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Pericarp browning and fruit decay severely reduce the postharvest quality of litchi. Improving the antioxidant capacity of the fruit is an effective way to solve these problems. In our study, the appropriate zinc oxide nanoparticles (ZnO NPs) treatment and its mechanism of action on the storability of litchi was investigated. Litchi fruit was soaked in a 100 mg·L−1 ZnO NPs suspension, water, and 500 mg·L−1 prochloraz for 2 min, respectively. The results showed that the ZnO NPs treatment delayed pericarp browning and decay in litchi fruit and was more effective than prochloraz treatment. The ZnO NPs-treated fruit showed significantly increased contents of total anthocyanin, total phenols, and activities of DPPH scavenging, superoxide dismutase, and glutathione peroxidase, as well as the lowest activities of polyphenol oxidase and laccase. ZnO NPs generated hydrogen peroxide and superoxide anion radicals, which were beneficial in slowing down the decay and inducing antioxidant capacity. However, these reactive oxygen species also consumed catalase, peroxidase, glutathione, and glutathione peroxidase. This means that litchi should be treated with an appropriate concentration of ZnO NPs. We concluded that treatment with a 100 mg·L−1 ZnO NPs suspension could induce antioxidant capacity, which is a promising and effective method to maintain the postharvest quality of litchi. [ABSTRACT FROM AUTHOR]

Conopomorpha sinensis (Lepidoptera: Gracillariidae), commonly known as the litchi fruit borer, is a devastating pest of litchi, leading to substantial economic losses in fruit production. The present study was incepted to supplement updated information on biology, morphometrics, integrative taxonomy, and phylogenetic analysis of C. sinensis. The duration of developmental stages such as egg, larval, pre-pupal, pupal, male and female adult lasts for 3.45 ± 1.13, 11.10 ± 2.52, 2.05 ± 0.51, 5.85 ± 0.88, 5.55 ± 1.00, and 9.00 ± 1.12 days, respectively. The average fecundity was 33.10 ± 6.84 eggs/female. The head capsule width for five larval instars was 0.11 ± 0.01, 0.18 ± 0.02, 0.34 ± 0.01, 0.58 ± 0.04, and 0.64 ± 0.06 mm, respectively. Phylogenetic analysis revealed distinct species-groups formed by C. sinensis with other fruit borer species considered (C. cramerella , C. litchiella Bradley, and Thaumatotibia batrachopa (Meyrick)). Understanding the life cycle of C. sinensis and its correct identification is crucial for targeted pest control strategies. Traditional and molecular taxonomy assist in rapid and accurate species identification and understanding of the evolutionary relationships among Conopomorpha species. [ABSTRACT FROM AUTHOR]

Ethephon (2-chloroethylphosphonic acid) is frequently used for flush management in order to maximize flowering in litchi. However, the optimal dosage of ethephon, which balances between flush control effect and the detrimental effect on leaves, is unknown. This study aimed to identify the optimal ethephon dosage and test more efficient ethephon application methods, using a drone for flush control and flowering promotion in litchi. The effects of a single manual full-tree spray of 250, 500 or 1000 mg/L of ethephon in early November on the bud break rate, leaf drop rate, net photosynthetic rate, LcFT1 expression and floral induction (panicle emergence rate and panicle number) in 'Jingganghongnuo' litchi were examined in the season of 2021–2022. In the season of 2022–2023, the effects of drone application of 1000 mg/L of ethephon in early November on bud growth and floral induction were observed. The results showed that the manual ethephon treatments were effective at enforcing bud dormancy and elongating the dormancy period and that the effects were positively dependent on dosage. One manual spray of 1000 mg/L of ethephon in late autumn enabled a dormancy period of 6 weeks. The treatments advanced seasonal abscission of old leaves in winter and caused short-term suppression on photosynthesis within 2 weeks after treatment. Ethephon treatments, especially at 1000 mg/L, enhanced the expression of LcFT1 in the mature leaves and promoted floral induction reflected by earlier panicle emergence and increased panicle emergence rate and number in the terminal shoot. The floral promotion effect was also positively dosage dependent. The cumulative chilling hours below 15 °C from the date of treatment to the occurrence of a 20% panicle emergence rate were lowered in ethephon treatments. A drone spray of 1000 mg/L of ethephon solution consumed a sixth of the manual spray solution volume and was two thirds less effective in suppressing bud break compared with manual spraying. However, it achieved a significant flowering promotion effect comparable to traditional manual spraying. The results suggest that ethephon application enhanced flowering responsiveness to chilling as well as enforced bud dormancy. The application of ethephon with a drone proved to be an efficient method for flush control and flower promotion. [ABSTRACT FROM AUTHOR]

Litchi exhibits a large number of flowers, many flowering batches, and an inconsistent ratio of male and female flowers, frequently leading to a low fruit-setting rate. Floral sexual differentiation is a crucial phase in perennial trees to ensure optimal fruit production. However, the mechanism behind floral differentiation remains unclear. The objective of the study was to identify the role of auxin in floral differentiation at the transcriptional level. The results showed that the ratio of female flowers treated with naphthalene acetic acid (NAA) was significantly lower than that of the control stage (M0/F0). The levels of endogenous auxin and auxin metabolites were measured in male and female flowers at different stages of development. It was found that the levels of IAA, IAA-Glu, IAA-Asp, and IAA-Ala were significantly higher in male flowers compared to female flowers. Next-generation sequencing and modeling were employed to perform an in-depth transcriptome analysis on all flower buds in litchi 'Feizixiao' cultivars (Litchi chinensis Sonn.). Plant hormones were found to exert a significant impact on the litchi flowering process and flower proliferation. Specifically, a majority of differentially expressed genes (DEGs) related to the auxin pathway were noticeably increased during male flower bud differentiation. The current findings will enhance our comprehension of the process and control mechanism of litchi floral sexual differentiation. It also offers a theoretical foundation for implementing strategies to regulate flowering and enhance fruit production in litchi cultivation. [ABSTRACT FROM AUTHOR]

Postharvest litchi is susceptible to browning that limits the development of litchi industry. Hydrogen sulfide (H2S) is an important bioactive molecule that can regulate many physiological processes. This study examined the effects of exogenous H2S on pericarp browning and related physiological mechanisms in postharvest litchi. The results exhibited that exogenous H2S treatment delayed the browning of litchi pericarp and reduced the damage to cell membrane integrity during storage. This treatment inhibited the energy losses of litchi fruit by increasing the activities of H+-ATPase, Ca2+- ATPase, cytochrome C oxidase (CCO) and succinate dehydrogenase (SDH) and regulating the expression of energy metabolism-related genes, including LcAtpB, LcSnRK2, LcAAC1, LcAOX1 and LcUCP1. In addition, H2S treatment increased the levels of fructose, glucose, sucrose, inositol, galactose and sorbose in litchi fruit, and promoted sucrose synthesis by regulating the activities of sucrose phosphate synthase (SPS), sucrose synthase (SS), acid invertase (AI) and neutral invertase (NI). Based on the current findings, we suggest that exogenous H2S enhances the energy supply and antioxidant activity of litchi by modulating energy and sugar metabolism, thereby inhibiting fruit browning and senescence. These results indicated that H2S treatment is an effective approach to maintaining the quality of litchi fruit and extending its shelf life. [ABSTRACT FROM AUTHOR]

In the last decade, unmanned aerial vehicles (UAVs) for plant protection have rapidly developed worldwide as a new method for pesticide application, especially in China and other Asian countries. To improve the deposition quality in UAV applications, adding appropriate types of spray adjuvants into pesticide solutions is one of the most effective ways to facilitate droplet deposition and control efficacy. At present, research on spray adjuvants for UAVs are mainly based on droplet drift and laboratory tests. Few studies have been conducted on the physicochemical properties of spray adjuvants and the effects of droplet deposition characteristics. To explore the properties of four different kinds of spray adjuvants (Mai Fei, Bei Datong, G-2801, and Agrospred 910) and the deposition characteristics of spray adjuvants on litchi leaves, an automatic surface tension meter, a contact angle measuring device, an ultraviolet visible spectrophotometer, and a DJI AGRAS T30 plant protection UAV was used to measure the surface tension, contact angle, and droplet deposition characteristics on litchi under UAV spraying operations. The results showed that the addition of spray adjuvants could significantly reduce the surface tension of the solution. The surface tension value of the solution after adding the spray additives was reduced by 53.1–68.9% compared with the control solution. Among them, the Agrospred 910 spray adjuvant had the best effect on reducing the surface tension of the solution. The contact angle of the control solution on the litchi leaves varied from 80.15° to 72.76°. With the increase in time, the contact angle of the spray adjuvant solution gradually decreased, the Agrospred 910 spray adjuvant had the best effect, and the contact angle decreased from 40.44° to 20.23° after the droplets fell on the litchi leaves for 60 s. The adjuvant solutions increased the droplet size, but the uniformity of the droplet size decreased. The Dv0.5 of different spray solutions ranged from 97.3 to 117.8 μm, which belonged to the fine or very fine droplets, and the Dv0.5 of adjuvants solutions were significantly greater than that of the control solution. The RSs of adjuvant solutions were very similar and ranged from 0.92 to 0.96, all of which were significantly greater than the result of the control solution (0.57). Compared with the deposition of the control solution, the Mai Fei, Bei Datong, and G-2801 solutions clearly increased spray deposition, with total depositions of 0.776, 0.705, and 0.721 μL/cm2, which are all greater than the total deposition of the control solution of 0.645 μL/cm2. The addition of tank-mixed adjuvants could effectively increase the uniformity of the spray deposition, and all the average CVs of adjuvant solutions were lower than 96.86%. On the whole, Mai Fei performed best in increasing the spray deposition and promoting penetration, followed by Bei Datong and G-2801. Meanwhile, the test can also provide a reference for improving the utilization rate of UAV pesticide applications. [ABSTRACT FROM AUTHOR]

The accurate detection of litchi fruit cluster is the key technology of litchi picking robot. In the natural environment during the day, due to the unstable light intensity, uncertain light angle, background clutter and other factors, the identification and positioning accuracy of litchi fruit cluster is greatly affected. Therefore, we proposed a method to detect litchi fruit cluster in the night environment. The use of artificial light source and fixed angle can effectively improve the identification and positioning accuracy of litchi fruit cluster. In view of the weak light intensity and reduced image features in the nighttime environment, we proposed the YOLOv8n-CSE model. The model improves the recognition of litchi clusters in night environment. Specifically, we use YOLOv8n as the initial model, and introduce the CPA-Enhancer module with chain thinking prompt mechanism in the neck part of the model, so that the network can alleviate problems such as image feature degradation in the night environment. In addition, the VoVGSCSP design pattern in Slimneck was adopted for the neck part, which made the model more lightweight. The multi-scale linear attention mechanism and the EfficientViT module, which can be deeply divided, further improved the detection accuracy and detection rate of YOLOv8n-CSE. The experimental results show that the proposed YOLOv8n-CSE model can not only recognize litchi clusters in the night scene, but also has a significant improvement over previous models. In mAP@0.5 and F1, YOLOv8n-CSE achieved 98.86% and 95.54% respectively. Compared with the original YOLOv8n, RT-DETR-l and YOLOv10n, mAP@0.5 is increased by 4.03%, 3.46% and 3.96%, respectively. When the number of parameters is only 4.93 m, F1 scores are increased by 5.47%, 2.96% and 6.24%, respectively. YOLOv8n-CSE achieves an inference time of 36.5ms for the desired detection results. To sum up, the model can satisfy the criteria of the litchi cluster detection system for extremely accurate nighttime environment identification. [ABSTRACT FROM AUTHOR]

Indiscriminate use of mineral fertilizers has a broad negative impact on soil health. Because of the above, there is an urgent need to search for natural organic alternatives, including using soil microbial resources to replenish soil nutrients for enhanced Agri productivity vis a vis sustainably maintaining soil health. The nitrogen-fixing rhizobacteria (NFR) are such type of bacteria which fix gaseous atmospheric nitrogen in the soil and in nodules of certain plant species in considerable amounts that are readily available for plants' uptake and may be considered as a viable alternative source of mineral nitrogen application. The present study was conducted to isolate the most potent nitrogen-fixing bacteria from the litchi rhizosphere. Hence, Five NFR (NFR1 to NFR5) were isolated from the rhizosphere of litchi orchard of Bihar Agricultural University, Sabour, Bhgalpur, India, based on their ability to fix atmospheric nitrogen in a nitrogen-free mineral salt medium. NFR2 was found to be the most potent in fixing atmospheric nitrogen (11.31 mg N per gram carbon source)among all the isolated rhizobacterial strains. Hence, on the basis of biological nitrogen fixation ability, the isolate NFR2 was subjected to 16S ribosomal RNA (16S rRNA) gene sequencing for molecular characterization. Based on 16S rDNA sequence analysis, NFR2 showed the closest sequence homology with Beijerinckia fluminensis and was identified and reported as Beijerinckia fluminensis strain BAUMS11, Accession number MN533953. The study noticeably indicated that the B. fluminensis strain BAUMS11 was found most efficient in fixing gaseous atmospheric nitrogen and may be used for the manufacturing of nitrogenous biofertilizer, which can fix atmospheric nitrogen to the tune-up to 30 kg N ha-1yr-1. [ABSTRACT FROM AUTHOR]

Non‐conventional starch sources have emerged as an interest due to their inherent physicochemical properties similar to conventional starches. This study aimed to enhance the value of non‐conventional litchi seed starch by employing anoxidizing process using different concentrations of sodium hypochlorite (NaOCl)(0.5, 1.5, 2.5, 3.5, 4.5%). The carbonyl and carboxyl content of oxidized starch was in the range of (0.019 – 0.323%) and (0.044 – 0.425%) showing an increase with the increasing concentration of NaOCl. The native and oxidized starches were further characterized for their functional and structural properties. The amylose content of native starch was 21.52% which was reduced to (19.34 – 13.43%) upon oxidation. The water and oil absorption capacities increased with theoxidation level. The swelling power(g/g) and solubility (g/100g) for native starch were 16.17 and 16.20 and 9.5 and 31.40 for modified starch. The oxidized starch produced clearer pastes. Scanning electron microscopy revealed surface erosion and cavities in oxidized starch granulesat higher concentrations. The oxidized starch showed higher relative crystallinity. FTIR was further used to assess structural changes in starches. Therefore, it can be concluded that oxidation significantly altered the characteristics of litchi seed starch, expanding its potential applications in various industries. [ABSTRACT FROM AUTHOR]

To address the problem that the traditional detection method for litchi sugar content is time-consuming and laborious and will destroy the tested sample, this paper proposed a non-destructive detection method for litchi sugar content based on near-infrared spectroscopy (NIR) and artificial intelligence algorithm. Firstly, to remove noise and other interference, the preprocessing methods for spectral data are studied. Nine preprocessing methods, such as moving average smoothing (MA), standard normal variate transform (SNV), and multiplicative scatter correction (MSC), are adopted to preprocess the spectral data. Then, to reduce the input dimension of the model and overcome the interference of redundant bands, the feature extraction methods for spectral data are examined. Two feature extraction methods, including Monte-Carlo uninformative variable elimination (MCUVE) and competitive adaptive reweighted sampling (CARS), are utilized to extract the features of spectral data. Finally, partial least squares regression (PLSR) and stochastic configuration network (SCN) are adopted to establish the prediction model of litchi sugar content. The experimental results show that the SNV-CARS-SCN prediction model has the highest accuracy. The coefficient of determination ( R 2 ), RMSE, and MAE of the training dataset are 0.9996, 0.1145, and 0.1154, respectively. R 2 , RMSE, and MAE of the test dataset are 0.9740, 0.4962, and 0.3818, respectively. The NIR detection system and SCN prediction model designed in this paper are of great significance for the design of litchi automatic sorting system. [ABSTRACT FROM AUTHOR]

BACKGROUND: The litchi fruit borer Conopomorpha sinensis Bradley is a major destructive pest of litchi and longan plants in China, India and South East Asia. Given its strong olfactory‐based oviposition behaviour, interfering with the chemical communication between this insect pest and its host plant may serve as a potential control strategy. However, the chemical compounds associated with its egg‐laying behaviour remain poorly understood. RESULTS: In this study, we investigated the olfactory preference of female C. sinensis for oviposition on intact mature fruits of the Feizixiao (FZX) and Guiwei (GW) varieties. Results showed that female C. sinensis preferred to lay eggs on FZX compared with GW fruits, and this preference was olfactory‐induced. In addition, we identified differences in the chemical composition of the volatile blend and proportions between FZX and GW fruits, with terpenes being the main volatile components contributing to this divergence. Compounds that induced electrophysiological activity in female borers were subsequently screened from FZX. d‐Limonene exhibited the strongest oviposition attraction among four candidates. Furthermore, this compound served as a volatile olfactory cue for recognition and orientation in female C. sinensis. CONCLUSION: The results of this study provide a deeper understanding of the olfactory preferences of female C. sinensis for oviposition on specific litchi varieties. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study uses litchi from Conghua and Zengcheng regions in Guangzhou as insurance targets, and combines the meteorological disasters throughout the entire growth period of litchi to design litchi meteorological index insurance products and verify insurance payout rates. Based on the litchi yield data and historical meteorological data, litchi yield reduction rate models are structured. Based on the correlation between meteorological factors and yield reduction rate, key meteorological indicators that affect litchi yield are screened. Further, the distribution of litchi meteorological index is fitted, the insurance pure premium rate and the insurance amount per unit area for different meteorological index grades which trigger compensation are determined. The meteorological index is set to 2 to 4 levels; different weather index levels of the amount of compensation are determined; and the rationality of compensation rates at different time scales is verified. In this study, the time scale of litchi yield and planting area data is from 2001 to 2020, while the time scale of meteorological data is from 1959 to 2020. The results show that the precipitation index at the flowering stage of litchi in Conghua district, the low-temperature index at the heading stage, and the precipitation index at the ripening stage of litchi in Zengcheng district are the key meteorological indicators that lead to the reduction of litchi yield in the two regions mentioned above, respectively. When the cumulative precipitation in Conghua district reaches 350 mm at the flowering stage of litchi, the minimum temperature is 3.3 ℃ at the heading stage of litchi, and the cumulative daily rainfall of ≥100 mm at the ripening stage of litchi lasts 2 days in Zengcheng district, a claim is triggered. The premium amounts corresponding to different levels of three meteorological indices are between 448-2582 yuan/hm2, 522-2567 yuan/hm2, 1403-3284 yuan/hm2, respectively. The compensation ratios for different meteorological indices and levels are between 7%-10%, 7%-10%, and 10%-12%, respectively. The average payout rates of Conghua district and Zengcheng district at three times in 10, 20 and 30 years are 77.0%, 69.6% and 63.7% respectively, which is consistent with the requirement of 65%-75% of the insurance company’s claim rate. The designed insurance product of Litchi Meteorological Index can provide a reference for a new round of policy agricultural insurance in Guangzhou, and provide technical support for litchi farmers to disperse and transfer the risk of meteorological disasters.

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Mitogen-activated protein kinase (MAPK) cascades have been discovered to play a fundamental role in regulating organ abscission. However, the identity of protein substrates targeted by MAPK cascades, as well as whether the role of MAPK protein cascades in the abscission process is conserved across different plant species, remain unknown. Here, the role of homologs of MPK3 and MPK6 in regulating fruit abscission were characterized in litchi. Ectopic expression of LcMPK3 or LcMPK6 in Arabidopsis mpk3 mpk6 mutant rescued the deficiency in floral organ abscission, while silencing of LcMPK3 or LcMPK6 in litchi significantly decreased fruitlet abscission. Importantly, a total of 49 proteins interacting with LcMPK3 were identified through yeast two-hybrid screening, including two components of the MAPK signaling cascade, five transcription factors, and two aquaporins. Furthermore, the interaction between LcMPK3/6 with LcBZR1/2, core components in brassinosteroids signaling that suppress litchi fruitlet abscission, was confirmed using in vitro and in vivo assays. Moreover, phos-tag assays demonstrated that LcMPK3/6 could phosphorylate LcBZR1/2, with several phosphorylation residues identified. Together, our findings suggest that LcMPK3 and LcMPK6 play a positive regulatory role in fruitlet abscission in litchi, and offer crucial information for the investigation of mechanisms underlying MPK3/6-mediated organ abscission in plants.

Insect pollinators and flowering plants have a long‐standing, coevolutionary, mutualistic relationship. One such example is the litchi tree (Litchi chinensis Sonn.), a fruit crop that relies on insect pollination. Litchi flowers are hermaphroditic, but they cannot self‐pollinate due to self‐sterility, unlike self‐pollinating plants. Therefore, insect pollinators are crucial to successful fruit development. To understand the pollinator's foraging behaviour and diversity associated with litchi under hot and subhumid conditions, the present study was conducted on the Shahi variety of litchi at the ICAR‐Research Complex for Eastern Region, Farming System Research Centre for Hill and Plateau, Ranchi (Jharkhand), India. During the flowering period, a total of 19 species of insect pollinators from the orders Hymenoptera, Diptera, Lepidoptera, and Coleoptera were observed visiting litchi inflorescences. Apis mellifera and Apis dorsata were the most dominant pollinator species. Each species displayed distinct characteristics in terms of abundance and diversity. Varied foraging speeds (stay times) were also noted, with A. dorsata (6.94 s) being the fastest and Musca domestica (2.88 s) being the slowest. Pollinator activity was highest in the eastern direction, between 8:00 a.m. and 10:00 a.m. Apis florea had the highest foraging rate (visitation rate) (14.02 flowers visited per minute), followed by Apis mellifera, while Episyrphus taeniops​ had the lowest. Apis species were identified as the most abundant and frequent visitors in litchi orchards. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase (MAPK) cascades have been discovered to play a fundamental role in regulating organ abscission. However, the identity of protein substrates targeted by MAPK cascades, as well as whether the role of MAPK protein cascades in the abscission process is conserved across different plant species, remain unknown. Here, the role of homologs of MPK3 and MPK6 in regulating fruit abscission were characterized in litchi. Ectopic expression of LcMPK3 or LcMPK6 in Arabidopsis mpk3 mpk6 mutant rescued the deficiency in floral organ abscission, while silencing of LcMPK3 or LcMPK6 in litchi significantly decreased fruitlet abscission. Importantly, a total of 49 proteins interacting with LcMPK3 were identified through yeast two-hybrid screening, including two components of the MAPK signaling cascade, five transcription factors, and two aquaporins. Furthermore, the interaction between LcMPK3/6 with LcBZR1/2, core components in brassinosteroids signaling that suppress litchi fruitlet abscission, was confirmed using in vitro and in vivo assays. Moreover, phos-tag assays demonstrated that LcMPK3/6 could phosphorylate LcBZR1/2, with several phosphorylation residues identified. Together, our findings suggest that LcMPK3 and LcMPK6 play a positive regulatory role in fruitlet abscission in litchi, and offer crucial information for the investigation of mechanisms underlying MPK3/6-mediated organ abscission in plants. [ABSTRACT FROM AUTHOR]

Lychee pepper spot, a field disease affecting lychee fruit skin, pedicels and petioles, is caused by Colletotrichum siamense, a fungal pathogen within the gloeosporioides species complex. Members of Colletotrichum from the gloeosporioides species complex and occasionally those from the acutatum species complex also cause postharvest anthracnose of lychee. Pepper spot was first described in Australia many years after anthracnose on lychee was first described, giving rise to the hypothesis that a novel species or strain within the gloeosporioides species complex causes pepper spot. In the present study, 19 isolates of Colletotrichum spp., collected from pepper spot and anthracnose symptoms on lychee fruit, representing 13 different genotypes across five species, were inoculated onto lychee fruit in the field or on detached fruit in the laboratory, to understand more about their pathogenic diversity. We found that symptoms were specific to genotype of the pathogen, as three genetically similar isolates of C. siamense consistently caused pepper spot and anthracnose, whilst other isolates caused anthracnose only. Cross‐inoculation studies on detached fruit of lychee, banana, avocado and mango also provided some evidence of host specialization in isolates of C. siamense infecting lychee in Australia. Our experiments provided further evidence that detached fruit assays cannot be used as a reliable proxy for field inoculation studies. This research confirms that C. siamense is a causal agent of both lychee pepper spot and lychee anthracnose in Australia, and Colletotrichum alienum and Colletotrichum queenslandicum are reported as causal agents of anthracnose of lychee for the first time. [ABSTRACT FROM AUTHOR]

Litchi downy blight (LDB) caused by Peronophythora litchii destroys 20–30% of litchi fruit every year and causes significant economic losses. Some Exiguobacterium strains exhibit considerable promise in both agricultural and industrial sectors. E. acetylicum SI17, isolated from the litchi fruit carposphere, demonstrated significant biocontrol activity against LDB through pre-harvest treatment. To elucidate its underlying regulatory mechanisms, the genome of SI17 was sequenced and analyzed, revealing a circular chromosome spanning 3,157,929 bp and containing 3541 protein-coding genes and 101 RNA genes. Notably, 94 genes were implicated in the production of secondary metabolites. Among the 29 Exiguobacterium strains so far sequenced, SI17 possessed the largest genome. In the phylogenomic analysis encompassing the entire genome, SI17 was clustered into Group I. Treating litchi fruit with SI17 before harvesting resulted in a decrease in H2O2 content in the fruit peel and an increase in superoxide dismutase activity, thus enhancing resistance to LDB. Interestingly, SI17 did not display plate antagonism against Peronophythora litchii SC18. It can be inferred that SI17 generates secondary metabolites, which enhance litchi's resistance to LDB. This study represents the first documentation of an Exiguobacterium strain exhibiting a role in litchi plant disease and showcasing significant potential for the biological control of LDB. [ABSTRACT FROM AUTHOR]

Phytoseiid mites have been frequently found in association with the lychee erinose mite, Aceria litchii, on lychee plants in Brazil, suggesting that they are promising candidates as biological control agents against this pest. Here, we investigated whether phytoseiids would suppress A. litchii infestation, i.e. formation of erinea, on lychee plants under field conditions. Four groups of A. litchii-infested plants were randomly distributed in the field, with each group receiving either Phytoseius intermedius, Amblyseius herbicolus, A. herbicolus supplemented with cattail pollen or no predator. During a three-month period, the released predators, along with others present in the surrounding environment, were allowed to freely walk among all plants. In each plant, we evaluated the occurrence of phytoseiid species, their abundance, and the dynamics of erinea formation. A total of 2,097 mites, including 13 other phytoseiid species were identified. The most abundant species were Iphiseiodes zuluagai and Euseius ho, rather than the two predator species that were released. A. herbicolus and P. intermedius failed to establish populations in the majority of the plants, regardless of the presence of pollen, suggesting their ineffectiveness in controlling A. litchii infestations. While there was a significant difference in the proportion of erinea among the four treatments, this contrast was not associated with the presence of phytoseiids, suggesting that other factors might have hindered erinea formation on lychee plants. The reasons behind this outcome are further explored and discussed. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Many species of Sapindaceae, such as lychee, longan, and rambutan, provide nutritious and delicious fruit. Understanding the molecular genetic mechanisms that underlie the regulation of flowering is essential for securing flower and fruit productivity. Most endogenous and exogenous flowering cues are integrated into the florigen encoded by FLOWERING LOCUS T. However, the regulatory mechanisms of flowering remain poorly understood in Sapindaceae. Here, we identified 60 phosphatidylethanolamine-binding protein-coding genes from six Sapindaceae plants. Gene duplication events led to the emergence of two or more paralogs of the FT gene that have evolved antagonistic functions in Sapindaceae. Among them, the FT1-like genes are functionally conserved and promote flowering, while the FT2-like genes likely serve as repressors that delay flowering. Importantly, we show here that the natural variation at nucleotide position − 1437 of the lychee FT1 promoter determined the binding affinity of the SVP protein (LcSVP9), which was a negative regulator of flowering, resulting in the differential expression of LcFT1, which in turn affected flowering time in lychee. This finding provides a potential molecular marker for breeding lychee. Taken together, our results reveal some crucial aspects of FT gene family genetics that underlie the regulation of flowering in Sapindaceae. [ABSTRACT FROM AUTHOR]

An analytical method was established for the simultaneous determination of 29 pesticides in litchi by a high-performance liquid chromatography-tandem quadrupole-time of flight-mass spectrometry (HPLC-Q-TOF/MS) technique combined with an optimized QuEChERS procedure. The samples were extracted by acetonitrile and the acetonitrile supernatant was collected for purification after salting-out (magnesium sulfate anhydrous and sodium chloride) and centrifugation.Under the optimized chromatographic and mass spectrometric conditions, the data were collected by electrospray ionization (ESI) sources in positive and negative ion modes. The calibration curves of 29 pesticides showed good linearity in a concentration range of 0.001-0.2 mg/L (R²>0.99). The average recoveries were 70.2%-102.4% at three spiked levels (0.01, 0.1, 0.50 mg/kg), while the relative standard deviations (RSD) were 2.4%-6.2%. The limits of detection and limits of quantification ranged from 0.1 μg/kg to 3 μg/kg and 0.3 μg/kg to 10 μg/kg, respectively. This method was a simple and efficient method with high sensitivity and precision and had practical value for the rapid detection of residues of 29 pesticides in litchi. [ABSTRACT FROM AUTHOR]

In the post-harvest phase, fruit is inexorably subjected to extrinsic stressors that expedite energy expenditure and truncate the storage lifespan. The present study endeavors to elucidate the response strategies of litchi to the alterations of energy state caused by 2,4-Dinitrophenol (DNP) treatment through energy metabolism and sugar metabolism. It was observed that the DNP treatment reduced the energy state of the fruit, exacerbated membrane damage and triggered rapid browning in the pericarp after 24 h of storage. Furthermore, the expression of genes germane to energy metabolism (LcAtpB, LcAOX1, LcUCP1, LcAAC1, and, LcSnRK2) reached their peak within the initial 24 h of storage, accompanied by an elevation in the respiratory rate, which effectively suppressed the rise in browning index of litchi pericarp. The study also posits that, to cope with the decrease of energy levels and membrane damage, litchi may augment the concentrations of fructose, glucose, inositol, galactose, and sorbose, thus safeguarding the canonical metabolic functions of the fruit. Collectively, these findings suggest that litchi can modulate energy and sugar metabolism to cope with fruit senescence under conditions of energy deficiency. This study significantly advances the understanding of the physiological responses exhibited by litchi fruit to post-harvest external stressors. [ABSTRACT FROM AUTHOR]

Lychee, a key economic crop in southern China, has numerous similar-looking varieties. Classifying these can aid farmers in understanding each variety's growth and market demand, enhancing agricultural efficiency. However, existing classification techniques are subjective, complex, and costly. This paper proposes a lychee classification method using an improved ResNet-34 residual network for six common varieties. We enhance the CBAM attention mechanism by replacing the large receptive field in the SAM module with a smaller one. Attention mechanisms are added at key network stages, focusing on crucial image information. Transfer learning is employed to apply ImageNet-trained model weights to this task. Test set evaluations demonstrate that our improved ResNet-34 network surpasses the original, achieving a recognition accuracy of 95.8442%, a 5.58 percentage point improvement. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop and characterize reduced-fat ice cream formulations with the addition of dehydrated cassava bagasse (CB) and lychee pulp (LP). The ice cream formulations were prepared with different proportions of palm fat (0 to 5%), CB (0 to 5%) and LP (1 to 8%) and were evaluated in terms of chemical and microbiological composition, and in relation to the technological, antioxidant and sensory properties. The use of higher levels of CB (5%) and LP (8%) allowed obtaining a higher fiber content and lower fat content. All formulations were safe for consumption and showed adequate values for overrun, melting rate and color. The ice creams showed adequate sensory acceptance, with emphasis on the formulations containing different amounts of CB addition (2 to 5%) and until 3% LP. The higher LP content the higher total phenolic content and the antioxidant capacity were found in ice cream formulations. These results showed the viability of applying CB and LP in ice cream formulations, especially in the proportion of 5% and 1%, promoting the sustainability by using a natural source of antioxidants and a fiber-rich agro-industrial by-product. [ABSTRACT FROM AUTHOR]

The 'Feizixiao' litchi cultivar, predominantly grown in Hainan Province, faces the issue of "sugar receding" during fruit ripening. The application of mixed foliar nutrients containing calcium and magnesium (Ca+Mg) during the fruit pericarp's full coloring stage was investigated to overcome this issue. Experimental trials unveiled significant alterations in litchi pulp physiochemical properties, including the main nutrient and flavor quality, the total respiration rates of the main respiratory pathways, and the activities of some important enzymes associated with Embden–Meyerhof–Parnas (EMP), the tricarboxylic acid cycle (TCA) and the pentose phosphate pathway (PPP). The Ca+Mg treatment showed higher sugar levels than the control (CK) during ripening. Notably, the application of Ca+Mg in litchi pulp inhibited respiration rates through the EMP, TCA, and PPP pathways, resulting in a strong effect. RNA sequencing analysis revealed the impact of Ca+Mg treatment on respiratory pathways, revealing differentially expressed genes (DEGs) such as pyruvate PK1, PK2 (pyruvate kinase), and PDC (pyruvate dehydrogenase complex), validated through qRT-PCR with a significant correlation to RNA-seq results. In general, Ca+Mg treatment during litchi fruit ripening overcame "sugar receding" by inhibiting the expression of respiration key metabolic pathway genes. These findings provide insights for enhancing cultivation management strategies. [ABSTRACT FROM AUTHOR]

Litchi (Litchi chinensis Sonn.) fruit, with its bright red color and sweet and juicy aril, is an important fruit crop in Asia, Africa, Australia, and South America. A major cause of the postharvest loss of litchi fruit is browning and decay. Chlorophyll breakdown and flavonoid synthesis occur simultaneously during the maturation of this nonclimacteric fruit. However, once litchi fruit is harvested, pericarp desiccation and membrane breakdown occur, which leads to browning with the rate of browning and later microcracking paralleling water loss rate. In addition, chilling injury can contribute to and increase pericarp browning and membrane leakage. Polyphenol oxidase and peroxidase are possibly key enzymes in the early stages of browning. An increase in the leakage of the pericarp membrane also occurs that correlates with browning. Many chemical treatments have been evaluated to retard pericarp browning, such as melatonin, hot water, acidified calcium sulfate (ACS), adenosine triphosphate, and tea seed oil. During long distance transportation, chemical treatments that involve sulfur are used, including SO2 fumigation, acid dip after SO2 fumigation, SO2 fumigation and sulfur sheet package, or SO2 fumigation followed by controlled atmosphere (CA), if approved by the importing country. Other treatments that avoid the use of SO2 include melatonin, ACS, and hot water brushing combined with an acid dip, CA, and modified atmosphere packaging. Anthracnose is a common disease that accelerates browning and decay. Penicillium species as a saprophyte is also common with fruit infection occurring in the field, during harvest, in the packhouse, cold rooms, and shipping containers. Sulfur sheet or CA is used to reduce fruit rot after SO2 fumigation and Sportak (prochloraz) for the control of penicillium. However, a replacement for postharvest SO2 use is still urgently needed. Core Ideas: Litchi (Litchi chinensis Sonn.) in the Sapindaceae is a tropical fruit that is highly prized worldwide.The edible juicy aril is surrounded by a thin leathery pericarp.Major causes of postharvest loss are pericarp browning and decay.The cause and control of pericarp browning is a major focus of research. [ABSTRACT FROM AUTHOR]

medium supplemented with exogenous putrescine(Put), spermidine(Spd), and spermine(Spm). The results were as follows:(1)Exogenous Put, Spd and Spm treatments significantly increased the EC proliferation rate and reduced the amount of induced somatic embryos and number of germinations. The proliferated EC cells after exogenous PA treatments were more consistent in size and stained deeply and evenly. Furthermore, multicellular proembryos in EC were reduced, and fully differentiated early cotyledon embryos could be seen. (2)All the exogenous PA treatments significantly increased the endogenous PA content in EC. Among them, Put treatment had the highest content of each endogenous PA component and total PA. When the EC proliferated on the medium containing exogenous PAs was transferred to the medium without exogenous PAs(recovery culture)for proliferating, the Put content in the EC was still significantly higher than the control, however, the endogenous Spd and Spm were significantly decreased. (3)Exogenous Put treatment significantly increased the activities of ornithine decarboxylase(ODC), arginine decarboxylase(ADC), and diamine oxidase(DAO)in EC, while exogenous Spd and Spm treatments significantly reduced the activities of ODC and ADC in EC, and exogenous Spd significantly increased the polyamine oxidase(PAO)activity. When transferred to the recovery culture medium, the ADC and DAO activities of newly proliferated EC were significantly lower than those of EC cultured with exogenous PAs, but there was no significant difference in ODC and PAO activities. In summary, the exogenous PAs can affect endogenous PAs content by regulating the activities of enzymes related to PAs metabolism, thereby affecting EC proliferation and somatic embryo induction in litchi. These results provide a basis for further study on the mechanism of PAs regulating embryogenesis, and improve litchi regeneration efficiency in vitro. [ABSTRACT FROM AUTHOR]

During the ripening of litchi (Litchi chinensis Sonn.) fruit, anthocyanin biosynthesis is crucial in providing vibrant coloring. Previous studies on anthocyanin-related transcription factors have made significant discoveries relating to plants. However, the role of the SQUAMOSA promoter-binding protein-like (SPL) transcription factors in anthocyanin biosynthesis has rarely been studied in litchi. SPL genes are widely involved in the developmental mechanisms of plants. In this study, a total of 17 SPL genes have been identified from the litchi genome. Phylogenetic analysis revealed that these genes were divided into eight groups (Group I-VIII). Analysis of gene structure conserved domains, conserved motifs, and miR156 target prediction showed that LcSPLs were highly conserved during evolution. RNA-seq analysis of litchi revealed that six LcSPL genes have a role in regulating anthocyanin biosynthesis. Further, weighted correlation network analysis (WGCNA) revealed LcSPL7's role in anthocyanin synthesis and chlorophyll degradation in litchi fruit ripening. These findings collectively suggest that the LcSPL gene family plays an essential role in anthocyanin biosynthesis in litchi pericarp. In summary, comprehensive bioinformatics analysis of the SPL family expands our understanding of anthocyanin synthesis in litchi pericarp. [ABSTRACT FROM AUTHOR]

Obtaining consistent multi-view images of litchis is crucial for various litchi-related studies, such as data augmentation and 3D reconstruction. This paper proposes a two-stage model that integrates the Mask2Former semantic segmentation network with the Wonder3D multi-view generation network. This integration aims to accurately segment and extract litchis from complex backgrounds and generate consistent multi-view images of previously unseen litchis. In the first stage, the Mask2Former model is utilized to predict litchi masks, enabling the extraction of litchis from complex backgrounds. To further enhance the accuracy of litchi branch extraction, we propose a novel method that combines the predicted masks with morphological operations and the HSV color space. This approach ensures accurate extraction of litchi branches even when the semantic segmentation model's prediction accuracy is not high. In the second stage, the segmented and extracted litchi images are passed as input into the Wonder3D network to generate multi-view of the litchis. After comparing different semantic segmentation and multi-view synthesis networks, the Mask2Former and Wonder3D networks demonstrated the best performance. The Mask2Former network achieved a mean Intersection over Union (mIoU) of 79.79% and a mean pixel accuracy (mPA) of 85.82%. The Wonder3D network achieved a peak signal-to-noise ratio (PSNR) of 18.89 dB, a structural similarity index (SSIM) of 0.8199, and a learned perceptual image patch similarity (LPIPS) of 0.114. Combining the Mask2Former model with the Wonder3D network resulted in an increase in PSNR and SSIM scores by 0.21 dB and 0.0121, respectively, and a decrease in LPIPS by 0.064 compared to using the Wonder3D model alone. Therefore, the proposed two-stage model effectively achieves automatic extraction and multi-view generation of litchis with high accuracy. [ABSTRACT FROM AUTHOR]

Oxidative damage leading to loss of nutritional quality and pericarp discoloration of harvested litchi fruits drastically limits consumer acceptance and marketability. In the present investigation, the impact of postharvest melatonin application at different concentrations, i.e., 0.1 mM, 0.25 mM, and 0.5 mM, on fruit quality and shelf life of litchi fruits under cold storage conditions was studied. The results revealed the positive effect of melatonin application at all concentrations on fruit quality and shelf life. However, treatment with 0.5 mM concentration of melatonin resulted in minimum weight loss, decay loss, pericarp discoloration, and also retained higher levels of TSS, acidity, total sugar, ascorbic acid, anthocyanin, antioxidant, and phenolics content during cold storage. Melatonin administration also restricted the enzymatic activity of the polyphenol oxidase (PPO) and peroxidase (POD) enzymes in the fruit pericarp and maintained freshness of the fruits up to 30 days in cold storage. At the molecular level, a similar reduction in the expression of browning-associated genes, LcPPO, LcPOD, and Laccase, was detected in preserved litchi fruits treated with melatonin. Anthocyanin biosynthetic genes, LcUFGT and LcDFR, on the other hand showed enhanced expression in melatonin treated fruits compared to untreated fruits. Melatonin, owing to its antioxidant properties, when applied to harvested litchi fruits retained taste, nutritional quality and red color pericarp up till 30 days in cold storage. [ABSTRACT FROM AUTHOR]

Summary: Plant cell death is regulated in plant–pathogen interactions. While some aspartic proteases (APs) participate in regulating programmed cell death or defense responses, the defense functions of most APs remain largely unknown.Here, we report on a virulence factor, PlPeL8, which is a pectate lyase found in the hemibiotrophic pathogen Peronophythora litchii. Through in vivo and in vitro assays, we confirmed the interaction between PlPeL8 and LcAP1 from litchi, and identified LcAP1 as a positive regulator of plant immunity.PlPeL8 induced cell death associated with NbSOBIR1 and NbMEK2. The 11 conserved residues of PlPeL8 were essential for inducing cell death and enhancing plant susceptibility. Twenty‐three LcAPs suppressed cell death induced by PlPeL8 in Nicotiana benthamiana depending on their interaction with PlPeL8. The N‐terminus of LcAP1 was required for inhibiting PlPeL8‐triggered cell death and susceptibility. Furthermore, PlPeL8 led to higher susceptibility in NbAPs‐silenced N. benthamiana than the GUS‐control.Our results indicate the crucial roles of LcAP1 and its homologs in enhancing plant resistance via suppression of cell death triggered by PlPeL8, and LcAP1 represents a promising target for engineering disease resistance. Our study provides new insights into the role of plant cell death in the arms race between plants and hemibiotrophic pathogens. [ABSTRACT FROM AUTHOR]

The lychee tree (Litchi chinensis Sonn.) still needs adequate nutritional management and fertilization recommendations in Brazil. An adequate supply of nutrients for the lychee tree is the main requirement contributing to higher-quality fruit production. This work aimed to evaluate nutrient leaf contents in the phenological stages of the "Bengal" lychee tree. The experiment was conducted with the "Bengal" cultivar in the period corresponding to the years 2019–2022 at the São Manuel Experimental Farm of the Faculty of Agricultural Sciences (FCA), Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP). The investigation collected leaf samples the plant's four phenological stages. It evaluated the contents of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese, and zinc. The design was completely randomized, conducted in split plots (4 × 3), stage × cycle, with 10 repetitions. The plots represented phenological stages: full flowering (FF), fruit maturity (FM), 40 days after harvest (PC), and vegetative phase (VP). The subplots represented the evaluation cycles: cycle 1 (2019/2020 harvest), cycle 2 (2020/2021 harvest), and cycle 3 (2021/2022 harvest). There were climatic differences between the three evaluation cycles (years); the most significant water deficit was in 2020. There was a difference in nutrient content between production cycles and lychee tree phenological stages. The average contents in the leaves, at the different sampling times, followed the macronutrient order N > K>Mg > Ca > P>S, and Mn > Fe > B>Zn > Cu for the micronutrients. [ABSTRACT FROM AUTHOR]

Class III peroxidases (CIII PRXs) are plant-specific enzymes with high activity that play key roles in the catalysis of oxidation-reduction reactions. In plants, CIII PRXs can reduce hydrogen peroxide to catalyze oxidation–reduction reactions, thereby affecting plant growth, development, and stress responses. To date, no systematic analysis of the CIII PRX gene family in litchi (Litchi chinensis Sonn.) has been documented, although the genome has been reported. In this study, a total of 77 CIII PRX (designated LcPRX) gene family members were predicted in the litchi genome to provide a reference for candidate genes in the responses to abiotic stresses during litchi growth and development. All of these LcPRX genes had different numbers of highly conserved PRX domains and were unevenly distributed across fifteen chromosomes. They were further clustered into eight clades using a phylogenetic tree, and almost every clade had its own unique gene structure and motif distribution. Collinearity analysis confirmed that there were eleven pairs of duplicate genes among the LcPRX members, and segmental duplication (SD) was the main driving force behind the LcPRX gene expansion. Tissue-specific expression profiles indicated that the expression levels of all the LcPRX family members in different tissues of the litchi tree were significantly divergent. After different abiotic stress treatments, quantitative real-time PCR (qRT-PCR) analysis revealed that the LcPRX genes responded to various stresses and displayed differential expression patterns. Physicochemical properties, transmembrane domains, subcellular localization, secondary structures, and cis-acting elements were also analyzed. These findings provide insights into the characteristics of the LcPRX gene family and give valuable information for further elucidating its molecular function and then enhancing abiotic stress tolerance in litchi through molecular breeding. [ABSTRACT FROM AUTHOR]

At the physiological level, the interplay between auxin and ethylene has long been recognized as crucial for the regulation of organ abscission in plants. However, the underlying molecular mechanisms remain unknown. Here, we identified transcription factors involved in indoleacetic acid (IAA) and ethylene (ET) signaling that directly regulate the expression of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) and its receptor HAESA (HAE), which are key components initiating abscission. Specifically, litchi IDA‐like 1 (LcIDL1) interacts with the receptor HAESA‐like 2 (LcHSL2). Through in vitro and in vivo experiments, we determined that the auxin response factor LcARF5 directly binds and activates both LcIDL1 and LcHSL2. Furthermore, we found that the ETHYLENE INSENSITIVE 3‐like transcription factor LcEIL3 directly binds and activates LcIDL1. The expression of IDA and HSL2 homologs was enhanced in LcARF5 and LcEIL3 transgenic Arabidopsis plants, but reduced in ein3 eil1 mutants. Consistently, the expressions of LcIDL1 and LcHSL2 were significantly decreased in LcARF5‐ and LcEIL3‐silenced fruitlet abscission zones (FAZ), which correlated with a lower rate of fruitlet abscission. Depletion of auxin led to an increase in 1‐aminocyclopropane‐1‐carboxylic acid (the precursor of ethylene) levels in the litchi FAZ, followed by abscission activation. Throughout this process, LcARF5 and LcEIL3 were induced in the FAZ. Collectively, our findings suggest that the molecular interactions between litchi AUXIN RESPONSE FACTOR 5 (LcARF5)–LcIDL1/LcHSL2 and LcEIL3–LcIDL1 signaling modules play a role in regulating fruitlet abscission in litchi and provide a long‐sought mechanistic explanation for how the interplay between auxin and ethylene is translated into the molecular events that initiate abscission. [ABSTRACT FROM AUTHOR]

Summary: Longidorus sanlitanensis n. sp. was recovered from the rhizosphere of Melilotoides ruthenica and Chamaerhodos erecta in the Inner Mongolia Autonomous Region, P.R. China, and was described and illustrated using morphological and molecular data. The new species is characterised by medium body length of females (4.0-4.8 mm), lip region anteriorly rounded and separated from the rest of the body by a depression, pocket-shaped amphidial pouches, the guiding ring located at 58.4-66.0 μ m from the anterior end, odontostyle and odontophore 107.2-114.6 and 71.6-77.8 μ m long, respectively, the pharyngeal bulb 68.7-79.7 μ m long, a short conical tail with a broadly rounded terminus, four juvenile developmental stages (J1 was not detected) and males absent. By similarities in the distance of the guiding ring from the anterior body end, body and odontostyle length and lip region shape, the new species was compared with nine similar species, namely: L. litchi , L. diadecturus , L. fursti , L. himalayensis , L. jonesi , L. wiesae , L. macromucronatus , L. fangi and L. zhengi. The matrix code of the new species is: A4-B2-C5-D4-E1-F2-G2-H12-I2-J1-K?. The phylogenetic relationships of the new species with other relevant species were reconstructed using near-full-length 18S, ITS1 and 28S D2-D3 regions of rRNA gene and the resulted topologies were discussed. In 18S phylogeny, L. sanlitanensis n. sp. formed a clade with L. litchi inside a major clade, including species with a posteriorly located guiding ring, and in 28S phylogeny it showed close relationships with species having a posteriorly located guiding ring. This is the 22nd Longidorus species recorded from China. [ABSTRACT FROM AUTHOR]

Anthocyanidin reductase (ANR) is a key enzyme regulating anthocyanin synthesis and accumulation in plants. Here, lychee ANR genes were globally identified, their sequence and phylogenetic characteristics were analyzed, and their spatiotemporal expression patterns were characterized. A total of 51 ANR family members were identified in the lychee genome. The length of the encoded amino acid residues ranged from 87 aa to 289 aa, the molecular weight ranged from 9.49 KD to 32.40 KD, and the isoelectric point (pI) ranged from 4.83 to 9.33. Most of the members were acidic proteins. Most members of the LcANR family were located in the cytoplasm. The 51 LcANR family members were unevenly distributed in 11 chromosomes, and their exons and motif conserved structures were significantly different from each other. Promoters in over 90% of LcANR members contained anaerobically induced response elements, and 88% contained photoresponsive elements. Most LcANR family members had low expression in nine lychee tissues and organs (root, young leaf, bud, female flower, male flower, pericarp, pulp, seed, and calli), and some members showed tissue-specific expression patterns. The expression of one gene, LITCHI029356.m1, decreased with the increase of anthocyanin accumulation in 'Feizixiao' and 'Ziniangxi' pericarp, which was negatively correlated with pericarp coloring. The identified LcANR gene was heterologously expressed in tobacco K326, and the function of the LcANR gene was verified. This study provides a basis for the further study of LcANR function, particularly the role in lychee pericarp coloration. [ABSTRACT FROM AUTHOR]

Litchi chinensis (lychee) is one of the most important tropical fruit crops in Asia. Despite the annual increase in research on lychee fungal pathogens, few studies have been conducted on saprobic lychee litter fungi, which may also be sources of pathogens. We collected samples from Guangdong Province, China during our biodiversity survey on leaf litter fungi. The collected species were isolated and identified using morphological characteristics and phylogenetic analyses of combined internal transcribed spacer nrDNA (ITS), large subunit nrDNA (LSU), small subunit nrDNA (SSU), and translation elongation factor 1-alpha (tef1-α). Based on morphological and molecular data, we herein introduce a new genus, Pseudoneohendersonia, belonging to Neohendersoniaceae with the type species P. guangdongensis sp. nov. Additionally, we identified three new host records associated with L. chinensis viz. Crassiparies quadrisporus, Rhytidhysteron neorufulum, and Rhytidhysteron tectonae. We provide full descriptions, illustrations, and multigene phylogenetic trees for the novel genus and new records. This study expands the understanding of lychee associated saprobic fungal diversity. [ABSTRACT FROM AUTHOR]

The MeanShift algorithm is a nonparametric method based on gradient ascent and it can effectively handle complex variations in lychee orchard scenes as well as changes in lychee tree canopies due to its adaptability, multi-scale analysis capabilities, and robustness, making it widely used in the segmentation processing of drone-based remote sensing images of lychee orchards. However, due to the high computational complexity of the MeanShift algorithm, its performance in processing large-scale drone remote sensing images of lychee tree canopies is not highly efficient, leading to low segmentation efficiency, which hampers its broader application. To address these issues, this study proposes high-speed MeanShift parallel segmentation algorithms for drone remote sensing images of lychee tree canopies based on MapReduce and Spark distributed computing frameworks. In this study, a cluster consisting of four nodes with Hadoop and Spark was set up, and 4000 drone remote sensing images were used as test data to evaluate the algorithm. Experimental results show that, the MeanShift algorithm based on MapReduce reduced the task execution time by 86.1% compared to the traditional MeanShift algorithm, while the MeanShift algorithm based on Spark reduced the task execution time by 88.0%, without compromising segmentation accuracy. The MeanShift parallel segmentation algorithm based on Hadoop and Spark platform can overcome the bottleneck of task execution efficiency and significantly enhance computational speed on a single machine. [ABSTRACT FROM AUTHOR]

BACKGROUND: The wettability of target crop surfaces affects pesticide wetting and deposition. The structure and properties of the leaf surface of litchi leaves undergo severe changes after infestation by Aceria litchii (Keifer). The objective of this study was to systematically investigate the surface texture and wettability of litchi leaves infested. RESULTS: Firstly, the investigation focused on the surface structure and physicochemical properties of litchi leaves infested with Aceria litchii. Subsequently, different levels of Contact Angle (CA) were measured individually on the infested litchi leaves. Lastly, Surface Free Energy (SFE) and its polar and dispersive components were calculated using the Owens‐Wendt‐Rabel‐Kaelble (OWRK) method. The outcomes revealed distinctive 3D surface structures of the erineum at various stages of mycorrhizal growth. At stage NO. 1, the height of the fungus displayed a peaked appearance, with the skewness value indicating a surface characterized by more crests. In contrast, at stages NO. 2 and NO. 3, the surface appeared relatively flat. Furthermore, post‐infestation of litchi leaves, the CA of droplets on the abaxial surface of diseased leaves exhibited an increase, while the SFE value on the abaxial surface of leaves decreased significantly, in contrast to the abaxial surface of healthy leaves. CONCLUSION: The infestation behavior of Aceria litchii changed the surface structure and chemistry of litchi leaves, which directly affected the CA value of foliar liquids and the SFE value of leaves, changing the surface wettability of litchi leaves from hydrophobic to superhydrophobic. This study provides useful information for improving the wetting and deposition behavior of liquid droplets on the surface of infested leaves. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In order to evaluate the dietary risk of imazalil and prochloraz residues in whole fruit, peel and pulp of litchi, this study reported a gas chromatography-tandem mass spectrometry (GC-MS/MS) to determine the residue of imazalil, prochloraz and their metabolites simultaneously. The limit of detection and limit of quantitation of this method were 2.0 and 6.0 µg/kg for imazalil, 3.0 and 10.0 µg/kg for prochloraz, 6.0 and 20.0 µg/kg for imidazole ethanol, as well as 0.3 and 1.0 µg/kg for 2,4,6-trichlorophenol, respectively. The average recoveries in whole fruit, peel and pulp of litchi were 78.9%~107%. The relative standard deviation (RSD) ranges from 2.6% to 5.8%. The results of preservation showed that the higher the concentration of imazalil and prochloraz the higher the residual amount. The residue gradually migrated from peel to pulp with the increases in storage time. After freshness processing, the residues of imazalil and prochloraz in whole fruit and peel decreased, while the pulp increased to the maximum value on the 7th day, and then gradually decreased. Imidazole ethanol and 2,4,6-trichlorophenol increased with the increase of storage time. The risk of chronic and acute dietary intake within 14 days of safe interval was within acceptable range.

Litchi is prone to deterioration in quality after harvest due to degradation of anthocyanins and respiratory metabolism, and chlorine dioxide (ClO2) has multiple effects on color protection and respiratory inhibition. In this study, 0.1 g (T1), 0.4 g (T2), and 1.2 g (T3) of ClO2 slow-releasing preservatives were used to treat lychees with 0 g (CK) as the control to evaluate the preservation effect by quality index, color index and anthocyanin, and correlation analysis was applied to explore the association between them. The results showed that the litchi of the T1 showed the optimal qualities. On the 7 th day, the total soluble solids and a* values of litchi in the T1 were significantly (P

Litchi and longan pests significantly affect crop yield and quality. Chemical prevention and control are very effective for production; therefore, it is crucial to study fate assessment and appropriate field efficacy before pesticide application on crops to appropriately assess the health and ecological risks linked with these agents. This study conducted Good Agricultural Practice (GAP) field trials and laboratory experiments to elucidate the dissipation, terminal residues, and efficacy of methoxyfenozide on litchi and longan in six locations throughout China. To detect methoxyfenozide residues on litchi and longan, a QuEChERS/UPLC-MS/MS-based method was designed. The initial methoxyfenozide levels in litchi and longan ranged from 2.21–2.86 to 0.83–0.95 mg kg−1 and indicated half-lives of 5.1–5.3 and 5.3–5.7 days, respectively. After 7 days of foliage treatment, the concentrations of terminal methoxyfenozide residue were 0.78–2.61 and 0.02–1.01 mg kg−1, which were less than the established maximum residue limit for methoxyfenozide in litchi and longan. The chronic (acceptable daily intake = 0.0055–0.0331%) dietary intake risk analysis for methoxyfenozide in longan and litchi indicated acceptable concentrations of terminal residue for the general population. Methoxyfenozide in litchi and longan was readily degraded in first-order kinetics models, the degradation rate on longan was higher than that on litchi, and their dietary risks were negligible to consumers. Two hundred forty grams per liter of methoxyfenozide suspension concentrate (SC) represents a highly efficacious insecticidal dose to control litchi and longan pests and indicates a significant application potential as it is rapidly degraded and linked with reduced post-treatment residue levels. [ABSTRACT FROM AUTHOR]

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Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)