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1.
Environ Sci Pollut Res Int ; 31(17): 24852-24867, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38460034

RESUMO

Two applications of spirotetramat were done to study the dissipation and persistence of spirotetramat and its four different metabolites in chilli and soil at 10 days interval. Total spirotetramat residues were estimated by LC-MS/MS instrument. The mean initial deposits of total spirotetramat after application of spirotetramat 15.31 OD @ 60 (X dose), 75 (1.25 × dose) and 120 (2 × dose) g a.i. ha-1 on green chilli were found to vary from 0.38 to 0.83 mg kg-1 during the initial year. Spirotetramat and its metabolite residues in green chilli were found to be below limit of quantification (0.01 mg kg-1) after 15 days of application. The spirotetramat cis enol (the major metabolite) was formed in both the soil and the plant. The residues of spirotetramat-monohydroxy were below LOQ irrespective of any substrate during the estimation. In soil, the total initial spirotetramat deposits for the 1st year were found 0.09 for X dose, 0.12 for 1.25 × dose and 0.20 mg kg-1 for 2 × dose. After 3 days for both X and 1.25 × doses and 5 days for 2 × dose, the total spirotetramat residues were below LOQ. The spirotetramat's half-life values have been determined to be between 3.19 and 3.93 days and 1.00 and 1.59 days, respectively, in soil and green chilli fruits. One day waiting period is proposed for the safe consumption of green chilli when the spirotetramat was applied irrespective of the dose.


Assuntos
Compostos Aza , Inseticidas , Resíduos de Praguicidas , Poluentes do Solo , Compostos de Espiro , Inseticidas/análise , Cromatografia Líquida , 60705 , Solo/química , Espectrometria de Massas em Tandem , Poluentes do Solo/análise , Resíduos de Praguicidas/análise , Meia-Vida
2.
Food Chem ; 444: 138528, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38310775

RESUMO

The addition of Sudan dyes with carcinogenic effects to food threatens human health. Herein, a ratiometric fluorescence strip consisting of core-shell upconversion particles (NaYF4:Yb,Tm@NaYF4:Yb,Er), metal-organic frameworks and dual-template molecularly imprinted polymers was developed to selectively and sensitively detect four Sudan dyes based on inner filter effect (detection time only takes 8 min). The high adsorption capacity of metal-organic frameworks and the greater overlap between the emission of NaYF4:Yb,Tm@NaYF4:Yb,Er and the absorbance of four Sudan dyes enable the signal responses to be more sensitive. The limits of detection in chilli powder samples are as low as 29.87 ng/g, 37.55 ng/g, 47.89 ng/g and 51.02 ng/g, with satisfactory recovery (93.32-103.4%) and minor relative standard deviations (≤4.3%). This method broadens the idea for low-cost and portable detection of multiple illegal additives in complex substrates with high selectivity and sensitivity based on one kind of fluorescent strip.


Assuntos
Estruturas Metalorgânicas , Impressão Molecular , Humanos , Corantes , Fluorescência , Alimentos
3.
Heliyon ; 10(1): e23476, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38169832

RESUMO

Chillies are considered a universal ingredient for imparting flavor and pungency to foods. Pakistan stood in the top twenty countries worldwide by producing 82 thousand Tons of chillies during 2022-23. Chilli fungal contamination and aflatoxin production during drying is a common problem during post-harvest process. Gasses treatment and Ionizing radiations are efficient methods for reducing toxigenic and pathogenic microbial growth in food items. The current study was designed to compare the effects of ethylene oxide (ETO), gamma (GB) & electron beam (EB) treatments on two red chilli local cultivars (Kunri and Hybrid) of Pakistan. After treatment, the chilli samples were analyzed for aflatoxins, physicochemical, quality & safety attributes. All results were subjected to Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), dendrogram and ANOVA to check the correlations, grouping and level of significance within the varieties and treatments. The results showed that moisture and water activity mainly designated PC-2 directions and are slightly positively correlated. Conversely, both fat and proteins have a negative correlation with moisture, ash and water activity. Besides, carotenoids and ABTS assay mainly designated PC-2 directions and are slightly positively correlated. Color, flavonoids and TPC also possess positive correlations among them. ETO depicts effectiveness in the reduction of E. coli but is not effective in saving antioxidant potential such as total flavonoids. Similarly, gamma irradiations showed strong reduction trends in fungal and pathogenic count, however same trend was observed in ascorbic acid too. Besides, the electron beam with dosage levels of 12 and 15 kGy has shown effectiveness against Aspergillus spp., aflatoxins and pathogenic microbial load in addition to saving antioxidant potential (phenolics and flavonoids), physicochemical parameters and color values compared to other applied methods especially in Kunri variety. It was evident from the research that varietal combination in addition to applied treatment must be specially considered while designing a treatment for chillies.

4.
J Econ Entomol ; 117(2): 585-594, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38227632

RESUMO

Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is an invasive, early-season pest of strawberry in Florida, causing feeding injury to young foliage that results in stunted plant growth and yield loss. Spinetoram, an effective insecticide for thrips pests with up to 3 applications per season permitted in strawberry, is often applied repeatedly during the early-season (Oct-Nov) to manage S. dorsalis, leaving few or no applications for flower thrips pests later in the season (Dec-Mar). Therefore, new strategies are needed to manage S. dorsalis with less insecticide, with the hypothesis that the first insecticide application can be delayed because young strawberry plants can compensate for minor feeding injury without compromising strawberry yield. Experiments conducted in strawberry field plots in Balm, FL, during 2018 and 2019 showed that delaying a spinetoram application for 14 days after infesting a plant with zero, 5, 10, or 20 S. dorsalis adults did not reduce the plant vigor and yield compared to spinetoram application after 4 days. Furthermore, young plants recovered from injury (10-30% bronzing injury on leaf veins and petioles) due to 1 or 2 S. dorsalis adults or larvae per trifoliate. A strategy of delaying the first spinetoram application when plants have 4-5 trifoliates should help reduce the number of insecticide applications needed for S. dorsalis management and reserve spinetoram applications for later in the season. Lower input costs in Florida strawberry without compromising yields due to thrips damage will improve the economics and sustainability of production systems.


Assuntos
Fragaria , Inseticidas , Macrolídeos , Tisanópteros , Animais , Florida
5.
J Food Sci Technol ; 61(2): 201-219, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38196718

RESUMO

Chilli has dominated and retained an important place amongst the spices worldwide. They are dried ripe fruits intuitively consumed as a spice, condiment, culinary, and medicinal purposes. The global consumption pattern is intriguing because of the inherent pungency, aroma, taste, spicy flavour, and therapeutic properties. Predominantly, the colour and pungency decide the quality features and are actively responsible for organized marketing and trade of the dried chillies. India is one of the leading producers and exporters of chilli. The chemical composition of the chillies varies substantially with agro-climatic zones and post-harvest management strategies. The quantum of post-harvest loss of 25-35% hampers the farmer's income and affects the wholesale/retail marketing. This review paper is intended to provide a deep insight into the advancements in various post-harvest unit operations of dried red chillies. A detailed overview of post-harvest operations (drying, grading, destalking, packaging, storage) and processing techniques for value-added products (chilli powder, dried flakes, seeds, oleoresin) is discussed in this paper. The presented information will help the researchers and the industry personnel engaged in the post-harvest processing and value addition of dried red chillies.

6.
Food Res Int ; 177: 113902, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38225144

RESUMO

A microtiter plate (MTP) method was developed to screen 1064 unique microorganisms-substrate fermentations for production of 68 target aroma compounds. Based on the number of hits identified by GC-MS, 50 fermentations were repeated at 50-mL scale in flasks. Comparison of GC-MS data showed that scaling up from MTP to flask did not generally result in large differences between the volatile profiles, even with a wide variety of substrates (juice, food slurry and food side-streams) and microorganisms (yeast, bacteria and fungi) used. From the screening results, Lactobacillus plantarum fermentation of chilli pepper was further studied as a high amount of phenols, especially guaiacol and 4-ethylphenol, was produced after fermentation. From HPLC-MS and sensory analysis, capsaicin was shown to be a probable precursor for these phenols and a potential mechanism was proposed. The protocol described herein to screen aroma compounds from fermentation of agri-food products and side streams can support development of clean label flavourful food ingredients.


Assuntos
Ensaios de Triagem em Larga Escala , Odorantes , Fermentação , Ensaios de Triagem em Larga Escala/métodos , Fenóis , Saccharomyces cerevisiae
7.
Food Res Int ; 173(Pt 1): 113263, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37803576

RESUMO

A multiclass analysis approach was developed using magnetic multiwalled carbon nanotubes sorbents and ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) for the rapid screening and simultaneous determination of 216 contaminants including 15 mycotoxins, 9 synthetic colourants, and 192 pesticides in chilli powder. The sample preparation process was optimized. The optimal preparation procedure utilized NaCl and NaAc as the salting-out agents, and Fe3O4-MWCNTs as the sorbents, resulting in reduced chemical consumption, improved cleaning performance, and facilitated high-throughput analysis. The proposed method was validated, and satisfactory parameters were obtained. Approximately 85.6% of the target analytes exhibited a weak matrix effect, with the matrix effects falling within the range of 0.8 âˆ¼ 1.2. The method demonstrated acceptable recoveries of the analytes, falling within the range of 62.14%∼119.76% at three fortified levels with relative standard deviations (RSDs) of less than 20%. Additionally, the method's limit of quantification (LOQ) ranged from ranged from 0.50 µg·kg-1 to 49.56 µg·kg-1. The method was further applied for analysis of 27 chilli powder samples, demonstrating its potential for screening and quantification of multiclass contaminants for spices.


Assuntos
Capsicum , Nanotubos de Carbono , Nanotubos de Carbono/química , Espectrometria de Massas em Tandem/métodos , Pós , Cromatografia Líquida de Alta Pressão/métodos , Capsicum/química , Fenômenos Magnéticos
8.
3 Biotech ; 13(11): 361, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37840878

RESUMO

Chilli (Capsicum annuum L.) is an important vegetable crop grown in the Indian sub-continent and is prone to viral infections under field conditions. During the field survey, leaf samples from chilli plants showing typical symptoms of disease caused by cucumber mosaic virus (CMV) such as mild mosaic, mottling and leaf distortion were collected. DAC-ELISA analysis confirmed the presence of CMV in 71 out of 100 samples, indicating its widespread prevalence in the region. Five CMV isolates, named Gu1, Gu2, BA, Ho, and Sal were mechanically inoculated onto cucumber and Nicotiana glutinosa plants to study their virulence. Inoculated plants expressed the characteristic symptoms of CMV such as chlorotic spots followed by mild mosaic and leaf distortion. Complete genomes of the five CMV isolates were amplified, cloned, and sequenced, revealing RNA1, RNA2, and RNA3 sequences with 3358, 3045, and 2220 nucleotides, respectively. Phylogenetic analysis classified the isolates as belonging to the CMV-IB subgroup, distinguishing them from subgroup IA and II CMV isolates. Recombination analysis showed intra and interspecific recombination in all the three RNA segments of these isolates. In silico protein-protein docking approach was used to decipher the mechanism behind the production of mosaic symptoms during the CMV-host interaction in 13 host plants. Analysis revealed that the production of mosaic symptoms could be due to the interaction between the coat protein (CP) of CMV and chloroplast ferredoxin proteins. Further, in silico prediction was validated in 13 host plants of CMV by mechanical sap inoculation. Twelve host plants produced systemic symptoms viz., chlorotic spot, chlorotic ringspot, chlorotic local lesion, mosaic and mild mosaic and one host plant, Solanum lycopersicum produced mosaic followed by shoestring symptoms. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03777-8.

9.
Physiol Mol Biol Plants ; 29(7): 1049-1059, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37649884

RESUMO

To deal with the vagaries of climate change, it is essential to develop climate-resilient agricultural practices, which improve crop productivity, and ensure food security. The impacts of high temperature and water deficit stress conditions pose serious challenges to a sustainable crop production. Several adaptation measures are practiced globally to address these challenges and among these altering the crop's typical growing season is one of the key management practices. Application of biostimulants and other growth hormones helps in compensating yield losses under abiotic stress significantly. Therefore, this study was conducted to evaluate the influence of vegetal protein hydrolysate based biostimulant to reduce the yield losses of off-season crops (soybean and chilli in summer and chickpea in early Kharif) when the temperature was higher than the regular season under water deficit stress conditions. The experiments were carried out with the foliar application of different protein hydrolysates (PHs) concentrations. The study revealed that the application of PHs significantly improved the membrane stability index, relative water content, total chlorophyll and proline content of leaves. Consequently, it led to an increase in the number of pods in soybean and chickpea, and fruits in chilli, leading to improved yields when plants were treated with the appropriate amount of PHs. Compared to untreated plants, PHs helped improve the efficiency of PS-II with significantly high photochemical efficiency (QYmax) even at higher excised leaf water loss or reduction in loss of relative water content. This study concluded that foliar application of PHs at 4, 2, and 6 ml L-1 can be beneficial for soybean, chickpea and chilli, which exhibited 17, 30, and 25% yield improvement respectively, over the untreated plants under water deficit stress. It is suggested that the benefits of PHs can be realized in soybean, chickpea and chilli under high temperature and water deficit stress. Therefore, vegetal PHs may be able to assist farmers in arid regions for boosting their income by raising market value and decreasing production barriers during the off-season. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01334-4.

10.
Viruses ; 15(7)2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37515116

RESUMO

An isolate of chilli veinal mottle virus (ChiVMV; genus Potyvirus) of Solanum nigrum L. from southwest China (ChiVMV-YunN/Yuxi) was identified and sequenced (GenBank: OP404087). Comparison with other ChiVMV isolates and recombination analyses suggested a recombinant origin. The most significant recombination event among all 21 complete ChiVMV isolates was an ending breakpoint at 1408-1488 for ChiVMV-YunN/Yuxi with ChiVMV-TaiW and ChiVMV-YunN/Ca operating as the respective major and minor parents. Interestingly, the 5' UTR of ChiVMV-YunN/Yuxi is 15 nucleotides ('AAAAATAAAACAACC') longer than other reported isolates. A full-length clone of ChiVMV-YunN/Yuxi was constructed and was shown to be infectious in Nicotiana benthamiana. The additional 15 nt of 5' UTR in ChiVMV-YunN/Yuxi was stable when transmitted through three generations. Experiments with modified clones showed that the additional 15 nt are essential for infection by this isolate.


Assuntos
Potyvirus , Solanum nigrum , Regiões 5' não Traduzidas , China , Doenças das Plantas
11.
Environ Sci Pollut Res Int ; 30(40): 91902-91914, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37480533

RESUMO

Dissipation and persistence of fenazaquin residues in chilli and soil were studied for 2 years following two applications of fenazaquin at 10-day interval. The limit of detection and limit of quantification were 0.003 and 0.01 mg kg-1. The mean initial deposits of fenazaquin 10 EC on green chilli fruits were found to be 0.74, 1.17, and 1.79 mg kg-1 after the application @ 125 (X dose), 156.25 (1.25X dose), and 250 (2X dose) g a.i. ha-1, respectively, during the first year followed by 0.78, 1.20, and 1.70 mg kg-1, respectively, during the next year. The mean initial deposits in soil were found to be 0.18, 0.25, and 0.44 mg kg-1 for the X, 1.25X, and 2X doses, respectively, during the first year and 0.19, 0.22, and 0.39 mg kg-1, respectively, during second year. The residues of fenazaquin in green chilli dissipated above 96% at 20 days in the three different doses whereas in red chilli, the residues were present on 25 days and at maturity, residues were below the limit of quantification (LOQ). In soil, the residues dissipated below the LOQ at 15 days for X and 1.25X while 20 days for the 2X dose, respectively. The half-life values in green chilli fruits and soil for the fenazaquin were found to be in the range of 3.22-3.93 days and 2.41-3.35 days, respectively. The waiting period was calculated to be 3, 5, and 8 days for green chilli after the application of fenazaquin at 25, 156.25, and 250 g a.i. ha-1, respectively.


Assuntos
Solo , Espectrometria de Massas em Tandem , Cromatografia Líquida , Quinazolinas
12.
Int J Mol Sci ; 24(12)2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37373321

RESUMO

Alzheimer's Disease (AD) is a progressive neurodegenerative disorder characterised by cognitive impairment, and amyloid-ß plaques and neurofibrillary tau tangles at neuropathology. Capsaicin is a spicy-tasting compound found in chili peppers, with anti-inflammatory, antioxidant, and possible neuroprotective properties. Capsaicin intake has been associated with greater cognitive function in humans, and attenuating aberrant tau hyperphosphorylation in a rat model of AD. This systematic review discusses the potential of capsaicin in improving AD pathology and symptoms. A systematic analysis was conducted on the effect of capsaicin on AD-associated molecular changes, cognitive and behaviour resulting in 11 studies employing rodents and/or cell cultures, which were appraised with the Cochrane Risk of Bias tool. Ten studies showed capsaicin attenuated tau deposition, apoptosis, and synaptic dysfunction; was only weakly effective on oxidative stress; and had conflicting effects on amyloid processing. Eight studies demonstrated improved spatial and working memory, learning, and emotional behaviours in rodents following capsaicin treatment. Overall, capsaicin showed promise in improving AD-associated molecular, cognitive, and behavioural changes in cellular and animal models, and further investigations are recommended to test the readily available bioactive, capsaicin, to treat AD.


Assuntos
Doença de Alzheimer , Humanos , Ratos , Animais , Doença de Alzheimer/patologia , Capsaicina/farmacologia , Capsaicina/uso terapêutico , Peptídeos beta-Amiloides/farmacologia , Emaranhados Neurofibrilares/patologia , Cognição , Proteínas tau , Modelos Animais de Doenças
13.
J Food Sci Technol ; 60(7): 1970-1980, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37206413

RESUMO

Aflatoxin contamination is a major concern in dry chilli pods during storage, which renders chilli flakes, and chilli powder unsafe for consumption and unfit for trade. Traditional method of storage also results in both qualitative as well as quantitative losses. In our study, we evaluated Purdue improved crop storage (PICS) based triple layer hermetic bags (PICS triple bags) for their efficacy in safe storage of dry chilli pods. Four different types of storage bags including untreated jute bag, polythene bag, triple layer hermetic bag, and fungicide treated jute bag were tested for three different storage periods (2, 4, and 6 month). Results suggest that aflatoxin levels resulting from Aspergillus flavus infection were below detectable levels in chilli pods stored in PICS triple bags owing to the modified atmospheric conditions of hypoxia and hypercarbia conditions created inside the bags. Further, dry chilli pods stored in PICS triple bags for 2, 4 and 6 month recorded no loss in test weight (1000 seeds) and no change in moisture content, whereas significantly moisture loss was observed in remaining treatment bags. Germination percentage of the seeds from the PICS triple bags at 2, 4 and 6 month storage was highest (72%) compared to all other treatment bags. Overall, we conclude that the PICS triple bags were effective in safe storage of dry chilli pods by ensuring detrimental environment to Aspergillus flavus growth and preserved both qualitative and quantitative characteristics including test weight, moisture content, and per cent germination compared to other storage bags.

14.
Food Res Int ; 169: 112856, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37254430

RESUMO

Chili pepper (Capsicum spp.) is one of the world's most popular vegetables and spices. Aroma is an important quality indicator of pepper, but the nature of the related volatiles is still not clear. In this study, we investigated the fruit of two pepper varieties, one with strong fruity aroma 'CC' Capsicum chinense and one without 'TJ' Capsicum annuum at four different developmental stages using transcriptomic and metabolomic analysis. The results showed that the content of green leaf volatiles (GLVs) was higher in TJ than in CC and was higher in the young fruit stage in both varieties. GLVs content was positively correlated with the expression of 13-LOX1, 2, 5 and HPL. But the levels of branched-chain (BC) esters and capsaicin were higher in CC, and were positively correlated with the expression of IMPS4 and DADH1. Our findings shed light on the molecular mechanism of aroma biosynthesis in pepper and provide a theoretical basis for the molecular breeding of high-quality pepper fruits.


Assuntos
Capsaicina , Capsicum , Capsicum/genética , Capsicum/metabolismo , Frutas/química , Transcriptoma , Ésteres/análise , Verduras/metabolismo
15.
Microb Pathog ; 180: 106127, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37119939

RESUMO

Eggplant is one of the important vegetable crops grown across the world, and its production is threatened by both biotic and abiotic stresses. Diseases caused by viruses are becoming major limiting factors for its successful cultivation. A survey for begomovirus-like symptoms in 72 eggplant fields located in six different Indian states revealed a prevalence of disease ranging from 5.2 to 40.2%, and the symptoms recorded were mosaic, mottling, petiole bending, yellowing, and upward curling, vein thickening, and enation of the leaves, and stunting of plants. The causal agent associated with these plants was transmitted from infected leaf samples to healthy eggplant seedlings via grafting and whiteflies (Bemisia tabaci). The presence of begomovirus was confirmed in 72 infected eggplant samples collected from the surveyed fields exhibiting leaf curl and mosaic disease by PCR using begomovirus specifc primers (DNA-A componet), which resulted in an expected amplicon of 1.2 kb. The partial genome sequence obtained from amplified 1.2 kb from all samples indicated that they are closely related begomovirus species, tomato leaf Karnataka virus (ToLCKV, two samples), tomato leaf curl Palampur virus (ToLCPalV, fifty eggplant samples), and chilli leaf curl virus (ChLCuV, twenty samples). Based on the partial genome sequence analysis, fourteen representative samples were selected for full viral genome amplification by the rolling circle DNA amplification (RCA) technique. Analyses of fourteen eggplant isolates genome sequences using the Sequence Demarcation Tool (SDT) indicated that one isolate had the maximum nucleotide (nt) identity with ToLCKV and eight isolates with ToLCPalV. Whereas, four isolates four isolates (BLC1-CH, BLC2-CH, BLC3-CH, BLC4-CH) are showing nucleotide identity of less than 91% with chilli infecting viruses begomoviruses with chilli infecting begomoviruses and as per the guidelines given by the ICTV study group for the classification of begomoviruses these isolates are considered as one novel begomovirus species, for which name, Eggplant leaf curl Chhattisgarh virus (EgLCuChV) is proposed. For DNA-B component, seven eggplant isolates had the highest nt identity with ToLCPalV infecting other crops. Further, DNA satellites sequence analysis indicated that four betasatellites identified shared maximum nucleotide identity with the tomato leaf curl betasatellite and five alphasatellites shared maximum nucleotide identity with the ageratum enation alphasatellite. Recombination and GC plot analyses indicated that the bulk of begomovirus genome and associated satellites presumably originated from of previously known mono and bipartite begomoviruses and DNA satellites. To the best of our knowledge, this is India's first report of ToLCKV and a noval virus, eggplant leaf curl Chhattisgarh virus associated with eggplant leaf curl disease.


Assuntos
Begomovirus , Solanum melongena , Filogeografia , Filogenia , DNA Viral/genética , Índia , Doenças das Plantas
16.
Viruses ; 15(4)2023 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-37112834

RESUMO

Chilli is an important commercial crop grown in tropical and subtropical climates. The whitefly-transmitted chilli leaf curl virus (ChiLCV) is a serious threat to chilli cultivation. Vector migration rate and host-vector contact rate, the major drivers involved in the epidemic process, have been pinpointed to link management. The complete interception of migrant vectors immediately after transplantation has been noted to increase the survival time (to remain infection free) of the plants (80%) and thereby delay the epidemic process. The survival time under interception (30 days) has been noted to be nine weeks (p < 0.05), as compared to five weeks, which received a shorter period of interception (14-21 days). Non-significant differences in hazard ratios between 21- and 30-day interceptions helped optimize the cover period to 26 days. Vector feeding rate, estimated as a component of contact rate, is noted to increase until the sixth week with host density and decline subsequently due to plant succulence factor. Correspondence between the peak time of virus transmission or inoculation rate (at 8 weeks) and contact rate (at 6 weeks) suggests that host succulence is of critical importance in host-vector interactions. Infection proportion estimates in inoculated plants at different leaf stages have supported the view that virus transmission potential with plant age decreases, presumably due to modification in contact rate. The hypothesis that migrant vectors and contact rate dynamics are the primary drivers of the epidemic has been proved and translated into rules to guide management strategies.


Assuntos
Begomovirus , Hemípteros , Animais , Doenças das Plantas
17.
Neotrop Entomol ; 52(3): 512-520, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36884146

RESUMO

Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is an invasive pest that is popularly known as chilli thrips. This insect pest has a wide range of hosts distributed across 72 plant families, causing damage to numerous crops of great economic importance. In the Americas, it is present in the USA, Mexico, Suriname, Venezuela, Colombia, and some Caribbean Islands. Knowing the regions which have environmentally suitable conditions for the survival of this pest is important for phytosanitary monitoring and inspection. Thus, our objective was to forecast the distribution potential of S. dorsalis with a focus on the Americas. Models were produced to design this distribution, in which the environmental variables used were made available in Wordclim version 2.1. The algorithms used for the modeling were the generalized additive model (GAM), generalized linear model (GLM), maximum entropy (MAXENT), random forest (RF), and Bioclim, in addition to the ensemble, which consisted of the grouping of the algorithms used. The metrics used to evaluate the models were area over the curve (AUC), true ability statistics (TSS), and Sorensen score. All models had satisfactory results (> 0.8) for all metrics used. In North America, the model showed favorable regions on the west coast of the USA and east coast near New York. In South America, the potential distribution of the pest is significant, encompassing regions in all countries. It is concluded that S. dorsalis has suitable areas for the occurrence in the three American subcontinents and, in particular, a large part of South America.


Assuntos
Tisanópteros , Animais , Insetos , América do Sul , Produtos Agrícolas , Ecossistema
18.
Life (Basel) ; 13(2)2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36836783

RESUMO

Chilli is an universal spice cum solanaceous vegetable crop rich in vitamin A, vitamin C, capsaicin and capsanthin. Its cultivation is highly threatened by fruit rot disease which cause yield loss as high as 80-100% under congenial environment conditions. Currently actinobacteria are considered as eco-friendly alternatives to synthetic fungicides at pre and post-harvest pathosystems. Hence, this research work focuses on the exploitation of rhizospheric, phyllospheric and endophytic actinobacteria associated with chilli plants for their antagonistic activity against fruit rot pathogens viz., Colletotrichum scovillei, Colletotrichum truncatum and Fusarium oxysporum. In vitro bioassays revealed that the actinobacterial isolate AR26 was found to be the most potent antagonist with multifarious biocontrol mechanisms such as production of volatile, non-volatile, thermostable compounds, siderophores, extracellular lytic enzymes. 16S rRNA gene sequence confirmed that the isolate AR26 belongs to Streptomyces tuirus. The results of detached fruit assay revealed that application of liquid bio-formulation of Stretomyces tuirus @ 10 mL/L concentration completely inhibited the development of fruit rot symptoms in pepper fruits compared to methanol extracts. Hence, the present research work have a great scope for evaluating the biocontrol potential of native S. tuirus AR26 against chilli fruit rot disease under field condition as well against a broad spectrum of post-harvest plant pathogens.

19.
Theory Biosci ; 142(1): 47-60, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36607541

RESUMO

Chilli leaf curl Ahmedabad virus (ChiLCAV), a begomovirus belonging to the family Geminiviridae, has been reported for its occurrence in India, infecting chilli and tomato plants. The viral proteins associated with ChiLCAV involves in the primary pathogenesis and transmission of the virus by whitefly. Viral protein interactions with host proteins show the dynamics of structural binding and interaction in their infection cycle. At the same time, plants have multiple defence mechanisms against bacterial and viral infections. Secondary metabolites play a significant role in the inborne defence mechanism of plants. Host proteins are also the prime producers of secondary metabolites. In the present study, we evaluated the host protein SnRK1 interaction with all six viral proteins (V1, V2, C1, C2, C3 and C4). Apart from C4, all the other viral proteins showed appreciable binding and interaction with SnRK1. SnRK1 has the regulation mechanism for the accumulation of diterpenoids, secondary metabolites. Flavonoids are secondary metabolites produced by the plant under stress conditions. Further, we studied the binding and interaction of six selected flavonoids produced by Solanaceae family members with all the ChiLCAV proteins. All six selected flavonoids showed considerable binding energy with all viral proteins. Each flavonoid showed high binding energy with different viral proteins. Molecular docking is carried out for both flavonoids and the host protein SnRK1. These in silico interactions and docking studies could be useful for understanding the plants defence mechanism against viral infections at the molecular level.


Assuntos
Begomovirus , Proteínas Virais , Proteínas Virais/química , Proteínas Virais/metabolismo , Begomovirus/metabolismo , Simulação de Acoplamento Molecular
20.
Rev. bras. entomol ; 67(1): e20220036, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1423213

RESUMO

ABSTRACT Some psyllids transmit 'Candidatus Liberibacter solanacearum' (Lso), the causal agent of devastating plant diseases of cultivated Solanaceae and Apiaceae. The recent detection of Bactericera cockerelli and Lso in Ecuador seriously threatens these crops in South America. There, neither the role of native psyllids in the Lso epidemiology nor the psyllid fauna of vegetables are known. With the aim to identify potential vectors and risk scenarios for the spread of Lso in South America, a survey of the psyllid fauna of Solanaceae and Apiaceae crops and associated weeds was conducted in Brazil. Samples were taken at 29 localities in four states. A total of 2857 specimens were sampled, representing at least 37 species of 23 genera and seven families. The most frequent species on carrot, chilli pepper and potato were Russelliana solanicola, R. capsici and Isogonoceraia divergipennis, respectively. Immatures of R. capsici were found on chilli pepper and of R. solanicola on carrot and potato, confirming these plants as hosts. The two psyllid species have been suspected previously to transmit plant pathogens of unknown identity. Russelliana solanicola is one of the few polyphagous species. Here the species is reported for the first time from carrot. Recent collections in Rio Grande do Sul suggest that Solanum laxum represents the original host of R. capsici, which subsequently shifted to chilli pepper. Both, adaptation to agricultural crops and the possibility of ability to transmit pathogens, make the two Russelliana species dangerous potential vectors of Lso and other plant pathogens in South America.

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