Green Fruit Stage Research Articles

Green Fruit‐Stem Pairing and Clustering for Machine Vision System in Robotic Thinning of Apples

ABSTRACTApples are one of the most highly‐valued specialty crops in the United States. Recent labor shortages have made crop production difficult for fruit growers, including the task of green fruit thinning. Current methods including hand, chemical, and mechanical thinning impose tradeoffs between selectivity, cost, tree damage, and speed. A robotic green fruit thinning system could potentially selectively thin fruit in a quick, cost‐effective, and non‐damaging manner. The machine vision system would be a critical component for robotic thinning, and would not only need to perform green fruit detection/segmentation, but also fruit‐stem pairing and clustering to facilitate proper decision‐making for thinning. A neural network‐based fruit and stem pairing algorithm was devised and evaluated; an LSTM‐based clustering algorithm was devised and compared to the density‐based clustering algorithm, OPTICS. The algorithms were evaluated on an image data set consisting of GoldRush, Fuji, and Golden Delicious cultivars at the green fruit stage, with evaluations on overall performance, cultivar‐wise performance, cluster size‐specific performance, and feature importance. For fruit and stem pairing, the neural network‐based pairing algorithm achieved an AP of 81.4% on all fruits and stems, and that reached 90.6% when only fruits and stems with labeled angles were considered. For green fruit clustering, the LSTM‐based clustering achieved a clustering success rate of 68.4%, whereas the OPTICS algorithm obtained 50.9%. The algorithms will be further implemented in a pipeline of a future green fruit thinning vision system, as well as integrate the use of point clouds and other 3D orchard information to improve pairing and clustering performance.

Mapping and cloning of pepper fruit color-related genes based on BSA-seq technology.

Fruit color is an important qualitative trait that greatly influences the marketability of peppers. Fruit color can be divided into two categories. Green fruit color denotes commercial maturity, whereas ripe fruit indicates physiological maturity. Herein, segregation populations were created using the 'D24' with pale green in the green fruit stage, orange in the mature fruit stage, and 'D47' with green in the green fruit stage and red in the mature fruit stage. BSA-seq and genetic linkage map analysis revealed green fruit color was linked to (gyqtl1.1) on Chr1 and (gyqtl10.1) on Chr10, while mature fruit color was linked to Chr6. Using functional annotation, sequence, and expression analysis, we speculate that an SNP mutation in the CapGLK2 gene at the gyqtl10.1 interval could initiate premature termination of translation, thus yielding green to pale green fruits in D47. Conversely, the orange color in mature D24 fruits is due to the Indel-mediated premature termination of translation of the CapCCS gene. Our research offers a theoretical foundation for choosing different varieties of pepper fruit based on their color.

Study on the Changes in the Microbial Community in Rhizosphere Soil of Blueberry Plants at Different Growth Stages

In order to clarify the relationship between mineral nutrients and rhizosphere microorganisms at different growth and development stages of blueberry (Vaccinium spp.), this work studied the dynamic changes in element content and microbial quantity in different parts of blueberry plants. The test material was a 12-year-old half-highbush blueberry variety (‘Beilu’). The changes in the mineral nutrient elements in leaves, branches and the soil of blueberry plants were studied at the full bloom stage (T1), green fruit stage (T2), mature stage (T3) and late mature stage (T4), and the correlations of the average contents of mineral elements in the four periods were studied. The bacterial community in the rhizosphere soil was determined and analyzed using 16S rRNA high-throughput sequencing technology. The results showed that the changes in other mineral elements in various parts of blueberry plants varied in different periods. Nitrogen (N) showed a downward trend in branches, leaves and soil, especially in leaves (p < 0.05). The N contents in T2, T3 and T4 decreased by 9.9%, 26.4% and 29.9%, respectively. The N contents in the leaves and branches showed a downward trend at different growth stages, especially in leaves. The phosphorus (P) content in leaves showed a trend of increasing first and then decreasing, while it continued to increase in branches. The content of potassium (K) in leaves changed significantly, where it increased first and then decreased. The content of calcium (Ca) in leaves decreased first and then increased, while the content of magnesium (Mg) in branches and leaves decreased first and then increased, and the relative change was significant. The contents of iron (Fe) and zinc (Zn) in leaves decreased first and then increased, while the contents of manganese (Mn) and copper (Cu) were relatively stable. Cu decreased first and then increased in leaves and soil, and it increased first and then decreased in branches. The mineral nutrients in different growth stages of blueberry showed significant correlation in leaves, branches and soil. Mn in leaves was significantly positively correlated with P, Ca, Mg, Mn, Cu and Zn in soil (p < 0.01). Nitrogen and calcium in leaves were significantly correlated with manganese and phosphorus in soil, respectively. Ca in branches was significantly positively correlated with N and K in soil and was significantly positively correlated with Zn in soil (p < 0.01). Magnesium was significantly negatively correlated with iron in soil. The bacterial community structure of the blueberry rhizosphere soil changed significantly over time (p < 0.05), and the relative abundance showed the following trend: T4 > T2 > T3 > T1. At the phylum level, Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi and Verrucomicrobia were the dominant bacteria in different periods. Candidatus solibacter and Bryobacter were significantly higher in T1 and T3 than in T1 and T4. Bradyrhizobium flora increased significantly at T3. Sphingomonas increased significantly at T1 (p < 0.05).

Role of Rubus chingii BBX gene family in anthocyanin accumulation during fruit ripening.

The B-box (BBX) family, which is a class of zinc finger transcription factors, exhibits special roles in plant growth and development as well as in plants' ability to cope with various stresses. Even though Rubus chingii is an important traditional medicinally edible plant in east Asia, there are no comprehensive studies of BBX members in R. chingii. In this study, 32 RcBBX members were identified, and these were divided into five groups. A collinearity analysis showed that gene duplication events were common, and when combined with a motif analysis of the RcBBX genes, it was concluded that group V genes might have undergone deletion of gene fragments or mutations. Analysis of cis-acting elements revealed that each RcBBX gene contained hormone-, light-, and stress-related elements. Expression patterns of the 32 RcBBX genes during fruit ripening revealed that highest expression occurred at the small green fruit stage. Of note, the expression of several RcBBX genes increased rapidly as fruit developed. These findings, combined with the expression profiles of anthocyanin biosynthetic genes during fruit ripening, allowed us to identify the nuclear-targeted RcBBX26, which positively promoted anthocyanin production in R. chingii. The collective findings of this study shed light on the function of RcBBX genes in different tissues, developmental stages, and in response to two abiotic stresses.

Dynamic Changes of Phytohormone Concentrations during <i>Prunella vulgaris</i> L. Development and Impact of Rosmarinic Acid Accumulation through Exogenous ABA Application

Background: Plant hormones not only participate in regulating the growth and development process of plants, but also play an important regulatory role in the synthesis of secondary metabolites. Prunella vulgaris L. (P. vulgaris) is a perennial herb that has a long history for use as a kind of medicinal and edible plant. In order to understand the relationship between plant hormones and Prunella vulgaris L. (P. vulgaris) development. Methods: The quantification of indoleacetic acid (IAA), salicylic acid (SA), jasmonates (JAs), abscisic acid (ABA), 1-aminocyclopropane-1-carboxylic acid (ACC) and cytokinins (CKs) of P. vulgaris during development was performed by a liquid chromatography-mass spectrometry (LC-MS). Furthermore, the effect of exogenous ABA on rosmarinic acid (RA) accumulation was verified. Results: Nuts formation was related to the concentrations of IAA, ABA and ACC in the green-fruit stage, and IAA and ABA levels increased rapidly in this stage. High IAA concentrations can promote an increase in ACC. SA, JAs, ethylene (ET) and ABA were related to the defence response of plants to pathogens. SA concentrations increased sharply after the turning stage, while the concentration of JAs, which are antagonistic to SA, was low. The decrease in ABA concentration after this period may be related to the antagonistic effect of IAA or SA. The CKs trans-zeatin (tZ) and trans-zeatin riboside (tZR) promoted the growth and development of early P. vulgaris, and their concentrations decreased in the late period, leading to withering and senescence of P. vulgaris. The CKs cis-zeatin (cZ) and N6-(2-isopentenyl) adenine (iP) were presumed to be present in nuts. After elicitation with 10 μg/mL ABA, an increase of RA content was observed (p < 0.05). Conclusion: This study can provide an improved basis for elucidating the growth and development mechanism of P. vulgaris in the future, as well as a better understand of the effects of ABA application on RA accumulations.

Characterization of N-methyltransferase Genes in Coffea liberica var. liberica

Caffeine biosynthesis in Coffea evolved independently through tandem gene duplication and subsequent neofunctionalization of ancestral N-methyltransferases (NMTs). The bulk of our understanding of this process in Coffea is centered on two species: C. arabica and C. canephora. To gain a wider perspective of caffeine biosynthesis in Coffea, this study focused on the less popular but commercially available C. liberica var. liberica, locally known as “kapeng barako.” This study aimed to determine the genomic and coding sequences of the three NMTs – mainly, xanthosine methyltransferase (XMT), 7-methylxanthine-N-methyltransferase (MXMT), and dimethylxanthine methyltransferase (DXMT) – through Sanger sequencing. Relative expression levels of these NMTs in the leaves, flower bud, green fruit, and red fruit stages were also determined through polymerase chain reaction amplification of synthesized cDNA and then gel electrophoresis. Results reveal that the genetic sequences of NMTs of C. liberica were similar to the C. eugenioides-derived NMTs of C. arabica. Results also indicate that there is a possibility that more than one NMT gene for each NMT cluster (XMT, MXMT, DXMT) exists. This study has also identified genomic sequences and transcripts, whose sequences were in between the XMT and MXMT gene clusters. The function of these novel sequences is yet to be determined. NMT expression levels in C. liberica were similar to those observed in C. arabica and C. canephora, wherein expression peaks at the green fruit stage and then diminishes, as the fruit ripens fully. Although the NMTs of C. liberica have a lot of similarities with C. arabica and C. canephora, discovering the function and role in caffeine biosynthesis of these novel genomic sequences and transcripts will help us further understand the evolution of caffeine biosynthesis in Coffea.

Genome-wide identification of grape ANS gene family and expression analysis at different fruit coloration stages

BackgroundAnthocyanin synthase (ANS) is the enzyme downstream of the anthocyanins synthesis pathway and the rate-limiting enzyme of the synthesis pathway. It catalyzes the conversion of colorless anthocyanins to anthocyanins and plays an important role in plant color presentation and stress resistance. However, ANS gene is rarely studied in grapes.ResultsIn this study, 121 VvANS genes were identified and distributed on 18 chromosomes, VvANS family members were divided into 8 subgroups. Secondary structure prediction showed mainly irregular coils and α-helices, and subcellular localization indicated that VvANS gene family is mainly located in chloroplast, cytoplasm and nucleus. The promoter region of the VvANS gene family contains multiple cis-acting elements that are associated with light, abiotic stress, and hormones. Intraspecific collinearity analysis showed that there were 13 pairs of collinearity between VvANS genes. Interspecific collinearity analysis showed that there was more collinearity between grape, apple and Arabidopsis, but less collinearity between grape and rice. Microarray data analysis showed that VvANS17, VvANS23 and VvANS75 had higher expression levels in flesh and peel, while VvANS25, VvANS64 and VvANS106 had higher expression levels in flower. The results of qRT-PCR analysis showed that VvANS genes were expressed throughout the whole process of fruit coloring, such as VvANS47 and VvANS55 in the green fruit stage, VvANS3, VvANS64 and VvANS90 in the initial fruit color turning stage. The expression levels of VvANS21, VvANS79 and VvANS108 were higher at 50% coloring stage, indicating that these genes play an important role in the fruit coloring process. VvANS4, VvANS66 and VvANS113 had the highest expression levels in the full maturity stage.ConclusionsThese results indicated that different members of VvANS gene family played a role in different coloring stages, and this study laid a foundation for further research on the function of ANS gene family.

Ellagic Acid from Hull Blackberries: Extraction, Purification, and Potential Anticancer Activity.

Ellagic acid (EA) is present at relatively high concentrations in many berries and has many beneficial health effects, including anticancer properties. To improve the development and utilization of blackberry fruit nutrients, we divided Hull blackberry fruits into five growth periods according to color and determined the EA content in the fruits in each period. The EA content in the green fruit stage was the highest at 5.67 mg/g FW. Single-factor tests and response surface methodology were used to optimize the extraction process, while macroporous resin adsorption and alkali dissolution, acid precipitation, and solvent recrystallization were used for purification. The highest purity of the final EA powder was 90%. The anticancer assessment results determined by MTT assay showed that EA inhibited HeLa cells with an IC50 of 35 μg/mL, and the apoptosis rate of the cells increased in a dose-dependent manner, with the highest rate of about 67%. We evaluated the changes in the mRNA levels of genes related to the EA-mediated inhibition of cancer cell growth and initially verified the PI3K/PTEN/AKT/mTOR pathway as the pathway by which EA inhibits HeLa cell growth. We hope to provide a theoretical basis for the deep exploration and utilization of this functional food.

Genome-Wide Identification and Expression Analysis of ANS Family in Strawberry Fruits at Different Coloring Stages.

To elucidate the structural characteristics, phylogeny and biological function of anthocyanin synthase (ANS) and its role in anthocyanin synthesis, members of the strawberry ANS gene family were obtained by whole genome retrieval, and their bioinformatic analysis and expression analysis at different developmental stages of fruit were performed. The results showed that the strawberry ANS family consisted of 141 members distributed on 7 chromosomes and could be divided into 4 subfamilies. Secondary structure prediction showed that the members of this family were mainly composed of random curls and α-helices, and were mainly located in chloroplasts, cytoplasm, nuclei and cytoskeletons. The promoter region of the FvANS gene family contains light-responsive elements, abiotic stress responsive elements and hormone responsive elements, etc. Intraspecific collinearity analysis revealed 10 pairs of FvANS genes, and interspecific collinearity analysis revealed more relationships between strawberries and apples, grapes and Arabidopsis, but fewer between strawberries and rice. Chip data analysis showed that FvANS15, FvANS41, FvANS47, FvANS48, FvANS49, FvANS67, FvANS114 and FvANS132 were higher in seed coat tissues and endosperm. FvANS16, FvANS85, FvANS90 and FvANS102 were higher in internal and fleshy tissues. Quantitative real-time PCR (qRT-PCR) showed that the ANS gene was expressed throughout the fruit coloring process. The expression levels of most genes were highest in the 50% coloring stage (S3), such as FvANS16, FvANS19, FvANS31, FvANS43, FvANS73, FvANS78 and FvANS91. The expression levels of FvANS52 were the highest in the green fruit stage (S1), and FvANS39 and FvANS109 were the highest in the 20% coloring stage (S2). These results indicate that different members of the FvANS gene family play a role in different pigmentation stages, with most genes playing a role in the expression level of the rapid accumulation of fruit coloring. This study lays a foundation for further study on the function of ANS gene family.

Effects of Endogenous Melatonin Deficiency on the Growth, Productivity, and Fruit Quality Properties of Tomato Plants

Caffeic acid O-methyltransferase 1 (COMT1) is a key enzyme that is involved in melatonin synthesis, affecting the melatonin content in plants. In this experiment, tomato plants (slcomt1) with silenced SlCOMT1 gene expression were used to investigate the effects of SlCOMT1 deficiency on fruit growth, development, and quality formation. The results show that the slcomt1 plants exhibited prolonged fruit development, with reductions in the relative expression levels of SlCOMT1 by 71.1%, 79.7%, 83.9%, and 90.6% during the green fruit, breaker, orange ripening, and red ripening stages, respectively. The endogenous melatonin content also decreased by 29.4%, 43%, 45%, and 61.4% in the corresponding stages. Furthermore, the slcomt1 plants showed a decrease in the individual fruit weight, seed number per fruit, and fruit set rate by approximately 51.1%, 48.2%, and 30.4%, respectively. The slcomt1 plants exhibited an increase in the titratable acid content by 32.1%, 22.1%, 10.3%, and 24.4% during the green fruit, breaker, orange ripening, and red ripening stages, while the sugar-to-acid ratio decreased by 44.9%, 32.6%, 22.7%, and 36.8%. The slcomt1 plants also displayed increased fruit firmness, along with reductions in the relative expression levels of the cell wall and carotenoid-related genes and carotenoid content. Specifically, the Vc content in the slcomt1 plants decreased by 80.7% during the green fruit stage, and by 11.5%, 17.1%, and 2.6% during the breaker, orange ripening, and red ripening stages, respectively. The soluble protein content exhibited a decreasing trend in the corresponding stages. This study highlights the important role of endogenous melatonin in fruit physiology and quality formation, providing insights for further research and application of melatonin in agriculture.

Comparative analysis of differentially expressed genes for biosynthesis of active ingredients in fruits of different cultivars of Lycium barbarum L. based on transcriptome sequencing

To explore the differentially expressed genes (DEGs) related to biosynthesis of active ingredients in wolfberry fruits of different varieties of Lycium barbarum L. and reveal the molecular mechanism of the differences of active ingredients, we utilized Illumina NovaSeq 6000 high-throughput sequencing technology to conduct transcriptome sequencing on the fruits of 'Ningqi No.1' and 'Ningqi No.7' during the green fruit stage, color turning stage and maturity stage. Subsequently, we compared the profiles of related gene expression in the fruits of the two varieties at different development stages. The results showed that a total of 811 818 178 clean reads were obtained, resulting in 121.76 Gb of valid data. There were 2 827, 2 552 and 2 311 DEGs obtained during the green fruit stage, color turning stage and maturity stage of 'Ningqi No. 1' and 'Ningqi No. 7', respectively, among which 2 153, 2 050 and 1 825 genes were annotated in six databases, including gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG) and clusters of orthologous groups of proteins (KOG). In GO database, 1 307, 865 and 624 DEGs of green fruit stage, color turning stage and maturity stage were found to be enriched in biological processes, cell components and molecular functions, respectively. In the KEGG database, the DEGs at three developmental stages were mainly concentrated in metabolic pathways, biosynthesis of secondary metabolites and plant-pathogen interaction. In KOG database, 1 775, 1 751 and 1 541 DEGs were annotated at three developmental stages, respectively. Searching the annotated genes against the PubMed database revealed 18, 26 and 24 DEGs related to the synthesis of active ingredients were mined at the green fruit stage, color turning stage and maturity stage, respectively. These genes are involved in carotenoid, flavonoid, terpenoid, alkaloid, vitamin metabolic pathways, etc. Seven DEGs were verified by RT-qPCR, which showed consistent results with transcriptome sequencing. This study provides preliminary evidences for the differences in the content of active ingredients in different Lycium barbarum L. varieties from the transcriptional level. These evidences may facilitate further exploring the key genes for active ingredients biosynthesis in Lycium barbarum L. and analyzing their expression regulation mechanism.

Colletotrichum infections during flower development and fruit ripening in four olive cultivars

Olive anthracnose, caused by Colletotrichum, is an important disease in olive-growing regions, with the most destructive symptoms being fruit rot and blossom blight. Susceptibility of fruit to Colletotrichum increases with maturity, but differences between cultivars and Colletotrichum species have been reported, still information on flower susceptibility during development is scarce. The susceptibility of the olive cultivars Arbequina, Coratina, Frantoio and Picual was evaluated during flower development and fruit maturity to Colletotrichum acutatum s.s., C. nymphaeae, C. fioriniae, C. theobromicola and C. alienum. Susceptibility to anthracnose begins in early stages during flower development and increases during blossoming. Flowers of Arbequina, Coratina and Picual were susceptible, whereas those of Frantoio were moderately susceptible. Green fruit developed less anthracnose than mature fruit. At the green fruit stage, Arbequina and Frantoio were the most susceptible, Coratina was intermediate, and Picual was moderately susceptible, while no differences were found among the cultivars at mature fruit stages. No mayor differences were found among the Colletotrichum species with exception of C. theobromicola, which caused greatest severity at the green fruit stage. Future research should focus on developing anthracnose management strategies to minimize the disease progress from early stages of flower development and fruit ripening, especially in the most susceptible olive cultivars.

Gene actions of resistance to anthracnose (Colletotrichum acutatum) of six F1 hybrid chili cultivars at the mature green fruit stage

Gene actions of resistance to anthracnose (<i>Colletotrichum acutatum</i>) of six F₁ hybrid chili cultivars at the mature green fruit stage

Genome-Wide Identification of the SQUAMOSA Promoter-Binding Protein-like (SPL) Transcription Factor Family in Sweet Cherry Fruit.

Plant-specific SQUAMOSA promoter-binding protein-like (SPL) transcription factors play important regulatory roles during plant growth and development, fruit ripening, inflorescence branching, and biotic and abiotic stresses. However, there have been no identification or systematic studies of the SPL gene family in the sweet cherry. In this study, 12 SPL genes were identified in the sweet cherry reference genome, which were distributed over 6 chromosomes and classified into six groups according to phylogenetic relationships with other SPL gene families. Nine PavSPLs were highly expressed at green fruit stages and dramatically decreased at the onset of fruit ripening, which implied that they were important regulators during fruit development and ripening. The expression patterns of PavSPL genes under ABA, GA, and MeJA treatments showed that the PavSPLs were involved in the process of fruit ripening. A subcellular localization experiment proved that PavSPL4 and PavSPL7 proteins were localized in the nucleus. The genome-wide identification of the SPL gene family provided new insights while establishing an important foundation for sweet cherry studies.

Citrus green fruit detection via improved feature network extraction.

It is crucial to accurately determine the green fruit stage of citrus and formulate detailed fruit conservation and flower thinning plans to increase the yield of citrus. However, the color of citrus green fruits is similar to the background, which results in poor segmentation accuracy. At present, when deep learning and other technologies are applied in agriculture for crop yield estimation and picking tasks, the accuracy of recognition reaches 88%, and the area enclosed by the PR curve and the coordinate axis reaches 0.95, which basically meets the application requirements.To solve these problems, this study proposes a citrus green fruit detection method that is based on improved Mask-RCNN (Mask-Region Convolutional Neural Network) feature network extraction. First, the backbone networks are able to integrate low, medium and high level features and then perform end-to-end classification. They have excellent feature extraction capability for image classification tasks. Deep and shallow feature fusion is used to fuse the ResNet(Residual network) in the Mask-RCNN network. This strategy involves assembling multiple identical backbones using composite connections between adjacent backbones to form a more powerful backbone. This is helpful for increasing the amount of feature information that is extracted at each stage in the backbone network. Second, in neural networks, the feature map contains the feature information of the image, and the number of channels is positively related to the number of feature maps. The more channels, the more convolutional layers are needed, and the more computation is required, so a combined connection block is introduced to reduce the number of channels and improve the model accuracy. To test the method, a visual image dataset of citrus green fruits is collected and established through multisource channels such as handheld camera shooting and cloud platform acquisition. The performance of the improved citrus green fruit detection technology is compared with those of other detection methods on our dataset. The results show that compared with Mask-RCNN model, the average detection accuracy of the improved Mask-RCNN model is 95.36%, increased by 1.42%, and the area surrounded by precision-recall curve and coordinate axis is 0.9673, increased by 0.3%. This research is meaningful for reducing the effect of the image background on the detection accuracy and can provide a constructive reference for the intelligent production of citrus.

Transcriptome and hormones analysis provide insights into elongated fruit somaclonal mutant in ‘Akihime’ strawberry

Fruit shape is an important agronomic trait. However, the regulatory mechanism of strawberry fruit shape remains largely unknown. In this study, we firstly compared cultivated strawberry ‘Akihime’ with its elongated fruit somaclonal mutant (finger strawberry). The plant height, crown diameter, leaf length and some photosynthetic indexes were no significant changes between ‘Akihime’ and finger strawberry, while the fruit shape of them had obvious differences. Histological observation showed that fruit shape changes mainly resulted from the change of cell area, especially cell length, at small green fruit stage of ‘Akihime’ and finger strawberry. Next, the endogenous hormone contents of small green fruit of ‘Akihime’ and finger strawberry were investigated by HPLC-MS/MS. We found that the auxin content in the finger strawberry dramatically increased compared with ‘Akihime’, while the content of gibberellin and brassinosteroids had no significant difference between ‘Akihime’ and finger strawberry. Finally, small green fruits of ‘Akihime’ and finger strawberry were used for identifying key genes responsible for the elongated fruit phenotype through RNA-seq. A total of 674 differentially expressed genes (DEGs) were identified, including 248 up-regulated genes and 426 down-regulated genes. GO and KEGG enrichment analysis showed the DEGs were mainly enriched in DNA replication, cell cycle, plant hormone synthesis and signal transduction. Interestingly, auxin-related genes such as FaIAA33, FaSAUR76, FaSAUR34, FaARF and some transcription factors such as FaMYBs, FabHLHs, FaNACs were differentially expressed in ‘Akihime’ and finger strawberry, which may play a crucial role in the formation of elongated fruit mutant phenotype. These results will provide some insights into the regulatory mechanism of strawberry fruit shape and are helpful for appearance quality improvement of strawberry.

Integrated omics analysis identified genes and their splice variants involved in fruit development and metabolites production in Capsicum species.

To date, several transcriptomic studies during fruit development have been reported; however, no comprehensive integrated study on expression diversity, alternative splicing, and metabolomic profiling was reported in Capsicum. This study analyzed RNA-seq data and untargeted metabolomic profiling from early green (EG), mature green (MG), and breaker (Br) fruit stages from two Capsicum species, i.e., C. annuum (Cann) and C. frutescens (Cfrut) from Northeast India. A total of 117,416 and 96,802 alternatively spliced events (AltSpli-events) were identified from Cann and Cfrut, respectively. Among AltSpli-events, intron retention (IR; 32.2% Cann and 25.75% Cfrut) followed by alternative acceptor (AA; 15.4% Cann and 18.9% Cfrut) were the most abundant in Capsicum. Around 7600 genes expressed in at least one fruit stage of Cann and Cfrut were AltSpli. The study identified spliced variants of genes including transcription factors (TFs) potentially involved in fruit development/ripening (Aux/IAA 16-like, ETR, SGR1, ARF, CaGLK2, ETR, CaAGL1, MADS-RIN, FUL1, SEPALLATA1), carotenoid (PDS, CA1, CCD4, NCED3, xanthoxin dehydrogenase, CaERF82, CabHLH100, CaMYB3R-1, SGR1, CaWRKY28, CaWRKY48, CaWRKY54), and capsaicinoids or flavonoid biosynthesis (CaMYB48, CaWRKY51), which were significantly differentially spliced (DS) between consecutive Capsicum fruit stages. Also, this study observed that differentially expressed isoforms (DEiso) from 38 genes with differentially spliced events (DSE) were significantly enriched in various metabolic pathways such as starch and sucrose metabolism, amino acid metabolism, cysteine cutin suberin and wax biosynthesis, and carotenoid biosynthesis. Furthermore, the metabolomic profiling revealed that metabolites from aforementioned pathways such as carbohydrates (mainly sugars such as D-fructose, D-galactose, maltose, and sucrose), organic acids (carboxylic acids), and peptide groups significantly altered during fruit development. Taken together, our findings could help in alternative splicing-based targeted studies of candidate genes involved in fruit development and ripening in Capsicum crop.

Composition and Antioxidant Activity of Anthocyanins and Non-Anthocyanin Flavonoids in Blackberry from Different Growth Stages

The high nutritional value and unique flavor of blackberries make them a popular food choice among consumers. Anthocyanin content (AC) and non-anthocyanin flavonoid content (NAFC) are important functional components in blackberry. We tested the AC, NAFC, and antioxidant activities of two blackberry—Ningzhi 1 and Hull—during the following ripening stages: green-fruit stage (GFS), color-turning stage (CTS), reddening stage (RDS), and ripening stage (RPS). The results showed that NAFC decreased and AC increased gradually during the ripening stages. The NAFC of Hull blackberry was the highest during GFS (889.74 μg/g), while the AC of Ningzhi 1 blackberry was the highest during RPS (1027.08 μg/g). NAFC was the highest at the initial stage and gradually decreased with ripening. Anthocyanin accumulation mainly occurred during the later ripening stages. These results provide a reference for comparing the NAFC, AC, and antioxidant activity of Ningzhi 1 and Hull and their changes during different ripening stages.

Biometria do fruto e qualidade fisiológica da palmeira Veitchia merrilli (Becc) H. E. Moore de acordo com o estágio de maturação do fruto

ABSTRACT Veitchia merrilli (Becc) H. E. Moore is a palm tree widely used in gardening. Due to the continuous production of flowers on the inflorescences, there are fruits and seeds in various stages of maturation on the same plant, making it hard to determine the best fruit maturation stage for obtaining vigorous seeds. This study measured the biometric characteristics of the fruit at different stages of maturation and identified the best fruit maturation stage from which to obtain seeds with optimal physiological quality. Mature fruits were harvested from the tops of 10 trees and the ground, categorized according to their maturation stage and measured for overall length, equatorial diameter, and fresh weight. An experiment to identify the best fruit maturation stage for obtaining seeds of the V. merrilli with satisfactory physiological quality was carried out in a greenhouse, with five treatments (maturation stage) and ten replications; each plot was composed of 20 seeds. Plant height, root length, stem diameter, root and above ground dry weight, total dry weight, and Dickson’s quality index were measured. The green fruit stage is the most suitable for obtaining seeds of V. merrilli with the best physiological qualities. The fruits at the dark red maturity stage had the greatest length, while the those in the green transition stage had the greatest diameter and fresh weight.

Acai palm base temperatures and thermal time requirements in eastern Amazon

Abstract The objective of this work was to deter mine the base temperatures, thermal time requirements, and length of the main reproductive growth stages of acai palm (Euterpe oleracea) in the northeast of the state of Pará, in eastern Amazon, Brazil. The experiment was carried out from 2017 to 2019 in a 10 ha acai plantation, using the time-series analysis. Plant phenology was monitored weekly, and local weather conditions were monitored daily. The lower and upper base temperatures were of 12.92 and 32.46°C, respectively, for pre-flowering; 13.50 and 32.23°C for flowering; 12.14 and 32.55°C for green fruit stage; 11.64 and 32.78°C for fruit color-changing stage; and 11.23 and 32.94°C for maturation. The thermal time requirement and the average cycle length for the ideal harvest time of acai palm were 3,893.15 degree-days and 283 days, respectively. The thermal time requirement and the duration of the reproductive growth stage for acai palm are influenced by the period of the year and the variability of air temperature, which, when high, reduces the cycle of the crop, and when mild, increases it.