The Roles of Floral Organ Genes in Regulating Rosaceae Fruit Development

The function of floral organ identity genes, APETALA1/2/3, PISTILLATA, AGAMOUS, and SEPALLATA1/2/3, in flower development is highly conserved across angiosperms. Emerging evidence shows that these genes also play important roles in the development of the fruit that originates from floral organs following pollination and fertilization. However, their roles in fruit development may vary significantly between species depending on the floral organ types contributing to the fruit tissues. Fruits of the Rosaceae family develop from different floral organ types depending on the species, for example, peach fruit flesh develops from carpellary tissues, whereas apple and strawberry fruit flesh develop from extra-carpellary tissues, the hypanthium and receptacle, respectively. In this review, we summarize recent advances in understanding floral organ gene function in Rosaceae fruit development and analyze the similarities and diversities within this family as well as between Rosaceae and the model plant species Arabidopsis and tomato. We conclude by suggesting future research opportunities using genomics resources to rapidly dissect gene function in this family of perennial plants.

Identification of an Allelic Variant of the CsOr Gene Controlling Fruit Endocarp Color in Cucumber (Cucumis sativus L.) Using Genotyping-By-Sequencing (GBS) and Whole-Genome Sequencing

The cucumber is a major vegetable crop around the world. Fruit flesh color is an important quality trait in cucumber and flesh color mainly depends on the relative content of β-carotene in the fruits. The β-carotene serves as a precursor of vitamin A, which has dietary benefits for human health. Cucumbers with orange flesh contain a higher amount of β-carotene than white fruit flesh. Therefore, development of orange-fleshed cucumber varieties is gaining attention for improved nutritional benefits. In this study, we performed genotyping-by-sequencing (GBS) based on genetic mapping and whole-genome sequencing to identify the orange endocarp color gene in the cucumber breeding line, CS-B. Genetic mapping, genetic sequencing, and genetic segregation analyses showed that a single recessive gene (CsaV3_6G040750) encodes a chaperone DnaJ protein (DnaJ) protein at the Cucumis sativus(CsOr) locus was responsible for the orange endocarp phenotype in the CS-B line. The Or gene harbored point mutations T13G and T17C in the first exon of the coding region, resulting in serine to alanine at position 13 and isoleucine to threonine at position 17, respectively. CS-B line displayed increased β-carotene content in the endocarp tissue, corresponding to elevated expression of CsOr gene at fruit developmental stages. Identifying novel missense mutations in the CsOr gene could provide new insights into the role of Or mechanism of action for orange fruit flesh in cucumber and serve as a valuable resource for developing β-carotene-rich cucumbers varieties with increased nutritional benefits.

FRUIT QUALITY OF NEW INTRODUCED PLUM CULTIVARS UNDER THE CONDITIONS OF BULGARIA

Prunus domestica L. is one of the most commonly grown fruit species in Bulgaria due to its high ecological adaptation and multiple ways of fruit marketing. Fruit quality is associated with attributes such as appearance, texture, taste and colour. Breeding and new cvs. introduction are in constant search for cultivars with better fruit quality that would answer the increasing consumer requirements. In 2013 the Romanian plum cvs. ‘Pitestean’, ‘Roman’, ‘Romanta’, ‘Carpatin’ and ‘Tita’ were introduced in Bulgaria and planted in a collection orchard at the Fruit Growing Institute, Plovdiv. The study was conducted in the period 2016-2021. It aimed to evaluate the fruit quality when the cultivars are grown under the agro-environmental conditions of the region. For obtaining this objective, fruit weight, fruit flesh firmness, TSS (°Brix), skin colour with and without wax bloom and fruit flesh colour were measured. For evaluating consumer acceptance, a sensory analysis was performed. ‘Roman’ had the largest fruits with an average fruit weight of 46.66 g and the highest TSS content – 18.2°Brix. There were significant differences in the colour parameters L*, a*, b*, Chroma and Hue between the cultivars and the wax bloom had a significant effect on colour parameters. All fruits were appreciated by the testing panel of consumers and their taste qualities were evaluated as good and very good.

Physical Fruit Traits, Nutritional Composition, and Seed Oil Fatty Acids Profiling in the Main Date Palm (Phoenix dactylifera L.) Varieties Grown in Morocco

We investigated fruit physical traits and nutritional value in both seed and flesh in eight Moroccan date palm varieties. The greatest values of weight for whole fruit, flesh, seed, and flesh percentage were found in “Boufgous,” “Agondari,” and “Bouskri.” These two later varieties displayed also their superiority with respect to proximate composition. For fruit flesh, proximate composition, energy value, and reducing capacity ranged as follows: proteins (1.60–3.53%), moisture (5.31–17.31%), ash (2.08–2.50%), lipids (0.32–1.09%), carbohydrates (76.69–90.18%), energy value (338.30–385.89 kcal/100 g), and reducing capacity (100.14–1607.12 mg GAE/100 g). Corresponding values in seeds were as follows: proteins (3.20–5.00%), moisture (1.42–4.14%), ash (1.14–1.50%), lipids (6.30–7.40%), carbohydrates (83.39–85.55%), energy value (417.06–429.51 kcal/100 g), and reducing capacity (1427.71–6843.84 mg GAE/100 g dry weight). Among all minerals (K, Ca, Mg, B, Fe, Cu, Mn, Na, and Zn) found in both fruit parts, K had the highest records for both flesh (12047 mg/kg) and seed (6127.6 mg/kg), followed by Mg and Ca. Seeds lipidic fraction was dominated by monounsaturated fatty acid C18 : 1 (47.5%), followed by saturated fatty acids mostly C12 : 0 (18.0%), C14 : 0 (10.5%), and C16 : 0 (10.6%) and finally polyunsaturated fatty acid C18 : 2 (8.8%). It could be concluded that investigated varieties presented a great importance from a nutritional point of view, and seeds could present important opportunities of valorization.

Analisis Kandungan Proksimat Daging Buah dan Biji Tiga Varietas Durian (Durio zibethinus Murr.) yang Berasal dari Tempat Tumbuh yang Berdekatan

Studies to compare the proximate content of durian fruit flesh and seeds have not been widely employing. Hence, this study aimed to analyze and compare this content in fruit flesh and seeds of three durian varieties from adjacent growing areas. The following methods used for proximate analysis were carbohydrates (by difference), protein (micro Kjeldahl), lipid (soxhlet), crude fiber (washing), moisture content (oven), ash content (furnace). In evaluating the difference in proximate content in these parts of three durian varieties, the resulting data were tested statistically using ANOVA =5%, followed by the DMRT test. In determining the difference in the proximate content between the fruit flesh and durian seeds, the independent samples T-test was used with =5%. All data collected were then compared with the USDA National Nutrient and the Directorate of Nutrition at the Ministry of Health databases. The results showed that three durian varieties from adjacent growing areas had significantly different protein and carbohydrate content (in fruit flesh), ash content, protein, and carbohydrates (in seeds). The flesh part of the three varieties of durian contains water, protein, fat, crude fiber, which is significantly different from durian seeds. This study is higher than the comparison data

Genome‐wide Association Links Candidate Genes to Fruit Firmness, Fruit Flesh Color, Flowering Time, and Soluble Solid Content in Apricot (Prunus Armeniaca L.)

Background Apricots originated from China, Central Asia and the Near East and arrived in Anatolia, and particularly in their second homeland of Malatya province in Turkey. Apricots are outstanding summer fruits, with their beautiful attractive color, delicious sweet taste, aroma and high vitamin and mineral content. Methods and results In the current study, a total of 259 apricots genotypes from different geographical origins in Turkey were used. Significant variations were detected in fruit firmness (FF), fruit flesh color (FFC), flowering time (FT), and soluble solid content (SSC). A total of 11,532 SNPs based on DArT were developed and used in the analyses of population structure and association mapping (AM). According to the STRUCTURE (v.2.2) analysis, the apricot genotypes were divided into three groups. The mixed linear model with Q and K matrixes were used to detect the associations between the SNPs and four traits. A total of 131 SNPs were associated with FF, FFC, and SSC. No SNP marker was detected associated with FT. Conclusion The results demonstrated that AM had high potential of revealing the markers associated with economically important traits in apricot. The SNPs identified in the study can be used in future breeding programs for marker-assisted selection in apricot.

Yellow Sap Contamination on Mangosteen (Garcinia mangostana L.) Fruit in Relation to Soil Calcium Contents and Plant Tissue

Yellow sap contamination (YSC) is one of the mangosteen quality constrain in Indonesia. Calcium is the prominent nutrient that influence the incidence of yellow sap contamination. A research with objective to observe the relationship between incidence YSC and Ca availability in soil as well as plant tissue was done in ten locations in West Sumatra, Lampung and West Java provinces. Purposive random sampling method was used to determine the site locations. The plant and soil samples were collected from 10 sites and ten tree per sites. Correlation analysis was used to measure the relationship between incidence YSC and Ca content in fruit endocarp, mesocarp, peel, soil and leaf. The result showed that there was a variation of incidence YSC in site location with range of 8.7%−54.04%; 4.0−51.6%; and 17.7−78.6% for percentage of YSC in fruit flesh, segmentation and peel, respectively. Ca content in soil, endocarp, mesocarp and leaf were given significantly negative correlation toward incidence YSC in fruit flesh and segmentation. Ca content in leaf part correlates significantly to Ca availability in soil, endocarp and mesocarp. Ca content in leaf in the range of 1.40- 1.70% indicates YSC less than 10%.

Daucus carota DcPSY2 and DcLCYB1 as Tools for Carotenoid Metabolic Engineering to Improve the Nutritional Value of Fruits

Carotenoids are pigments with important nutritional value in the human diet. As antioxidant molecules, they act as scavengers of free radicals enhancing immunity and preventing cancer and cardiovascular diseases. Moreover, α-carotene and β-carotene, the main carotenoids of carrots (Daucus carota) are precursors of vitamin A, whose deficiency in the diet can trigger night blindness and macular degeneration. With the aim of increasing the carotenoid content in fruit flesh, three key genes of the carotenoid pathway, phytoene synthase (DcPSY2) and lycopene cyclase (DcLCYB1) from carrots, and carotene desaturase (XdCrtI) from the yeast Xanthophyllomyces dendrorhous, were optimized for expression in apple and cloned under the Solanum chilense (tomatillo) polygalacturonase (PG) fruit specific promoter. A biotechnological platform was generated and functionally tested by subcellular localization, and single, double and triple combinations were both stably transformed in tomatoes (Solanum lycopersicum var. Microtom) and transiently transformed in Fuji apple fruit flesh (Malus domestica). We demonstrated the functionality of the S. chilense PG promoter by directing the expression of the transgenes specifically to fruits. Transgenic tomato fruits expressing DcPSY2, DcLCYB1, and DcPSY2-XdCRTI, produced 1.34, 2.0, and 1.99-fold more total carotenoids than wild-type fruits, respectively. Furthermore, transgenic tomatoes expressing DcLCYB1, DcPSY2-XdCRTI, and DcPSY2-XdCRTI-DcLCYB1 exhibited an increment in β-carotene levels of 2.5, 3.0, and 2.57-fold in comparison with wild-type fruits, respectively. Additionally, Fuji apple flesh agroinfiltrated with DcPSY2 and DcLCYB1 constructs showed a significant increase of 2.75 and 3.11-fold in total carotenoids and 5.11 and 5.84-fold in β-carotene, respectively whereas the expression of DcPSY2-XdCRTI and DcPSY2-XdCRTI-DcLCYB1 generated lower, but significant changes in the carotenoid profile of infiltrated apple flesh. The results in apple demonstrate that DcPSY2 and DcLCYB1 are suitable biotechnological genes to increase the carotenoid content in fruits of species with reduced amounts of these pigments.