structuring the seed dispersal network, while sugar, amylase, dry matter, and alkaloids were identified as significant fruit traits. Overall, our findings highlight the value of integrating trait-based ecology into the framework of the seed dispersal network and provide new insights for mutualistic network conservation in disturbed habitats.

Comprehensive phenotypic evaluation by fruit quality traits and analysis of the genetic diversity of promising elite walnut forms bred in the North Caucasian Federal Scientific Center of Horticulture, Viticulture, and Winemaking

Walnuts are a source of benefi cial nutrients (fatty acids, vitamins, phenolic compounds) and are high in calories. In the breeding of this cultivated plant, one of the key areas is selection for fruit quality. A modern cultivar must meet the standards of fruit appearance (large fruit, light kernel color, round shape, easy shell-kernel separation). The study of the genetic structure of walnut collections using microsatellite markers is no less relevant. The article aims to comprehensively evaluate the economically valuable traits of fruits and analyze the genetic diversity of promising elite walnut forms bred by the North Caucasian Federal Scientific Center of Horticulture, Viticulture, and Winemaking employing microsatellite DNA markers. Morphological fruit evaluation was carried out according to 13 traits. The biochemical analysis included total fat content, phenolic compounds, macronutrients (Na, K, Mg, Ca), and water-soluble solids. The molecular genetic analysis was performed using eight SSR markers: WGA001, WGA069, WGA376, WGA276, WGA009, WGA202, WGA089, WGA321. The comprehensive phenotypic and biochemical evaluation of fruits resulted in the identifi cation of elite forms superior to the check cultivar. For these elite forms, the fruit weight was 17-1-18 (13.36 g), MP-82 (14.80 g), YaB-18 (13.47 g); the kernel content was 17-2-23 (61.24 %), 17-5-5 (58.49 %), 17-2-16 (57.7 %); the fat content – MP-34 (68 %), 17-1-18 (61 %), 17-2-16 (62 %), MP-39 (60 %), YaB-5 (60 %). The microsatellite analysis revealed an average allele value per locus of 7.13, which indicates a high level of genetic heterogeneity in the studied sample of elite forms. Using the UPGMA clustering method and PCoA analysis, we revealed the presence of two genetically distinct groups. Th e first one includes large-fruited samples that exceed the check cultivar in terms of fruit weight (MP-82, YaB-18). In the second group, high-oil-bearing forms with a large percentage of kernel yield (17-1-18, YaB-5, 17-2-23, 17-2-16, MP-39, MP-34, 17-5-5) and forms with good shell-kernel separation (17-2-5, 17-2-16, 17-5-5, 17-5-10, MP-39, MP-67, MP-69, MP-170) predominated. Th us, it can be concluded that crossing genetically distant forms is promising not only for solving breeding issues, but also for preserving and increasing the genetic heterogeneity of the breeding walnut gene pool.

An efficient method for detecting Camellia oleifera fruit under complex orchard environment

Efficient Camellia oleifera fruit detection in complex orchard environments is one of the most crucial technologies for automated picking and is significant for reducing labor costs. At present, Camellia oleifera fruit detection remains challenging due to the influence of fruit trait differences, cultivar differences, orchard environment differences, complex illumination, and occlusion. To address these challenges, a modified YOLOv7 model SDF-YOLO (SKConv-Decoupled Head-Focal EIoU-YOLOv7) has been developed. In SDF-YOLO, the selective kernel convolution (SKConv) is introduced to detect fruits of different sizes resulting from trait difference and occlusion with high performance, which utilizes multiple branches with different kernel sizes to fully extract and fuse the multi-scale information. To fully extract feature information of occlusion fruits, the decoupled head is used as the head network of SDF-YOLO to enhance the generalization performance of SDF-YOLO to cultivar differences and orchard environment differences. In addition, focal efficient intersection over union (Focal EIoU) loss is introduced to focus on high-quality bounding boxes, which can deal with positive and negative sample imbalance problems caused by occlusion and complex illumination. Experiment results demonstrate that SDF-YOLO can effectively detect Camellia oleifera fruits in complex orchard environments. Compared with eight mainstream models shows that SDF-YOLO achieves the highest precision of 94.91 %, recall of 93.01 %, F1 score of 93.95 %, and mAP of 96.65 % with an encouraging mean detection time of 36.57 ms. Moreover, SDF-YOLO exhibits robust adaptability to fruit trait differences, cultivar differences, orchard environment differences, complex illumination, and occlusion. These results indicated that SDF-YOLO is feasible for Camellia oleifera fruit detection in complex orchard environments, which provided a technical foundation for the automated picking of commercial orchards.

The seed dispersal syndrome hypothesis in ungulate-dominated landscapes

The Seed Dispersal Syndrome Hypothesis (SDSH) posits that fruit traits predict the main dispersers interacting with plant species. Mammalian dispersers, relying heavily on olfactory cues, are expected to select dull-colored, scented, and larger fruits compared to birds. However, challenges like overabundant seed predators and context-dependency of frugivore-plant interactions complicate SDSH expectations. We studied the Iberian pear, Pyrus bourgaeana, an expected mammal-dispersed tree based on its fruit traits. Extensive camera-trapping data (over 35,000 records) from several tree populations and years revealed visits from seven frugivore groups, with ungulate fruit predators (59–97%) and carnivore seed dispersers (1–20%) most frequent, while birds, lagomorphs, and rodents were infrequent (0–10%). Red deer and wild boar were also the main fruit removers in all sites and years but acted as fruit and seed predators, and thus likely exert conflicting selection pressures to those exerted by seed dispersers. Although, as predicted by the SDSH, most Iberian pear fruits were consumed by large and medium-sized mammals, the traits of Iberian pear fruits likely reflect selection pressures from dispersal vectors in past times. Our results do not challenge the SDHS but do reveal the importance of considering frugivore functional roles for its adequate evaluation.

Ploidy and fruit trait variation in oil-tea Camellia: Implications for ploidy breeding

Plant polyploidy often occurs in conjunction with higher yield and superior quality. Therefore, obtaining polyploid germplasms is a significant part of breeding. The oil-tea Camellia tree is an important native woody plant that produces high-quality edible oil and includes many species of Camellia with different ploidies. However, whether higher ploidy levels in oil-tea Camellia trees are related to better traits remains unclear. In this study, the ploidy levels of 30 different oil-tea Camellia strains in three different species in the Sect. Paracamellia were determined by flow cytometry and chromosome preparation, and the phenotypic characteristics and fatty acid compositions of the fruits were examined by field observations and laboratory analyses. The correlations between the ploidy level of oil-tea Camellia and the main traits of the fruit were investigated. Our results showed that 10 Camellia lanceoleosa strains were diploid, 10 Camellia meiocarpa strains were tetraploid and 10 Camellia oleifera strains were hexaploid. Hexaploid C. oleifera had larger fruit size and weight, more seeds per fruit, greater seed weight per fruit, higher oil content and greater yield per crown width than tetraploid C. meiocarpa and diploid C. lanceoleosa, but their fruit peel thickness and fresh seed rate were significantly lower, and these traits were significantly correlated with ploidy level. In addition, in terms of fatty acid composition, hexaploid C. oleifera had a higher oleic acid content than tetraploid C. meiocarpa and diploid C. lanceoleosa, but their linoleic acid, linolenic acid and arachidonic acid contents were lower. The contents of palmitic acid, stearic acid and total unsaturated fatty acids were not significantly correlated with ploidy level. In conclusion, certain correlations exist between the main characteristics of oil-tea Camellia fruit and the ploidy level, and increasing the ploidy level led to an increase in fruit yield with no effect on oil composition. The discovery of variations in the main characteristics of oil-tea Camellia fruit with different ploidies will facilitate germplasm innovation and lay a foundation for ploidy breeding and mechanistic research on fruit traits.

CPPU Improves Fruit Setting and Growth in Greenhouse-grown Oriental Melons (Cucumis melo L. var. makuwa Makino)

The production of melons (Cucumis melo L.) in greenhouses relies on pollination. Extreme temperature and insufficient light reduce not only flower visitation by pollinators but also pollen viability, resulting in inefficient pollination. In this study, we investigated the effects of forchlorfenuron [(N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU)] on the fruit setting and growth of oriental melons (C. melo L. var. makuwa Makino). The primary objective was to devise a new strategy for the management of oriental melons. Treatment with 5 mg·L−1 CPPU a day before flowering (T1), on the day of flowering (T2), and a day after flowering (T3) increased the fruit setting rate (by 20.1% to 30%) in melons subjected to artificial pollination (AP) or no pollination (NP) compared with the rate in those subjected to only artificial pollination without CPPU (CK). CPPU treatment induced unfertilized seeds; in addition, a tendency toward parthenocarpy was noted. The highest fruit setting rate (∼95%) was noted in plants subjected to the following treatments: AP+T1 and NP+T3. The rates of abnormal fruit formation decreased from 45.2% of CK group to 9.4% in plants subjected to AP+T1 and to 19.4% in those subjected to NP+T3. Elevated exogenous concentrations of CPPU markedly increased fruit weight. Plants subjected to NP+10 mg·L−1 CPPU bore the heaviest fruits (541.0 g), which were heavier than those borne by plants subjected to AP+10 mg·L−1 CPPU. CPPU treatment reduced the fruit cavity ratio in a concentration-dependent manner from 47.3% to 33.6% and increased the pulp thickness from 1.5 to 2.5 cm. Notably, supplementary CPPU treatment exerted no significant effects on fruit traits. Regarding taste, inconsistent results were obtained for sugar accumulation. Although the content of cucurbitacin B increased immediately after the initial CPPU treatment, it markedly decreased after 15 days of CPPU treatment. Therefore, mature melons did not have a bitter taste.

Morphological and molecular characterization of Sicilian carob (Ceratonia siliqua L.) accessions

The evergreen carob tree (Ceratonia siliqua) is considered one of the oldest trees in the world, cultivated since ancient times in the Mediterranean Basin, for its edible and high nutritional fruits, adapted to human and animal consumption. Spain is the main producer, followed by Italy, Portugal, Greece, Morocco, and Turkey. In Italy, the cultivation of carob is concentrated in a few provinces and insists on an area of more than 5,500 hectares. In this work 19 accessions, showing interesting fruit traits were analysed morphologically and genetically. Overall, 13 quantitative characters were considered regarding leaf (5 characters), pod (5) and seed (3). To investigate the genetic diversity 8 fluorescently labelled SSR primers were used, indicated as polymorphic in the literature. A UPGMA dendrogram was constructed to depict identity cases and relationships among the accessions. Clustering showed discrimination among accessions from Eastern and Western Sicily. The morphological characterisation does not clearly discriminate any of the cultivars recognized by the growers, similarly, the molecular analysis showed a reduced level of diversity. Since most of these local accessions are of unknown origin and that they are representative of the local germplasm they still warrant protection for their economic and environmental value.

Gum tragacanth, a novel edible coating, maintains biochemical quality, antioxidant capacity, and storage life in bell pepper fruits.

Bell pepper fruits (Capsicum annuum L.) are prone to both physiological and pathological deterioration following harvest, primarily due to their high metabolic activity and water content. The storage of bell peppers presents several challenges, including weight loss, softening, alterations in fruit metabolites and color, increased decay, and a decline in marketability. The application of edible coatings (ECs) is one of the environmentally friendly technologies that improves many post-harvest quantitative and qualitative characteristics of products. This research investigated the impact of different levels of gum tragacanth (GT) coating (0, 0.25, 0.5, 1, and 2%) on the physiological and biochemical traits of stored bell pepper fruits (BPFs) (8 ± 1°C, 90-95% RH) for 28 days. The results showed the positive effect of coating treatments with higher concentrations of GT, up to 1%. Increasing the concentration of GT to 2% decreased the marketability and quality characteristics of fruits compared to 1% GT. After storage, the physiological weight loss of the fruits treated with 1% GT (10.46%) was lower than that of the uncoated fruits (18.92%). Furthermore, the coated fruits (1% GT) had more firmness, total phenol content, ascorbic acid, and titratable acidity content than uncoated fruits during storage. At the end of storage, the coated BPFs with 1% GT showed higher SOD (97.02 U g-1), CAT (24.38 U g-1) and POD (0.11 U g-1) activities and antioxidant capacity (81.74%) as compared to other treatments. Total soluble solids, total carbohydrates, total carotenoids, pH, malondialdehyde, and electrolyte leakage content increased in coated fruit during storage but were significantly lower than in uncoated fruits. Moreover, the samples coated with GT (1%) maintained good marketability (about 75%), while the marketability of the control (about 40%) was unacceptable. The study shows that GT (1%) coating can be a promising novel treatment option for increasing the storage quality of BPFs.

Comparison and Genetic Variation Analysis of Important Fruit Traits in Jujube F1 Hybrids by Different Male Parents

The research on the genetic predisposition of key quality traits of fruit in jujube hybrid populations is a fundamental and crucial aspect in the field of jujube genetic breeding. In this study, the jujube hybridization experiments were conducted with the same female parent and different male parents since 2015, and a total of 238 strains were created in two F1 hybrid populations. The genetic variation of fruit external traits and intrinsic quality was analyzed and compared after the hybrid offspring results were stable in 2022. This study can provide a theoretical basis for selecting hybrid-breeding parents, predicting offspring traits, and innovating excellent germplasm resources by investigating the impact of different male parental configurations on the genetic variation of fruit traits in jujube hybrid offspring and identifying superior germplasm resources. The results showed that the inheritance of fruit shape, fruit size, and fruit-intrinsic nutrition-quality traits were quantitative traits controlled by multiple genes, and the offspring populations conformed to normal distribution or partial normal distribution. The six traits of fruit shape in offspring populations exhibited a segregation from their parents. The coefficients of variation of fruit size and intrinsic nutrition quality values ranged from 6.94% to 35.34%. Five intrinsic nutrition-quality traits exhibited significant separation at the super-parental level. This result indicated a rich genetic diversity in offspring traits in two hybrids offsprings. The fruit shape, fruit size, and titratable acidity of jujube hybrid offspring were mainly influenced by the male parent. It was found that the correlation between the single-fruit weight, length, and diameter, as well as the correlation between the fruit length and fruit transverse diameter, was very stable and significantly positive through the correlation analysis. More attention should be paid to fruit length when studying fruit shape, as a significant correlation was found between fruit length and fruit shape index. Finally, 10 superior hybrids were founded and selected as breeding materials for further breeding. Therefore, this study provides a theoretical basis for the early selection of hybrid breeding and the development and application of jujube germplasm resources.