Increased Fruit Size Research Articles

Impact of Cucurbita and Cucumis rootstocks on the performance and quality of Piel de Sapo melon

Melon grafting represent an increasingly important strategy against biotic and abiotic stresses. Cucurbita hybrid rootstocks have been extensively developed for this purpose, but it is necessary to find new alternatives. In this work, several experimental rootstocks of cultivated and wild resources from the Cucurbita and Cucumis genera have been evaluated using Piel de Sapo melon as scion. Cucurbita rootstocks tended to increase fruit size and seed cavity and offered more rounded shapes at the early stages of ripening, but this effect was later minimised. Cucumis rootstocks tended to show less vigour than those of Cucurbita. C. metuliferus hybrid rootstock caused plant collapse at specific environmental conditions, probably due to differences in the growth of rootstock and scion. One of the Cucurbita maxima x C. moschata and the Cucurbita pepo experimental hybrids were also less vigorous, delaying flowering and fruit set, and compromising yield. The effects of Cucurbita and Cucumis rootstocks on sugar and acid accumulation of Piel de Sapo were almost negligible, but they altered the volatile profile. This last impact depended on the specific scion x rootstock interaction and the environmental conditions. Cucumis rootstocks tended to minimise it, especially the hybrid Cucumis melo subsp. melo x C. melo subsp. agrestis Pat 81, which offered a volatile profile highly resembling the non-grafted control. Among Cucurbita alternatives, the commercial hybrid Cucurbita maxima x C moschata had the lowest impact, while other experimental hybrids C. moschata x C. moschata and C. maxima x C. moschata increased levels of alcohols. Among Cucumis rootstocks, the hybrids of wild species Cucumis ficifolius x C. anguria and C. ficifolius x C. myriocarpus, and C. metuliferus had a higher impact on the volatile profile.

Topping sweet orange trees as Diaphorina citri bait on the farm edge for huanglongbing management: Opportunities and limitations

Flush shoots of citrus have an important role in huanglongbing (HLB) epidemiology, as the insect vector of HLB, the Asian citrus psyllid (ACP), prefers them for feeding and reproduction. Additionally, ACP's acquisition and transmission of HLB bacteria mainly occurs in these flushes. As pruning stimulates sprouting, we hypothesized that periodically topping sweet orange trees on the orchard's edge (from 0 to 100 m) would attract ACPs from external areas to these flush shoots as bait, instead of ACPs dispersing throughout the orchard. Hence, it would direct HLB management on this edge width. For that, topped trees (TT) were compared to non-topped trees (NTT) located on the orchard's edge, with only NTT after edges (from 100 to 200 m). Vegetative growth, flushing frequency, ACP population, spray coverage, HLB incidence, fruit yield, and quality of Hamlin and Valencia Americana sweet orange trees were evaluated in commercial orchards over three growing seasons. Topping was performed frequently (every 30–45 d) on alternate rows to stimulate the year-round presence of shoot flushes within the orchard's edge. Insecticides were sprayed monthly to control ACP. Topping reduced tree height and canopy volume by 24 % and 20 % on average. Topped trees presented, on average, 3-fold more flush shoots than NTT over time. On Hamlin blocks, ACP numbers and cumulative HLB incidence were 70 % and 90 % higher, respectively, in TT compared to NTT. However, no consistent differences were observed for the Valencia Americana orchard. Moreover, ACP abundance and HLB incidence were similar after the edge regardless of topping. In the edge areas, although tree yield was reduced (∼65 % on average) on TT compared to NTT, topping significantly enhanced external fruit quality. This treatment increased fruit size and weight and promoted intense yellow coloration. Topping increased spray coverage at the top of Hamlin trees by 1.5-fold compared to control. Frequent topping as bait for ACP poses significant risks if the ACP population is not rigorously controlled, potentially leading to further reductions in yield from edge trees.

Effects of Promalin on Fruit Growth and Cuticle Properties of ‘Pinova’ Apple

Promalin (Valent BioSciences, Libertyville, IL, USA) is a proprietary mixture of gibberellin A4 + 7 and 6-benzyladenine that is widely used in apple production to improve the fruit shape, size, and skin quality. Promalin typically increases fruit size and length. However, the increased growth likely increases the strain in the fruit skin, which may exacerbate microcracking of the cuticle and, consequently, russeting. This study aimed to monitor the growth-stimulating effect of Promalin in three different regions of fruits and investigate whether Promalin affects cuticular microcracking via effects on the deposition of cuticular components or via the accumulation of strain in the cuticle. Four Promalin sprays (20 mg⋅L−1) were applied to runoff; the first was applied at full bloom, and the remaining sprays were applied at approximately weekly intervals thereafter. Fruit surface areas and fruit surface area growth rates of the Promalin-treated fruits were higher than those of the untreated control fruits. Promalin increased the fruit length, but it had no effect on the fruit equatorial diameter. In Promalin-treated fruits, the base of each sepal extended, thickened, and became fleshy as early as 15 days after full bloom (DAFB). Allometric growth analyses revealed higher constant differential growth ratios of the pedicel and calyx length (before 36 DAFB) in Promalin-treated fruits than in control fruits. After 36 DAFB, the difference in constant differential growth ratios between Promalin-treated fruits and control fruits decreased. Cuticle mass per unit area increased with time in all regions of the fruit surface and was slightly (+3.3%) but significantly higher in fruits treated with Promalin than in control fruits. Additionally, the biaxial strain release was slightly and significantly lower in Promalin-treated fruits than in control fruits. When the isolated, cuticle was ablated from the inner surface and dewaxed, strain relaxation in the control fruits was higher than that in the Promalin-treated fruits. It was concluded that Promalin treatment increases the length of the fruit by increasing the lengths of the pedicel and calyx regions early during fruit development. Promalin only slightly increased cuticle deposition and fixation of cuticular strain. Promalin had no effects on microcracking or russeting.

PbbHLH137 interacts with PbGIF1 to regulate pear fruit development by promoting cell expansion to increase fruit size.

The regulation of fruit development is a complex process and a core issue in the fruit tree industry. To investigate the role of PbGIF1 in pear fruit development, we identified a transcription factor PbbHLH137 that regulates pear (Pyrus bretschneideri) fruit development by screening a yeast library constructed from fruit cDNA. Yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BiFC), and split luciferase complementation (split-LUC) assays were performed to confirm the PbbHLH137-PbGIF1 interaction. By tracing the complete fruit development process, we found that PbbHLH137 expression was closely related to fruit size and highly involved at the late pear fruit development stage. Transgenic experiments showed that heterologous expression of PbbHLH137 or PbGIF1 promoted fruit enlargement. PbbHLH137 promoted mainly the expansion of fruit cell volume, whereas PbGIF1 mainly increased the number of cells. Further LUC experiments demonstrated that PbGIF1 promoted the transcriptional activation ability of PbbHLH137. Our work identified PbbHLH137 as a transcription factor that regulates fruit development, and showed that PbGIF1 played an ongoing role during fruit development, making it a candidate gene for genetic improvement of pear fruit development.

Effect of forchlorfenuron (CPPU) on fruits quality and residue analysis in kiwifruits

N-(2-Chloro-4-pyridyl)-N′-phenylurea (CPPU) is a plant growth regulator that promotes cell division and cell expansion in fruits. The present investigation was performed to observe the impact of CPPU on kiwifruit, specifically focusing on quantitative attributes, such as fruit size and shape, as well as the nutritional and residual levels of the fruit after CPPU application. This experiment was conducted on three kiwifruit varieties: Xuxiang, Jintao, and Zhonghua 50. The research entailed immersing the fruits in different concentrations of CPPU at 20 days after flowering. These findings demonstrate that CPPU has a positive impact on increasing fruit size and improving quality, while also preserving the ideal flavone, sugar-acid ratios and high levels of vitamin C. In addition, CPPU treatment enhanced the phenolic content of the fruit. Although high quantities of CPPU had a detrimental influence, the residues of CPPU in 'Xuxiang', 'Jintao', and 'Zhonghua 50' kiwifruits were 0.001, 0.002, and 0.002 mg/kg, respectively, at a dosage of 10 mg/kg. At a concentration of 20 mg/kg, the residues were 0.004, 0.003, and 0.003 mg/kg. No residues were detected at a concentration of 5 mg/kg. All residue levels were in accordance with China's national food safety regulations (MRL <0.05). Hence, this study proposes that a concentration of 10 mg/L CPPU shows potential for fruit cultivation, as it achieves a harmonious combination of improved fruit characteristics and adherence to food safety standards.

Bioprocess of Gibberellic Acid by Fusarium fujikuroi: The Challenge of Regulation, Raw Materials, and Product Yields.

Gibberellic acid (GA3) is a tetracyclic diterpenoid carboxylic acid synthesized by the secondary metabolism of Fusarium fujikuroi. This phytohormone is widely studied due to the advantages it offers as a plant growth regulator, such as growth stimulation, senescence delay, flowering induction, increased fruit size, and defense against abiotic or biotic stress, which improve the quality and yield of crops. Therefore, GA3 has been considered as an innovative strategy to improve agricultural production. However, the yields obtained at large scale are insufficient for the current market demand. This low productivity is attributed to the lack of adequate parameters to optimize the fermentation process, as well as the complexity of its regulation. Therefore, this article describes the latest advances for potentializing the GA3 production process, including an analysis of its origins from crops, the benefits of its application, the related biosynthetic metabolism, the maximum yields achieved from production processes, and their association with genetic engineering techniques for GA3 producers. This work provides a new perspective on the critical points of the production process, in order to overcome the limits surrounding this modern line of bioengineering.

Overexpression of Solanum lycopersicum DDB1 interacting protein 4 (SlDDI4) extends tomato shelf life by methylation-mediated suppression of softening-related genes expression

Prolonging the fruit storage period is strategically important due to the limitation of postharvest life determined by excessive softening. Efforts have been made to alleviate the issue of fruit softening in transgenic fruit by suppressing genes that encode cell wall-degrading proteins. However, individual genes related to the degradation of cell walls have limited ability, resulting in minimal success. SET domain-containing protein (SET protein) is widely expressed in most plant organs and crucial in plant growth and development. A tomato SET protein was previously identified as SlDDI4 (Solanum lycopersicum DDB1 interacting protein 4) with a H3K9 methyltransferase activity involving cell proliferation and organ size regulation. In this study, we demonstrated that SlDDI4 overexpression (SlDDI4-OE) promotes fruit firmness in addition to increased fruit size. Further experimental investigations revealed that the increased expression of SlDDI4 inhibited cellulase and pectinase activities, consequently increasing the proportion of cellulose and insoluble pectin. RNA-seq profiling indicated the genes involved in cell wall metabolism in SlDDI4-OE fruit were significantly down-regulated. DNA methylation and McrBC-PCR analysis at the SlCEL2, SlPG2, and SlEXP12 loci revealed that their down-regulation was associated with the elevated methylation level in the individual promoter regions. Furthermore, up-regulation of SlDDI4 generated fruit with increased lycopene content and prolonging shelf-life by approximately 20 d without adverse impacts on the flavor indicators. Thus, our results suggest that manipulation of SlDDI4 expression enables broad favorable effects on postharvest life as well as fruit size and quality through chromatin remodeling.

Selective Retention of Cross-Fertilised Fruitlets during Premature Fruit Drop of Hass Avocado

The productivity of many tree crops is limited by low yield, partly due to high rates of fruitlet abscission during early fruit development. Early studies suggested that cross-pollinated fruitlets may be selectively retained during fruit development, although paternity testing of fruitlets to test this hypothesis was technically challenging. We used MassARRAY genotyping to determine the effects of pollen parentage on fruitlet retention and fruit quality of Hass avocado. We identified the paternity of abscised and retained fruitlets at 6 and 10 weeks, and mature fruit at 36 weeks, after peak anthesis. We measured the embryo mass, pericarp mass, total mass and nutrient concentrations of fruitlets, and the seed mass, flesh mass, total mass, diameter, length, nutrient concentrations and fatty-acid composition of mature fruit. The percentages of progeny on the tree that were cross-fertilised increased from 4.6% at 6 weeks after peak anthesis to 10.7% at fruit maturity. Only 1.0% of freshly abscised fruitlets on the ground at 10 weeks after peak anthesis were cross-pollinated even though 6.5% of retained fruitlets on the tree were cross-pollinated. At this stage, cross-pollinated fruitlets had similar nutrient concentrations to self-pollinated fruitlets, but they had higher total contents of P, K, Al, Ca, Fe, Mn and Zn due to having greater fruitlet mass. At maturity, cross-pollinated fruit were 6% heavier and had 2% greater diameter than self-pollinated fruit, without significant differences in flesh nutrient concentrations or fatty acid composition. The results demonstrate that Hass avocado trees selectively retain cross-pollinated fruitlets, which are larger than self-pollinated fruitlets and ultimately produce larger mature fruit. Avocado growers can increase fruit size and yield by improving the opportunities for cross-pollination, possibly by closely interplanting type A and type B cultivars and introducing more beehives into orchards.

Analysis of quality evaluation and optimal harvest period of Aurantii Fructus from different sources using UHPLC-Q-TOF-MS/MS.

The active constituents in Aurantii Fructus sourced from different regions within Hunan Province exhibit variations, with certain samples demonstrating substandard quality. The aim of this study is to conduct a comparative analysis of the chemical composition and quality of Aurantii Fructus from various sources, establish a robust methodology for quality evaluation, and determine the optimal harvesting period. The components of Aurantii Fructus were qualitatively analyzed using a non-targeted metabolomics approach. Multivariate statistical analyses were conducted to identify potential markers, enabling qualitative and quantitative evaluation of the quality and optimal harvest period of Aurantii Fructus. Overall, 155 compounds were identified in Aurantii Fructus, with Huangpi exhibiting the highest number of components. Eleven potential markers were selected to assess the quality of Aurantii Fructus. The average content of Huangpi was the highest, indicating a high level of similarity. The samples' overall scores were ordered as follows: Huangpi > Xiangcheng > Choucheng > Daidai. Anren and Changde's Huangpi exhibited high contents, being rich in chemical components, resulting in favorable scores. Similarly, Changde's Xiangcheng displayed significant medicinal value. As the harvest time was delayed, there was an increase in fruit size, accompanied by thinner peels and a continuous decrease in the contents of potential markers. The best harvest period of Aurantii Fructus was within 1week before and after the Lesser Heat. The present study establishes a precise and efficient method for evaluating the quality of Aurantii Fructus, thereby providing more comprehensive insights into its composition. This research lays the foundation for subsequent development and utilization of Aurantii Fructus.

Effects of the Agrivoltaic System on Crop Production: The Case of Tomato (Solanum lycopersicum L.)

Climate change, with rising temperatures, water crises, and an increased frequency of climate disturbances, poses a threat to the ability of agroecosystems to ensure human access to food by affecting both the quantity and quality of crop production. Currently, there is growing knowledge about the fact that agrivoltaic systems may represent a direct strategy to cope with climate change driven by carbon dioxide emissions for energy production, preserving the capacity of agroecosystems to maintain food security. The aim of this work was to investigate the impact of environmental conditions generated by photovoltaic (PV) panels for sustaining open-field tomato (Solanum lycopersicum L.) fruit production under varying water supply regimes. Tomato plants were grown beneath PV panels or in full sunlight. In each scenario, two plots with an equal number of plants were subjected to different irrigation levels: high watering (HW) and low watering (LW). The results showed a lower number of tomato fruit produced grown under the PV panels, with an increased fruit size and water content under a normal water supply. The Brix degrees of the tomato fruits grown under the panel were more comparable to the fruits commercially available on the market than the Brix degree of the fruits grown in open-field sunlight. Thus, our data supported the conclusion that the agrivoltaic system, in the context of climate change with the enduring drought and long-term water scarcity, can be a good adaptation strategy to maintain favorable tomato production compared to the full sunlight conditions. Furthermore, these results can be important for planning breeding programs, since in many cases, the tomato fruits grown in full sunlight were seedless.

Development and optimization of a mechanized jackfruit processing unit for enhanced efficiency and commercial viability

AbstractThe jackfruit is the largest edible fruit but remains underutilized due to challenges such as sticky latex, labor‐intensive peeling/coring, and lack of mechanization. This study developed and evaluated a jackfruit peeling, coring, and cutting machine to enhance processing efficiency. Performance was modeled using response surface methodology (RSM) and artificial neural network (ANN). Three jackfruit sizes (small, medium, and large) and three machine speeds (90, 120, and 150 RPM) were evaluated for peeling time (26.1–50.3 s), peeling efficiency (71.6%–85.3%), coring time (15.5–29.9 s), coring efficiency (74.7%–96.0%), and bulb wastage (6.2%–17.6%). RSM showed high model adequacy (R2 ≥ 0.97) and ANN confirmed prediction reliability (R2 = 0.81–0.99; mean square error = 4.4–44.9). Increasing fruit size significantly increased peeling and coring times but decreased efficiencies. Machine speeds caused minor variations. Optimized conditions of 120 RPM fruit holder speed and 150 RPM corer speed gave maximum desirability (0.869). The machine had a payback period of 2 years and benefit–cost ratio of 2.32 versus 2.66 for manual peeling/coring. The mechanized jackfruit processing will promote enhanced utilization of this nutritious fruit.Practical applicationsThe mechanized jackfruit peeling‐coring‐cutting machine developed in this study has significant practical utility. By enabling efficient and rapid processing of jackfruits, the machine can help tap the underutilized potential of this highly nutritious and functionally beneficial fruit. The optimized machine parameters allow jackfruit processing industries to achieve higher throughput with reduced wastage, thereby boosting productivity and profits. Additionally, the mechanization facilitates value‐addition by enabling jackfruit utilization in various processed products like chips, flour, jam, etc. Further, the machine helps create livelihood opportunities in jackfruit value chains, as it reduces drudgery and enhances process efficiency as compared to manual methods. The simple fabrication and operation also enable adoption by farmer‐producer organizations, self‐help groups, and community‐based jackfruit processing enterprises. Overall, the mechanized solution provides an impetus for sustainable utilization of jackfruit, while also addressing issues like food loss, nutrition security, income support, and women empowerment. The practical insights on machine performance modeling using response surface methodology and artificial neural network approaches further facilitate quality improvements in equipment design.

SlMYC2 promotes SlLBD40-mediated cell expansion in tomato fruit development.

As a plant-specific transcription factor, lateral organ boundaries domain (LBD) protein was reported to regulate plant growth and stress response, but the functional research of subfamily II genes is limited. SlMYC2, a master regulator of Jasmonic acid response, has been found to exhibit high expression levels in fruit and has been implicated in the regulation of fruit ripening and resistance to Botrytis. However, its role in fruit expansion remains unknown. In this study, we present evidence that a subfamily II member of LBD, namely SlLBD40, collaborates with SlMYC2 in the regulation of fruit expansion. Overexpression of SlLBD40 significantly promoted fruit growth by promoting mesocarp cell expansion, while knockout of SlLBD40 showed the opposite result. Similarly, SlMYC2 knockout resulted in a significant decrease in cell expansion within the fruit. Genetic analysis indicated that SlLBD40-mediated cell expansion depends on the expression of SlMYC2. SlLBD40 bound to the promoter of SlEXPA5, an expansin gene, but did not activate its expression directly. While, the co-expression of SlMYC2 and SlLBD40 significantly stimulated the activation of SlEXPA5, leading to an increase in fruit size. SlLBD40 interacted with SlMYC2 and enhanced the stability and abundance of SlMYC2. Furthermore, SlMYC2 directly targeted and activated the expression of SlLBD40, which is essential for SlLBD40-mediated fruit expansion. In summary, our research elucidates the role of the interaction between SlLBD40 and SlMYC2 in promoting cell expansion in tomato fruits, thus providing novel insights into the molecular genetics underlying fruit growth.

A First Omics Data Integration Approach in Hass Avocados to Evaluate Rootstock-Scion Interactions: From Aerial and Root Plant Growth to Fruit Development.

Grafting, the careful selection of rootstocks and scions, has played a crucial role maintaining Chilean avocado fruit quality standards in a scenario in which climate change and drought-related issues have considerably decreased avocado fruit production in the last fifteen years. The historical use of seedling rootstocks in Chile has experienced a recent shift towards clonal rootstocks, driven by the potential to produce more consistent and predictable crops. This research aims to compare Hass avocado plants grafted on Mexicola seedling and Dusa® clonal rootstocks in a soilless and protected system using (i) a differential expression analysis of root and leaf samples and (ii) a fruit transcriptomic and metabolomic integration analysis to improve our understanding of rootstock-scion interaction and its impact on avocado tree performance and fruit quality. The results demonstrated that no significant transcriptomic and metabolomic differences were identified at fruit level in the ready-to-eat (RTE) stage for Hass avocado fruit from both rootstocks. However, Hass avocados grafted on the clonal rootstock showed greater aerial growth and slightly increased fruit size than the seedling rootstock due to the enrichment of cell wall-remodeling genes as revealed in leaves and fruit at harvest stage.

Potential of Endophytic Fungal Isolates in Improving Productivity and Postharvest Marketable Fruit Qualities of Tomato

In Tanzania, low tomato (Solanum lycopersicum) yield and postharvest marketable fruit qualities remain significant limitations for tomato grower’s profit. Seven endophytic fungal isolates from pyrethrum and Lemongrass leaf and or flowers were evaluated to promote tomato productivity and fruit qualities. The isolates were inoculated by priming the seeds in spore suspension, and the variations in the number of germinated seeds, seedling vigour, yield and fruit qualities were compared across the treatments. It was observed that only three isolates induced more than 50% seed germination. Epf1 and Epl1 isolates showed significant promotion of seed germination (F 0.05 (pdf, 23) = 8.121 and P = 0.001) and seedling vigour. Isolate Epf1 increased fruit number (18.4%) and weight (17%) but reduced fruit size (0.63%); the Epl1 increased fruit size (12%) and reduced fruit number (14.4%). The Epf1 induced delayed fruit ripening, colour development and softening, decaying, and prolonged shelf life by 9 days. These findings indicate that promoting tomato productivity and postharvest marketable fruit qualities is isolate-specific; therefore, it requires diligent screening. Incorporation of the Epf1 isolate through seed priming with fungal spore suspension demonstrated a high potential for increasing tomato productivity and postharvest marketable fruit qualities.

Effects of post-shooting sprays and bunch covering on yield attributes of Willium banana (Musa paradisiaca L.)

This research investigates the synergistic effects of post-shooting sprays and bunch covering materials on the growth, development, and yield of Willium banana (Musa paradisiaca L.). Gibberellic acid (GA3) at 100 mg/l emerges as a potent post-shooting spray, significantly enhancing bunch length, finger length, girth of finger, bunch weight, and overall fruit yield. The study highlights the pivotal role of GA3 in promoting both cell division and elongation, contributing to increased fruit size and weight. Non-woven material bag covering proves superior in creating an optimal microclimate, fostering enhanced air circulation, temperature control, and light interception. This material significantly boosts finger length, girth, bunch weight, and fruit yield. These findings provide valuable insights for banana cultivation, emphasizing the strategic use of GA3 and appropriate covering materials to optimize environmental conditions and hormonal balance for improved crop outcomes. The study contributes to the evolving field of banana cultivation practices and offers practical implications for enhancing fruit quality and yield.

Productivity and water saving of ‘Fortune’ plum under different water regimes

This study was conducted over four consecutive years (2015-2018) in the Sefrou region of Morocco, between Sais and the Middle Atlas Mountains. The goal of the study was to assess how plum trees respond to three different irrigation strategies: a normal supply of water (T2) to meet 100% of crop water needs; an irrigation deficit (T1) that provides only 75% of the water needs; and an additional water supply of 25% (T3) above the crop needs. The study found that deficient irrigation (T1) had no significant effect on plum yield or average fruit weight at harvest, but an excess water supply of 25% (T3) over the requirements (T2) resulted in higher yields and average fruit weight than the control. T3 also showed an increase in fruit size at harvest compared to the control, but not in T1 compared to T2. However, the excess water input for T3 did not justify the excess yield in terms of water use efficiency (WUE). On the other hand, T1 maintained the same level of production as the control while saving water, which resulted in a higher WUE compared to T2 and T3..

Análise econômica dos efeitos do ponto de colheita sobre a qualidade e a produtividade de maçãs ‘Fuji Suprema’

Abstract This study aimed to analyze the effect of harvest date on ‘Fuji Suprema’ apple quality, productivity, and economic profitability at harvest and after storage. Apples were harvested at the beginning of the commercial harvest window (H1), ten days after H1 (H2), and 22 days after H1 (H3) in the 2008 and 2009 growing seasons. A total of six samples with ~400 kg of fruit (~2,900 apples) each were picked at each growing season and harvest date, which were assessed at harvest (six subsamples of 100 fruit) and after 250 days of controlled atmosphere storage at 0.8 °C. The economic analysis considered fixed and variable production costs in the orchard and postharvest practices and the productivity of packaged apples (pack-out). Early harvested (H1) apples had greater flesh firmness, acidity, and lower soluble solids content than late-harvested apples (H3), both at harvest and after storage. Delaying harvest by 22 days increased the production by 10.2% due to increased fruit size but reduced the production by 3.6% due to severe sunburn and pre-harvest decay incidence. Late harvest also increased production losses due to decay by 4.4% and 10.9% during storage and shelf, respectively, but reduced production losses due to superficial scald by 17.1 to 22.7%. The net revenue (R$ ha-1) is higher for apples harvested late (H3, flesh firmness of 15.6 lb and starch index of 7.1) than for apples harvested early (H1 and H2) when the fruit is marketed soon after harvest (between April and May). However, for apples marketed after long-term storage, economic profitability is maximum when harvested at an intermediate maturity stage (H2, flesh firmness of 16.4 lb and starch index of 6).

Comparative transcriptome analysis of persimmon somatic mutants (Diospyros kaki) identifies regulatory networks for fruit maturation and size.

Bud sports in fruit crops often result in new cultivars with unique traits, such as distinct fruit size and color, compared to their parent plants. This study investigates the phenotypic differences and gene expression patterns in Tonewase and Ohtanenashi persimmon bud sports compared to those in their parent, Hiratanenashi, based on RNA-seq data. Tonewase is characterized by early maturation, whereas Ohtanenashi is noted for its larger fruit size. Despite the importance of these traits in determining fruit quality, their molecular bases in persimmons have been understudied. We compared transcriptome-level differences during fruit development between the bud sport samples and their original cultivar. Comprehensive transcriptome analyses identified 15,814 differentially expressed genes and 26 modules via weighted gene co-expression network analysis. Certain modules exhibited unique expression patterns specific to the different cultivars during fruit development, likely contributing to the phenotypic differences observed. Specifically, M11, M16, M22, and M23 were uniquely expressed in Tonewase, whereas M13 and M24 showed distinct patterns in Ohtanenashi. By focusing on genes with distinct expression profiles, we aimed to uncover the genetic basis of cultivar-specific traits. Our findings suggest that changes in the expression of genes associated with ethylene and cell wall pathways may drive Tonewase's earlier maturation, whereas genes related to the cell cycle within the M24 module appear crucial for Ohtanenashi's larger fruit size. Additionally, ethylene and transcription factor genes within this module may contribute to the increased fruit size observed. This study elucidates the differences in transcriptomic changes during fruit development between the two bud sport samples and their original cultivar, enhancing our understanding of the genetic determinants influencing fruit size and maturation.

Phased genomics reveals hidden somatic mutations and provides insight into fruit development in sweet orange.

Although revisiting the discoveries and implications of genetic variations using phased genomics is critical, such efforts are still lacking. Somatic mutations represent a crucial source of genetic diversity for breeding and are especially remarkable in heterozygous perennial and asexual crops. In this study, we focused on a diploid sweet orange (Citrus sinensis) and constructed a haplotype-resolved genome using high fidelity (HiFi) reads, which revealed 10.6% new sequences. Based on the phased genome, we elucidate significant genetic admixtures and haplotype differences. We developed a somatic detection strategy that reveals hidden somatic mutations overlooked in a single reference genome. We generated a phased somatic variation map by combining high-depth whole-genome sequencing (WGS) data from 87 sweet orange somatic varieties. Notably, we found twice as many somatic mutations relative to a single reference genome. Using these hidden somatic mutations, we separated sweet oranges into seven major clades and provide insight into unprecedented genetic mosaicism and strong positive selection. Furthermore, these phased genomics data indicate that genomic heterozygous variations contribute to allele-specific expression during fruit development. By integrating allelic expression differences and somatic mutations, we identified a somatic mutation that induces increases in fruit size. Applications of phased genomics will lead to powerful approaches for discovering genetic variations and uncovering their effects in highly heterozygous plants. Our data provide insight into the hidden somatic mutation landscape in the sweet orange genome, which will facilitate citrus breeding.

Enhancing the Fruit Yield and Quality in Pomegranate: Insights into Drip Irrigation and Mulching Strategies.

Pomegranate (Punica granatum L.) is a fruit tree that is globally distributed, especially in warm areas with low annual rainfall and limited water availability. This species exemplifies the critical role of water in agriculture and the need for efficient irrigation practices due to its characteristics, cultivation requirements, and geographic diffusion. In this study, we investigated the effects of drip irrigation and mulching on the vegetative growth, yield, and fruit quality attributes of pomegranate. The experiment involved three irrigation regimes (100% of evapotranspiration, 80%, and 60%) and three mulching treatments (no mulch, plastic mulch, and organic mulch) in a factorial combination. Both irrigation and mulching had significant positive influences on the yield and fruit quality attributes. Specifically, deficit irrigation strategies showed a negative impact on the fruit yield per tree, with a greater effect observed as the severity of the irrigation deficit increased. Mulching, on the other hand, led to a significant increase in the fruit yield, primarily attributed to an increase in fruit size. Furthermore, the analysis indicated that irrigation and mulching treatments had distinct effects on fruit traits such as the fruit length, width, volume, and rind thickness. Interestingly, the study highlighted that the effects of irrigation and mulching on fruit quality attributes were mostly independent of each other, suggesting an additive influence rather than an interaction between the two factors. These findings underscore the importance of considering irrigation and mulching practices for optimizing fruit quality in pomegranate cultivation, particularly in semi-arid regions. The results contribute valuable insights for farmers and researchers seeking to enhance fruit production and quality.