WorldWideScience

Sample records for citrus postharvest diseases

  1. Population Structure of the Sour Rot Pathogens Galactomyces citri-aurantii and G. geotrichum and Evaluation of Sterol Demethylation Inhibitors for Postharvest Management of Citrus Decays

    OpenAIRE

    McKay, Alistair Hartley

    2011-01-01

    Sour rot of citrus caused by Galactomyces citri-aurantii (anamorph: Geotrichum citri-aurantii (Ferraris) Butler) is an important postharvest disease that affects all varieties of citrus fruit grown in California and is particularly prevalent in the lemon industry since the fruit is stored at approximately 12°C and 95% relative humidity. The postharvest fungicides currently registered to manage green mold caused by Penicillium digitatum including imazalil, thiabendazole, as well as azoxystrobi...

  2. Biological control of postharvest diseases of fruits.

    Science.gov (United States)

    Janisiewicz, Wojciech J; Korsten, Lise

    2002-01-01

    Losses from postharvest fruit diseases range from 1 to 20 percent in the United States, depending on the commodity. The application of fungicides to fruits after harvest to reduce decay has been increasingly curtailed by the development of pathogen resistance to many key fungicides, the lack of replacement fungicides, negative public perception regarding the safety of pesticides and consequent restrictions on fungicide use. Biological control of postharvest diseases (BCPD) has emerged as an effective alternative. Because wound-invading necrotrophic pathogens are vulnerable to biocontrol, antagonists can be applied directly to the targeted area (fruit wounds), and a single application using existing delivery systems (drenches, line sprayers, on-line dips) can significantly reduce fruit decays. The pioneering biocontrol products BioSave and Aspire were registered by EPA in 1995 for control of postharvest rots of pome and citrus fruit, respectively, and are commercially available. The limitations of these biocontrol products can be addressed by enhancing biocontrol through manipulation of the environment, using mixtures of beneficial organisms, physiological and genetic enhancement of the biocontrol mechanisms, manipulation of formulations, and integration of biocontrol with other alternative methods that alone do not provide adequate protection but in combination with biocontrol provide additive or synergistic effects. PMID:12147766

  3. Genome sequence of the necrotrophic fungus Penicillium digitatum, the main postharvest pathogen of citrus

    OpenAIRE

    Marcet-Houben Marina; Ballester Ana-Rosa; de la Fuente Beatriz; Harries Eleonora; Marcos Jose F; González-Candelas Luis; Gabaldón Toni

    2012-01-01

    Abstract Background Penicillium digitatum is a fungal necrotroph causing a common citrus postharvest disease known as green mold. In order to gain insight into the genetic bases of its virulence mechanisms and its high degree of host-specificity, the genomes of two P. digitatum strains that differ in their antifungal resistance traits have been sequenced and compared with those of 28 other Pezizomycotina. Results The two sequenced genomes are highly similar, but important differences between ...

  4. Treatments with acetic acid followed by curing reduce postharvest decay on Citrus fruit.

    Science.gov (United States)

    Venditti, T; Angiolino, C; Dore, A; Molinu, M G; Petretto, A; D'Hallewin, G

    2009-01-01

    Citrus fruit are susceptible to many postharvest diseases and disorders, but Penicillium digitatum and Penicillium italicum are the most common and serious pathogens during storage and marketing. The continuous employ in packing houses of synthetic fungicides such as imazalil (IMZ) or thiabendazote for the control of these pathogens is promoting the selection of resistant biotypes. These considerations together with an increased attention for human health and the environment have multiplied the studies on new ecological technologies. In recent years researchers studies focused on alternatives to the chemical control of post-harvest decay, such as the utilization of GRAS compounds as well as physical methods. In the present study is reported the sequential use of acetic acid (AAC) followed by curing. The lemon variety "Verna" and the orange variety "Jaffa", naturally inoculated, were treated with vapours of AAC performed at three different concentration (15, 25 and 50 microL/L) for 15 minutes, after an incubation period of 24 hours at 27 degrees C and 90% relative humidity (RH). After treatments fruits were cured at 36 degrees C for 36 hours with 90% RH and subsequently stored at 8 degrees C and 90% of RH for eight weeks. Both citrus varieties were also treated with IMZ at a concentration of 200 mL/HL. At the end of the experiment decay and weight loss were evaluated. After 8 weeks of storage, in the lemon variety, the lowest percentage of infected wounds was 1.5% for both the fruit treated with IMZ or with AAC at 25 microL/L. Fruit treated with 15 mciroL/L or untreated (control) showed similar results with 13.6% and 16.6% of rotted fruit respectively. Different results were obtained with the orange variety, in this case the synthetic fungicide was the most effective at the end of the storage period, with 18.0% of decay. AAC treatments were not a successful as on lemons, the best result was achieved even in this case with AAC performed at 25 pL/L, but with 39.9% of

  5. Orthophenylphenol and phenylhydroquinone residues in citrus fruit and processed citrus products after postharvest fungicidal treatments with sodium orthophenylphenate in California and Florida.

    Science.gov (United States)

    Johnson, G D; Harsy, S G; Geronimo, J; Wise, J M

    2001-05-01

    Sodium orthophenylphenate (SOPP) has been used extensively for >40 years to control postharvest diseases of citrus fruits. Studies of the metabolism of [(14)C]SOPP have identified orthophenylphenol (OPP) as the major metabolite with phenylhydroquinone (PHQ) as a minor metabolite. The whole-fruit tolerance in the United States for OPP is 10 ppm. This study was conducted to quantify terminal OPP and PHQ residues in whole Navel oranges, grapefruit, and lemons following SOPP applications at maximum application rates and following commercial application and fruit storage practices. OPP and PHQ residues also were determined in products processed from treated Navel oranges. OPP residues in lemons, Navel oranges, and grapefruit treated with SOPP using foamer wash and shipping wax applications remained below the 10 ppm tolerance, and PHQ residues were all orange matrices except oil remained relatively stable with time in commercial storage; residues in oil declined substantially while in storage. PMID:11368626

  6. Citrus stubborn disease (CSD)

    Science.gov (United States)

    CSD is caused by Spiroplasma citri, a phloem-limited, cell-wall-less bacterium. S. citri is transmitted in a propagative, circulative manner by several leafhoppers including Circulifer tenellus and Scaphytopius nitridus in citrus-growing regions of California and Arizona and by C. haematoceps (syn....

  7. Salicylic acid treatment reduces the rot of postharvest citrus fruit by inducing the accumulation of H2O2, primary metabolites and lipophilic polymethoxylated flavones.

    Science.gov (United States)

    Zhu, Feng; Chen, Jiajing; Xiao, Xue; Zhang, Mingfei; Yun, Ze; Zeng, Yunliu; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2016-09-15

    To comprehensively analyze the effects of salicylic acid (SA) on the storability of Satsuma mandarin (Citrus unshiu), fruits were treated with 2mM SA. The disease incidence of control/SA-treated fruit at 50d and 120d after treatment was 23.3%/10% and 67.3%/23.3%, respectively, suggesting that SA treatment can significantly reduce the rot rate of postharvest citrus fruit. Fruit quality assays revealed that the treatment can maintain fruit firmness without affecting the inner quality. Furthermore, the contents of H2O2 and some defense-related metabolites, such as ornithine and threonine, in citrus pericarp, were significantly increased by SA treatment. Moreover, it was lipophilic polymethoxylated flavones, rather than flavanone glycosides, that accumulated in SA-treated fruits and these can directly inhibit pathogen development. These results suggest that the effects of SA on postharvest citrus fruit may be attributed to the accumulation of H2O2 and defense-related metabolites. PMID:27080881

  8. Genome sequence of the necrotrophic fungus Penicillium digitatum, the main postharvest pathogen of citrus

    Directory of Open Access Journals (Sweden)

    Marcet-Houben Marina

    2012-11-01

    Full Text Available Abstract Background Penicillium digitatum is a fungal necrotroph causing a common citrus postharvest disease known as green mold. In order to gain insight into the genetic bases of its virulence mechanisms and its high degree of host-specificity, the genomes of two P. digitatum strains that differ in their antifungal resistance traits have been sequenced and compared with those of 28 other Pezizomycotina. Results The two sequenced genomes are highly similar, but important differences between them include the presence of a unique gene cluster in the resistant strain, and mutations previously shown to confer fungicide resistance. The two strains, which were isolated in Spain, and another isolated in China have identical mitochondrial genome sequences suggesting a recent worldwide expansion of the species. Comparison with the closely-related but non-phytopathogenic P. chrysogenum reveals a much smaller gene content in P. digitatum, consistent with a more specialized lifestyle. We show that large regions of the P. chrysogenum genome, including entire supercontigs, are absent from P. digitatum, and that this is the result of large gene family expansions rather than acquisition through horizontal gene transfer. Our analysis of the P. digitatum genome is indicative of heterothallic sexual reproduction and reveals the molecular basis for the inability of this species to assimilate nitrate or produce the metabolites patulin and penicillin. Finally, we identify the predicted secretome, which provides a first approximation to the protein repertoire used during invasive growth. Conclusions The complete genome of P. digitatum, the first of a phytopathogenic Penicillium species, is a valuable tool for understanding the virulence mechanisms and host-specificity of this economically important pest.

  9. Citrus postharvest diseases and injuries related to impact on packing lines Doenças pós-colheita em citros e injúrias relacionadas ao impacto em linhas de beneficiamento

    Directory of Open Access Journals (Sweden)

    Ivan Herman Fischer

    2009-04-01

    Full Text Available Brazilian exports of fresh citrus represent less than 1% of the overall Brazilian production. Phytosanitary barriers and poor appearance stand out among the several reasons contributing to such low exporting/production ratio. The purpose of this work was to characterize postharvest injuries in 'Valencia' sweet oranges and 'Murcott' tangors produced for foreign markets after different processing stages in a packinghouse, as well as to identify critical points and impact extent on packing lines. Sampling was performed both after pre-washing and degreening the fruits, and also at the arrival on the packing table and in the pallet. They were stored for 21 days at 25ºC and 85% RH. The incidence of injuries was visually assessed every three days. An instrumented sphere with acceleration register was used to evaluate the extent of impacts (G, m/s² at the 19 transference points of the citrus processing line. There was low rot incidence (under 3.5% at the different stages of fruit processing, with slight increase after degreening in 'Valencia' orange and a decrease after fungicides treatment in 'Murcott' tangor. The main pathogens found in the oranges were Lasiodiplodia theobromae and Penicillium digitatum, which were surpassed by Colletotrichum gloeosporioides in the tangors. Impacts in the processing line were caused mainly by drops on hard surfaces, with 94.7% of them varying from 30 to 95 G. The greatest impacts were observed when fruits were transferred from the processing line to bins destined to degreening. Mechanical injuries related to oleocellosis increased until the arrival of fruits at the packing table.A exportação de frutos cítricos frescos representa menos que 1% da produção brasileira. Dentre os fatores atribuídos a esta baixa relação entre exportação e produção destacam-se as barreiras sanitárias e o aspecto visual de qualidade inferior. Este trabalho objetivou caracterizar os danos pós-colheita de frutos de laranja

  10. Citrus Canker and Citrus Huanglongbing, Two Exotic Bacterial Diseases Threatening the Citrus Industries of the Western Hemisphere

    Science.gov (United States)

    Two exotic Asian bacterial diseases of citrus are currently plaguing citrus industries in the Western Hemisphere. The two largest citrus producing areas in the Americas, located in Florida and the state of São Paulo Brazil, are presently battling these devastating diseases. The presence of these d...

  11. Effectiveness of Postharvest Treatment with Chitosan to Control Citrus Green Mold

    OpenAIRE

    Mohamed El Guilli; Abdelkhalek Hamza; Christophe Clément; Mohamed Ibriz; Essaid Ait Barka

    2016-01-01

    Control of green mold, caused by Penicillium digitatum, by fungicides raises several problems, such as emergence of resistant pathogens, as well as concerns about the environment and consumers’ health. As potential alternatives, the effects of chitosan on green mold disease and the quality attributes of citrus fruits were investigated. Fruits were wounded then treated with different concentrations of chitosan 24 h before their inoculation with P. digitatum. The results of in vitro experiment ...

  12. Comparative transcriptomics and proteomics analysis of citrus fruit, to improve understanding of the effect of low temperature on maintaining fruit quality during lengthy post-harvest storage

    OpenAIRE

    Yun, Ze; Jin, Shuai; Ding, Yuduan; Wang, Zhuang; Gao, Huijun; Pan, Zhiyong; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2012-01-01

    Fruit quality is a very complex trait that is affected by both genetic and non-genetic factors. Generally, low temperature (LT) is used to delay fruit senescence and maintain fruit quality during post-harvest storage but the molecular mechanisms involved are poorly understood. Hirado Buntan Pummelo (HBP; Citrus grandis × C. paradis) fruit were chosen to explore the mechanisms that maintain citrus fruit quality during lengthy LT storage using transcriptome and proteome studies based on digital...

  13. Assessment of Stubborn Disease Incidence in Citrus

    Science.gov (United States)

    Citrus stubborn disease, caused by Spiroplasma Citri, has occured in California for more than 90 years, however, detection methods for estimating disease incidence have not been well developed. Two 8 ha plots in Kern Co. CA were established and sampled in July and August, 2006. Different tissues o...

  14. Assessment of Stubborn Disease Incidence in Citrus

    Science.gov (United States)

    Citrus stubborn disease (CSD) has been a problem in California for over 90 years, yet, methods for rapidly detecting its causal agent, Spiroplasma citri, for use in estimating disease incidence have not been optimized. Two 8 ha blocks within two commercial groves were sampled in July and August, 20...

  15. Biofumigation on Post-Harvest Diseases of Fruits Using a New Volatile-Producing Fungus of Ceratocystis fimbriata.

    Directory of Open Access Journals (Sweden)

    Qian Li

    Full Text Available A variety of volatile organic compounds (VOCs produced by Ceratocystis fimbriata have strong bioactivity against a wide range of fungi, bacteria and oomycetes. Mycelial growth, conidial production, and spore germination of fungi and oomycetes were significantly inhibited after exposure to cultures of C. fimbriata, and colony formation of bacteria was also inhibited. Two post-harvest diseases, peach brown rot caused by Monilinia fructicola and citrus green mold caused by Penicillium digitatum, were controlled during a 4-day storage by enclosing wound-inoculated fruits with 10 standard diameter Petri plate cultures of C. fimbriata in a 15 L box. The fruits were freshly inoculated at onset of storage and the cultures of C. fimbriata were 6 days old. Percentage of control was 92 and 97%, respectively. After exposure to C. fimbriata VOCs, severely misshapen hyphae and conidia of these two post-harvest pathogens were observed by scanning electron microscopy, and their pathogenicity was lost or greatly reduced.

  16. Biofumigation on Post-Harvest Diseases of Fruits Using a New Volatile-Producing Fungus of Ceratocystis fimbriata.

    Science.gov (United States)

    Li, Qian; Wu, Lei; Hao, Jianjun; Luo, Laixin; Cao, Yongsong; Li, Jianqiang

    2015-01-01

    A variety of volatile organic compounds (VOCs) produced by Ceratocystis fimbriata have strong bioactivity against a wide range of fungi, bacteria and oomycetes. Mycelial growth, conidial production, and spore germination of fungi and oomycetes were significantly inhibited after exposure to cultures of C. fimbriata, and colony formation of bacteria was also inhibited. Two post-harvest diseases, peach brown rot caused by Monilinia fructicola and citrus green mold caused by Penicillium digitatum, were controlled during a 4-day storage by enclosing wound-inoculated fruits with 10 standard diameter Petri plate cultures of C. fimbriata in a 15 L box. The fruits were freshly inoculated at onset of storage and the cultures of C. fimbriata were 6 days old. Percentage of control was 92 and 97%, respectively. After exposure to C. fimbriata VOCs, severely misshapen hyphae and conidia of these two post-harvest pathogens were observed by scanning electron microscopy, and their pathogenicity was lost or greatly reduced. PMID:26147922

  17. Effect of Thymol and Linalool Fumigation on Postharvest Diseases of Table Grapes

    OpenAIRE

    Shin, Mi Ho; Kim, Jin-Hee; Choi, Hyo-Won; Keum, Yoong Soo; Chun, Se Chul

    2014-01-01

    Several postharvest diseases of table grapes (Vitis vinifera) occur during storage, and gray mold rot is a particularly severe disease because the causal agent, Botrytis cinerea, grows at temperatures as low as 0℃. Other postharvest diseases, such as those caused by Penicillium spp. and Aspergillus spp., also often lead to deterioration in the quality of table grapes after harvest. The use of plant essential oils such as thymol and linalool, to reduce postharvest diseases in several kinds of ...

  18. Citrus phytophthora diseases: Management challenges and successes

    OpenAIRE

    Graham, J; Feichtenberger, E.

    2015-01-01

    Phytophthora spp. are present in nearly all citrus groves in Florida and Brazil and phytophthora-induced diseases, especially foot and root rot, have the potential to cause economically important crop losses. Disease-related losses due to root rot are difficult to estimate because fibrous root damage and yield loss are not always directly proportional. Challenges from phytophthora diseases have been addressed in both countries by enacting phytosanitary requirements for production of pathogen-...

  19. High incidence of preharvest colonization of huanglongbing-symptomatic citrus sinensis fruit by Lasiodiplodia theobromae (Diplodia natalensis) and exacerbation of postharvest fruit decay by that fungus.

    Science.gov (United States)

    Zhao, Wei; Bai, Jinhe; McCollum, Greg; Baldwin, Elizabeth

    2015-01-01

    Huanglongbing (HLB), presumably caused by the bacterium "Candidatus Liberibacter asiaticus," is a devastating citrus disease associated with excessive preharvest fruit drop. Lasiodiplodia theobromae (diplodia) is the causal organism of citrus stem end rot (SER). The pathogen infects citrus fruit under the calyx abscission zone (AZ-C) and is associated with cell wall hydrolytic enzymes similar to plant enzymes involved in abscission. By means of DNA sequencing, diplodia was found in "Ca. Liberibacter asiaticus"-positive juice from HLB-symptomatic fruit (S) but not in "Ca. Liberibacter asiaticus"-negative juice. Therefore, the incidence of diplodia in fruit tissues, the impact on HLB-related postharvest decay, and the implications for HLB-related preharvest fruit drop were investigated in Hamlin and Valencia oranges. Quantitative PCR results (qPCR) revealed a significantly (P < 0.001) greater incidence of diplodia in the AZ-C of HLB-symptomatic (S; "Ca. Liberibacter asiaticus" threshold cycle [CT] of <30) than in the AZ-C of in asymptomatic (AS; "Ca. Liberibacter asiaticus" CT of ≥30) fruit. In agreement with the qPCR results, 2 weeks after exposure to ethylene, the incidences of SER in S fruit were 66.7% (Hamlin) and 58.7% (Valencia), whereas for AS fruit the decay rates were 6.7% (Hamlin) and 5.3% (Valencia). Diplodia colonization of S fruit AZ-C was observed by scanning electron microscopy and confirmed by PCR test and morphology of conidia in isolates from the AZ-C after surface sterilization. Diplodia CT values were negatively correlated with ethylene production (R = -0.838 for Hamlin; R = -0.858 for Valencia) in S fruit, and positively correlated with fruit detachment force (R = 0.855 for Hamlin; R = 0.850 for Valencia), suggesting that diplodia colonization in AZ-C may exacerbate HLB-associated preharvest fruit drop. PMID:25344245

  20. Effectiveness of Postharvest Treatment with Chitosan to Control Citrus Green Mold

    Directory of Open Access Journals (Sweden)

    Mohamed El Guilli

    2016-03-01

    Full Text Available Control of green mold, caused by Penicillium digitatum, by fungicides raises several problems, such as emergence of resistant pathogens, as well as concerns about the environment and consumers’ health. As potential alternatives, the effects of chitosan on green mold disease and the quality attributes of citrus fruits were investigated. Fruits were wounded then treated with different concentrations of chitosan 24 h before their inoculation with P. digitatum. The results of in vitro experiment demonstrated that the antifungal activity against P. digitatum was improved in concert to the increase of chitosan concentration. In an in vivo study, green mold was significantly reduced by chitosan treatments. In parallel, chitinase and glucanase activities were enhanced in coated fruits. Evidence suggested that effects of chitosan coating on green mold of mandarin fruits might be related to its fungitoxic properties against the pathogen and/or the elicitation of biochemical defense responses in coated fruits. Further, quality attributes including fruit firmness, surface color, juice content, and total soluble solids, were not affected by chitosan during storage. Moreover, the loss of weight was even less pronounced in chitosan-coated fruit.

  1. Antifungal Edible Coatings for Fresh Citrus Fruit: A Review

    OpenAIRE

    Lluís Palou; Valencia-Chamorro, Silvia A.; Pérez-Gago, María B.

    2015-01-01

    According to their origin, major postharvest losses of citrus fruit are caused by weight loss, fungal diseases, physiological disorders, and quarantine pests. Cold storage and postharvest treatments with conventional chemical fungicides, synthetic waxes, or combinations of them are commonly used to minimize postharvest losses. However, the repeated application of these treatments has led to important problems such as health and environmental issues associated with fungicide residues or waxes ...

  2. The occurrence of postharvest diseases on apples resistant to scab

    Directory of Open Access Journals (Sweden)

    Hanna Bryk

    2012-12-01

    Full Text Available The occurrence of storage diseases on fruit of seven scab resistant apple cultivars (Freedom, Rajka, Topaz, Rubinola, Enterprise, Goldstar, GoldRush grafted on M.9 was investigated in 2001-2005. The trees were planted in 1995. It was found that after storage (4 and 6 months at 2°C, 85-90% RH the most severe appeared to be bull's eye rot (Pezicula spp.. The most sensitive cultivars to this disease were: Topaz, Freedom, Goldstar, the least sensitive were Rubinola, Enterprise, Rajka. Other postharvest diseases like gray mold (Botrytis cinerea, blue mold (Penicillium expansum and brown rot (Monilinia fructigena were not common. 'Rajka' and 'Goldstar' were susceptible to bitter pit, and 'Freedom' to superficial scald.

  3. Gamma radiation influences postharvest disease incidence of pineapple fruits

    International Nuclear Information System (INIS)

    The application of gamma radiation for improving the storage of pineapple fruits [Ananas comosus (L.) Merr. cv. Queen] has been studied in an attempt to reduce decay caused by fungal pathogens such as Ceratocystis paradoxa (Dade)-Moreau and Penicillium purpurogenum Stoll. Gamma radiation at 50, 75, 100, 150, and 250 Gy improved shelf life. The maximum tolerable dose was approximately 250 Gy. Fruits irradiated with up to 150 Gy and then stored at 25 to 28C maintained their texture better than did the controls. Radiation, particularly at doses 250 Gy, caused browning of the skin and softening of tissues. Browning increased with increasing radiation dose and storage duration. Excessively high doses promoted spoilage. Doses in the range of 50 to 250 Gy, in combination with storage at 11 to 13C, can be used to reduce postharvest losses in pineapple due to fungal diseases and senescence, thereby extending shelf life

  4. High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

    OpenAIRE

    Zhao, Wei; Bai, Jinhe; McCollum, Greg; Baldwin, Elizabeth

    2014-01-01

    Huanglongbing (HLB), presumably caused by the bacterium “Candidatus Liberibacter asiaticus,” is a devastating citrus disease associated with excessive preharvest fruit drop. Lasiodiplodia theobromae (diplodia) is the causal organism of citrus stem end rot (SER). The pathogen infects citrus fruit under the calyx abscission zone (AZ-C) and is associated with cell wall hydrolytic enzymes similar to plant enzymes involved in abscission. By means of DNA sequencing, diplodia was found in “Ca. Liber...

  5. Pseudocercospora leaf and fruit spot disease of citrus: Achievements and challenges in the citrus industry: A review

    OpenAIRE

    Mohammed Yesuf

    2013-01-01

    Citruses are the worlds’ second fruit crops by volume next to banana. It is one of the most important commodity in tropical Africa as source of foreign currency, raw material for agro-industries and source of employment. The production and productivity of citrus in tropical Africa including Ethiopia are critically threatened by a number of diseases. Among others, pseudocercospora leaf and fruit spot of citrus caused by a fungus Pseudocercospora angolensis is the most destructive disease of c...

  6. Evaluation of sulfur dioxide-generating pads and modified atmosphere packaging for control of postharvest diseases in blueberries

    Science.gov (United States)

    Postharvest diseases are a limiting factor of storage and shelf life of blueberries. Gray mold caused by Botrytis cinerea is one of the most important postharvest diseases in blueberries grown in California. In this study, we evaluated the effects of sulfur dioxide (SO2)-generating pads (designated ...

  7. Chemical control of the Asian citrus psyllid and of huanglongbing disease in citrus.

    Science.gov (United States)

    Boina, Dhana Raj; Bloomquist, Jeffrey R

    2015-06-01

    By 2014, huanglongbing (HLB), the most destructive disease of citrus, and its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama), became established in all major citrus-growing regions of the world, including the United States, with the exception of California. At present, application of insecticides is the most widely followed option for reducing ACP populations, while application of antibiotics for suppressing HLB disease/symptoms is being practiced in some citrus-growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB-free seedlings and early detection and removal of symptomatic and asymptomatic trees, has been very effective in managing ACP. Area-wide management of ACP by application of insecticides at low volume in large areas of citrus cultivation has been shown to be effective in managing HLB and reducing management costs. As insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB-infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area-wide management programs with due consideration to the insecticide resistance problem. PMID:25491482

  8. Historical perspective on biological control of postharvest diseases – past, present, and future

    Science.gov (United States)

    The birth of the field of biological control of postharvest diseases can be traced back to 1984 when a researcher testing an antagonist (Bacillus subtilis) in the field to control brown rot of peaches (caused by Monilinia fructicola ) decided to apply the antagonist directly to the peach to control ...

  9. Effect of beneficial bacterial isolates from citrus roots in Florida on citrus Huanglongbing disease development

    OpenAIRE

    Li, J.; Trivedi, P.; Wang, N.

    2014-01-01

    Huanglongbing (HLB) is the most devastating disease of citrus in Florida. HLB is caused by the phloem-inhabiting bacterium ‘Candidatus Liberibacter asiaticus’ (Las), which is transmitted by psyllid vector Diaphorina citri. The current management strategies of HLB are to control psyllids and eradicate infected plants. However, these management practices have not been able to stop the spreading of HLB (Duan et al. 2009). Alternative approaches are needed to control HLB. In previous studies we i...

  10. Bacterial brown leaf spot of citrus, a new disease caused by Burkholderia andropogonis

    Science.gov (United States)

    A new bacterial disease of citrus was recently identified in Florida and named as bacterial brown leaf spot (BBLS) of citrus. BBLS-infected citrus displayed flat, circular and brownish lesions with water-soaked margins surrounded by a chlorotic halo on leaves. Based on Biolog carbon source metabolic...

  11. 佛手采后致病青霉的分离鉴定%Identification of Penicillium species causing post-harvest diseases of finger citron

    Institute of Scientific and Technical Information of China (English)

    李永强; 杨佳妮; 陈文荣; 路梅; 郭卫东

    2011-01-01

    Golden Finger citron (Citrusmedica var. Sarcodactylis Swingle), one of the traditional specialities of Jinhua.Zhejiang Province, has high ornamental and medicinal value. Green mould is the major fungus disease of Citrus fruits, causing substantial economic losses during the storage of post-harvest. To identify the exact species of the pathogenic fungus, an isolate belonged to genus Penicillium was isolated from the infected Golden Finger citron. Kochs postulation was completed by wounded-inoculation with the conidial suspension of Penicillium sp. On health Golden Finger. It was identified as Penicillium digitatum based on morphological characters and internal transcribed spacer (ITS) analysis. This result would be helpful for controlling post-harvest disease.%佛手(Citrusmedica var.sarcodactylis Swingle)又名九爪木、五指橘、佛手柑,为芸香科柑橘属常绿小乔木.主产于闽、粤、川、浙等省,其中浙江金华“金佛手”最为著名,被称为“果中之仙品,世上之奇卉”.其果形美观、色泽金黄、香味浓郁,具有药用价值高、贮藏期长的特点[1],是金华地区的传统特产之一.

  12. Effect of thymol and linalool fumigation on postharvest diseases of table grapes.

    Science.gov (United States)

    Shin, Mi Ho; Kim, Jin-Hee; Choi, Hyo-Won; Keum, Yoong Soo; Chun, Se Chul

    2014-09-01

    Several postharvest diseases of table grapes (Vitis vinifera) occur during storage, and gray mold rot is a particularly severe disease because the causal agent, Botrytis cinerea, grows at temperatures as low as 0℃. Other postharvest diseases, such as those caused by Penicillium spp. and Aspergillus spp., also often lead to deterioration in the quality of table grapes after harvest. The use of plant essential oils such as thymol and linalool, to reduce postharvest diseases in several kinds of fruits, including table grapes and oranges, has received much attention in European countries. However, to the best of our knowledge there has been no report of the use of thymol fumigation to control gray mold in table grapes in Korea. Thymol (30 µg/mL) and linalool (120 µg/mL) significantly inhibited mycelial growth and conidia germination of B. cinerea. The occurrence rate of gray mold rot of B. cinerea and other unknown fungi was significantly reduced by fumigation with 30 µg/mL thymol in several table grape cultivars, such as Campbell early, Muscat Bailey A, Sheridan, and Geobong. In this study, fumigation with 30 µg/mL thymol, had no influence on the sugar content and hardness of grapes, but reduced fungal infection significantly. This suggests that 30 µg/mL thymol could be utilized to reduce deterioration of grapes due to gray mold and other fungal infections during long-term storage. PMID:25346603

  13. Mechanisms of action for 2-phenylethanol isolated from Kloeckera apiculata in control of Penicillium molds of citrus fruits

    OpenAIRE

    Liu, Pu; Cheng, Yunjiang; Yang, Meng; Liu, Yujia; CHEN, KAI; Long, Chao-an; Deng, Xiuxin

    2014-01-01

    Background Green and blue mold decay, caused by Penicillium digitatum and P. italicum, respectively, are important postharvest diseases of citrus. Biocontrol by microbes is an alternative to synthetic fungicide application. In this study, the antagonistic yeast strain Kloeckera apiculata 34–9 was used to investigate the action mechanisms involved in the biocontrol of postharvest diseases. Results An antifungal substance, 2-phenylethanol (PEA), was isolated from K. apiculata and demonstrated t...

  14. Survival analysis: a tool in the study of post-harvest diseases in peaches

    OpenAIRE

    Cristiano Nunes Nesi; Silvia Emiko Shimakura; Paulo Justiniano Ribeiro Junior; Louise Larissa May De Mio

    2015-01-01

    Survival analysis is applied when the time until the occurrence of an event is of interest. Such data are routinely collected in plant diseases, although applications of the method are uncommon. The objective of this study was to use two studies on post-harvest diseases of peaches, considering two harvests together and the existence of random effect shared by fruits of a same tree, in order to describe the main techniques in survival analysis. The nonparametric Kaplan-Meier method, the log-ra...

  15. Disease stress detection on citrus using a leaf optical model and field spectroscopy

    Science.gov (United States)

    Badnakhe, Mrunalini R.; Durbha, Surya; Adinarayana, J.

    2015-10-01

    As citrus is progressively contributing to horticultural production, wealth and economy of a country, it is necessary to understand the factors impacting citrus production. Gummosis is one of the most serious diseases causing considerable loss of overall citrus production and yield quality. A qualitative and quantitative analysis of citrus leaf biochemical properties are necessary to monitor the crop health, disease /pest stress and production. Total leaf chlorophyll content (Cab) represents one of the key biochemical factors which contributes in water, carbon, and energy exchange processes. Photosynthesis process in citrus will be disturbed as gummosis disease life cycle progresses. It is important to study Cab to evaluate the photosynthesis rate and disease stress. In this study the potential of Radiative Transfer (RT) PROSPECT model to retrieve Cab in citrus orchards was undertaken at different sites. The main goal is to evaluate the relationship between Cab and gummosis disease stress for citrus at various phenological stages. Inversion of PROSPECT model on measured hyperspectral data is carried out to extract the leaf level parameters influencing the disease. This model was inverted with the ground truth hyperspectral reading. The testing was separately initiated for healthy and infected plant leaves. This can lead to understand the disease stress on citrus leaves. For accuracy, raw spectra are filtered and processed which is an input parameter for Inversion PROSPECT model. Here, retrieved Cab content was correlated with gummosis disease stress in terms of oozing with R2 = 0.6021 and RMSE= 0.481272.

  16. RNAi-Based Strategy for Asian Citrus Psyllid (Diaphorina citri) Control: A Method to Reduce the Spread of Citrus Greening Disease

    OpenAIRE

    Hawkings, Chloe; Morgan, K.; Shaffer, L.; Powell, C.; Borovsky, D.; Cave, R.; Dawson, B.; Gowda, S.; Shatters, Jr., R. G.

    2014-01-01

    Citrus greening disease is a serious bacterial disease of citrus worldwide and is vectored by the Asian citrus pysllid (Diaphorina Citri).  The only effective control strategy includes vigorous control of the psyllid, primarily through heavy reliance on pesticides. As a more sustainable and environmentally friendly method of psyllid control, we evaluated a RNA interference (RNAi) approach based on psyllid oral uptake of dsRNA molecules that target specific psyllid genes.  This approach is bas...

  17. Development of nursery for producing diseased free citrus propagation materials

    Directory of Open Access Journals (Sweden)

    Kirirat, P.

    2005-07-01

    Full Text Available A prototype of nursery house (5×8×3.80 m was established for producing disease free citrus propagation materials. The frame of prototype nursery house was made of galvanized pipe and it was covered with UV-resistance nylon net (32 mesh. Optimum temperature and relative humidity in the prototype nursery house were automatically controlled. It was compared with a commercial nethouse (6×9×4.40 m and a shade house (4×6×2.50 m. The capacity of the prototype nursery house, commercial nethouse and shade house was assessed by growth determination of plants grown inside for 3 months. The plant materials used for testing were Troyer seedlings, Shogun mandarin mother plants and Neck orange nursery trees. It was found that the plants grown in the prototype nursery house and commercial nethouse exhibited significantly higher growth than those plants in the shade house. Differences of temperature and relative humidity in the prototype nursery house, commercial nethouse and shade house were evaluated. It was prominent that the temperature and relative humidity during the experimental period in the commercial nethouse were highest, while they were lowest in the shade house. An occurrence of canker diseases markedly increased in the commercial nethouse because of high humidity and temperature. Leaf destruction by main insect pests wasa serious problem in the shade house. From the results, it is suggested that the prototype nursery house is suitable for producing disease free citrus propagation materials in southern Thailand.

  18. Transcriptome profiling of citrus fruit response to huanglongbing disease.

    Directory of Open Access Journals (Sweden)

    Federico Martinelli

    Full Text Available Huanglongbing (HLB or "citrus greening" is the most destructive citrus disease worldwide. In this work, we studied host responses of citrus to infection with Candidatus Liberibacter asiaticus (CaLas using next-generation sequencing technologies. A deep mRNA profile was obtained from peel of healthy and HLB-affected fruit. It was followed by pathway and protein-protein network analysis and quantitative real time PCR analysis of highly regulated genes. We identified differentially regulated pathways and constructed networks that provide a deep insight into the metabolism of affected fruit. Data mining revealed that HLB enhanced transcription of genes involved in the light reactions of photosynthesis and in ATP synthesis. Activation of protein degradation and misfolding processes were observed at the transcriptomic level. Transcripts for heat shock proteins were down-regulated at all disease stages, resulting in further protein misfolding. HLB strongly affected pathways involved in source-sink communication, including sucrose and starch metabolism and hormone synthesis and signaling. Transcription of several genes involved in the synthesis and signal transduction of cytokinins and gibberellins was repressed while that of genes involved in ethylene pathways was induced. CaLas infection triggered a response via both the salicylic acid and jasmonic acid pathways and increased the transcript abundance of several members of the WRKY family of transcription factors. Findings focused on the fruit provide valuable insight to understanding the mechanisms of the HLB-induced fruit disorder and eventually developing methods based on small molecule applications to mitigate its devastating effects on fruit production.

  19. The occurrence of postharvest diseases on apples resistant to scab

    OpenAIRE

    Hanna Bryk; Dorota Kruczyńska

    2012-01-01

    The occurrence of storage diseases on fruit of seven scab resistant apple cultivars (Freedom, Rajka, Topaz, Rubinola, Enterprise, Goldstar, GoldRush) grafted on M.9 was investigated in 2001-2005. The trees were planted in 1995. It was found that after storage (4 and 6 months at 2°C, 85-90% RH) the most severe appeared to be bull's eye rot (Pezicula spp.). The most sensitive cultivars to this disease were: Topaz, Freedom, Goldstar, the least sensitive were Rubinola, Enterprise, Rajka. Other po...

  20. Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB).

    Science.gov (United States)

    Hao, Guixia; Stover, Ed; Gupta, Goutam

    2016-01-01

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. Since no HLB-resistant citrus cultivars have been identified, we attempted to develop citrus resistant to both HLB and citrus canker through overexpression of a modified plant thionin. To improve effectiveness for disease resistance, we modified and synthesized the sequence encoding a plant thionin and cloned into the binary vector pBinPlus/ARS. The construct was then introduced into Agrobacterium strain EHA105 for citrus transformation. Transgenic Carrizo plants expressing the modified plant thionin were generated by Agrobacterium-mediated transformation. Successful transformation and transgene gene expression was confirmed by molecular analysis. Transgenic Carrizo plants expressing the modified thionin gene were challenged with X. citri 3213 at a range of concentrations, and a significant reduction in canker symptoms and a decrease in bacterial growth were demonstrated compared to nontransgenic plants. Furthermore, the transgenic citrus plants were challenged with HLB via graft inoculation. Our results showed significant Las titer reduction in roots of transgenic Carrizo compared with control plants and reduced scion Las titer 12 months after graft inoculation. These data provide promise for engineering citrus disease resistance against HLB and canker. PMID:27499757

  1. Twelve polymorphic microsatellite loci from the Asian Citrus Psyllid, Diaphorina citri Kuwayama, the vector for citrus greening disease Huanglongbing

    Science.gov (United States)

    Twelve polymorphic microsatellite markers were developed from microsatellite-enriched DNA libraries and mined from an EST library of Diaphorina citri, the vector of the devastating citrus greening disease (Huanglongbing). Analysis of 288 individuals from Florida, Texas, and Brazil showed allelic di...

  2. Antifungal Edible Coatings for Fresh Citrus Fruit: A Review

    Directory of Open Access Journals (Sweden)

    Lluís Palou

    2015-12-01

    Full Text Available According to their origin, major postharvest losses of citrus fruit are caused by weight loss, fungal diseases, physiological disorders, and quarantine pests. Cold storage and postharvest treatments with conventional chemical fungicides, synthetic waxes, or combinations of them are commonly used to minimize postharvest losses. However, the repeated application of these treatments has led to important problems such as health and environmental issues associated with fungicide residues or waxes containing ammoniacal compounds, or the proliferation of resistant pathogenic fungal strains. There is, therefore, an increasing need to find non-polluting alternatives to be used as part of integrated disease management (IDM programs for preservation of fresh citrus fruit. Among them, the development of novel natural edible films and coatings with antimicrobial properties is a technological challenge for the industry and a very active research field worldwide. Chitosan and other edible coatings formulated by adding antifungal agents to composite emulsions based on polysaccharides or proteins and lipids are reviewed in this article. The most important antifungal ingredients are selected for their ability to control major citrus postharvest diseases like green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, and include low-toxicity or natural chemicals such as food additives, generally recognized as safe (GRAS compounds, plant extracts, or essential oils, and biological control agents such as some antagonistic strains of yeasts or bacteria.

  3. Molecular Detection of Spiroplasma Citri Associated with Stubborn Disease in Citrus Orchards in Syria

    Science.gov (United States)

    Spiroplasma citri, a phloem-limited pathogen, causes citrus stubborn disease (CSD) and can be transmitted from plant to plant by several species of phloem-feeding leafhoppers. CSD is an important disorder in certain warm and arid citrus-growing areas, and its agent has been recorded from several Med...

  4. Targeting juvenile hormone metabolic genes in the Asian citrus psyllid (Diaphorina citri Kuwayama) as a strategy to reduce the spread of citrus greening disease

    OpenAIRE

    Van Ekert, Evelien; Borovsky, D.; Powell, C A; Cave, R. D.; Alessandro, R. T.; Shatters, Jr., R. G.

    2014-01-01

    Diaphorina citri Kuwayama, the Asian citrus psyllid (ACP), is a devastating citrus pest due to its transmission of a phloem-limited bacterial pathogen, Candidatus Liberibacter asiaticus, that causes citrus greening. Psyllid control is a major part of effective greening disease management, and our research targets perturbation of insect juvenile hormone metabolism as a new psyllid control strategy.  Previous studies have shown that application of a juvenile hormone (JH) analogue, pyriproxyfen,...

  5. Differential Reaction of Citrus Species in Malaysia to Huanglongbing (HLB Disease using Grafting Method

    Directory of Open Access Journals (Sweden)

    Hajivand Shokrollah

    2009-01-01

    Full Text Available Problem statement: Huanglongbing (HLB is a phloem limited disease in citrus caused by a fastidious bacterium called Candidatus Liberibacter found in Africa, Asia and United States of America (USA. HLB can severely reduce vigor and yield or kill all citrus trees within 5 years. There is a need to screen and identify suitable rootstock for propagation of clean plan materials for citrus in the tropics. This study was conducted to detect the presence of HLB on 18 selected citrus species and to categorize the level of infection and susceptibility of citrus species to HLB. Approach: Eighteen citrus species were assessed for susceptibility to HLB by graft transmission from source infection (Citrus reticulata. Results: HLB was detected in 15 species 6 months after grafting using PCR test. Conclusion: The species could be categorized in five groups: Severe group (72-58% severity which includes C. reticulata, C. sinensis, C. reshni cv. cleopatra, moderate group (50- 41% severity includes Fortunella sp. cv. Kasturi Chinai, C. macrophylla, C. microcarpa, mild group (25-17% severity which included C. medica, C. aurantifolia, Citrus sp. (natural biotype, C. jambhiri. The tolerant group which did not show any HLB symptoms but tested positive by PCR test includes C. aurantium and C. aurantifolia. The resistant groups which include C. grandis cv. Limau Bali, C. hysterix and Citrus sp. cv. Limau Tembikai showed no symptoms and were tested negative for HLB.

  6. Efeito de produtos alternativos para o controle do bolor verde (Penicillium digitatum em pós-colheita de citros Effect of the alternative products for control of green mold (Penicillium digitatum in post-harvest citrus fruit

    Directory of Open Access Journals (Sweden)

    DANIEL ANDRADE DE SIQUEIRA FRANCO

    2002-08-01

    Full Text Available O objetivo do trabalho foi verificar a ocorrência de sinergismo entre misturas de produtos alternativos aos fungicidas, para o controle do bolor verde (Penicillium digitatum em pós-colheita de citros. Foram testados dez produtos individualmente e trinta e cinco combinações destes produtos dois a dois, em comparação com tiabendazole e testemunha, com e sem inoculação. Os produtos testados não apresentaram efeito de sinergismo, exceto a mistura carbonato de Na + ácido bórico. Carbonato de Na e ácido bórico controlaram a doença em 78 e 87%, respectivamente, e, utilizando a mistura, o controle foi de 93%. Destacaram-se, ainda no controle da doença, o bicarbonato de Na, metabissulfito de Na e as misturas de bicarbonato de sódio + ácido bórico, carbonato de Na + carbonato de K, carbonato de Na + sorbato de K, bicarbonato de Na + carbonato de Na, controlando 92; 77; 81; 77; 75 e 71%, respectivamente. O tiabendazole utilizado como padrão controlou totalmente a doença.The objective of this work was verify the ocurrence of synergism of mixtures for alternative products to the fungicides for the control of the green mold (Penicillium digitatum in post-harvest citrus fruits. The efficiency of ten products, tested individually, and thirty five combinations among them, in pairs, were compared to thiabendazole and control, with and without inoculation. The products didn't present a synergism effect, except the mixture sodium carbonate + boric acid, that had a disease control of 93%. The products, sodium carbonate and boric acid controled 78 and 87%, respectively. The sodium bicarbonate, sodium methabisulphite and the mixtures of sodium bicarbonate + boric acid, sodium carbonate + potassium carbonate, sodium carbonate + potassium sorbate, sodium bicarbonate + sodium carbonate had a disease control of 92%, 77%, 81%, 77%, 75% and 71%, respectively. The fungicide treatment with thiabendazole used by standard had a whole disease control.

  7. [Visible-NIR spectral feature of citrus greening disease].

    Science.gov (United States)

    Li, Xiu-hua; Li, Min-zan; Won Suk, Lee; Reza, Ehsani; Ashish, Ratn Mishra

    2014-06-01

    Citrus greening (Huanglongbing, or HLB) is a devastating disease caused by Candidatus liberibacter which uses psyllids as vectors. It has no cure till now, and poses a huge threat to citrus industry around the world. In order to diagnose, assess and further control this disease, it is of great importance to first find a quick and effective way to detect it. Spectroscopy method, which was widely considered as a fast and nondestructive way, was adopted here to conduct a preliminary exploration of disease characteristics. In order to explore the spectral differences between the healthy and HLB infected leaves and canopies, this study measured the visible-NIR spectral reflectance of their leaves and canopies under lab and field conditions, respectively. The original spectral data were firstly preprocessed with smoothing (or moving average) and cluster average procedures, and then the first derivatives were also calculated to determine the red edge position (REP). In order to solve the multi-peak phenomenon problem, two interpolation methods (three-point Lagrangian interpolation and four-point linear extrapolation) were adopted to calculate the REP for each sample. The results showed that there were, obvious differences at the visible & NIR spectral reflectance between the healthy and HLB infected classes. Comparing with the healthy reflectance, the HLB reflectance was higher at the visible bands because of the yellowish symptoms on the infected leaves, and lower at NIR bands because the disease blocked water transportation to leaves. But the feature at NIR bands was easily affected by environmental factors such as light, background, etc. The REP was also a potential indicator to distinguish those two classes. The average REP was slowly moving toward red bands while the infection level was getting higher. The gap of the average REPs between the healthy and HLB classes reached to a maximum of 20 nm. Even in the dataset with relatively lower variation, the classification

  8. Candidate gene markers for Candidatus Liberibacter asiaticus for detecting citrus greening disease

    Indian Academy of Sciences (India)

    Madhugiri Nageswara-Rao; Mike Irey; Stephen M Garnsey; Siddarame Gowda

    2013-06-01

    Citrus Huanglongbing (HLB) also known as citrus greening is one of the most devastating diseases of citrus worldwide. The disease is caused by Candidatus Liberibacter bacterium, vectored by the psyllid Diaphorina citri Kuwayama and Trioza erytreae Del Guercio. Citrus plants infected by the HLB bacterium may not show visible symptoms sometimes for years following infection. The aim of this study was to develop effective gene-specific primer pairs for polymerase chain reaction based method for quick screening of HLB disease. Thirty-two different gene-specific primer pairs, across the Ca. Liberibacter asiaticus genome, were successfully developed. The possibility of these primer pairs for cross-genome amplification across `Ca. Liberibacter africanus’ and `Ca. Liberibacter americanus’ were tested. The applicability of these primer pairs for detection and differentiation of Ca Liberibacter spp. is discussed.

  9. The psorosis disease of citrus: a pale light at the end of the tunnel

    OpenAIRE

    Moreno, Pedro; Guerri, José; García, María Laura

    2015-01-01

    Abstract First reported in 1896, psorosis was the first citrus disease proven to be graft transmissible and also the first for which eradication and budwood certification programs were launched to prevent its economic damage. For many years psorosis etiology remained elusive and only in 1986 it was associated with the presence of virus-like particles in infected plants. However, in the last two decades a virus with unusual morphology (Citrus psorosis virus, CPsV) was characterized and closely...

  10. Role Bending: Complex Relationships Between Viruses, Hosts, and Vectors Related to Citrus Leprosis, an Emerging Disease.

    Science.gov (United States)

    Roy, Avijit; Hartung, John S; Schneider, William L; Shao, Jonathan; Leon, Guillermo; Melzer, Michael J; Beard, Jennifer J; Otero-Colina, Gabriel; Bauchan, Gary R; Ochoa, Ronald; Brlansky, Ronald H

    2015-07-01

    Citrus leprosis complex is an emerging disease in the Americas, associated with two unrelated taxa of viruses distributed in South, Central, and North America. The cytoplasmic viruses are Citrus leprosis virus C (CiLV-C), Citrus leprosis virus C2 (CiLV-C2), and Hibiscus green spot virus 2, and the nuclear viruses are Citrus leprosis virus N (CiLV-N) and Citrus necrotic spot virus. These viruses cause local lesion infections in all known hosts, with no natural systemic host identified to date. All leprosis viruses were believed to be transmitted by one species of mite, Brevipalpus phoenicis. However, mites collected from CiLV-C and CiLV-N infected citrus groves in Mexico were identified as B. yothersi and B. californicus sensu lato, respectively, and only B. yothersi was detected from CiLV-C2 and CiLV-N mixed infections in the Orinoco regions of Colombia. Phylogenetic analysis of the helicase, RNA-dependent RNA polymerase 2 domains and p24 gene amino acid sequences of cytoplasmic leprosis viruses showed a close relationship with recently deposited mosquito-borne negevirus sequences. Here, we present evidence that both cytoplasmic and nuclear viruses seem to replicate in viruliferous Brevipalpus species. The possible replication in the mite vector and the close relationship with mosquito borne negeviruses are consistent with the concept that members of the genus Cilevirus and Higrevirus originated in mites and citrus may play the role of mite virus vector. PMID:25775106

  11. Breeding, genetic and genomic of citrus for disease resistance

    OpenAIRE

    Machado, Marcos A; Mariângela Cristofani-Yaly; Marinês Bastianel

    2011-01-01

    Although the citriculture is one of the most important economic activities in Brazil, it is based on a small number of varieties. This fact has contributed for the vulnerability of the culture regarding the phytosanitary problems. A higher number of varieties/genotypes with potential for commercial growing, either for the industry or fresh market, has been one of the main objectives of citrus breeding programs. The genetic breeding of citrus has improved, in the last decades, due to the possi...

  12. Survival analysis: a tool in the study of post-harvest diseases in peaches

    Directory of Open Access Journals (Sweden)

    Cristiano Nunes Nesi

    2015-02-01

    Full Text Available Survival analysis is applied when the time until the occurrence of an event is of interest. Such data are routinely collected in plant diseases, although applications of the method are uncommon. The objective of this study was to use two studies on post-harvest diseases of peaches, considering two harvests together and the existence of random effect shared by fruits of a same tree, in order to describe the main techniques in survival analysis. The nonparametric Kaplan-Meier method, the log-rank test and the semi-parametric Cox's proportional hazards model were used to estimate the effect of cultivars and the number of days after full bloom on the survival to the brown rot symptom and the instantaneous risk of expressing it in two consecutive harvests. The joint analysis with baseline effect, varying between harvests, and the confirmation of the tree effect as a grouping factor with random effect were appropriate to interpret the phenomenon (disease evaluated and can be important tools to replace or complement the conventional analysis, respecting the nature of the variable and the phenomenon.

  13. Identification of citrus greening disease using FTIR spectroscopy and chemometric analysis

    Science.gov (United States)

    Huanglongbing (HLB), also called citrus greening disease, is difficult to detect in plants before visual symptoms appear, by which time the disease is likely to have spread to other nearby plants. An accurate, early detection method is needed to identify diseased plants. Current methods are both c...

  14. CITRUS AND COFFEE STRAINS OF XYLELLA FASTIDIOSA INDUCE PIERCES DISEASE IN GRAPEVINE

    Science.gov (United States)

    Xylella fastidiosa causes citrus variegated chlorosis disease in Brazil and Pierces Disease of grapevines in the United States. Both of these diseases cause significant production problems in the respective industries. The recent establishment of the glassy-winged sharpshooter in California has ra...

  15. CITRUS AND COFFEE STRAINS OF XYELLA FASTIDIOSA INDUCE PIERCE'S DISEASE IN GRAPEVINE

    Science.gov (United States)

    Xyella fastidiosa causes Citrus Varigated Chlorosis (CVC) and Coffee Leaf Scorch (CLS) diseases in Brazil and Pierce's Disease (PD) of grapvine in the United States. All three diseases cause significant production problems in the respective industries. The recent establishment of the glassy-winged...

  16. PERFORMANCE EVALUATION OF VARIOUS STATISTICAL CLASSIFIERS IN DETECTING THE DISEASED CITRUS LEAVES

    Directory of Open Access Journals (Sweden)

    SUDHEER REDDY BANDI

    2013-02-01

    Full Text Available Citrus fruits are in lofty obligation because the humans consume them daily. This research aims to amend citrus production, which knows a low upshot bourgeois on the production and complex during measurements. Nowadays citrus plants grappling some traits/diseases. Harm of the insect is one of the major trait/disease. Insecticides are not ever evidenced effectual because insecticides may be toxic to some gracious of birds. Farmers get outstanding difficulties in detecting the diseases ended open eye and also it is quite expensive.Machine vision and Image processing techniques helps in sleuthing the disease mark in citrus leaves and sound job. In this search, Citrus leaves of four classes like Normal, Greasy spot, Melanose and Scab are collected and investigated using texture analysis based on the Color Co-occurrence Method (CCM to take Hue, Saturation and Intensity (HSI features. In the arrangement form, the features are categorised for all leafage conditions using k-Nearest Neighbor (kNN, Naive Bayes classifier (NBC, Linear Discriminate Analysis (LDA classifier and Random Forest Tree Algorithm classifier (RFT. The experimental results inform that proposed attack significantly supports 98.75% quality in automated detection of regular and struck leaves using texture psychotherapy based CCM method using LDA formula. Eventually all the classifiers are compared using Earphone Operative Characteristic contour and analyzed the performance of all the classifiers.

  17. Antifungal Activity of Some Constituents of Origanum vulgare L. Essential Oil Against Postharvest Disease of Peach Fruit.

    Science.gov (United States)

    Elshafie, Hazem S; Mancini, Emilia; Sakr, Shimaa; De Martino, Laura; Mattia, Carlo Andrea; De Feo, Vincenzo; Camele, Ippolito

    2015-08-01

    Plant essential oils (EOs) can potentially replace synthetic fungicides in the management of postharvest fruit and vegetable diseases. The aim of this study was to evaluate in vitro and in vivo effectiveness of thymol, carvacrol, linalool, and trans-caryophyllene, single constituents of the EO of Origanum vulgare L. ssp. hirtum against Monilinia laxa, M. fructigena, and M. fructicola, which are important phytopathogens and causal agents of brown rot of pome and stone fruits in pre- and postharvest. Moreover, the possible phytotoxic activity of these constituents was assessed and their minimum inhibitory concentration (MIC) was determined. In vitro experiment indicated that thymol and carvacrol possess the highest antifungal activity. Results of in vivo trials confirmed the strong efficacy of thymol and carvacrol against brown rot of peach fruits. The thymol MIC resulted to be 0.16 μg/μL against M. laxa and M. fructigena and 0.12 μg/μL against M. fructicola, whereas for carvacrol they were 0.02 μg/μL against the first two Monilinia species and 0.03 μg/μL against the third. Results of this study indicated that thymol and carvacrol could be used after suitable formulation for controlling postharvest fruit diseases caused by the three studied Monilinia species. PMID:25599273

  18. The control of postharvest blue and green molds of citrus in relation with essential oil-wax formulations, adherence and viscosity.

    OpenAIRE

    Kouassi, Kouadio Hugues Sosthène; Bajji, Mohammed; Jijakli, Haissam

    2012-01-01

    The use of wax coatings enriched with antifungals has significantly contributed to quality maintaining of harvested citrus fruit. On the other hand, interest in essential oils (EOs) as an alternative to synthetic fungicides has recently gained momentum. In this study, Cinnamomum zeylanicum EO was incorporated into a variety of commercial citrus waxes (shellac, carnauba, paraffin and polyethylene). The biological activity of these formulations against green and blue rots as well as their visco...

  19. Preventive and curative activity of combined treatments of sodium carbonates and Pantoea agglomerans CPA-2 to control postharvest green mold of citrus fruit

    Science.gov (United States)

    Preventive and curative activity of 2 min dips in 3% sodium carbonate (SC) or sodium bicarbonate (SBC) aqueous solutions heated to 40ºC, alone of followed by the application of 2 x 108 CFU/ml of the biocontrol agent Pantoea agglomerans CPA-2 (BA), in the control of postharvest green mold, caused by ...

  20. Discrimination of Five Citrus Diseased Leaves by FTIR Spectroscopy

    OpenAIRE

    Zhao, Xingxiang; Liu, Gang; Li, Weixing; Wang, Xiaohua; Hao, Jianming; Zhou, Xiangping

    2014-01-01

    In this paper, citrus brown spot, huanglongbing, canker, fuliginous, cercospora sp. and healthy leaves were studied using Fourier transform infrared spectroscopy (FTIR) combined with statistical analysis. The results showed that the spectra of the samples were similar, whereas there were obvious differences in the second derivatives of infrared spectra in the range of 1500-700 cm-1. The correlative analysis were evaluated, results showed that the correlation coefficients were larger than 0.91...

  1. The genetics of tolerance to tristeza disease in citrus rootstocks

    Directory of Open Access Journals (Sweden)

    Rita Bordignon

    2004-01-01

    Full Text Available Controlled pollinations between four elite citrus rootstocks, Citrus limonia - 'Limeira' rangpur lime (Cravo, C. sunki - 'Sunki' mandarin (Sunki, C. aurantium - 'São Paulo' sour orange (Azeda and Poncirus trifoliata - 'Davis A' trifoliate orange (Trifoliata, resulted in 1614 nucelar and 1938 hybrid plants identified by the isozyme loci Pgi-1, Pgm-1, Got-1, Got-2, Aps-1, Me-1, Prxa-1 and or by the morphological markers broadness of leaf petiole wing or trifoliolate leaves. Tolerance to the citrus tristeza virus (CTV was evaluated under nursery and field conditions for several years by the reaction of Valencia orange infected with a severe strain of CTV and grafted onto the hybrids and nucellar clones. Genetic analyses indicated that tolerance was controlled by at least two loci designated here as Az and t interacting in dominant-recessive epistasis. Genotypes Az__ __ __ and __ __ tt were tolerant while azaz T__ was intolerant. The intolerant Azeda was azaz TT, the tolerant rootstocks Sunki and Cravo were Azaz tt and the Trifoliata was Azaz TT. The different degrees of intolerance seen in some hybrids may reflect the inability of segregating modifiers from parental clones to overcome the epistatic interaction that controls the major tolerance reaction.

  2. Portable fluorescence spectroscopy platform for Huanglongbing (HLB) citrus disease in situ detection

    Science.gov (United States)

    Mota, Alessandro D.; Rossi, Giuliano; de Castro, Guilherme Cunha; Ortega, Tiago A.; de Castro N., Jarbas C.

    2014-02-01

    In this work, the development of a portable fluorescence spectroscopy platform for Huanglongbing (HLB) citrus disease in situ detection is presented. The equipment consists of an excitation blue LED light source, a commercial miniature spectrometer and embedded software. Measurements of healthy, HLB-symptomatic and HLB-asymptomatic citrus leafs were performed. Leafs were excited with the blue LED and their fluorescence spectra collected. Embedded electronics and software were responsible for the spectrum processing and classification via partial least squares regression. Global success rates above 80% and 100% distinction of healthy and HLB-symptomatic leafs were obtained.

  3. Breeding, genetic and genomic of citrus for disease resistance

    Directory of Open Access Journals (Sweden)

    Marcos A. Machado

    2011-10-01

    Full Text Available Although the citriculture is one of the most important economic activities in Brazil, it is based on a small number of varieties. This fact has contributed for the vulnerability of the culture regarding the phytosanitary problems. A higher number of varieties/genotypes with potential for commercial growing, either for the industry or fresh market, has been one of the main objectives of citrus breeding programs. The genetic breeding of citrus has improved, in the last decades, due to the possibility of an association between biotechnological tools and classical methods of breeding. The use of molecular markers for early selection of zygotic seedlings from controlled crosses resulted in the possibility of selection of a high number of new combination and, as a consequence, the establishment of a great number of hybrids in field experiments. The faster new tools are incorporated in the program, the faster is possibility to reach new genotypes that can be tested as a new variety. Good traits should be kept or incorporate, whereas bad traits have to be excluded or minimized in the new genotype. Scion and rootstock can not be considered separately, and graft compatibility, fruit quality and productivity are essential traits to be evaluated in the last stages of the program. The mapping of QTLs has favored breeding programs of several perennial species and in citrus it was possible to map several characteristics with qualitative and quantitative inheritance. The existence of linkage maps and QTLs already mapped, the development of EST and BAC library and the sequencing of the Citrus complete genome altogether make very demanding and urgent the exploration of such data to launch a wider genetic study of citrus. The rising of information on genome of several organisms has opened new approaches looking for integration between breeding, genetic and genome. Genome assisted selection (GAS involves more than gene or complete genome sequencing and is becoming

  4. Radiation preservation of foods of plant origin. Part IV. Subtropical fruits: citrus, grapes, and avocados

    International Nuclear Information System (INIS)

    Current information on the use of ionizing radiation for improving the storage of subtropical fruits like citrus, grapes, and avocados is reviewed. The feasibility of applying radiation either alone or in combination with other physical or chemical treatments for the control of postharvest fungal diseases is considered. Irradiation effects on the physiology of the fruits as related to respiration, ethylene evolution, changes in major chemical constituents, and quality are discussed. The recent trends in the possible use of irradiation as an alternative treatment to chemical fumigants for disinfestation of citrus and avocados and the prospects for the future application of irradiation for preservation of some of these fruits are outlined. 128 references

  5. Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease.

    Science.gov (United States)

    Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B; Yang, Bing; White, Frank F; Wang, Nian; Jones, Jeffrey B

    2014-01-28

    Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccA(w), induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

  6. Citrus Genomics

    OpenAIRE

    Talon, Manuel; Gmitter, Fred G.Jr.

    2008-01-01

    Citrus is one of the most widespread fruit crops globally, with great economic and health value. It is among the most difficult plants to improve through traditional breeding approaches. Currently, there is risk of devastation by diseases threatening to limit production and future availability to the human population. As technologies rapidly advance in genomic science, they are quickly adapted to address the biological challenges of the citrus plant system and the world's industries. The hist...

  7. Evaluation of yeasts obtained from Antarctic soil samples as biocontrol agents for the management of postharvest diseases of apple (Malus x domestica)

    Science.gov (United States)

    Psychrotrophic yeasts isolated from soils collected in Antarctica and selected by its capacity of growing in apple juice at low temperatures were evaluated for their potential as biocontrol agents for the management of postharvest diseases of apple during cold storage. Among the species recovered, ...

  8. Generating Asian citrus Psyllid Diaphorina citri Kuwayama (Homoptera: Psyllidae) with twisting wings to prevent the spread of citrus greening disease

    OpenAIRE

    El-Shesheny, I.; Harjeri, S.; Gowda, S.; Killiny, N.

    2014-01-01

    Huanglongbing (HLB) is seriously threatening and causing considerable economic losses to the citrus groves. Its Management depends critically on the control of the Asian citrus Psyllid (ACP), the vector of the cause of HLB, Candidatus Liberibacter asiaticus bacteria (CLas). Silencing genes by RNA interference (RNAi) is a promising technique to control pests. In this study, the abnormal disk wing (awd) has been selected from the available psyllid annotated genome. It has been known that awd ge...

  9. Effects of two kinds of medicinal plant extracts on citrus postharvest preservation%两种药用植物提取物对柑橘保鲜的影响

    Institute of Scientific and Technical Information of China (English)

    戴素明; 曾建国; 程辟; 陈义明; 周翔; 邓子牛

    2012-01-01

    为筛选能应用于柑橘保鲜的药用植物提取物,测定了博落回和虎杖提取物对柑橘绿霉菌的抑菌活性以及对柑橘保鲜的效果.结果表明:博落回和虎杖提取物均能抑制绿霉菌的生长,二者的有效中质量浓度分别为184.32、538.48 mg/L,博落回的抑菌效果比虎杖好;与清水对照相比,2种提取物处理柑橘的腐烂率均显著降低;与常规化学保鲜剂相比,2种提取物冰糖橙的腐烂率差异均无统计学意义,但椪柑的腐烂率均显著升高;2种提取物处理冰糖橙的失水率与常规化学保鲜剂处理的差异均无统计学意义,但显著高于清水处理,2种提取物对冰糖橙的防腐、保鲜能达到常规化学保鲜剂的效果.%For selection of medicinal plant extracts to be applied into citrus postharvest preservation, the inhibition effect of Macleaya cordata and Polygonum cuspidatum on Penicillium digitatum and its preservation effect during citrus storage were studied. The results were as follows: Both M. Cordata and P. Cuspidatum could inhibit growth of P. Digitatum, ED50 of which were 184.32 and 538.48 mg/L respectively, especially the inhibition effect of M cordata was better. With comparison of water treatment, the two kinds of medicinal plant extracts could both effectively prevent Bingtangcheng from decay. With comparison of conventional chemical preservative, the decay rates of Bingtangcheng respectively treated by the two kinds of medicinal plant extracts had no statistical significance, but Ponkan significantly increased. The water losing rates of Bingtangcheng respectively treated by the two kinds of medicinal plant extracts were no statistical significance compared with conventional chemical preservative, but the water losing rates of these three treatments were significantly lower than water treatment. The effects of the two kinds of medicinal plant extracts on decay and fresh-keeping of Bingtangcheng were similar to conventional chemical

  10. Citrus tristeza virus-based RNAi in citrus plants induces gene silencing in Diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (Huanglongbing).

    Science.gov (United States)

    Hajeri, Subhas; Killiny, Nabil; El-Mohtar, Choaa; Dawson, William O; Gowda, Siddarame

    2014-04-20

    A transient expression vector based on Citrus tristeza virus (CTV) is unusually stable. Because of its stability it is being considered for use in the field to control Huanglongbing (HLB), which is caused by Candidatus Liberibacter asiaticus (CLas) and vectored by Asian citrus psyllid, Diaphorina citri. In the absence of effective control strategies for CLas, emphasis has been on control of D. citri. Coincident cohabitation in phloem tissue by CLas, D. citri and CTV was exploited to develop a novel method to mitigate HLB through RNA interference (RNAi). Since CTV has three RNA silencing suppressors, it was not known if CTV-based vector could induce RNAi in citrus. Yet, expression of sequences targeting citrus phytoene desaturase gene by CTV-RNAi resulted in photo-bleaching phenotype. CTV-RNAi vector, engineered with truncated abnormal wing disc (Awd) gene of D. citri, induced altered Awd expression when silencing triggers ingested by feeding D. citri nymphs. Decreased Awd in nymphs resulted in malformed-wing phenotype in adults and increased adult mortality. This impaired ability of D. citri to fly would potentially limit the successful vectoring of CLas bacteria between citrus trees in the grove. CTV-RNAi vector would be relevant for fast-track screening of candidate sequences for RNAi-mediated pest control. PMID:24572372

  11. Inhibition of Colletotrichum gloeosporioides and Control of Postharvest Anthracnose Disease on Mango Fruit Using Propionic Acid Combined with Bee-Carnauba Wax Emulsion

    OpenAIRE

    Do Chi Thinh; Kaewalin Kunasakdakul

    2013-01-01

    Anthracnose caused by Colletotrichum gloeosporioides is the most significant postharvest disease of mangos and negatively affect handling and marketing of mango fruits in Vietnam. A mixture of bee-carnauba wax and propionic acid has successfully inhibited linear growth and spore germination of C. gloeosporioides (in vitro) and prevented anthracnose diseases of mango fruits (in vivo). A complete reduction in mycelial growth and spore germination was observed when a mixture of 0.09% propionic a...

  12. Comparison on the Control Effects of Different Fungicides on Postharvest Citrus Green Mould%不同杀菌剂对采后柑桔绿霉病的防治效果比较

    Institute of Scientific and Technical Information of China (English)

    夏长秀; 李红叶; 王明爽; 彭龙; 娄伟; 严翔; 赖华荣; 凌永河; 朱从一; 方贻文

    2012-01-01

    在柑桔果实先刺伤接种柑桔绿霉病菌Penicillium digitatum孢子悬浮液再进行药剂浸果的条件下,研究了不同类型、不同浓度药剂对抗苯并咪唑类和咪唑类杀菌剂(双抗)或双敏感菌系的防治效果.结果表明:500或1 000 mg/L的甲基硫菌灵、咪鲜胺(扑霉灵)和抑霉唑(500mg/L)单剂,甲基硫菌灵和咪鲜胺(或扑霉灵)混剂对双抗菌系防治作用均低于50%;1 000 mg/L百可得单剂,500、1 000 mg/L百可得混配相同浓度咪鲜胺(或扑霉灵)均可控制双抗菌系引起的腐烂,防治效果在83%以上;1000mg/L咯菌腈对双抗菌系的防治效果为83.3%,500和1 000 mg/L嘧霉胺对双抗菌系的防治效果分别为91.1%和98.9%.500mg/L百可得、抑霉唑和嘧霉胺单剂,500mg/L百可得混配相同浓度咪鲜胺(或扑霉灵),500 mg/L甲基硫菌灵混配相同浓度扑霉灵对敏感菌系均有88%以上防治效果.基于研究结果,建议不再使用苯并咪唑类和咪唑类杀菌剂单剂或这两类杀菌剂混剂防治柑桔采后病害,可选择1 000 mg/L百可得(双胍辛烷苯基磺酸盐)单剂,500mg/L百可得和相同浓度咪唑类混剂.同时建议将嘧霉胺登记用于柑桔采后处理.%Effects of different types and concentrations of fungicides on post-harvest green mould disease were evaluated after wound- inoculation of the fruit with spore suspensions of Penicillium digitatum. Results showed that the control efficacy of 500 or 1 000 mg/L of thiophanate-methyl, 500 or 1 000 mg/L of prochlorazalone, 500 mg/L of imazalil, 500 mg/L of thiophanate-methyl plus 500 mg/L of prochloraz was lower than 50%. However, 1 000 mg/L of Bellkute, 500 mg/L of Bellkute + 500 mg/L of Prochloraz, 1 000 mg/L of Bellkute + 1 000 mg/L of Prochloraz showed good control results toward the double resistance isolates. The control efficacy of fludioxonil at 1 000 mg/L, pyrimethanil at 500 and 1 000 mg/L was 83. 3%, 91. 1% and 98. 9%, respectively. The control efficacy

  13. Chilling Temperature Enhances Ouality Reduction in Postharvest 'Shatangju' ( Citrus reticulata Blanco) Fruit%冷害导致砂糖橘果实品质劣变

    Institute of Scientific and Technical Information of China (English)

    庞学群; 陈燕妮; 黄雪梅; 汪跃华; 胡位荣; 张昭其

    2008-01-01

    将砂糖橘(Citrus reticulata Blanco)果实分别置于1、3、6和9℃下贮藏,比较其贮藏效果及冷害对果实品质的影响.结果表明:砂糖橘最适贮藏温度为6℃,在1~3℃贮藏易发生冷害.冷害导致果实外观品质下降,果肉乙醛和乙醇含量累积,果肉异味,品质下降.1℃贮藏的果实呼吸速率和乙烯释放速率较6℃高,丙二醛(MDA)含量增加,丙酮酸脱羧酶(PDC)和乙醇脱氢酶(ADH)活性大幅度提高.说明在冷害温度下,砂糖橘果肉异味是由于乙醛和乙醇累积产生,而果实呼吸速率的提高与PDC和ADH活性的增加密切相关.

  14. “Candidatus liberibacter sp.”, without koch's postulates completed, can the bacterium be considered as the causal agent of citrus Huanglongbing (yellow shoot disease)?

    Science.gov (United States)

    Huanglongbing (HLB) or yellow shoot disease is a destructive disease that threatens citrus production worldwide. The emergence of HLB in Sao Paulo, State of Brazil in 2004 and in Florida of the U.S. in 2005 has increased concern in the citrus production community in the USA. Intensive research is cu...

  15. Detection of phytoplasma and Candidatus Liberibacter asiaticus in citrus showing Huanglongbing (yellow shoot disease) symptoms in Guangdong, P. R. China

    Science.gov (United States)

    Huanglongbing (HLB) or yellow shoot disease (ex. greening disease) is highly destructive to citrus production worldwide. HLB is currently known to be associated with Candidatus Liberibacter asiaticus in China. However, Koch’s postulates have not been fulfilled. It also remains unclear if other plant...

  16. Comparative Genomic Analysis of Xanthomonas axonopodis pv. citrumelo F1, Which Causes Citrus Bacterial Spot Disease, and Related Strains Provides Insights into Virulence and Host Specificity ▿ #

    OpenAIRE

    Jalan, Neha; Aritua, Valente; Kumar, Dibyendu; Yu, Fahong; Jones, Jeffrey B; Graham, James H; Setubal, João C; Wang, Nian

    2011-01-01

    Xanthomonas axonopodis pv. citrumelo is a citrus pathogen causing citrus bacterial spot disease that is geographically restricted within the state of Florida. Illumina, 454 sequencing, and optical mapping were used to obtain a complete genome sequence of X. axonopodis pv. citrumelo strain F1, 4.9 Mb in size. The strain lacks plasmids, in contrast to other citrus Xanthomonas pathogens. Phylogenetic analysis revealed that this pathogen is very close to the tomato bacterial spot pathogen X. camp...

  17. Comprehensive meta-analysis, co-expression, and miRNA nested network analysis identifies gene candidates in citrus against Huanglongbing disease

    OpenAIRE

    Rawat, Nidhi; Kiran, Sandhya P.; Du, Dongliang; Gmitter, Fred G; Deng, Zhanao

    2015-01-01

    Background Huanglongbing (HLB), the most devastating disease of citrus, is associated with infection by Candidatus Liberibacter asiaticus (CaLas) and is vectored by the Asian citrus psyllid (ACP). Recently, the molecular basis of citrus–HLB interactions has been examined using transcriptome analyses, and these analyses have identified many probe sets and pathways modulated by CaLas infection among different citrus cultivars. However, lack of consistency among reported findings indicates that ...

  18. Yeasts isolated from figs (Ficus carica L.) as biocontrol agents of postharvest fruit diseases.

    Science.gov (United States)

    Ruiz-Moyano, S; Martín, A; Villalobos, M C; Calle, A; Serradilla, M J; Córdoba, M G; Hernández, A

    2016-08-01

    Fresh fruit is highly perishable during postharvest life, mainly due to fungal growth. Thus, fungal control is an important goal for the fruit industry. In this work, a selection of antagonistic yeasts isolated from fig and breba crops were screened in vitro. The isolated yeasts were challenged with three moulds isolated from decayed figs and breba crops, identified as Penicillium expansum M639 and Cladosporium cladosporioides M310 and M624, and pathogenic moulds Botrytis cinerea CECT20518 and Monilia laxa CA1 from culture collections. Two yeast isolates, Hanseniaspora opuntiae L479 and Metschnikowia pulcherrima L672, were selected for their ability to inhibit the growth of aforementioned moulds. These yeasts reduced the radial growth of moulds on PDA by between 45.23% and 66.09%. Antagonistic activity was associated with the interaction of live yeast cells with moulds. M. pulcherrima L672 apparently parasitised C. cladosporioides isolates. In addition, challenges were assayed using wounded apples and nectarines, with significant reductions in percent infection and lesion size for all moulds tested. To our knowledge, this is the first report identifying H. opuntiae as an antagonist against different pathogenic moulds. PMID:27052701

  19. Effect of amino acid application on induced resistance against citrus canker disease in lime plants

    Directory of Open Access Journals (Sweden)

    Hasabi Vahideh

    2014-07-01

    Full Text Available Citrus bacterial canker, caused by Xanthomonas citri subsp. citri (Xcc, is a destructive disease. So far, the chemicals used to control this pathogen are either ineffective or harmful to the environment. To improve control of this disease, lime (Citrus aurantifolia were treated with L-arginine, L-methionine, L-ornithine, and distilled water. Plants were inoculated with Xcc, 48 hours post treatment. Lesion diameters of inoculated leaves were evaluated four weeks after inoculation with a bacterial suspension. Changes in β-1,3-glucanase transcript levels and activity of antioxidant enzymes, catalase, peroxidase, and phenylalanine ammonia-lyase were investigated at 48 hours post treatment and 24, 48, and 72 hours post inoculation. Based on the results of phenotypic, antioxidant enzyme activity and a molecular study of the stressed plants, it was found that those plants treated with the amino acid methionine significantly increased the plant induced resistance as well as decreased the severity of disease by reducing necrotic lesion size.

  20. Effects of Organic Acids and Salts on the Development of Penicillium italicum: The Causal Agent of Citrus Blue Mold

    OpenAIRE

    Boudyach El Hassane; Serghini Mohammed Amine; Boubaker Hassan; Talibi Idriss; Askarne Latifa; Ait Ben Aoumar Abdellah

    2011-01-01

    Control of Citrus blue mold, caused by Penicillium italicum, has been accomplished by postharvest application of synthetic fungicides. However, the development of resistant fungal strains and increasing public concern over food safety and the environment are driving a search for alternative disease control strategies. In vitro trials were conducted to evaluate the effect of several organic acid and salt compounds on mycelial growth, sporulation, spore germination and germ tube elongation of P...

  1. Genetic variation and recombination of RdRp and HSP 70h genes of Citrus tristeza virus isolates from orange trees showing symptoms of citrus sudden death disease

    Directory of Open Access Journals (Sweden)

    Pappas Georgios J

    2008-01-01

    Full Text Available Abstract Background Citrus sudden death (CSD, a disease that rapidly kills orange trees, is an emerging threat to the Brazilian citrus industry. Although the causal agent of CSD has not been definitively determined, based on the disease's distribution and symptomatology it is suspected that the agent may be a new strain of Citrus tristeza virus (CTV. CTV genetic variation was therefore assessed in two Brazilian orange trees displaying CSD symptoms and a third with more conventional CTV symptoms. Results A total of 286 RNA-dependent-RNA polymerase (RdRp and 284 heat shock protein 70 homolog (HSP70h gene fragments were determined for CTV variants infecting the three trees. It was discovered that, despite differences in symptomatology, the trees were all apparently coinfected with similar populations of divergent CTV variants. While mixed CTV infections are common, the genetic distance between the most divergent population members observed (24.1% for RdRp and 11.0% for HSP70h was far greater than that in previously described mixed infections. Recombinants of five distinct RdRp lineages and three distinct HSP70h lineages were easily detectable but respectively accounted for only 5.9 and 11.9% of the RdRp and HSP70h gene fragments analysed and there was no evidence of an association between particular recombinant mosaics and CSD. Also, comparisons of CTV population structures indicated that the two most similar CTV populations were those of one of the trees with CSD and the tree without CSD. Conclusion We suggest that if CTV is the causal agent of CSD, it is most likely a subtle feature of population structures within mixed infections and not merely the presence (or absence of a single CTV variant within these populations that triggers the disease.

  2. Small RNA profiling reveals phosphorus deficiency as a contributing factor in symptom expression for Citrus Huanglongbing Disease

    Science.gov (United States)

    Huanglongbing (HLB) is a devastating citrus disease that is associated with bacteria of the genus Candidatus Liberibacter(Ca. L.). Powerful diagnostic tools and management strategies are desired to control HLB. Host small Ribonucleic acid (sRNA) play a vital role in regulating host responses to pa...

  3. Resistance to Gas Diffusion in Internal Tissues of Citrus Fruit

    OpenAIRE

    Dirpan, Andi

    2015-01-01

    Japan is a major citrus fruit-producing country, and Ehime Prefecture is one of the main citrus fruit producing regions in Japan. As many as 20 major citrus varieties are cultivated in Ehime. To further develop postharvest technology for quality preservation such as modified atmosphere packaging (MAP) and controlled atmosphere (CA) storage, creating an optimum gas concentration around fruit and vegetables have to be precisely achieved. However, the external atmosphere of fresh products in MAP...

  4. Incidence of post-harvest fungal diseases of ripe papaya in Mymensingh

    OpenAIRE

    Hamim, I.; Alam, M.Z.; Ali, M. A.; M. Ashrafuzzaman

    2014-01-01

    A survey was conducted during November, 2012 to May, 2013 to assess the status of major post harvest diseases of papaya fruits in the local markets of Mymensingh. Average percentage of diseased fruits at the markets were 29.83 and diseased fruits ranged from 20.40% to 38.04% during the study period. Highest percentage of diseased fruits (38.04%) was recorded in the month of May, 2013 followed by March, 2013 (37.98%). The minimum percentage of diseased fruits (20.40%) was recorded in January, ...

  5. Caracterização dos danos pós-colheita em citros procedentes de "packinghouse" Characterization of post-harvest damages in citrus fruits from the packinghouse

    Directory of Open Access Journals (Sweden)

    Ivan H. Fischer

    2007-08-01

    Full Text Available As doenças pós-colheita representam um sério obstáculo à citricultura, uma vez que comprometem a qualidade e quantidade dos frutos colhidos. Este trabalho objetivou caracterizar as injúrias pós-colheita de frutos de laranja 'Pêra', 'Lima' e 'Natal' e de tangor 'Murcott', destinados ao mercado interno, após diferentes etapas do beneficiamento em "packinghouse". Foram coletados cem frutos na chegada ao "packinghouse", na banca de embalagem e no palete, após embalamento em caixas de madeira. Os frutos foram individualizados e submetidos à câmara úmida por 24 horas, permanecendo por mais 20 dias a 25ºC e 85% de umidade relativa. A incidência de podridões foi avaliada visualmente após a retirada da câmara úmida e a cada três dias. Os patógenos fúngicos encontrados tiveram a patogenicidade confirmada através da inoculação em frutos sadios. Não houve diferença significativa na incidência de doenças pós-colheita nas diferentes fases do processamento nas variedades Lima e Natal. Na variedade Pêra e no tangor 'Murcott', a incidência de doenças foi menor nas amostras coletadas na chegada ao "packinghouse". O bolor verde (Penicillium digitatum foi a principal doença encontrada nos diferentes frutos cítricos. Outras doenças importantes foram a antracnose (Colletotrichum gloeosporioides, as podridões pedunculares (Lasiodiplodia theobromae e Phomopsis citri e a podridão azeda (Geotrichum candidum.Post-harvest diseases represent a serious problem for citriculture, reducing fruit quality and crop yield. This work aimed to characterize the post-harvest injuries of oranges 'Pêra', 'Lima' and 'Natal' and tangor 'Murcott', during handling in the packinghouse. Samples of one hundred fruits were collected on arrival at the packinghouse, before culling and in the pallet, after hand packing into wood boxes. The fruits were individualized and submitted to humid chambers for 24 hours. Fruits were incubated for 20 days at 25ºC and 85

  6. Small RNA Profiling Reveals Phosphorus Deficiency as a Contributing Factor in Symptom Expression for Citrus Huanglongbing Disease

    Institute of Scientific and Technical Information of China (English)

    Hongwei Zhao; Ruobai Sun; Ute Albrecht; Chellappan Padmanabhan; Airong Wang; Michael D.Coffey; Thomas Girke

    2013-01-01

    Huanglongbing (HLB) is a devastating citrus disease that is associated with bacteria of the genus "Candidatus Liberibacter' (Ca.L.).Powerful diagnostic tools and management strategies are desired to control HLB.Host small RNAs (sRNA) play a vital role in regulating host responses to pathogen infection and are used as early diagnostic markers for many human diseases,including cancers.To determine whether citrus sRNAs regulate host responses to HLB,sRNAs were profiled from Citrus sinensis 10 and 14 weeks post grafting with Ca.L.asiaticus (Las)-positive or healthy tissue.Ten new microRNAs (miRNAs),76 conserved miRNAs,and many small interfering RNAs (siRNAs) were discovered.Several miRNAs and siRNAs were highly induced by Las infection,and can be potentially developed into early diagnosis markers of HLB.miR399,which is induced by phosphorus starvation in other plant species,was induced specifically by infection of Las but not Spiroplasma citri that causes citrus stubborn--a disease with symptoms similar to HLB.We found a 35% reduction of phosphorus in Las-positive citrus trees compared to healthy trees.Applying phosphorus oxyanion solutions to HLB-positive sweet orange trees reduced HLB symptom severity and significantly improved fruit production during a 3-year field trial in south-west Florida.Our molecular,physiological,and field data suggest that phosphorus deficiency is linked to HLB disease symptomology.

  7. Chitosan and fungicides on postharvest control of Guignardia citricarpa and on quality of 'Pêra Rio' oranges

    Directory of Open Access Journals (Sweden)

    Maria Cristina Canale Rappussi

    2011-09-01

    Full Text Available Citrus fruits are affected by the black spot disease caused by the fungus Guignardia citricarpa. Chitosan can be used as covering for fruits and may delay the ripening process and inhibit the growth of some fungi. Thus, the control of citrus black spot using chitosan and the fungicides thiabendazole and imazalil was assessed in addition to the physicochemical quality of 'Pêra Rio' oranges. The oranges were immersed into chitosan, thiabendazole or imazalil, and in chitosan mixed with both fungicides. The fruits were then stored at 25 °C, 80% RH, for 7 days and, after this storage period, subjected to physicochemical analyses. Chitosan in association with the fungicides reduced black spot in 'Pêra Rio' oranges and delayed the change in the orange skin colour from green to yellow during the postharvest storage. Total soluble solids, titratable acidity, pH, ascorbic acid content and ratio were not influenced by the treatments. Thus, chitosan applied with the fungicides thiabendazole and imazalil showed potential to control the development of black spot lesions on 'Pêra Rio' oranges during the postharvest period.

  8. In vitro and in vivo activity of essential oils against major postharvest pathogens of Kinnow (Citrus nobilis × C. deliciosa) mandarin.

    Science.gov (United States)

    Jhalegar, Md Jameel; Sharma, R R; Singh, Dinesh

    2015-04-01

    The present study envisages the influence of essential oils namely lemon grass, eucalyptus, clove and neem on Kinnow mandarin with the objective to combat major post harvest diseases and to prolong its availability for longer time in the season. For this, in vitro and in vivo studies were conducted. Poisoned food technique was used for in vitro studies, and for in vivo studies, Kinnow fruit were pre-inoculated with pathogens (Penicillium digitatum and P. italicum), treated with different essential oils and then stored at 5 °C ±1 °C temperature and 85-90 % RH). Our results indicated that all essential oils inhibited the growth (colony diameter) of both pathogens over untreated PDA plates, but the inhibition was the strongest by lemon grass oil. Similarly, under in vivo conditions, all essential oils influenced decay incidence, decay loss, lesion diameter, respiration rate, ethylene evolution, overall acceptability and physiological loss in weight but lemon grass was the most effective. And also the incidence of Penicillium italicum was more noticed in fruits than P. digitatum, however, it was reverse under in vitro conditions. The decay rot at all stages of storage was less in EOs treated fruits than untreated fruits, thereby increasing their storage life significantly. Thus, it is evident from our studies that essential oils have the potential to control green and blue mold without causing any injury or harmful effects on Kinnow mandarin, and EOs can be recommended as a safe method for extending its storage life while maintaining fruit quality. PMID:25829604

  9. Evaluation of food additives as alternative or complementary chemicals to conventional fungicides for the control of major postharvest diseases of stone fruit for the control of major postharvest diseases of stone fruit

    Science.gov (United States)

    Among more than twenty food additives and GRAS (generally regarded as safe) compounds that were tested at three concentrations in in vivo primary screenings with several cultivars of California peaches, nectarines, and plums that had been artificially inoculated with seven major postharvest pathogen...

  10. Qualidade pós-colheita de pomelos (Citrus paradisi Macf. produzidos em plantações iniciais no estado do Ceará, Brasil Postharvest quality of grapefruit (Citrus paradisi Macf. produced from initial plantings in Ceará state, Brazil

    Directory of Open Access Journals (Sweden)

    Francisca Ligia de Castro Machado

    2011-12-01

    Full Text Available O estado do Ceará, nordeste do Brasil, vem ganhando atenção como o mais emergente Estado produtor de frutos no país. Citros, incluindo pomelos, tradicionalmente cultivados no sul, vem sendo plantados no Estado. No entanto, ainda não existem informações sobre qualidade de pomelos cultivados localmente. Este estudo objetivou examinar a qualidade pós-colheita de pomelos 'Star Ruby' e 'Ruby Red' quanto ao tamanho e forma, coloração da polpa, espessura da casca, rendimento do suco, sólidos solúveis (SS, acidez titulável (AT, pH, relação SS/AT e níveis de ácido ascórbico na colheita e após 15 dias de armazenamento. Um segundo lote de frutos foi examinado quanto a perda de massa e coloração externa. Os resultados sugerem que os pomelos apresentam bom tamanho e forma, com coloração externa alaranjada e interna avermelhada e espessura da casca apropriada. Frutos apresentaram um bom rendimento de suco, rico em ácido ascórbico, e com valores de SS, AT e pH comparáveis aos reportados para frutos cultivados em áreas tradicionais do país. A relação SS/AT encontra-se acima do mínimo necessário para um bom sabor. A coloração da casca variou de amarelado a alaranjado. Perda de massa aumentou, enquanto o ângulo de cor hue decresceu, seguindo o mesmo padrão para as duas variedades.Ceará state, northeast Brazil, is gaining attention as the most significant emerging fruit production region in the country. Citrus, including grapefruit, traditionally cultivated in the south, was recently implanted. However, data on postharvest quality of grapefruit grown under local conditions are nonexistent. A study was designed to examine postharvest quality of locally grown 'Star Ruby' and 'Ruby Red' grapefruits. Fruits were assessed for size and shape, pulp color, peel thickness, juice content, soluble solids (SS, titratable acidity (TA, pH, SS/TA ratio, and ascorbic acid at harvest and at the fifteenth day of storage. A second set of fruits

  11. Biocontrol Efficacy of Two Antagonistic Yeasts Against Postharvest Diseases in Peach Fruits During Storage Periods

    Institute of Scientific and Technical Information of China (English)

    LIN Li; TIAN Shi-ping; QIN Guo-zheng; XU Yong

    2003-01-01

    Two antagonistic yeasts, Thichosporon pullulans and Cryptococcus laurentii, were investigated for their biocontrol potential to blue mold rot and rhizopus rot on harvested peach fruits (Prunus persica L. Batsch, cv. Okubao), alone or in combination with a Iow dose of iprodione (50 μg mi-1 ). The results indicated that T. pullulans and C. laurentii were effective at reducing disease incidence and severity of blue mold rot and rhizopus rot in peach fruits. Biocontrol efficacy of C. laurentii and T. pullulans were significantly enhanced by combination with a Iow dose of iprodione (50 μg mi-1) against blue mold and rhizopus rot in peach fruits. T. pullulans and C. laurentii combined with a low dose of iprodione (50 μg mi-1 ) resulted in better disease control than either iprodione or the yeasts used alone. Dipping fruits in suspensions of antagonist cells showed the similar control effect as the treatment with iprodione (500 μg ml-1 ).

  12. Advance in research on biological control of postharvest diseases of fruits by Bacillus subtilis%枯草芽孢杆菌防治果实采后病害的研究进展

    Institute of Scientific and Technical Information of China (English)

    张彩霞; 李壮; 康国栋; 张利益; 丛佩华; 田义

    2009-01-01

    Postharvest fruit diseases have produced a severe effect on the storage and quality of fruits. Health hazard and environmental pollution concerns regarding use of fungicides has enhanced interest in finding effective alternative to pesticides for control of postharvest diseases of fruits. Beneficial bacteria like Bacillus subtilis, a model organism of Gram-positive bacteria, were proven to be an efficient alternative antagonistic hacterium to synthetic fungicides to suppress postharvest diseases of fruits. This paper introduces the mechanisms of the antagonist B. subtilis against postharvest diseases of fruits, reviews the recent research advances, exhibits the availability and potential of B. subtilis toward postharvest fruit diseases, and provides important references to the future development of new postharvest biocontrol products.%果实采后病害严重影响水果的贮藏及果品质量.因化学杀菌剂在应用中存在危害人体健康及污染环境等一系列问题.利用枯草芽孢杆菌(Bacillus subtilis)防治果实采后病害的生物防治手段作为一种有效替代方法受到人们的广泛关注.枯草芽孢杆菌是革兰氏阳性细菌研究的模式菌株,为重要的生防菌源.在探讨枯草芽孢杆菌防治果实采后病害拮抗机制的基础上,阐述了该领域的研究成果和最新进展,展示了枯草芽孢杆菌应用于果实采后病害生物防治的可行性和潜力,为今后果实采后生防产品的开发提供新的研究思路.

  13. Antioxidant activity of Citrus fruits.

    Science.gov (United States)

    Zou, Zhuo; Xi, Wanpeng; Hu, Yan; Nie, Chao; Zhou, Zhiqin

    2016-04-01

    Citrus is well-known for its nutrition and health-promotion values. This reputation is derived from the studies on the biological functions of phytochemicals in Citrus fruits and their derived products in the past decades. In recent years, the antioxidant activity of Citrus fruits and their roles in the prevention and treatment of various human chronic and degenerative diseases have attracted more and more attention. Citrus fruits are suggested to be a good source of dietary antioxidants. To have a better understanding of the mechanism underlying the antioxidant activity of Citrus fruits, we reviewed a study on the antioxidant activity of the phytochemicals in Citrus fruits, introduced methods for antioxidant activity evaluation, discussed the factors which influence the antioxidant activity of Citrus fruits, and summarized the underlying mechanism of action. Some suggestions for future study were also presented. PMID:26593569

  14. Bioactivity of citrus seed for mosquito-borne diseases larval control.

    Science.gov (United States)

    Sumroiphon, Suchada; Yuwaree, Chumporn; Arunlertaree, Chumlong; Komalamisra, Narumon; Rongsriyam, Yupha

    2006-01-01

    This study aimed to determine the activity of citrus-seed extract against Ae. aegypti and Cx. quinquefasciatus larvae. The results indicated that ethanol citrus-seed extract showed the best killing effect on Ae. aegypti larvae, followed by local liquor, and water, with LC50 of 2,267.71, 6,389.22, and 135,319.40 ppm, respectively, whereas against Cx. quinquefasciatus larvae, the LC50 were 2,639.27, 5,611.66, and 127,411.88 ppm, respectively. Temephos was tested against Ae. aegypti larvae; the LC50 was 0.00057 ppm, which was nearly 4,000,000 times less than ethanol citrus-seed extract. When ethanol citrus-seed extract and temephos were tested with Nile tilapia (Oreochromis niloticus), a standard environmental organism, using LC50 of Ae. aegypti larvae at 2,267 and 0.00057 ppm, respectively, fish mortality was 0%. The results suggested that ethanol citrus-seed extract had no harmful effect on the fish, and that temephos, which is recommended by WHO, was safe for use in drinking water. However, when the LC50 dose that killed Ae. aegypti larvae for local liquor (6,389 ppm) and water extract (135,319 ppm) were tested with fish, the mortality rates were 35% and 100%, respectively. On the whole, the results suggested that ethanol citrus-seed extract is environmentally friendly and can be used in the control of Ae. aegypti and Cx. quinquefasciatus larvae. PMID:17547066

  15. CITRUS CANKER: PLANT PATHOLOGY VERSUS PUBLIC POLICY

    Science.gov (United States)

    Increasing international travel and trade has resulted in an unprecedented number of plant pathogen introductions, including Xanthomonas axonopodis pv citri, (Xac), the bacterium that causes citrus canker. The disease affects commercial and dooryard citrus, and has far-reaching politi...

  16. Control of fruit postharvest diseases by thermotherapy: understanding the mechanisms of action by –omics approaches

    OpenAIRE

    Spadoni, Alice

    2014-01-01

    In recent years the hot water treatment (HW) represents an effective and safe approach for managing postharvest decay. This study reported the effect of an HW (60°C for 60 s and 45°C for 10 min) on brown rot and blue mould respectively. Peaches was found more thermotolerant compared to apple fruit, otherwise Penicillium expansum was more resistant to heat with respect to Monilinia spp. In semi-commercial and commercial trials, the inhibition of brown rot in naturally infected peaches was high...

  17. Yeasts from native Brazilian Cerrado plants: Occurrence, diversity and use in the biocontrol of citrus green mould.

    Science.gov (United States)

    Sperandio, Eugenio Miranda; do Vale, Helson Mario Martins; Moreira, Geisianny Augusta Monteiro

    2015-11-01

    Yeasts are some of the most important postharvest biocontrol agents. Postharvest oranges frequently deteriorate due to green mould (Penicillium digitatum), which causes significant losses. The aims of this study were to determine the composition and diversity of yeasts on plants of the Brazilian Cerrado and to explore their potential for inhibiting citrus green mould. Leaves and fruit of Byrsonima crassifolia and Eugenia dysenterica were collected from Cerrado conservation areas, and thirty-five yeasts were isolated and identified by sequencing the D1-D2 domain of the rDNA large subunit (26S). The isolates represented the Aureobasidium, Meyerozyma, Candida, and Pichia genera. Three isolates identified as Aureobasidium pullulans exhibited potential for the control of P. digitatum in both in vitro and in vivo tests; these isolates reduced the incidence of disease and increased the storage time of fruit. Aureobasidium. pullulans has immense potential for the biological control of filamentous fungi. PMID:26466874

  18. Detection of citrus canker and Huanglongbing using fluorescence imaging spectroscopy and support vector machine technique.

    Science.gov (United States)

    Wetterich, Caio Bruno; Felipe de Oliveira Neves, Ruan; Belasque, José; Marcassa, Luis Gustavo

    2016-01-10

    Citrus canker and Huanglongbing (HLB) are citrus diseases that represent a serious threat to the citrus production worldwide and may cause large economic losses. In this work, we combined fluorescence imaging spectroscopy (FIS) and a machine learning technique to discriminate between these diseases and other ordinary citrus conditions that may be present at citrus orchards, such as citrus scab and zinc deficiency. Our classification results are highly accurate when discriminating citrus canker from citrus scab (97.8%), and HLB from zinc deficiency (95%). These results show that it is possible to accurately identify citrus diseases that present similar symptoms. PMID:26835778

  19. Quantitative Distribution of Candidatus Liberibacter asiaticus in Citrus Plants and Fruits Infected by Citrus Huanglongbing

    Science.gov (United States)

    Citrus huanglongbing (HLB), or greening disease, is caused by any of three non culturable Gram-negative bacteria belonging to Candidatus Liberibacter spp. The pathogens are transmitted by citrus psyllids to all commercial varieties of citrus. The diseases are lethal and have recently become widespr...

  20. Cost-effective control of plant disease when epidemiological knowledge is incomplete: modelling Bahia bark scaling of citrus.

    Directory of Open Access Journals (Sweden)

    Nik J Cunniffe

    2014-08-01

    Full Text Available A spatially-explicit, stochastic model is developed for Bahia bark scaling, a threat to citrus production in north-eastern Brazil, and is used to assess epidemiological principles underlying the cost-effectiveness of disease control strategies. The model is fitted via Markov chain Monte Carlo with data augmentation to snapshots of disease spread derived from a previously-reported multi-year experiment. Goodness-of-fit tests strongly supported the fit of the model, even though the detailed etiology of the disease is unknown and was not explicitly included in the model. Key epidemiological parameters including the infection rate, incubation period and scale of dispersal are estimated from the spread data. This allows us to scale-up the experimental results to predict the effect of the level of initial inoculum on disease progression in a typically-sized citrus grove. The efficacies of two cultural control measures are assessed: altering the spacing of host plants, and roguing symptomatic trees. Reducing planting density can slow disease spread significantly if the distance between hosts is sufficiently large. However, low density groves have fewer plants per hectare. The optimum density of productive plants is therefore recovered at an intermediate host spacing. Roguing, even when detection of symptomatic plants is imperfect, can lead to very effective control. However, scouting for disease symptoms incurs a cost. We use the model to balance the cost of scouting against the number of plants lost to disease, and show how to determine a roguing schedule that optimises profit. The trade-offs underlying the two optima we identify-the optimal host spacing and the optimal roguing schedule-are applicable to many pathosystems. Our work demonstrates how a carefully parameterised mathematical model can be used to find these optima. It also illustrates how mathematical models can be used in even this most challenging of situations in which the underlying

  1. Citrus tristeza virus-host interactions

    OpenAIRE

    Dawson, William O.; Garnsey, Stephen M.; Satyanarayana eTatineni; Folimonova, Svetlana Y.; Scott J Harper; S eGowda

    2013-01-01

    Citrus tristeza virus (CTV) is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or symptomless in most of their host range. There is little understanding of how the virus causes severe disease in some citrus and none in others. Movement and distribution of CTV differs considerably...

  2. Characterizing culturable microflora of nectarines: bacteria and their potential for biological control of postharvest fruit decay

    Science.gov (United States)

    Microorganisms isolated from fruit surfaces have been used to control postharvest decays of fruit. However, there is little information on microflora colonizing surfaces of fruits other than grapes, apples, and citrus. We characterized bacterial microflora on nectarine fruit surfaces during fruit ...

  3. Effect of Application of β-aminobutyric Acid on Maintaining Quality of Crimson Seedless Grape and Controlling Postharvest Diseases under Cold Storage Conditions

    Directory of Open Access Journals (Sweden)

    M.A. EL-Metwally

    2014-01-01

    Full Text Available The effect of application β-Aminobutyric Acid (BABA on Crimson Seedless grape vine was studied in 2012 and 2013 seasons, as an alternative to traditional chemical compounds that are harmful to the environment to control the pre and postharvest diseases. The vines were dipped in three levels of BABA (200, 250, 300 ppm two weeks before harvest. The linear growth and dry weight of Botrytis cinerea isolated from Crimson Seedless grape were greatly influenced by the increase in BABA concentration up to 300 ppm. In both seasons, prolonging the marketing stage resulted in decreased in disease infection with the increase in concentrations, at 300 ppm concentration, BABA gave the maximum reduction in disease infection caused by Botrytis cinerea, in addition to the improvement of fruit quality at harvest and during cold storage (for 60 days at 0±1°C with 90-95% RH, as well as 3 days marketing period at room temperature. Clusters treated with 300 ppm BABA developed less decay shatter and total loss. Moreover, it was more effective in rising SSC, titratable acidity, total sugar and anthocyanin accumulation in the skin of berry during cold storage conditions and marketing period compared with the other treatments. While, BABA 250 ppm showed high berry firmness and adherence strength.

  4. Physical Changes in Satsuma Mandarin Leaf after Infection of Elsinoë fawcettii Causing Citrus Scab Disease

    Directory of Open Access Journals (Sweden)

    Dilli Prasad Paudyal

    2015-12-01

    Full Text Available Citrus scab disease is one of the destructive diseases that reduce the value of fruit for the fresh market. We analyzed the process of symptom development after infection with scab pathogen Elsinoë fawcettii in the susceptible satsuma mandarin leaves to observe the structural modification against pathogen. The cuticle and epidermal cells along with 3–5 layers of mesophyll tissue were degraded 1–2 days post inoculation. Surrounding peripheral cells of degraded tissues grew rapidly and then enveloped the necrotic area along with the growing conidia. Cross sections through the lesion revealed hyphal colonization in epidermis and mesophyll tissues. In response to the pathogen colonization, host cell walls were lignified, inner cells were rapidly compartmentalized and a semi-circular boundary was formed that separated the infected region from the non-infected region, and finally prevented the intercellular pathogen spread.

  5. Java project on periodontal diseases: effect of vitamin C/calcium threonate/citrus flavonoids supplementation on periodontal pathogens, CRP and HbA1c

    NARCIS (Netherlands)

    A. Amaliya; M.L. Laine; B.G. Loos; U. van der Velden

    2015-01-01

    Objective To assess in a periodontally diseased rural population deprived from regular dental care and having poor dietary conditions, the effect of vitamin C/calcium threonate/citrus flavonoids (VitC/Ca/Fl) supplementation on subgingival microbiota and plasma levels of vitamin C, HbA1c and hsCRP. M

  6. Electronic tongue response to chemicals in orange juice that change concentration in relation to harvest maturity and citrus greening or Huanglongbing (HLB) disease

    Science.gov (United States)

    In an earlier study, the electronic tongue system (etongue) was used to differentiate between orange juice made from healthy fruit and from fruit affected by the citrus greening or Huanglongbing (HLB) disease. This study investigated the reaction of an etongue system to the main chemicals in orange ...

  7. 采后贮藏环境诱导柑橘果皮油胞病的发病机制%Oleocellosis Mechanism of Postharvest Citrus Peel Induced by Storage Conditions

    Institute of Scientific and Technical Information of China (English)

    刘丽丹; 曾凯芳

    2012-01-01

    柑橘在采后贮藏期间由于贮藏环境的变化很容易诱导其果皮产生油胞病,贮藏环境的影响因素主要有贮藏温度、相对湿度及气体水平。过高或者过低的贮藏温度,以及温度的波动都会影响果皮的抗氧化活性系统及水分的迁移,从而加速柑橘果皮油胞病的发病。不适宜的贮藏相对湿度通过影响果皮水分散失,改变果皮水位导致白皮层脱水,进而诱导柑橘果皮油胞病的发生。低O2高C02的气体水平影响柑橘果实呼吸作用及其他生理代谢,造成果实皮层水分及膜脂的变化,引起柑橘果皮油胞病的发病加剧。本文通过介绍贮藏条件对柑橘果皮油胞病发病机制的影响,为进一步深入了解柑橘果皮油胞病的发病原因、发病机理以及控制措施提供理论依据。%Oleocellosis, a physiological disorder of citrus fruits, can be easily induced by changes in storage conditions such as storage temperature, relative humidity (RH) and gas level. Meanwhile, oleocellosis can also be aggravated by too high or too low storage temperature and fluctuated storage temperature, thus affecting antioxidant activity and water transportation. In addition, inappropriate relative humidity can result in water loss in fruits, which can cause albedo dehydration due to altered water potential in the albedo of citrus fruits and corresponding occurrence of oleoceUosis in citrus peel. Moreover, oleocellosis also can be induced by low 02 and high CO2 level, thereby resulting in an obvious change in respiration intensity and other physiological metabolisms of citrus as well as changes in water content and cell membrane lipid of citrus peel. In this article, the effects of storage conditions on the pathogenesis of oleocellosis are discussed, which will provide a theoretical support for a thorough understanding of the causes, mechanisms and control strategies of oleocellosis.

  8. Determination and control of the main pathogens of post-harvest fruit and vegetables rot disease in Ningxia%果蔬采后致腐病菌检测及防治

    Institute of Scientific and Technical Information of China (English)

    顾沛雯; 张光弟; 王华荣; 丁波

    2012-01-01

    It was showed that the main pathogens of post-harvest fruit and vegetables rot disease postharvest fruit and vegetables rot disease were Botrytis, Aspergillus, Penicillium, Rhizopus and Alternaria through isolating, purifing, pathogenicity determination, identification and ways of infection in Ningxia. Among these pathogens, Aspergillus sp. and Rhizopus sp. were the chief pathogens during post-harvest transportation and marketing because they cause rot disease during high temperature, yet Botrytis sp. , Alternaria sp. , and Penicillium sp. were the major pathogens during transportation and storage under 10-15℃. Through two preservation tests of post-harvest fruit and vegetables with 2-butanamine fumigating and chlorine dioxide immersing, it is showed that combination of low temperature and antistaling agent can obviously prolong 9-11 days delivery period and shelf life.%引起果蔬采后腐烂的病原菌主要分属于葡萄孢属(Botrytis)、曲霉属(Aspergillus)、青霉属(Penicillium)、根霉属(Rhizopus)和链格孢属(Alternaria).其中A.sp.和R.sp.是果蔬常温运输过程中的主要致腐菌,B.sp.、A.sp.和P.sp.是果蔬低温贮运条件下的主要致腐菌.采用仲丁胺和二氧化氯2种药剂对采后蔬菜进行熏蒸和浸泡保鲜处理.结果表明:低温与保鲜剂处理相结合,可明显提高果蔬采后运输及货架期9~11d.

  9. Advances in Biological Control of Citrus Psyllid Diaphorina citri, a Vector Insect of Citrus Huanglongbing Disease%黄龙病媒介昆虫柑橘木虱生物防治新进展

    Institute of Scientific and Technical Information of China (English)

    代晓彦; 任素丽; 周雅婷; 任顺祥; 邱宝利

    2014-01-01

    The citrus psyllid, Diaphorina citri Kuwayama, is the primary vector of citrus Huanglongbing disease, Candidatus Liberibacter asiaticus, which has the huge potential threats to the development of citrus industry in China. Based on the comprehensive understanding of D. citri control technologies, we reviewed the latest advances in biological control of D. citri and forecasted its future prospects. The main biological control resources of citrus psyllid currently are natural enemy insects and entomopathogenic fungi, among which predatory ladybeetles, lacewings, spiders and hover flies are the dominant species of predator, while Tamarixia radiata and Diaphorencyrtus aligarhensis are the two dominant parasitoids in China. Several representative entomopathogenic fungi include Lecanicillium lecanii, Isaria fumosorosea, Beauveria bassiana and Hirsutella citriformis have been reported with high virulence to citrus psyllid. This current review is expected to provide technical support and theoretical reference for efficient and sustainable control of citrus psyllid in the future.%柑橘木虱Diaphorina citri Kuwayama是柑橘黄龙病的重要媒介昆虫,对我国柑橘产业的健康发展潜在着巨大的威胁。本文在综合国内柑橘木虱防控技术的基础上,对近年来柑橘木虱生物防治的最新研究进展进行了综述,并且对其生物防治的发展前景给予了展望。目前应用于柑橘木虱生物防治的天敌资源主要是天敌昆虫及昆虫病原真菌,其中捕食性天敌主要包括瓢虫、食蚜蝇、草蛉和蜘蛛,寄生性天敌昆虫主要包括啮小蜂和跳小峰;昆虫病原真菌主要包括蜡蚧轮枝菌、拟青霉、白僵菌、桔形被毛孢等。期望通过对柑橘木虱生物防治工作的综述,为我国今后柑橘木虱的科学、高效防控及其可持续治理提供参考,不断推动我国柑橘产业的健康发展。

  10. Recent advances in Citrus psorosis virus

    OpenAIRE

    Achachi, Asmae; Ait Barka, Essaïd; Ibriz, Mohammed

    2014-01-01

    Psorosis is a globally devastating disease of citrus caused by an infectious filamentous ophiovirus, Citrus psorosis virus (CPsV), which causes annual losses of about 5 % and a progressive decline of trees by affecting the conductive tissues. The disease can be harboured asymptomatically in many citrus species. In the field, the most characteristic symptoms of the disease in adult trees are bark scaling in the trunk and main branches and also internal staining in the underlying wood. The viru...

  11. A transcriptomic approach highlights induction of secondary metabolism in citrus fruit in response to Penicillium digitatum infection

    OpenAIRE

    González-Candelas Luis; Alamar Santiago; Sánchez-Torres Paloma; Zacarías Lorenzo; Marcos Jose F

    2010-01-01

    Abstract Background Postharvest losses of citrus fruit due to green mold decay, caused by the fungus Penicillium digitaum, have a considerable economic impact. However, little is known about the molecular processes underlying the response of citrus fruit to P. digitatum. Results Here we describe the construction of a subtracted cDNA library enriched in citrus genes preferentially expressed in response to pathogen infection followed by cDNA macroarray hybridization to investigate gene expressi...

  12. Fourier transform infra-red spectroscopy using an attenuated total reflection probe to distinguish between Japanese larch, pine and citrus plants in healthy and diseased states

    Science.gov (United States)

    Gandolfo, D. S.; Mortimer, H.; Woodhall, J. W.; Boonham, N.

    2016-06-01

    FTIR spectroscopy coupled with an Attenuated Total Reflection (ATR) sampling probe has been demonstrated as a technique for detecting disease in plants. Spectral differences were detected in Japanese Larch (Larix kaempferi) infected with Phytophthora ramorum at 3403 cm-1 and 1730 cm-1, from pine (Pinus spp.) infected with Bursaphelenchus xylophilus at 1070 cm-1, 1425 cm-1, 1621 cm-1 and 3403 cm-1 and from citrus (Citrus spp.) infected with 'Candidatus liberibacter' at 960 cm-1, 1087 cm-1, 1109 cm-1, 1154 cm-1, 1225 cm-1, 1385 cm-1, 1462 cm-1, 1707 cm-1, 2882 cm-1, 2982 cm-1 and 3650 cm-1. A spectral marker in healthy citrus has been identified as Pentanone but is absent from the diseased sample spectra. This agrees with recent work by Aksenov, 2014. Additionally, the spectral signature of Cutin was identified in the spectra of Pinus spp. and Citrus spp. and is consistent with work by Dubis, 1999 and Heredia-Guerrero, 2014.

  13. A Novel Study of Interactions of Arabidopsis thaliana With Candidatus Liberibacter psyllaurous When Transmitted by psyllid Bactericera cockerelli to Develop a Chemical Genomics Based Approach That can aid in Development of Control Strategies for Huanglongbing Disease in Citrus

    OpenAIRE

    Zadgaonkar, Sai

    2015-01-01

    Huanglongbing (HLB) is a bacterial disease associated with Candidatus Liberibacter asiaticus (CLas), Candidatus Liberibacter americanus, and Candidatus Liberibacter africanus. These bacterial species are transmitted by hemipteran psyllids. For many years, this disease has caused substantial damage to citrus around the world and in recent years, it has significantly impacted citrus production in the U.S.A. The lack of effective control and curative measures against psyllids and the pathogen ar...

  14. A new postharvest fruit rot in apple and pear caused by Phacidium lacerum

    Science.gov (United States)

    During surveys for postharvest diseases of apples and pears, an unknown postharvest fruit rot was observed in Washington State. The disease appeared to originate from infection of the stem and calyx tissue of the fruit or wounds on the fruit. An unknown pycnidial fungus was consistently isolated fro...

  15. Current Situation of Citrus Huanglongbing in Guangdong, P. R. China

    Science.gov (United States)

    Guangdong Province is an important citrus production region in China. Citrus Huanglongbing (HLB, yellow shoot disease) was observed in Guangdong probably in the late 1800’s and the disease was first studied there. Since the 1990’s, citrus production in Guangdong has gradually shifted from the coasta...

  16. Trailers transporting oranges to processing plants move Asian citrus psyllids

    Science.gov (United States)

    Huanglongbing (citrus greening) is one of the most serious of citrus diseases. Movement of the disease occurs as a result of natural vector-borne infection and by movement of plant material. We demonstrate here that Diaphorina citri Kuwayama (vector of citrus greening pathogens) can be transported i...

  17. First report of citrus leprosis virus nuclear type in Colombia

    Science.gov (United States)

    Citrus leprosis is a difficult viral disease causing significant damage to citrus fruit in South America and Central America. The disease is marked by dramatic lesions on fruit, leaves and stems resulting in unmarketable product. Citrus leprosis virus cytoplasmic types (CiLV-C and CiLV-C2) wer edete...

  18. Disrupt the bacterial growth in the insect vector to block the transmission of Candidatus Liberibacter asiaticus to citrus, the causal agent of citrus greening disease

    OpenAIRE

    Killiny, N.; Hajeri, S.; Gowda, S.; Davis, M. J.

    2014-01-01

    The genome of Candidatus Liberibacter asiaticus (CLas) reveals the presence of luxR, encodingLuxR protein, one of a two component cell-to-cell communication system. However, the genome lacks the second component, luxl, that produces acyl-homoserine lactones (AHLs), suggesting that CLas has a solo LuxR system. Interestingly, we detected compounds that may act as AHLs in the insect vector (psyllids) that are healthy or infected with CLas, but not in the citrus plants. This finding suggests that...

  19. Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

    OpenAIRE

    Neelam Mallick; Rafeeq Alam Khan

    2016-01-01

    Objective: Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypo...

  20. Movement of Diaphorina citri Kuwayama (Hemiptera: Liviidae) adults between huanglongbing-affected and healthy citrus

    Science.gov (United States)

    Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a vector transmitting the pathogen of citrus huanglongbing (HLB, also called yellow shoot disease or citrus greening disease). A typical symptom of citrus HLB is leaf yellowing. ACP adults behaved differently on HLB-affe...

  1. Detection of citrus huanglongbing-associated 'Candidatus Liberibacter asiaticus' in citrus and Diaphorina citri in Pakistan, seasonal variability, and implications for disease management.

    Science.gov (United States)

    Razi, Muhammad F; Keremane, Manjunath L; Ramadugu, Chandrika; Roose, Mikeal; Khan, Iqrar A; Lee, Richard F

    2014-03-01

    We report the detection of the huanglongbing (HLB)-associated bacterium 'Candidatus Liberibacter asiaticus' from both plants and insects in Pakistan and the seasonal variability in the numbers of 'Ca. L. asiaticus'-positive psyllid vector, Diaphorina citri. Our studies showed that 'Ca. L. asiaticus' was detectable from trees in areas with maximum temperatures reaching nearly 50°C (average maximum of 42°C). However, the bacterium was present at very low levels in psyllids both in summer (June to August) and autumn (September to November) in contrast to reports from Florida, where the bacterium was detectable at very high levels during October to November. We hypothesize that hot summer temperatures in Pakistan may interfere with acquisition and replication of 'Ca. L. asiaticus' in psyllids and may lead to dead or non transmissible 'Ca. L. asiaticus' in plants. Psyllid counts were very low in both summer and winter, showed a population peak ('Ca. L. asiaticus'-positive vectors) in spring, and showed a larger peak ('Ca. L. asiaticus'-free psyllids) in autumn. Natural thermotherapy during hot summers and a low vector population during environmental extremes may have played a major role in long-term survival of the citrus industry in Pakistan. These results may be useful in developing management strategies for U.S. citrus industries in Texas and California. PMID:24134720

  2. Epidemic and research advance of Citrus Black Spot%柑橘黑斑病(Citrus Black Spot)发生危害现状和研究进展

    Institute of Scientific and Technical Information of China (English)

    王兴红; 陈国庆; 王卫芳; 李红叶

    2011-01-01

    柑橘黑斑病(Citrus Black Spot,CBS)主要危害果实,在果皮上形成各种病斑而影响果实的外观品质和销售价格,严重时可造成田间落果和贮藏期果实腐烂。同时,黑斑病被欧盟列为A1类外来有害生物,美国对此也有严格的限制。因此,该病害影响柑橘鲜果的国际贸易。黑斑病的病原属球座菌(Guignardia),其无性态为叶点霉菌(Phyl-losticta)。宽皮柑橘(Citrus reticulata)、橙类(C.sinensis)和柠檬(C.limon)上为柑橘球座菌(G.citricarpa),无性态为%Citrus Black Spot(CBS) attacks citrus fruits,produces various spots on citrus rind,gives rise to the decrease in external quality and commercial value.It causes immature fruit-dropping in fields or postharvest decaying in storage houses when disease occurs severely.Meanwhile,CBS is regulated as an A1 quarantine pest by several countries of European Union,as well as USA,so international trade of fresh citrus is restricted by this disease.The causal agents of CBS belong to genus Guignardia(anamorph Phyllosticta).G.citricarpa(anamorph P.citricarpa) is responsible to the CBS of mandarins(C.reticulata),oranges(C.sinensis) and lemon(C.limon),whereas P.citriasiana(teleomorph unknown) is responsible to tan spot of pomeloes(C.grandis).In addition,an endophyte,P.capitalensis is commonly present on citrus,which often interferes the detection of CBS.CBS is a common disease in China,significant losses often be leaded to some susceptible varieties.However,the knowledge of CBS is handful in China.To satisfy the requirement of broad readers to full scenario of CBS,in current paper,we integrate the published information of inter-and intra-nation regarding CBS,and give a detail introduction on the aspects of disease history,distribution,significance,symptom,etiology,prevalence,detection control,etc.

  3. Biological control agents for suppression of post-harvest diseases of potatoes: strategies on discovery and development

    Science.gov (United States)

    As used in plant pathology, the term "biological control" or its short form “biocontrol” commonly refers to the decrease in the inoculum or the disease-producing activity of a pathogen accomplished through one or more organisms, including the host plant but excluding man. Biological control of plant...

  4. Antagonism of local isolates of Trichoderna spp.on citrus root rot disease by Fusarium solani in the mekong delta of vietnam

    Institute of Scientific and Technical Information of China (English)

    Duong Minh; Jozef Coosemans; Le Lam Cuong; Ester Vandersmissen; Pham Van Kim

    2004-01-01

    @@ The local isolates of Trichoderrma spp. and Fusariun solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch's postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderna spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.

  5. Characterization of a Proposed Dichorhavirus Associated with the Citrus Leprosis Disease and Analysis of the Host Response

    Directory of Open Access Journals (Sweden)

    José Luis Cruz-Jaramillo

    2014-07-01

    Full Text Available The causal agents of Citrus leprosis are viruses; however, extant diagnostic methods to identify them have failed to detect known viruses in orange, mandarin, lime and bitter orange trees with severe leprosis symptoms in Mexico, an important citrus producer. Using high throughput sequencing, a virus associated with citrus leprosis was identified, belonging to the proposed Dichorhavirus genus. The virus was termed Citrus Necrotic Spot Virus (CNSV and contains two negative-strand RNA components; virions accumulate in the cytoplasm and are associated with plasmodesmata—channels interconnecting neighboring cells—suggesting a mode of spread within the plant. The present study provides insights into the nature of this pathogen and the corresponding plant response, which is likely similar to other pathogens that do not spread systemically in plants.

  6. Control of speck rot in apple fruit caused by Phacidiopycnis washingtonensis with pre- and postharvest fungicides

    Science.gov (United States)

    Speck rot caused by Phacidiopycnis washingtonensis is a recently reported postharvest fruit rot disease of apple. Infection of apple fruit by the fungus occurs in the orchard, but symptoms develop during storage. In this study, selected pre- and postharvest fungicides were evaluated for control of s...

  7. Intercropping of citrus and guava trees for management of Huanglongbing

    Science.gov (United States)

    Recent studies conducted in Viet Nam by Vietnamese, Japanese and Australian scientists indicate that interplanting citrus with guava negated infestations of Asian citrus psyllid and consequently huanglongbing, a serious disease caused by a bacterium vectored by the psyllid. Young citrus interplanted...

  8. Screening of citrus and its close relatives for tolerance to huanglongbing

    OpenAIRE

    Ramadugu, C.; Keremane, M.; Stover, E; Halbert, S.; Duan, Y. P.; Lee, R. F.

    2014-01-01

    Huanglongbing (HLB), a devastating disease of citrus, has become a serious problem for the citrus industries in Brazil and Florida, and both the disease and its psyllid vector, Diaphorina citri continue to spread to other citrus growing regions. Host resistance or tolerance to the pathogen would be extremely valuable to the citrus industry. A field trial was established in Fort Pierce, Florida where HLB has become endemic to assess the HLB tolerance level of different cultivars of citrus and ...

  9. Detection of a new medium for budwood culture in vitro of citrus

    OpenAIRE

    SERTKAYA, Gülşen ŞAŞ; ÇINAR, Ahmet

    1998-01-01

    The transfer of new and quality citrus species and cultivars from one country or growing area to another may lead to the introduction of new pests and diseases. Therefore the import and direct production of citrus budwood without adequate control measures has a high risk. The citrus virus and virus-like disease agents can be successfully eliminated using the shoot-tip grafting (STG) technique which is routinely used to obtain virus-free plants in citrus improvement programs in major citrus...

  10. Autologistic model with an application to the citrus "sudden death" disease Modelo autologístico com aplicação para a doença "morte súbita" dos citrus

    Directory of Open Access Journals (Sweden)

    Elias Teixeira Krainski

    2008-01-01

    Full Text Available The citrus sudden death (CSD disease affects dramatically citrus trees causing a progressive plant decline and death. The disease has been identified in the late 90's in the main citrus production area of Brazil and since then there are efforts to understand the etiology as well as the mechanisms its spreading. One relevant aspect of such studies is to investigate spatial patterns of the occurrence within a field. Methods for determining whether the spatial pattern is aggregated or not has been frequently used. However it is possible to further explore and describe the data by means of adopting an explicit model to discriminate and quantify effects by attaching parameters to covariates which represent aspects of interest to be investigated. One alternative involves autologistic models, which extend a usual logistic model in order to accommodate spatial effects. In order to implement such model it is necessary to take into account the reuse of data to built spatial covariates, which requires extensions in methodology and algorithms to assess the variance of the estimates. This work presents an application of the autologistic model to data collected at 11 time points from citrus fields affected by CSD. It is shown how the autologistic model is suitable to investigate diseases of this type, as well as a description of the model and the computational aspects necessary for model fitting.A morte súbita dos citros (MSC é uma doença com efeitos dramáticos em árvores de citros causando declínio progressivo e morte. Ela foi identificada no final da década de 90 em uma das principais áreas de produção no Brasil e desde então esforços são empregados para entender a sua etiologia e os seus mecanismos de dispersão. Um aspecto relevante para estudos é a investigação do padrão espacial da incidência dentro de um campo. Métodos para determinar se o padrão espacial é agregado ou não têm sido freqüentemente utilizados. Entretanto é poss

  11. Electronic Tongue Response to Chemicals in Orange Juice that Change Concentration in Relation to Harvest Maturity and Citrus Greening or Huanglongbing (HLB) Disease

    OpenAIRE

    Smita Raithore; Jinhe Bai; Anne Plotto; John Manthey; Mike Irey; Elizabeth Baldwin

    2015-01-01

    In an earlier study, an electronic tongue system (e-tongue) has been used to differentiate between orange juice made from healthy fruit and from fruit affected by the citrus greening or Huanglongbing (HLB) disease. This study investigated the reaction of an e-tongue system to the main chemicals in orange juice that impact flavor and health benefits and are also impacted by HLB. Orange juice was spiked with sucrose (0.2–5.0 g/100 mL), citric acid (0.1%–3.0% g/100 mL) and potassium chloride (0....

  12. Postharvest treatments of fresh produce

    OpenAIRE

    Mahajan, P. V.; Caleb, O. J.; Z. Singh; Watkins, C. B.; M. Geyer

    2014-01-01

    Postharvest technologies have allowed horticultural industries to meet the global demands of local and large-scale production and intercontinental distribution of fresh produce that have high nutritional and sensory quality. Harvested products are metabolically active, undergoing ripening and senescence processes that must be controlled to prolong postharvest quality. Inadequate management of these processes can result in major losses in nutritional and quality attributes, outbreaks of foodbo...

  13. Sweetpotato post-harvest assessment

    OpenAIRE

    Rees, Debbie; Van Oirschot, Quirien; Kapinga, Regina

    2003-01-01

    For any crop cultivar to be successful it must not only have good production characteristics but also characteristics that ensure the harvested crop is acceptable and suitable for its intended use. Sweetpotato Post-harvest Assessment summarizes work carried out on postharvest aspects of sweetpotato between 1994 and 2002 within collaborative projects involving the Natural Resources Institute (UK), the International Potato Center and the Tanzanian Ministry of Agriculture, with input from the Ke...

  14. Effect of Liberibacter infection (Huanglongbing or "greening" disease) of citrus on orange juice flavor quality by sensory evaluation

    Science.gov (United States)

    There have been some anecdotal reports that Liberibacter asiaticus [(+) Las] infection of citrus trees, recently introduced in Florida, imparts off flavor to orange juice. It is of interest to the industry to know how much Liberibacter infection affects juice quality with respect to variety, maturit...

  15. Variation in flavonoid levels in Citrus benikoji Hort. ex. Tan. infected by Colletotrichum gloeosporioides.

    Science.gov (United States)

    Jeong, Sung Woo; Kim, Hae Gyeong; Park, Semin; Lee, Jung Han; Kim, Yun-Hi; Kim, Gon-Sup; Jin, Jong Sung; Kwak, Youn-Sig; Huh, Moo Ryong; Lee, Ji Eun; Song, Yi; Shin, Sung Chul

    2014-04-01

    Anthracnose caused by Colletotrichum gloeosporioides is one of the most serious postharvest diseases of citrus fruit. Fruit peels infected with C. gloeosporioides and the peels of healthy fruit were analysed for flavonoids, using high performance liquid chromatography-tandem mass spectroscopy, to evaluate variations in flavonoid levels in Citrus benikoji Hort. ex. Tan. Seventeen flavonoids were characterised from the fruit peels. The flavonoids were validated using structurally related standards and quantified. Among the 17 flavonoids, the concentration of component 3 was the highest and that of component 10 was the lowest. During 8 days after inoculation, the concentration of the seven flavonoids 1-3, 5, 6, 13, and 14 increased gradually up to day 8. Flavonoid 4 was detected from day 7. The seven minor flavonoid components, 8-12, 15, and 16 increased to day 5 and then decreased. However, flavonoids level variations were not significantly different from that of the non-infected fruits during the experimental period. The monitoring suggested that the constitutively formed seven polymethoxyflavones (8-12, 15, and 16) may act as phytoanticipins in the defence mechanism against the fungus, and that hespertin 7-O-glucoside (4), produced de novo on day 6 after infection, may function as a phytoalexin. PMID:24262558

  16. 植物精油防控果蔬采后病害的应用探究%Inquiry on Application of Botanical Essential Oils in Prevention and Control of Fruits and Vegetables' Postharvest Diseases

    Institute of Scientific and Technical Information of China (English)

    薛山; 谭谊谈

    2011-01-01

    The production and marketing of domestic fruit and vegetable was one the most-impact in the world.While fruits and vegetables were satisfying the people's needs,it also faced to a severe problem of storage.As a natural preservative from plant,the tapping and applying of this essential oil-preservation had gained widely attention.The essential oils were mainly extracted from the flowers,leaves,stems,roots or fruits of spice and herbal plants,which had significant antibacterial effect.Therefore,the essential oils were widely used in the defense of postharvest diseases of fruits and vegetables.At present,the study on the essential oil and its antimicrobial components in the postharvest storage had made some achievements in the country.However,compared with the foreign research,the domestic were relatively unenlightened.This article aims to provide theoretical basis and practical reference on the killing of pathogenic microbes and prevention of physiological of disease during the postharvest storage of fruits and vegetables.%我国是世界果蔬产销大国之一。果品蔬菜在满足人们需求的同时,也面临着严峻的贮藏问题。作为一种天然植物源保鲜剂,精油类果蔬防腐保鲜剂的研发与应用广受关注。植物精油多提取于香辛料及中草药植物的花、叶、茎、根或果实,具有显著的抑菌效果,因而被广泛用于果蔬采后病害的防控。目前,精油及其抑菌成分在国内果蔬采后贮藏的应用研究已取得了一定的成效,但较之国外的研究还相对落后。该文依据国外内最新的研究动态,通过综述精油的植物源种类、应用现状趋势的最新研究进展,以期为果蔬采后病原微生物的抑杀和生理性病害的防控提供理论基础和实践参考。

  17. Exploring the potential of biobeds for the depuration of pesticide-contaminated wastewaters from the citrus production chain: Laboratory, column and field studies

    International Nuclear Information System (INIS)

    The high wastewater volumes produced during citrus production at pre- and post-harvest level presents serious pesticide point-source pollution for groundwater bodies. Biobeds are used for preventing such point-source pollution occurring at farm level. We explored the potential of biobeds for the depuration of wastewaters produced through the citrus production chain following a lab-to-field experimentation. The dissipation of pesticides used pre- or post-harvest was studied in compost-based biomixtures, soil, and a straw-soil mixture. A biomixture of composted grape seeds and skins (GSS-1) showed the highest dissipation capacity. In subsequent column studies, GSS-1 restricted pesticides leaching even at the highest water load (462 L m−3). Ortho-phenylphenol was the most mobile compound. Studies in an on-farm biobed filled with GSS-1 showed that pesticides were fully retained and partially or fully dissipated. Overall biobeds could be a valuable solution for the depuration of wastewaters produced at pre- and post-harvest level by citrus fruit industries. - Highlights: ► High pesticide amounts are used for pre- and post-harvest treatments of citrus fruits. ► Pesticide-containing wastewaters from citrus production activities require depuration. ► Biobeds is a possible means for the depuration of wastewaters from the citrus industry. ► Biomixture and water management of biobeds were optimized via lab and column studies. ► On-farm offset biobed showed a high dissipation capacity against citrus pesticides. - Biobeds provide an effective solution for the depuration of wastewaters produced by the citrus production industry at both on-farm and post-harvest level.

  18. Biocontrol of Postharvest Anthracnose of Mango Fruit with Debaryomyces Nepalensis and Effects on Storage Quality and Postharvest Physiology.

    Science.gov (United States)

    Luo, Shanshan; Wan, Bin; Feng, Shuhan; Shao, Yuanzhi

    2015-11-01

    Anthracnose is presently recognized as one of the most important postharvest disease of mango worldwide. To control the disease, chemical fungicides for a long time was widely used among fruit farmers, but recently found that pathogen had developed increasingly resistance to it. With people's growing desire of healthy and green food, finding new and environmentally friendly biological control approach was very necessary. In this paper, we provided a kind of new antagonistic yeast which enriched the strain resources and the efficacy of Debaryomyces nepalensis against postharvest anthracnose of mango fruit and the influence on quality parameters were investigated. The results showed that the decay incidence and lesion diameter of postharvest anthracnose of mango treated by D. nepalensis were significantly reduced compared with the control fruit stored at 25 °C for 30 d or at 15 °C for 40 d, and the higher concentration of D. nepalensis was, the better the efficacy of the biocontrol was. Study also found that 1 h was the best treatment duration and antagonistic yeast inoculated earlier had good biocontrol effect on anthracnose. Meanwhile, treatment by D. nepalensis could significantly reduce postharvest anthracnose of mango, delay the decrease in firmness, TSS, TA, and ascorbic acid value, and do not impair surface color during postharvest storage. Moreover, the increase in MDA (malondialdehyde) content and increase in cell membrane permeability of fruit treated by D. nepalensis was highly inhibited. The results suggested D. nepalensis treatment could not only maintain storage quality of mango fruit, but also decrease the decay incidence to anthracnose disease. All these results indicated that D. nepalensis has great potential for development of commercial formulations to control postharvest pathogens of mango fruit. PMID:26445226

  19. Enhancement of the citrus immune system provides effective resistance against Alternaria brown spot disease.

    Science.gov (United States)

    Llorens, Eugenio; Fernández-Crespo, Emma; Vicedo, Begonya; Lapeña, Leonor; García-Agustín, Pilar

    2013-01-15

    In addition to basal defense mechanisms, plants are able to develop enhanced defense mechanisms such as induced resistance (IR) upon appropriate stimulation. We recently described the means by which several carboxylic acids protect Arabidopsis and tomato plants against fungi. In this work, we demonstrate the effectiveness of hexanoic acid (Hx) in the control of Alternaria brown spot (ABS) disease via enhancement of the immune system of Fortune mandarin. The application of 1mM Hx in irrigation water to 2-year-old Fortune plants clearly reduced the incidence of the disease and led to smaller lesions. We observed that several of the most important mechanisms involved in induced resistance were affected by Hx application. Our results demonstrate enhanced callose deposition in infected plants treated with Hx, which suggests an Hx priming mechanism. Plants treated with the callose inhibitor 2-DDG were more susceptible to the fungus. Moreover, polygalacturonase-inhibiting protein (PGIP) gene expression was rapidly and significantly upregulated in treated plants. However, treatment with Hx decreased the levels of reactive oxygen species (ROS) in infected plants. Hormonal and gene analyses revealed that the jasmonic acid (JA) pathway was activated due to a greater accumulation of 12-oxo-phytodienoic acid (OPDA) and JA along with a rapid accumulation of JA-isoleucine (JA-Ile). Furthermore, we observed a more rapid accumulation of abscisic acid (ABA), which could act as a positive regulator of callose deposition. Thus, our results support the hypothesis that both enhanced physical barriers and the JA signaling pathway are involved in hexanoic acid-induced resistance (Hx-IR) to Alternaria alternata. PMID:23260526

  20. Temperature Studies with the Asian Citrus Psyllid, Diaphorina citri: Cold Hardiness and Temperature Thresholds for Oviposition

    OpenAIRE

    Hall, David G.; Wenninger, Erik J.; Hentz, Matthew G.

    2011-01-01

    This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was d...

  1. Identification of putative TAL effector targets of the citrus canker pathogens shows functional convergence underlying disease development and defense response

    OpenAIRE

    Pereira, Andre LA; Carazzolle, Marcelo F.; Abe, Valeria Y; de Oliveira, Maria LP; Domingues, Mariane N; Silva, Jaqueline C; Cernadas, Raul A; Benedetti, Celso E.

    2014-01-01

    Background Transcriptional activator-like (TAL) effectors, formerly known as the AvrBs3/PthA protein family, are DNA-binding effectors broadly found in Xanthomonas spp. that transactivate host genes upon injection via the bacterial type three-secretion system. Biologically relevant targets of TAL effectors, i.e. host genes whose induction is vital to establish a compatible interaction, have been reported for xanthomonads that colonize rice and pepper; however, citrus genes modulated by the TA...

  2. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing

    OpenAIRE

    Yang, Chuanyu; Powell, Charles A.; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The res...

  3. Transcriptomic profiling of citrus fruit peel tissues reveals fundamental effects of phenylpropanoids and ethylene on induced resistance

    NARCIS (Netherlands)

    Ballester Frutos, A.R.; Lafuente, M.T.; Forment, J.; Gadea, J.; Vos, de C.H.R.; Bovy, A.G.; Gonzalez-Candelas, L.

    2011-01-01

    Penicillium spp. are the major postharvest pathogens of citrus fruit in Mediterranean climatic regions. The induction of natural resistance constitutes one of the most promising alternatives to avoid the environmental contamination and health problems caused by chemical fungicides. To understand the

  4. Detection of Citrus Huanglongbing by Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR) Spectroscopy

    Science.gov (United States)

    Citrus Huanglongbing (HLB, also known as citrus greening disease) was discovered in Florida in 2005 and is spreading rapidly amongst the citrus growing regions of the state. Detection via visual symptoms of the disease is not a long term viable option. New techniques are being developed to test fo...

  5. First Report of Dodder Transmission of Huanglongbing from Naturally Infected Murraya paniculata to Citrus

    Science.gov (United States)

    Huanglongbing (HLB) or “greening” disease of citrus is caused by phloem-limited, uncultured bacteria in the genus “Candidatus Liberibacter”. HLB is one of the most destructive diseases of citrus worldwide and is considered so dangerous to a U.S. citrus production that the USDA has listed “Ca. Liberi...

  6. Investigations of the feasibility for managing the Asian citrus pysllid using Isaria fumosorosea

    Science.gov (United States)

    The Asian citrus psyllid (AsCP), Diaphorina citri, transmits one of the most devastating diseases of citrus, the plant pathogenic bacterium Candidatus Liberibacter asiaticus, which is strongly associated with the occurrence of huanglongbing (HLB), also known as citrus greening disease. In Florida, g...

  7. An evaluation of different plant genotypes for rearing Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psylloidea)

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is the vector of bacteria responsible for a serious citrus disease known as huanglongbing (also known as citrus greening disease). Many research endeavors on ACP are dependent on a steady supply of ACP, which can be facilitated using a laboratory or greenhouse colony m...

  8. Young citrus leaves decrease dispersal distance of Diaphorina citri Kuwayama (Hemiptera: Liviidae)

    Science.gov (United States)

    To manage citrus Huanglongbing, understanding factors that affect dispersal behavior of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is required to answer questions related to disease epidemiology and to improve management tactics. Currently, little is known about cues medi...

  9. Characterization of an ATP/ADP translocase in the citrus huanglongbing bacterium, Candidatus Liberibacter

    Science.gov (United States)

    Citrus huanglongbing (HLB), a disease currently threatening the citrus industry worldwide, has been associated with three different species of Alphaproteobacteria known as Candidatus Liberibacter. A complete genome sequence was recently obtained via metagenomics for Ca. L. asiaticus (Las), the prom...

  10. Can Florida’s citrus industry be saved while preserving the environment? An economic analysis for the bio-control of the Asian Citrus Psyllid

    OpenAIRE

    Alvarez, Sergio; Solis, Daniel; Thomas, Michael

    2015-01-01

    The Asian citrus psyllid (ACP) is the insect vector of a fatal disease for citrus known as Huanglongbing (HLB) or citrus greening disease. HLB has been responsible for significant economic losses in Asia and Africa with crop losses between 30 to 100% in many production areas. In 1998, HLB was first detected in Florida and by 2005 this pest had spread to most commercial citrus groves in the State, threatening the sustainability of Florida’s Citrus industry. Since no cure for this disease is ye...

  11. Genome-wide comparative analysis reveals possible common ancestors of nucleotide-binding sites domain containing genes in hybrid Citrus sinensis genome and original Citrus clementina genome

    Science.gov (United States)

    We identified and re-annotated candidate disease resistance (R) genes with nucleotide-binding sites (NBS) domain from a Citrus clementina genome and two complete Citrus sinensis genome sequences (one from the USA and one from China). We found similar numbers of NBS genes from three citrus genomes, r...

  12. Development of PMA real-time PCR method to quantify viable cells of Pantoea agglomerans CPA-2, an antagonist to control the major postharvest diseases on oranges.

    Science.gov (United States)

    Soto-Muñoz, Lourdes; Teixidó, Neus; Usall, Josep; Viñas, Inmaculada; Crespo-Sempere, Ana; Torres, Rosario

    2014-06-16

    Dilution plating is the quantification method commonly used to estimate the population level of postharvest biocontrol agents, but this method does not permit a distinction among introduced and indigenous strains. Recently, molecular techniques based on DNA amplification such as quantitative real-time PCR (qPCR) have been successfully applied for their high strain-specific detection level. However, the ability of qPCR to distinguish viable and nonviable cells is limited. A promising strategy to avoid this issue relies on the use of nucleic acid intercalating dyes, such as propidium monoazide (PMA), as a sample pretreatment prior to the qPCR. The objective of this study was to optimize a protocol based on PMA pre-treatment samples combined with qPCR to distinguish and quantify viable cells of the biocontrol agent P. agglomerans CPA-2 applied as a postharvest treatment on orange. The efficiency of PMA-qPCR method under the established conditions (30μM PMA for 20min of incubation followed by 30min of LED light exposure) was evaluated on an orange matrix. Results showed no difference in CFU or cells counts of viable cells between PMA-qPCR and dilution plating. Samples of orange matrix inoculated with a mixture of viable/dead cells showed 5.59log10 CFU/ml by dilution plating, 8.25log10 cells/ml by qPCR, and 5.93log10 cells/ml by PMA-qPCR. Furthermore, samples inoculated with heat-killed cells were not detected by dilution plating and PMA-qPCR, while by qPCR was of 8.16log10 cells/ml. The difference in quantification cycles (Cq) among qPCR and PMA-qPCR was approximately 16cycles, which means a reduction of 65,536 fold of the dead cells detected. In conclusion, PMA-qPCR method is a suitable tool for quantify viable CPA-2 cells, which could be useful to estimate the ability of this antagonist to colonize the orange surface. PMID:24786552

  13. Citrus breeding, genetics and genomics in Japan.

    Science.gov (United States)

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional breeding methods. To promote citrus molecular breeding in Japan, a genetic mapping was initiated in 1987, and the experimental tools and resources necessary for citrus functional genomics have been developed in relation to the physiological analysis of satsuma mandarin. In this paper, we review the progress of citrus breeding and genome researches in Japan and report the studies on genetic mapping, expression sequence tag cataloguing, and molecular characterization of breeding characteristics, mainly in terms of the metabolism of bio-functional substances as well as factors relating to, for example, fruit quality, disease resistance, polyembryony, and flowering. PMID:27069387

  14. Potential applications of ionizing radiation in postharvest handling of fresh fruits and vegetables

    International Nuclear Information System (INIS)

    The advantages and limitations of potential uses of ionizing radiation of harvested fresh fruits and vegetables are discussed. Potential applications include: sprout inhibition of tuber, bulb, and root vegetables; inhibition of post-harvest growth of asparagus and mushrooms; insect disinfestation; alteration of ripening and senescence in fresh fruits; and post-harvest microorganism disease control. Cost, consumer acceptance, and logistical problems are cited as possible limiting factors. Factors influencing response also are discussed

  15. Early detection of fungal disease infection in strawberry fruits by e-nose during postharvest storage%电子鼻对草莓采后贮藏早期霉菌感染的检测

    Institute of Scientific and Technical Information of China (English)

    朱娜; 毛淑波; 潘磊庆; 袁丽佳; 屠康

    2013-01-01

      为了实现电子鼻对草莓贮藏期常见霉菌感染的早期检测,对草莓果实分别接种灰霉、扩展青霉和根霉3种主要病原菌,以无菌水处理为对照组,每2 d采用PEN3电子鼻获取草莓的气味,并用气质联用技术分析草莓气味.结果表明,草莓接种病原菌2 d后,主成分分析能够正确区分正常果实(对照组)与病害果实,且可以较好区分草莓感染病原菌种类,多元方差分析结果也显示接种不同病原菌对草莓果实挥发性物质的影响差异显著(P<0.05),通过 Fisher 判别建立的回归函数对3种病原菌灰霉、扩展青霉和根霉及对照组的判别正确率分别为100%、93.3%、86.7%和100%.载荷分析及气质联用技术结果表明病原菌对草莓果实挥发性物质的影响主要体现在烃类及酯类的变化.研究结果可为实现草莓采后贮藏和流通过程中质量变化和病原微生物的感染进行无损快速检测和监测提供参考.%Strawberry postharvest diseases usually cause heavy losses in storage. Electronic nose (PEN3) containing an array of 10 different metal oxide sensors was used to detect and classify three kinds of common postharvest fungal diseases of strawberry fruit:Botrytis sp. (BC), Penicillium sp. (PE) and Rhizopus sp. (RH) in this paper. Ripe strawberry fruits were inoculated individually with the three pathogens and non-inoculated samples with sterile water treatment as control. Volatile compounds emanating from strawberry fruit were assessed using PEN3 every two days after inoculation. On the second day after invocation, the principal component analysis (PCA) of volatile profiles can clearly distinguish between normal and infection strawberry fruit; Furthermore, it can discriminate three groups of strawberry fruit with different pathogenic bacteria. Multivariate analysis of variance (MANOVA) was conducted on the e-nose sensors’response to the strawberry fruit with different treatment on

  16. Pest control in postharvest nuts

    Science.gov (United States)

    This chapter discusses the impact of insect infestations on the quality of postharvest nuts. The chapter first reviews the biology of key field pests that may be found in harvested nuts, and pests found in nut storage and processing facilities. The chapter then reviews current and developing control...

  17. Progress on Dissecting and Controlling the Citrus Huanglongbing Complex

    OpenAIRE

    Duan, Yongping; Zhou, Lijuan; Zhang, Muqing; Benyon, Lesley; Armstrong-Vahling, Cheryl; Hoffman, Michele; Hao, Guixia; Zou, Huasong; Doud, Melissa; Ding, Fang; Morgan, Kent

    2014-01-01

    Citrus huanglongbing (HLB) is a century-old and emerging disease that impedes citrus production worldwide. ‘Candidatus Liberibacter asiaticus’ (Las) is the globally prevalent species of HLB bacteria. Here we describe our molecular characterizations of Las, and our newly-developed control methods for citrus HLB. From a genomics standpoint, we revealed Las has a significantly reduced genome (1.26Mb) and unique features adapted to its intracellular life style.  Although the genome is small, Las ...

  18. Reasoned opinion on the modification of the existing MRLs for propiconazole in citrus fruits

    OpenAIRE

    European Food Safety Authority

    2012-01-01

    In accordance with Article 6 of Regulation (EC) No 396/2005, Spain, herewith referred to as the evaluating Member State (EMS), received an application from Makhteshim Agan España S.A. to modify the existing MRL for the active substance propiconazole in citrus fruits. In order to accommodate for the intended post-harvest use of propiconazole, the EMS proposed to raise the existing MRL in citrus fruit from the limit of quantification (0.05 mg/kg) to 5 mg/kg. According to EFSA the data are suffi...

  19. HLB resistance and tolerance in citrus scion development at the US Horticultural Research Laboratory

    Science.gov (United States)

    Huanglongbing (HLB) is severely impacting Florida citrus and threatening industries in the rest of the US. Productivity declines in many HLB-affected trees. Fruit size and quality often diminish as the disease advances. The USDA citrus scion breeding program is charged with producing improved citrus...

  20. Complete Genome sequence of citrus huanglongbing bacterium, ‘Candidatus Liberibacter asiaticus’ obtained through metagenomics

    Science.gov (United States)

    Citrus huanglongbing (HLB) is the most destructive disease of citrus worldwide. It is spread by the citrus psyllids (Diaphorina citri and Trioza erytreae), and is associated with low-titer, phloem-limited infections by any of the three uncultured species of a-Proteobacteria: 'Candidatus Liberibact...

  1. The screening of xanthomonas lactose – positive strains among bacterial populations of citrus canker disease isolated from Iran

    Directory of Open Access Journals (Sweden)

    Mahyat Jafari

    2013-01-01

    Full Text Available Introduction: Xanthan is a heteropolysaccharide that is produced by the group of plant pathogen bacteria from Xanthomonas genus. Usually, the media containing glucose, sucrose and starch is used for xanthan production. Because their preparation and transferring is expensive, the final cost of xanthan production by these carbon sources is high. On the other hand, many Xanthomonas species such as X.campestris are not able to use cheap media rich of lactose such as whey to produce xanthan due to the low expression and sometimes the defect of their β-galactosidase enzyme. The access to bacterial strains capable of decomposing lactose will provide a possibility for producing a valuable commercial product (xanthan from an inexpensive carbon source (whey.Materials and methods: In the present study, a collection containing 210 isolated Xanthomonas citrisubsp.citri Iranian strains from citrus orchards in south Iran was studied. Then, the genus of these bacteria was determined by using molecular techniques and sequencing of 16S-rDNA gene. Also, their growth in lactose – based medium was investigated.Results: Among 210 strains, 27 strains were able to grow on lactose rich medium. Then, the genus of these bacteria was proved by sequencing of 16S-rDNA gene and comparison with another 16S-rDNA gene sequences existing in NCBI. Also, these bacteria had considerable growth in lactose-based medium. Discussion and conclusion: At last, we can say that separated lactose-positive Xanthomonas strains from southern citrus orchards have good ability to utilize lactose and in the near future, it would be possible to apply these native strains for xanthan production in cheaper lactose media such as whey.

  2. Transcriptome analysis of root response to citrus blight based on the newly assembled Swingle citrumelo draft genome

    OpenAIRE

    Zhang, Yunzeng; Barthe, Gary; Grosser, Jude W.; Wang, Nian

    2016-01-01

    Background Citrus blight is a citrus tree overall decline disease and causes serious losses in the citrus industry worldwide. Although it was described more than one hundred years ago, its causal agent remains unknown and its pathophysiology is not well determined, which hampers our understanding of the disease and design of suitable disease management. Results In this study, we sequenced and assembled the draft genome for Swingle citrumelo, one important citrus rootstock. The draft genome is...

  3. Odorants for Surveillance and Control of the Asian Citrus Psyllid (Diaphorina citri)

    OpenAIRE

    Coutinho-Abreu, Iliano V; Forster, Lisa; Guda, Tom; Ray, Anandasankar

    2014-01-01

    Background The Asian Citrus Psyllid (ACP), Diaphorina citri, can transmit the bacterium Candidatus Liberibacter while feeding on citrus flush shoots. This bacterium causes Huanglongbing (HLB), a major disease of citrus cultivation worldwide necessitating the development of new tools for ACP surveillance and control. The olfactory system of ACP is sensitive to variety of odorants released by citrus plants and offers an opportunity to develop new attractants and repellents. Results In this stud...

  4. Characterization of the RNA Interference Response in the Asian Citrus Psyllid

    OpenAIRE

    Shaffer, Lindsay; Shatters, Jr., R. G.; Powell, C.; Cave, R.; Borovsky, D.

    2014-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri, is a major pest of citrus since it is the only known vector of ‘Candidatus Liberibactor’ species, the bacterium associated with citrus greening disease.  Since control of the psyllid is the only effective defense so far against citrus greening, and heavy reliance upon pesticides is not sustainable, an RNA interference (RNAi) strategy for ACP control was investigated. RNA interference is an innate immune response triggered by the cellular uptak...

  5. Electronic Tongue Response to Chemicals in Orange Juice that Change Concentration in Relation to Harvest Maturity and Citrus Greening or Huanglongbing (HLB) Disease.

    Science.gov (United States)

    Raithore, Smita; Bai, Jinhe; Plotto, Anne; Manthey, John; Irey, Mike; Baldwin, Elizabeth

    2015-01-01

    In an earlier study, an electronic tongue system (e-tongue) has been used to differentiate between orange juice made from healthy fruit and from fruit affected by the citrus greening or Huanglongbing (HLB) disease. This study investigated the reaction of an e-tongue system to the main chemicals in orange juice that impact flavor and health benefits and are also impacted by HLB. Orange juice was spiked with sucrose (0.2-5.0 g/100 mL), citric acid (0.1%-3.0% g/100 mL) and potassium chloride (0.1-3.0 g/100 mL) as well as the secondary metabolites nomilin (1-30 µg/mL), limonin (1-30 µg/mL), limonin glucoside (30-200 µg/mL), hesperidin (30-400 µg/mL) and hesperetin (30-400 µg/mL). Performance of Alpha MOS sensor sets #1 (pharmaceutical) and #5 (food) were compared for the same samples, with sensor set #1 generally giving better separation than sensor set #5 for sucrose, sensor set #5 giving better separation for nomilin and limonin, both sets being efficient at separating citric acid, potassium chloride, hesperitin and limonin glucoside, and neither set discriminating hesperidin efficiently. Orange juice made from fruit over the harvest season and from fruit harvested from healthy or HLB-affected trees were separated by harvest maturity, disease state and disease severity. PMID:26633411

  6. Electronic Tongue Response to Chemicals in Orange Juice that Change Concentration in Relation to Harvest Maturity and Citrus Greening or Huanglongbing (HLB Disease

    Directory of Open Access Journals (Sweden)

    Smita Raithore

    2015-12-01

    Full Text Available In an earlier study, an electronic tongue system (e-tongue has been used to differentiate between orange juice made from healthy fruit and from fruit affected by the citrus greening or Huanglongbing (HLB disease. This study investigated the reaction of an e-tongue system to the main chemicals in orange juice that impact flavor and health benefits and are also impacted by HLB. Orange juice was spiked with sucrose (0.2–5.0 g/100 mL, citric acid (0.1%–3.0% g/100 mL and potassium chloride (0.1–3.0 g/100 mL as well as the secondary metabolites nomilin (1–30 µg/mL, limonin (1–30 µg/mL, limonin glucoside (30–200 µg/mL, hesperidin (30–400 µg/mL and hesperetin (30–400 µg/mL. Performance of Alpha MOS sensor sets #1 (pharmaceutical and #5 (food were compared for the same samples, with sensor set #1 generally giving better separation than sensor set #5 for sucrose, sensor set #5 giving better separation for nomilin and limonin, both sets being efficient at separating citric acid, potassium chloride, hesperitin and limonin glucoside, and neither set discriminating hesperidin efficiently. Orange juice made from fruit over the harvest season and from fruit harvested from healthy or HLB-affected trees were separated by harvest maturity, disease state and disease severity.

  7. First steps towards rescuing Las-infected citrus germplasm

    Science.gov (United States)

    Huanglongbing (HLB) disease is having significant impact on the USDA citrus breeding program as it has shown up in a number of trees which exist only in a virtually irreplaceable collection of diverse citrus types. It is critical that we rescue HLB-free budwood from elite germplasm that is HLB-patho...

  8. Evaluation of Thermotherapy against Huanglongbing (Citrus Greening) under Laboratory Conditions

    OpenAIRE

    Fan, Guocheng; Xia, Yulu; Lin, Xiongjie; Cai, Zijian; Hu, Hanqing; Wang, Xianda; Ruan, Chuanqing; Lu, Lianming; Sequeira, Ronald; Liu, Bo

    2014-01-01

    Huanglongbing (HLB, citrus greening) is the most destructive disease of citrus. The disease is associated with “Candidatus Liberibacter asiaticus”. Few management options are available, besides preventive measures such as the removal of affected plants, planting disease-free stock and maintaining vector-free production in quarantine areas. In this study, we assessed the efficacy of thermotherapy against the disease under controled laboratory conditions. A total of sixty, 2-year old graft-infe...

  9. Coccinellid predators do not track populations of the Asian citrus phyllid (Diaphorina citri) in citrus in Puerto Rico

    Science.gov (United States)

    Yellow sticky cards were used to survey populations of Diaphorina citri, the vector of Huanglongbing, the most devastating bacterial disease of citrus worldwide. The numbers of coccinellids, potential predators of Diaphorina citri, were also surveyed. Citrus surveyed included a variety of species (V...

  10. Metabolic Interplay between the Asian citrus psyllid and its Profftella symbiont: An Achilles’ heel of the citrus greening insect vector

    Science.gov (United States)

    ‘Candidatus Liberibacter asiaticus’ (CLas), the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including ‘Candidatus Profftella armatura’, are likely to impact tra...

  11. Incidence of the Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae) and its parasitoid Tamarixia radiata (Hymenoptera: Eulophidae) in Florida citrus

    Science.gov (United States)

    Diaphorina citri Kuwayama, vectors the bacterium Candidatus Liberibacter asiaticus, one of the causal organisms of the devastating citrus disease “huanglongbing” or citrus greening. In the United States, D. citri was first discovered in Florida, in 1998. Tamarixia radiata Waterston, was imported fro...

  12. Citrus Waste Biomass Program

    Energy Technology Data Exchange (ETDEWEB)

    Karel Grohman; Scott Stevenson

    2007-01-30

    Renewable Spirits is developing an innovative pilot plant bio-refinery to establish the commercial viability of ehtanol production utilizing a processing waste from citrus juice production. A novel process based on enzymatic hydrolysis of citrus processing waste and fermentation of resulting sugars to ethanol by yeasts was successfully developed in collaboration with a CRADA partner, USDA/ARS Citrus and Subtropical Products Laboratory. The process was also successfully scaled up from laboratory scale to 10,000 gal fermentor level.

  13. Phenology of Asian citrus psyllid (Hemiptera: Liviidae) and associated parasitoids on two species of Citrus, kinnow mandarin and sweet orange, in Punjab Pakistan.

    Science.gov (United States)

    Khan, Shouket Zaman; Arif, Muhammad Jalal; Hoddle, Christina D; Hoddle, Mark S

    2014-10-01

    The population phenology of Asian citrus psyllid, Diaphorina citri Kuwayama, was monitored weekly for 110 wk on two species of Citrus, kinnow mandarin and sweet orange, at two different research sites in Faisalabad, Punjab Pakistan. Citrus flush growth patterns were monitored and natural enemy surveys were conducted weekly. Flush patterns were similar for kinnow and sweet orange. However, flush on sweet orange was consistently more heavily infested with Asian citrus psyllid than kinnow flush; densities of Asian citrus psyllid eggs, nymphs, and adults were higher on sweet orange when compared with kinnow. When measured in terms of mean cumulative insect or Asian citrus psyllid days, eggs, nymphs, and adults were significantly higher on sweet orange than kinnow. Two parasitoids were recorded attacking Asian citrus psyllid nymphs, Tamarixia radiata (Waterston) and Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal). The dominant parasitoid species attacking Asian citrus psyllid nymphs on kinnow and sweet orange was T. radiata, with parasitism averaging 26%. D. aligarhensis parasitism averaged 17%. Generalist predators such as coccinellids and chrysopids were collected infrequently and were likely not important natural enemies at these study sites. Immature spiders, in particular, salticids and yellow sac spiders, were common and may be important predators of all Asian citrus psyllid life stages. Low year round Asian citrus psyllid densities on kinnow and possibly high summer temperatures, may, in part, contribute to the success of this cultivar in Punjab where Candidatus Liberibacter asiaticus, the putative causative agent of huanglongbing, a debilitating citrus disease, is widespread and vectored by Asian citrus psyllid. PMID:25198345

  14. Citrus Flavonoids as Regulators of Lipoprotein Metabolism and Atherosclerosis.

    Science.gov (United States)

    Mulvihill, Erin E; Burke, Amy C; Huff, Murray W

    2016-07-17

    Citrus flavonoids are polyphenolic compounds with significant biological properties. This review summarizes recent advances in understanding the ability of citrus flavonoids to modulate lipid metabolism, other metabolic parameters related to the metabolic syndrome, and atherosclerosis. Citrus flavonoids, including naringenin, hesperitin, nobiletin, and tangeretin, have emerged as potential therapeutics for the treatment of metabolic dysregulation. Epidemiological studies reveal an association between the intake of citrus flavonoid-containing foods and a decreased incidence of cardiovascular disease. Studies in cell culture and animal models, as well as a limited number of clinical studies, reveal the lipid-lowering, insulin-sensitizing, antihypertensive, and anti-inflammatory properties of citrus flavonoids. In animal models, supplementation of rodent diets with citrus flavonoids prevents hepatic steatosis, dyslipidemia, and insulin resistance primarily through inhibition of hepatic fatty acid synthesis and increased fatty acid oxidation. Citrus flavonoids blunt the inflammatory response in metabolically important tissues including liver, adipose, kidney, and the aorta. The mechanisms underlying flavonoid-induced metabolic regulation have not been completely established, although several potential targets have been identified. In mouse models, citrus flavonoids show marked suppression of atherogenesis through improved metabolic parameters as well as through direct impact on the vessel wall. Recent studies support a role for citrus flavonoids in the treatment of dyslipidemia, insulin resistance, hepatic steatosis, obesity, and atherosclerosis. Larger human studies examining dose, bioavailability, efficacy, and safety are required to promote the development of these promising therapeutic agents. PMID:27146015

  15. A survey of FLS2 genes from multiple citrus species identifies candidates for enhancing disease resistance to Xanthomonas citri ssp. citri.

    OpenAIRE

    Qingchun Shi; Febres, Vicente J.; Jones, Jeffrey B; MOORE, Gloria A.

    2016-01-01

    Pathogen-associated molecular patterns (PAMPs)-triggered immunity (PTI) is an important component of plant innate immunity. In a previous study, we showed that the PAMP flg22 from Xanthomonas citri ssp. citri (Xflg22), the causal agent of citrus canker, induced PTI in citrus, which correlated with the observed levels of canker resistance. Here, we identified and sequenced two bacterial flagellin/flg22 receptors (FLS2-1 and FLS2-2) from ‘Duncan’ grapefruit (Citrus paradisi, CpFLS2-1 and CpFLS2...

  16. Inhibition of citrus fungal pathogens by using lactic acid bacteria.

    Science.gov (United States)

    Gerez, C L; Carbajo, M S; Rollán, G; Torres Leal, G; Font de Valdez, G

    2010-08-01

    The effect of lactic acid bacteria (LAB) on pathogenic fungi was evaluated and the metabolites involved in the antifungal effect were characterized. Penicillium digitatum (INTA 1 to INTA 7) and Geotrichum citri-aurantii (INTA 8) isolated from decayed lemon from commercial packinghouses were treated with imazalil and guazatine to obtain strains resistant to these fungicides. The most resistant strains (4 fungal strains) were selected for evaluating the antifungal activity of 33 LAB strains, among which only 8 strains gave positive results. The antifungal activity of these LAB strains was related to the production of lactic acid, acetic acid, and phenyllactic acid (PLA). A central composite design and the response surface methodology were used to evaluate the inhibitory effect of the organic acids produced by the LAB cultures. The antifungal activity of lactic acid was directly related to its concentration; however, acetic acid and PLA showed a peak of activity at 52.5 and 0.8 mM, respectively, with inhibition rates similar to those obtained with Serenade((R)) (3.0 ppm) imazalil (50 ppm) and guazatine (50 ppm). Beyond the peak of activity, a reduction in effectiveness of both acetic acid and PLA was observed. Comparing the inhibition rate of the organic acids, PLA was about 66- and 600-fold more effective than acetic acid and lactic acid, respectively. This study presents evidences on the antifungal effect of selected LAB strains and their end products. Studies are currently being undertaken to evaluate the effectiveness in preventing postharvest diseases on citrus fruits. PMID:20722936

  17. Postharvest Biocontrol: Introspection and Paradigm Shifts

    Science.gov (United States)

    The use of postharvest biocontrol agents as an alternative to the synthetic, chemical fungicides on a widespread basis has many constraints. During the last twenty years, the field of postharvest biocontrol research has significantly grown and developed and seen the creation of several products. Des...

  18. 晚熟温州蜜柑 NBS-LRR类抗病基因同源序列的克隆及分析%Cloning and Analysis of NBS-LRR Disease-Resistant Gene Analogs in Citrus unshiu Marc.

    Institute of Scientific and Technical Information of China (English)

    刘登全; 王园秀; 崔朝宇; 秦双林; 欧阳慧; 蒋军喜

    2016-01-01

    为加深对柑橘黄龙病抗性机理的了解和为黄龙病抗性基因的克隆提供依据,根据已知植物抗病基因NBS-LRR保守结构域设计简并引物,以柑橘黄龙病抗性品种“晚熟温州蜜柑”为供试材料,对其基因组DNA进行PCR扩增、克隆和序列测定,结果共获得17条抗病基因同源序列(resistance gene analogs,RGAs),其在NCBI中的登录号为KJ019189~KJ019199,KR815564~KR815569。序列分析表明,这17个RGAs与甜橙、柚等柑橘属中推测的一些抗病蛋白基因或其他相关蛋白基因具有显著高的同源性。其中一些RGAs与拟南芥抗霜霉病RPP13基因、柑橘抗衰退病毒基因Ctv或烟草抗TMV基因N具有51.7%~79.0%的氨基酸序列同源性。依据论文结果,笔者认为,晚熟温州蜜柑中存在较丰富的NBS-LRR类抗病基因,但具体哪些病基因与抗黄龙病相关尚需进一步研究。%In order to deepen understanding of the resistant mechanism of Citrus to Candiadatus Liberi-bacter asiaticus( CLas) and lay the foundation for cloning of citrus huanglongbing( HLB)-resistant gene,a pair of degenerate primers was designed from the conserved domains of NBS-LRR type plant disease-resistant gene and used for amplifying the disease-resistant gene analogs( RGAs) by polymerase chain reaction( PCR) from the genomic DNA of Citrus unshiu Marc.,a citrus cultivar resistant to HLB.After cloning and sequencing the PCR products,the nucleotide sequences and their deduced amino acid sequences of 17 RGAs were obtained and deposited in GenBank with the accession number of KJ019189-KJ019199 and KR815564-KR815569.Se-quence analysis showed that these 17 RGAs shared significantly high homology with some putative disease-re-sistant genes and other protein genes in Citrus sinensis or Citrus clementina, some of which shared 51.7%-79.0%amino acid sequence homology with the known disease gene of RPP13,Ctv,or N.Based on these re-sults,it is concluded

  19. Cloning and Analysis of NBS-LRR Disease-Resistant Gene Analogs in Citrus unshiu Marc.%晚熟温州蜜柑 NBS-LRR类抗病基因同源序列的克隆及分析

    Institute of Scientific and Technical Information of China (English)

    刘登全; 王园秀; 崔朝宇; 秦双林; 欧阳慧; 蒋军喜

    2016-01-01

    为加深对柑橘黄龙病抗性机理的了解和为黄龙病抗性基因的克隆提供依据,根据已知植物抗病基因NBS-LRR保守结构域设计简并引物,以柑橘黄龙病抗性品种“晚熟温州蜜柑”为供试材料,对其基因组DNA进行PCR扩增、克隆和序列测定,结果共获得17条抗病基因同源序列(resistance gene analogs,RGAs),其在NCBI中的登录号为KJ019189~KJ019199,KR815564~KR815569。序列分析表明,这17个RGAs与甜橙、柚等柑橘属中推测的一些抗病蛋白基因或其他相关蛋白基因具有显著高的同源性。其中一些RGAs与拟南芥抗霜霉病RPP13基因、柑橘抗衰退病毒基因Ctv或烟草抗TMV基因N具有51.7%~79.0%的氨基酸序列同源性。依据论文结果,笔者认为,晚熟温州蜜柑中存在较丰富的NBS-LRR类抗病基因,但具体哪些病基因与抗黄龙病相关尚需进一步研究。%In order to deepen understanding of the resistant mechanism of Citrus to Candiadatus Liberi-bacter asiaticus( CLas) and lay the foundation for cloning of citrus huanglongbing( HLB)-resistant gene,a pair of degenerate primers was designed from the conserved domains of NBS-LRR type plant disease-resistant gene and used for amplifying the disease-resistant gene analogs( RGAs) by polymerase chain reaction( PCR) from the genomic DNA of Citrus unshiu Marc.,a citrus cultivar resistant to HLB.After cloning and sequencing the PCR products,the nucleotide sequences and their deduced amino acid sequences of 17 RGAs were obtained and deposited in GenBank with the accession number of KJ019189-KJ019199 and KR815564-KR815569.Se-quence analysis showed that these 17 RGAs shared significantly high homology with some putative disease-re-sistant genes and other protein genes in Citrus sinensis or Citrus clementina, some of which shared 51.7%-79.0%amino acid sequence homology with the known disease gene of RPP13,Ctv,or N.Based on these re-sults,it is concluded

  20. RNA Interference Screening Reveals Redox Processes to be Most Responsive to Low dsRNA Doses in Asian Citrus Psyllid

    OpenAIRE

    Ramos, John E.; Shatters, Robert G; Powell, Charles A.; Borovsky, Dov; Jain, Ritesh; Shaffer, Lindsay; Ben-Mahmoud, Sulley K.

    2014-01-01

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is an invasive Homopteran that has crippled citrus production in Florida with the spread of the Huanglongbing (Citrus Greening) disease, which yields small discolored and bitter fruit. The disease is associated with the bacterium ‘Candidatus’ Liberibacter and is rapidly spreading to other citrus producing states. Gene targets were competitively deposited by experts from diverse fields for RNAi screening through an Innocentive challenge fund...

  1. Métodos para identificação e controle da tristeza dos citros Methods of identification and control of tristeza disease of citrus

    Directory of Open Access Journals (Sweden)

    S. Moreira

    1954-01-01

    s vezes é possível o emprego de pés francos provenientes dos embriões nucelares. Nas plantações já existentes pode-se fazer a substituição total ou parcelada (individual das plantas, conforme se constate predominância de afídios muito ou pouco eficientes e de estirpes fortes ou fracas do vírus. A sub-enxertia ("inarching", a sôbre-enxertia ("topworking" e o afrancamento do enxerto são outras tantas modalidades de controle da tristeza, as quais podem ser vantajosamente empregadas em determinadas condições. Medidas de quarentena podem retardar a invasão das zonas ainda livres da tristeza, -sendo de interesse o esclarecimento do público quanto ao perigo representado pela importação de plantas ou suas partes vivas, exceto as sementes.The tristeza disease of citrus has not yet been reported from European countries nor from various other citrus growing areas of the world. Investigations on the disease have been carried out in various countries, such as Argentina, Australia, Brazil, South Africa, and United States. Knowledge obtained from these investigations enables citrus experts from areas not invaded by tristeza to recognize its presence in the orchards and to prevent disastrous losses for the industry. General decline symptoms of tristeza resemble those caused by foot rot, but root examination permits the differentiation of the two diseases. Presence of pitting symptoms in trees of West Indian limes or of grapefruits permits easy diagnosis of tristeza in the orchards. Stock-scion combinations may be tolerant or intolerant to tristeza. Thus, it be comes important to determine the rootstock in case of plants showing decline symptoms. This fact can be established by direct examination of sprouts from the rootstock or by observing the degree of congeniality of rootstock and scion. The colorimetric tests made with bark of the rootstock may help to determine it. Field observation of symptoms complemented by Schneider's histological tests may replace the

  2. Relations between behavior of HLB and Iron application to Citrus trees

    OpenAIRE

    Matsuyama, T.; Muraki, S.; Subandiyah, S.; Joko, T.; Ono, H.; Masaoka, Y

    2014-01-01

    Citrus Greening Disease or Huanglongbing (HLB) is one of the most serious citrus diseases in the world. There are no effective methods to cure this disease, and major countermeasures include detection of initial detection and cutting down  infected trees. Thus, HLB delivers serious impact to the agricultural economy. It is well known that an HLB infected tree shows specific symptoms like micronutrient deficiency. We revealed that iron (Fe) content of citrus leaves showing symptoms f...

  3. In vitro and In vivo Antifungal Activities of Organic and Inorganic Salts Against Citrus Sour Rot Agent Geotrichum candidum

    OpenAIRE

    El Hassane Boudyach; Hassan Boubaker; Latifa Askarne; Idriss Talibi; Abdellah Ait Ben Aoumar

    2011-01-01

    The aim of this study was to find an alternative to the chemical fungicide currently used in the control of postharvest citrus sour rot. Here we screened thirty-two salt compounds, considered as common food additives, for their activity against Geotrichum candidum, causal agent of citrus sour rot. The lowest Minimum Inhibitory Concentrations (MICs) values were obtained by ammonium carbonate and EDTA at a concentration of 0.1% (w/v) and boric acid, sodium carbonate and sodium metabisulfi...

  4. The filamentous phage XacF1 causes loss of virulence in Xanthomonas axonopodis pv. citri, the causative agent of citrus canker disease

    Directory of Open Access Journals (Sweden)

    Abdelmonim Ali Ahmad

    2014-07-01

    Full Text Available In this study, filamentous phage XacF1, which can infect Xanthomonas axonopodis pv. citri (Xac strains, was isolated and characterized. Electron microscopy showed that XacF1 is a member of the family Inoviridae and is about 1000 nm long and 16 nm in width. The genome of XacF1 is 7325 nucleotides in size, containing 13 predicted open reading frames (ORFs, some of which showed significant homology to Ff-like phage proteins such as ORF1 (pII, ORF2 (pV, ORF6 (pIII, and ORF8 (pVI. XacF1 showed a relatively wide host range, infecting seven out of 11 strains tested in this study. Frequently, XacF1 was found to be integrated into the genome of Xac strains. This integration occurred at the host dif site (attB and was mediated by the host XerC/D recombination system. The attP sequence was identical to that of Xanthomonas phage Cf1c. Interestingly, infection by XacF1 phage caused several physiological changes to the bacterial host cells, including lower levels of extracellular polysaccharide production, reduced motility, slower growth rate, and a dramatic reduction in virulence. In particular, the reduction in virulence suggested possible utilization of XacF1 as a biological control agent against citrus canker disease.

  5. Utilization of an apple microarray for gene expression profiling in stone fruit-postharvest pathogen interactions

    Science.gov (United States)

    Brown rot disease (Monilinia fructicola Honey) is a major cause of Prunus spp. fruit losses in pre- and post-harvest settings. As part of an on-going effort to develop biological approaches for managing diseases of temperate fruit crops, we are seeking to better understand the mechanisms by which M...

  6. Postharvest respiration rate and sucrose content of Rhizoctonia-infected sugarbeet roots

    Science.gov (United States)

    Rhizotonia crown and root rot of sugarbeet, caused by Rhizoctonia solani AG 2-2, is increasing in Minnesota and North Dakota. As the disease increases in prevalence and severity, more diseased roots are being stored in piles where they affect storability and postharvest quality. The objective of th...

  7. Controle de doenças foliares e de flores e qualidade pós-colheita do morangueiro tratado com Saccharomyces cerevisiae Control of leaf and flower diseases and postharvest quality of strawberry plants treated with Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Alfredo de Gouvea

    2009-12-01

    Full Text Available O efeito de diferentes preparações de Saccharomyces cerevisiae foi avaliado sobre o desenvolvimento das doenças do morangueiro, como mancha-de-micosferela (Mycosphaerella fragariae, mancha-de-dendrofoma (Dendrophoma obscurans e flor-preta (Colletotrichum acutatum além da qualidade pós-colheita dos frutos. O trabalho foi realizado entre 2004 e 2005 na Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos. Os tratamentos consistiram de pulverizações semanais de cinco diferentes preparados a partir da levedura S. cerevisiae: suspensão com fermento biológico fresco comercial, suspensão de células de levedura, suspensão autoclavada de células, filtrado de cultura em meio líquido e Agro-MOS®, produto comercial formulado a partir da levedura, além da testemunha com água destilada e do tratamento controle com fungicidas. Nenhuma das preparações apresentou efeito contra a mancha-de-micosferela; preparações com a presença de células vivas e o produto Agro-MOS® apresentaram efeito contra mancha-de-dendrofoma; preparações com suspensão do produto comercial e filtrado de cultura líquida reduziram a incidência de flor-preta em flores e frutos. Preparações de S. cerevisiae com suspensão de células, suspensão autoclavada de células e filtrado de cultura líquida promoveram aumento na produtividade dos morangueiros que variou de 589,6 a 617,8 g planta-1. Preparações de S. cerevisiae, com presença de células vivas ou não, alteraram o metabolismo do morangueiro, aumentando a atividade das enzimas quitinase e glucanase, envolvidas na resistência sistêmica adquirida. Todos os tratamentos, com exceção do tratamento com suspensão autoclavada de células, reduziram a incidência de mofo-cinzento em pós-colheita de frutos.The effect of Saccharomyces cerevisiae was evaluated on the development of strawberry diseases and postharvest quality of fruits. The research was carried out in 2004 and 2005 in Paraná State

  8. A survey of FLS2 genes from multiple citrus species identifies candidates for enhancing disease resistance to Xanthomonas citri ssp. citri.

    Science.gov (United States)

    Shi, Qingchun; Febres, Vicente J; Jones, Jeffrey B; Moore, Gloria A

    2016-01-01

    Pathogen-associated molecular patterns (PAMPs)-triggered immunity (PTI) is an important component of plant innate immunity. In a previous study, we showed that the PAMP flg22 from Xanthomonas citri ssp. citri (Xflg22), the causal agent of citrus canker, induced PTI in citrus, which correlated with the observed levels of canker resistance. Here, we identified and sequenced two bacterial flagellin/flg22 receptors (FLS2-1 and FLS2-2) from 'Duncan' grapefruit (Citrus paradisi, CpFLS2-1 and CpFLS2-2) and 'Sun Chu Sha' mandarin (C. reticulata, CrFLS2-1 and CrFLS2-2). We were able to isolate only one FLS2 from 'Nagami' kumquat (Fortunella margarita, FmFLS2-1) and gene flanking sequences suggest a rearrangement event that resulted in the deletion of FLS2-2 from the genome. Phylogenetic analysis, gene structure and presence of critical amino acid domains all indicate we identified the true FLS2 genes in citrus. FLS2-2 was more transcriptionally responsive to Xflg22 than FLS2-1, with induced expression levels higher in canker-resistant citrus than in susceptible ones. Interestingly, 'Nagami' kumquat showed the highest FLS2-1 steady-state expression levels, although it was not induced by Xflg22. We selected FmFLS2-1, CrFLS2-2 and CpFLS2-2 to further evaluate their capacity to enhance bacterial resistance using Agrobacterium-mediated transient expression assays. Both FmFLS2-1 and CrFLS2-2, the two proteins from canker-resistant species, conferred stronger Xflg22 responses and reduced canker symptoms in leaves of the susceptible grapefruit genotype. These two citrus genes will be useful resources to enhance PTI and achieve resistance against canker and possibly other bacterial pathogens in susceptible citrus types. PMID:27222722

  9. Localized autoinoculation and dissemination of Isaria fumosorosea for control of the Asian citrus psyllid in South Texas

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors the causal organism of citrus greening disease. Integrated strategies are needed to control D. citri in south Texas. Control approaches involving entomopathogenic fungi may be useful on ornamental and abandoned citrus and other rutaceous...

  10. Huanglongbing resistance and tolerance in citrus

    Science.gov (United States)

    Huanglongbing (HLB) is severely impacting Florida citrus. Productivity declines in many HLB-affected genotypes, often with greatly thinned canopies. Fruit size and quality are often adversely affected as the disease advances. HLB was assessed in diverse cultivars in commercial groves with high HLB-i...

  11. Behavioral, Ultrastructural, and Chemical Studies on the 'Honeydew' Excretions in Nymphs and Adults of the Asian Citrus Psyllid

    OpenAIRE

    Ammar, E. D.; Alessandro, R.; Shatters, R G; Hall, D.G.

    2014-01-01

    The Asian citrus psyllid (ACP) Diaphorina citri (Hemiptera:  Psyllidae) is the main vector of bacteria responsible for citrus huanglongbing (citrus greening), the most serious citrus disease worldwide. Behavioral and ultrastructural studies on ‘honeydew’ excretions by ACP indicated interesting differences between nymphs, males and females. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adults. Video recordings showed ...

  12. Measuring the amount of vitamin C in citrus fruits by atwo step oxidation-

    OpenAIRE

    M.A. Ebrahimzadeh; S.J. Hosseinimehr; M Mahmodi; M.R. Gayekhloo; M. Hoseiani

    2005-01-01

    Background and purpose:Epidemiological evidence has suggested that consumption of fruits reduces the risk of chronic diseases such as cancer and cardiovascular disease. These benefits are often attributed to their high antioxidant components such as vitamin C (ascorbic acid). Citrus species are extremely rich sources for this vitamin, therefore we decided to determine the amount of vitamin C in some citrus fruits.Materials and methods : 13 species of commonly used citrus fruits were collected...

  13. Postharvest biology and technology of pomegranate.

    Science.gov (United States)

    Pareek, Sunil; Valero, Daniel; Serrano, María

    2015-09-01

    Pomegranate is a subtropical and tropical fruit of great importance from a health point of view. Despite increasing consumer awareness of the health benefits of pomegranate, consumption of the fruit is still limited owing to poor postharvest handling, storage recommendations, short shelf life and quality deterioration during transportation, storage and marketing. The occurrence of physiological disorders such as husk scald, splitting and chilling injury is another challenge reducing marketability and consumer acceptance. Recently, notable work on postharvest biology and technology has been done. Pomegranate is highly sensitive to low-oxygen (marketing of pomegranates, good results were obtained with polyamine, heat, salicylic acid, methyl jasmonate or methyl salicylate treatments prior to cold storage. This article reviews the maturity indices, changes during maturation and ripening, postharvest physiology and technology of pomegranate fruit as well as the various postharvest treatments for maintaining fruit quality. PMID:25565362

  14. Comparison of PCR,DIA and Pathogenicity Assay for Detection of Xanthomonas axonopodis pv.citri,the Causal Agent of Citrus Bacterial Canker Disease

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-kang; SUN Xian-yun; YIN You-ping; ZHOU Chang-yong; XIA Yu-xian

    2004-01-01

    Polymerase chain reaction (PCR) approach based on newly designed primers, JYF5/JYR5, was applied for specific detection of Xanthomonas axonopodis pv.citri(Xac). The efficiency and reliability of PCR method were compared with dot immunobinding assay (DIA) and classical pathogenicity test techniques for detecting suspensions of pure cells of Xac and soaking sap of citrus tissues. Detection sensitivity of PCR was about 4.5 cells or 1.56 pg target DNA per reaction which was higher than that of DIA (ca. 450 cells per dot).These three techniques (PCR assay, DIA and Pathogenecity test) could always detect Xac from symptomatic citrus samples. Different performances were obtained from citrus materials without symptoms, and the positive detection frequency was PCR, DIA and pathogenicity test.

  15. Stylet Morphometrics and Ultrastructure in Relation to Feeding Behavior and Pathogen Transmission by Nymphs and Adults of the Asian Citrus Psyllid Diaphorina citri, Vector of Citrus Huanglongbing Bacterium

    OpenAIRE

    Ammar, E. D.; Shatters, R G; Hall, D.G.

    2014-01-01

    The feeding behavior and stylet morphometrics were studied in nymphs and adults of the Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera, Psyllidae), vector of Candidatus Liberibacter asiaticus (Las) associated with citrus huanglongbing (HLB) disease. The stylet length of first instar nymphs averaged 266 µm (83% of body length) whereas that of 5th instar nymphs was 615 µm (34% of body length). Younger ACP nymphs feed only on young citrus leaves on smaller veins or on the sides of the mi...

  16. Sustainable postharvest handling of horticultural products

    OpenAIRE

    Antunes, Maria Dulce; Miguel, Maria Graça; Neves, A.

    2007-01-01

    Sustainable commercial horticultural success depends on satisfying consumer requirements. Fresh fruits and vegetables are important components of human food. However, horticultural products are highly perishable and losses can be of great importance if postharvest correct measures are not provided. Quality of fresh horticultural products can not be improved by postharvest technologies, only can be maintained, what means horticultural products must be of high quality at harvest. There is a wor...

  17. Differences in secondary metabolites in leaves from orange trees (Citrus sinensis L.) affected with greening disease (Huanglongbing) (HLB)

    Science.gov (United States)

    Preliminary analyses by HPLC-MS of methanolic extracts of two sets of orange leaves that are symptomatic of the Greening Disease (HLB) have shown several consistent differences. The main flavonoids in symptomatic and nonsymptomatic leaves were monitored in the HPLC chromatograms at 330 nm, and signi...

  18. Preharvest treatments with chitosan and other alternatives to conventional fungicides to control postharvest decay of strawberry.

    Science.gov (United States)

    Feliziani, Erica; Landi, Lucia; Romanazzi, Gianfranco

    2015-11-01

    The effectiveness of the control of postharvest decay of strawberry (Fragaria × ananassa, 'Alba' and 'Romina' cvs.) fruit following field applications of chitosan, laminarin, extracts of Abies spp., Polygonum spp., and Saccharomyces spp., an organic acids and calcium combination, and benzothiadiazole, were compared with a fungicide strategy. These compounds were sprayed every 5 days on the strawberry canopy, from flowering to ripening, in 2012 and 2013. The treatments with alternative compounds provided ∼ 30% reduction in postharvest decay of strawberry compared to the water-treated controls, mainly against gray mold and Rhizopus rot, and without negatively affecting fruit color and firmness. Chitosan and benzothiadiazole were the most effective alternative treatments. Preharvest spraying with these alternative treatments can complement the use of conventional fungicides in the control of postharvest decay of strawberry fruit, especially when disease pressure is low. PMID:26256331

  19. The Asian Citrus Psyllid Genome (Diaphorina citri, Hemiptera)

    OpenAIRE

    Hunter, Wayne B.; Reese, Justin; International Psyllid Genome Consortium, The

    2014-01-01

    The Asian citrus psyllid, Diaphorina citri (Hemiptera), is an important pest of citrus because it vectors bacteria responsible for huanglongbing, which is one of the most serious diseases of citrus worldwide.  The first genome draft of D. citri (DIACI_1.0) was completed in 2011 (ARS, Ft. Pierce, FL), however, gaps in the assembly prompted additional sequencing using the long run PacBio system at the Los Alamos National Lab, NM.  The revised draft genome (DIACI_1.1) was assembled using the new...

  20. Selection and testing of epiphytic yeasts to control anthacnose in post-harvest of papaya fruit

    NARCIS (Netherlands)

    Capdeville, G.; Souza, M.T.; Santos, J.R.P.; Miranda, S.P.; Caetano, A.R.; Torres, F.A.G.

    2007-01-01

    Anthracnose, caused by Colletotrichum gloeosporioides, is a major post-harvest disease in papaya fruit. The major objectives of the present work were to isolate, select and test the in vitro and in vivo ability of epiphytic microorganisms, isolated from papaya fruit and leaf surfaces, in controlling

  1. Chitosan and fungicides on postharvest control of Guignardia citricarpa and on quality of 'Pêra Rio' oranges

    OpenAIRE

    Maria Cristina Canale Rappussi; Eliane Aparecida Benato; Patrícia Cia; Sérgio Florentino Pascholati

    2011-01-01

    Citrus fruits are affected by the black spot disease caused by the fungus Guignardia citricarpa. Chitosan can be used as covering for fruits and may delay the ripening process and inhibit the growth of some fungi. Thus, the control of citrus black spot using chitosan and the fungicides thiabendazole and imazalil was assessed in addition to the physicochemical quality of 'Pêra Rio' oranges. The oranges were immersed into chitosan, thiabendazole or imazalil, and in chitosan mixed with both fung...

  2. Identification of the pathogens of postharvest apricot fruit diseases and indoor screening of fungicides%杏采后病害病原菌鉴定及室内药剂筛选

    Institute of Scientific and Technical Information of China (English)

    张瑾; 徐秉良; 梁巧兰; 张文利; 吴步梅

    2011-01-01

    [Objective] To identify the main pathogens causing fruit rot of storage apricots and screen the effective fungicides, so as to prolong the storage period of apricots and decrease the losses. [Method] Isolation and identification, as well as pathogenicity test and return inoculation experiments were made for the pathogen causing fruit rot of storage apricots in Lanzhou City, Gansu Province. The effective fungicides for the main pathogens were also screened in the laboratory. [Result] Six fungi were identified as the pathogens causing fruit rot of storage apricots, which were Trichothecium roseum Lk. Ex Fr., Alternaria alternata (Fr.) Keissl., Rhizopus nigricans (Ehrenb), Penicillium frequentans, Botrytis cinerea and Monilinia laxa (Aderh. & Ruhl.) Honey. The main pathogens causing postharvest diseases of apricots were A. Alternata, R. Nigricans and T. Roseum. The isolation frequencies of them were 28. 5%, 48. 9% and 9. 4%, respectively. After artificial inoculation with or without wounds, the incidence of fruits infected by A. Alternata, R. Nigricans and T. Roseum were 100%, 100% and 83%, respectively. The results of chemical screening showed that, in PDA media plate, the fludioxonil (50%WP) and iprodione (50% SC) were most effective in controlling the three main pathogens, and the average effect reached more than 94%. The test of fungicides antisepsis of fruits showed that apricots were dipped in the 9000× diluted solution of fludioxonil (50%WP) or in the 1000 X diluted solution of iprodione (50%SC) for 3 min and stored at room temperature (25℃) for 7 days and 13 days. The control effects of fludioxonil against T. Roseum, A. Alternata and R. Nigricans were 78.3%/65%, 79% /67.5% and 80.3%/69.6%, respectively, and the con-trol effects of iprodione were 76%/64.3%, 78. 3%/64.4% and 78.6%/66.4%, respectively. [Conclusion] Theresults may provide a reference for the control of postharvest diseases of apricots.%[目的]确定引起杏采后病害的主要病原菌及

  3. PHARMACOLOGICAL IMPORTANCE OF CITRUS FRUITS

    Directory of Open Access Journals (Sweden)

    Amita Tomar *, Mridula Mall and Pragya Rai

    2013-01-01

    Full Text Available This paper reviews the pharmacological importance of citrus fruits. Citrus fruits are used for various pharmacological importance. According to literature the citrus fruit possess anti-cancer, antimicrobial, antioxidant, antiulcer, anti-inflammatory, and hypolipidemic and hepatoprotective properties.

  4. Postharvest diseases and physicochemical characteristics of mango / Doenças e características físicas e químicas pós-colheita em manga

    Directory of Open Access Journals (Sweden)

    Eliane Maria Ravasi Stefano Simionato

    2009-07-01

    Full Text Available The objective of this work was to identify and to quantify the postharvest diseases and to evaluate the physical and chemical characteristics of mango fruits cvs. Haden, Tommy Atkins, Palmer and Keitt, submitted or not to the treatment with the fungicide carbendazim. The fruits had been harvested in a commercial orchard in President Prudente-SP, individualized and kept in a humid chamber for 24h, remaining eight days at 25±2ºC and 70-80% RH. The incidence of diseases, the firmness and the loss of mass were evaluated periodically, during nine days. Before and to the end of the storage, the fruits had been characterized to titratable acidity and soluble solids content. There was high occurrence of rots in the four mango cultivars. Anthracnose was the most frequent disease, with practically 100% of incidence in the fruits. The Lasiodiplodia stem-end rot had greater incidence in cv. Tommy Atkins (68%, followed for the Haden (36%. The treatment with carbendazim presented changeable efficiency in the control of the rots, in function of mango cultivar. This treatment is recommended for the control of the stem-end in cvs. Haden and Palmer and also to reduce the severity of anthracnose in cvs. Haden and Keitt. The fungicide application did not influence soluble solids and titratable acidity content and ratio of mango cultivars, except in Palmer that presented minor ratio when treated with fungicide. The ethefon application did not influence the ripening process of mango cv. Haden.O presente trabalho objetivou identificar e quantificar as doenças pós-colheita e avaliar as características físicas e químicas de frutos de manga cultivares Haden, Tommy Atkins, Palmer e Keitt submetidos, ou não, ao tratamento com o fungicida carbendazim. Os frutos foram colhidos em um pomar comercial em Presidente Prudente-SP, individualizados e submetidos a 24h de câmara úmida, permanecendo por mais oito dias a 25±2ºC e 70-80% de UR. A incidência de doenças, a

  5. Reasoned opinion on the setting of an import tolerance for didecyldimethylammonium chloride (DDAC in citrus

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2013-05-01

    Full Text Available In accordance with Article 6 of Regulation (EC No 396/2005, The Netherlands, hereafter referred to as the evaluating Member State (EMS, received an application from Exponent International Ltd (on behalf of ICA International Chemicals (PTY Ltd to set an import tolerance in citrus from South Africa for the active substance didecyldimethylammonium chloride (DDAC at the level of 6 mg/kg. The Netherlands drafted an evaluation report in accordance with Article 8 of Regulation (EC No 396/2005, which was submitted to the European Commission and forwarded to EFSA. According to EFSA, the data require the setting of an import tolerance of 6 mg/kg for citrus. However, additional information on the typical South African post-harvest treatment practice should be provided to decide whether the submitted trials are representative of the authorised GAP. A sufficiently validated analytical method to enforce the proposed MRL of DDAC on citrus is available. EFSA concludes that the consumer risk assessment did not identify a consumer health risk resulting from the post harvest uses of DDAC on citrus fruits. However it should be noted that the risk assessment is affected by a high degree of uncertainties which result from data gaps identified in the dossier. Finally, EFSA concludes that risk managers have to decide whether the setting of an import tolerance of 6 mg/kg is acceptable since the MRL currently into force for citrus in South Africa is 2 mg/kg only.

  6. Metalized Polyethylene Mulch to Reduce Incidence of Huanglongbing and Improve Growth of New Citrus Plantings

    OpenAIRE

    Croxton, S.; Stansly, P.

    2014-01-01

    Polyethylene mulch was evaluated for deterring colonization by Asian citrus psyllid (ACP) Diaphorina citri, reducing incidence of huanglongbing (HLB) or citrus greening disease and accelerating growth of young citrus.  UV reflective low density polyethylene mulch metalized with aluminum, low density whitefaced polyethylene mulch and bare ground all using drip irrigation in a randomized complete block design were tested and compared to the current grower standard using micro-sprinkler irrigati...

  7. Evaluation of antibiotics against the bacteria, Candidatus Liberibacter for control of citrus Huanglongbing

    OpenAIRE

    Zhang, Muqing; Guo, Ying; Powell, Charles A.; Duan, Yongping

    2014-01-01

    Citrus Huanglongbing (HLB) is one of the most serious diseases of citrus worldwide. The present study was undertaken to screen antibiotics against Candidatus Liberibacter asiaticus (Las) while simultaneously assessing phytotoxicity to citrus. Twenty-eight antibiotics from ten classes of medical-antibiotics and three agricultural-antibiotics were tested for in vivo activities against HLB bacterium using the previously optimized graft-based chemotherapy method (Zhang et al., 2012). First, sampl...

  8. Analyses of proteomic expression profiles and nutrient status of citrus plants in response to Huanglongbing

    OpenAIRE

    H. Lin; Nwugo, C. C.; Duan, Y.

    2014-01-01

    Huanglongbing (HLB) is a highly devastating citrus disease and represents a major threat to the citrus industries in US. The etiology of HLB worldwide is associated with three insect-transmissible phloem-limited members of the bacterial group ‘Candidatus Liberibacter spp.’, prevalently ‘Candidatus Liberibacter asiaticus’ (Las). All citrus cultivars are susceptible to HLB. To better understand the physiological and molecular processes involved in host responses to Las, proteomic analyses via 2...

  9. Molecular Interactions between the Citrus Bacterial Pathogen Candidatus Liberbacter asiaticus and Its Insect Vector the Asian Citrus Psyllid Diaphorina citri

    OpenAIRE

    Wang, Linling; Killiny, Nabil

    2014-01-01

    Huanglongbing (HLB), the most serious disease of citrus, is attributed in the United States to Candidatus Liberibacter asiaticus (CLas), a gram-negative, phloem-restricted α-proteobacterium transmitted by the Asian citrus psyllid (Diaphorina citri). Despite the fact that the psyllid is well recognized as the vector of CLas, to the best of our knowledge, little research has so far been conducted on molecular interactions between CLas and the psyllid. Many gram-negative bacterial pathogens have...

  10. Metabolic Interplay between the Asian Citrus Psyllid and Its Profftella Symbiont: An Achilles’ Heel of the Citrus Greening Insect Vector

    OpenAIRE

    Ramsey, John S; Johnson, Richard S.; Hoki, Jason S.; Kruse, Angela; Mahoney, Jaclyn; Hilf, Mark E.; Hunter, Wayne B.; Hall, David G.; Schroeder, Frank C.; MacCoss, Michael J.; Cilia, Michelle

    2015-01-01

    ‘Candidatus Liberibacter asiaticus’ (CLas), the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including ‘Candidatus Profftella armatura’, are likely to impact transmission of CLas. We used quantitative mass spectrometry to compare the proteomes of CLas(+) and CLas(-) populations of D. citri, and found that proteins involved in polyketide biosynthesis by the ...

  11. 78 FR 63369 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Science.gov (United States)

    2013-10-24

    ... Animal and Plant Health Inspection Service 7 CFR Part 301 RIN 0579-AD29 Citrus Canker, Citrus Greening... published an interim rule \\1\\ in the Federal Register (76 FR 23449-23459, Docket No. APHIS-2010-0048) that....usda.gov/plant_health/plant_pest_info/citrus/index.shtml and on Regulations.gov (see footnote 1...

  12. 75 FR 17289 - Citrus Seed Imports; Citrus Greening and Citrus Variegated Chlorosis

    Science.gov (United States)

    2010-04-06

    ... Animal and Plant Health Inspection Service 7 CFR Part 319 RIN 0579-AD07 Citrus Seed Imports; Citrus... of nursery stock to prohibit the importation of propagative seed of several Rutaceae (citrus family... are also requiring propagative seed of these genera imported from all other countries to...

  13. Comparison of FTIR spectra between huanglongbing (citrus greening) and other citrus maladies

    Science.gov (United States)

    Fourier Transform Infrared Spectroscopy has the ability to quickly identify the presence of specific carbohydrates in plant materials. The presence of the disease Huanglongbing(HLB) in the leaves of infected citrus plants has a distinctive spectrum that can be used to distinguish an infected plant ...

  14. Citrus Improvement Using Mutation Techniques

    International Nuclear Information System (INIS)

    Pineapple orange, and the University of Florida a seedless Murcot tangor. Mutation has been also important in lemon breeding, and a seedless lemon, with tolerance to a devastating lemon disease was recently reported, in addition to earlier reports of a thornless lemon mutant produced by gamma irradiation. Gamma irradiation is currently an important component of our breeding programme and several potentially improved cultivars of grapefruit, pummelos, and lemons are in the pipeline. Additional details of citrus irradiation programmes in the US will be provided. (author)

  15. Commercial risk-based survey for HLB and implications for efficacy of Citrus Health Management Areas (CHMAs)

    OpenAIRE

    Gottwald, T.; Luo, W.; Riley, T; Parnell, S.

    2014-01-01

    The USDA, APHIS, PPQ has been conducting a risk-based multi-pest survey (MPS) for the past two years.  The initial 6 statewide survey cycles were conducted on a 6 week basis, whereas the subsequent 20 cycles have been conducted on a 3-week basis.  HLB and ACP are the two main pests addressed by the MPS but other citrus pests and diseases, i.e., Asiatic Citrus Canker (ACC), Citrus Leprosis Virus (CLiV), Citrus Black Spot (CBS) and Citrus Variegated Chlorosis (CVC) were also given lesser emphas...

  16. Multiplexed lateral flow microarray assay for detection of citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis pv citri

    Science.gov (United States)

    Cary; R. Bruce; Stubben, Christopher J.

    2011-03-22

    The invention provides highly sensitive and specific assays for the major citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis, including a field deployable multiplexed assay capable of rapidly assaying for both pathogens simultaneously. The assays are directed at particular gene targets derived from pathogenic strains that specifically cause the major citrus diseases of citrus variegated chlorosis (Xylella fastidiosa 9a5c) and citrus canker (Xanthomonas axonopodis pv citri). The citrus pathogen assays of the invention offer femtomole sensitivity, excellent linear dynamic range, and rapid and specific detection.

  17. Effects of Ionizing Radiation on Postharvest Fungal Pathogens.

    Science.gov (United States)

    Jeong, Rae-Dong; Shin, Eun-Jung; Chu, Eun-Hee; Park, Hae-Jun

    2015-06-01

    Postharvest diseases cause losses in a wide variety of crops around the world. Irradiation, a useful nonchemical approach, has been used as an alternative treatment for fungicide to control plant fungal pathogens. For a preliminary study, ionizing radiations (gamma, X-ray, or e-beam irradiation) were evaluated for their antifungal activity against Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer through mycelial growth, spore germination, and morphological analysis under various conditions. Different fungi exhibited different radiosensitivity. The inhibition of fungal growth showed in a dose-dependent manner. Three fungal pathogens have greater sensitivity to the e-beam treatment compared to gamma or X-ray irradiations. The inactivation of individual fungal-viability to different irradiations can be considered between 3-4 kGy for B. cinerea and 1-2 kGy for P. expansum and R. stolonifer based on the radiosensitive and radio-resistant species, respectively. These preliminary data will provide critical information to control postharvest diseases through radiation. PMID:26060436

  18. The ability of the antagonist yeast Pichia guilliermondii strain Z1 to suppress green mould infection in citrus fruit

    Directory of Open Access Journals (Sweden)

    Rachid Lahlali

    2014-12-01

    Full Text Available In previous studies it was shown that Pichia guilliermondii strain Z1, isolated from healthy Moroccan citrus Valencia-Late oranges, was effective against Penicillium italicum. Here the effectiveness of strain Z1 was assessed against Penicillium digitatum, the causal agent of green mould, under different temperature (5-25°C and relative humidity (RH (45-100% regimes for its reliable and largescale application in packinghouse. All main effects and interactions were significant (P80%. Its applications as a formulated product significantly reduced the incidence of infected fruit (55% and the percentage of infected wounds (47% compared to the only pathogen control treatment. However, disease control with formulated product was significantly less than that obtained with thiabendazole (30% or strain Z1 culturable cells (35%. These results highlight that strain Z1 is an effective biological control agent for control of green mould under varying environmental conditions, and control may be optimized by combining its use with other environmentally-safe post-harvest treatments or improved formulation.

  19. Sequence analysis of three citrus viroids infecting a single Tunisian citrus tree (Citrus, reticulata, Clementine

    Directory of Open Access Journals (Sweden)

    Amine Elleuch

    2006-01-01

    Full Text Available We report the nucleotide sequences of three citrus viroids belonging to three different genera: Citrus exocortis viroid (CEVd, Hop stunt viroid (HSVd and Citrus viroid-III (CVd-III isolated from a single natural infected Citrus reticulata var. Clementine tree growing in a tree nursery in Manouba (near Tunis Capital. We describe the sequence variability of these viroids from their natural host without using an alternative passage by an indicator host or an artificial inoculation. This work confirms that naturally occurring viroid infections contain a mixture of sequence variants. These are the first sequences of citrus viroids from Africa.

  20. Characteristics of the perception of different severity measures of citrus canker and the relations between the various symptom types

    Science.gov (United States)

    Citrus canker is a disease of citrus and is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac). Ways of managing the disease are being sought, and accurate, precise, reproducible disease assessment is needed for monitoring epidemics. The objective of this study was to investigate...

  1. Behavioral, Ultrastructural and Chemical Studies on the Honeydew and Waxy Secretions by Nymphs and Adults of the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Psyllidae)

    OpenAIRE

    Ammar, El-Desouky; Alessandro, Rocco; Shatters Jr, Robert G.; Hall, David G.

    2013-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae) is the primary vector of the bacterium causing citrus huanglongbing (citrus greening), the most serious disease of citrus worldwide. Psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. Behavioral, ultrastructural and chemical studies on ACP, its honeydew and waxy secretions showed important differences ...

  2. Citrus tristeza virus-host interactions

    Directory of Open Access Journals (Sweden)

    William O. Dawson

    2013-05-01

    Full Text Available Citrus tristeza virus (CTV is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or symptomless in most of their host range. There is little understanding of how the virus causes severe disease in some citrus and none in others. Movement and distribution of CTV differs considerably from that of well-studied viruses of herbaceous plants where movement occurs largely through adjacent cells. In contrast, CTV systemically infects plants mainly by long-distance movement with only limited cell-to-cell movement. The virus is transported through sieve elements and occasionally enters an adjacent companion or phloem parenchyma cell where virus replication occurs. In some plants this is followed by cell-to-cell movement into only a small cluster of adjacent cells, while in others there is no cell-to-cell movement. Different proportions of cells adjacent to sieve elements become infected in different plant species. This appears to be related to how well viral gene products interact with specific hosts. CTV has three genes that are not necessary for infection of most of its hosts, but are needed in different combinations for infection of certain citrus species. These genes apparently were acquired by the virus to extend its host range. Some specific viral gene products have been implicated in symptom induction. Remarkably, the deletion of these genes from the virus genome can induce large increases in stem pitting symptoms. The p23 gene, which is a suppressor of RNA silencing and a regulator of viral RNA synthesis, has been shown to be the cause of seedling yellows symptoms in sour orange. Most isolates of CTV in nature are populations of different strains of CTV. The next frontier of CTV biology is the understanding how the virus variants in

  3. Huanglongbing Resistance and Tolerance in Citrus

    OpenAIRE

    Stover, E; McCollum, G.; Driggers, R.; Duan, Y.; Shatters, Jr., R. G.; Ritenour, M.; Hall, D.G.; J. Chaparro

    2014-01-01

    Huanglongbing (HLB) is severely impacting Florida citrus. Productivity declines in many HLB-affected genotypes, often with greatly thinned canopies. Fruit size and quality are often adversely affected as the disease advances. HLB was assessed in diverse cultivars in commercial groves with high HLB-incidence. ‘Temple’ had the lowest HLB symptoms and Liberibacter (Las) titer, while ‘Murcott’ and ‘Minneola’ had the highest. The USDA Ft. Pierce, FL farm is managed to reveal genotype responses to ...

  4. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing

    Science.gov (United States)

    Yang, Chuanyu; Powell, Charles A.; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB. PMID:26207823

  5. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing.

    Directory of Open Access Journals (Sweden)

    Chuanyu Yang

    Full Text Available Huanglongbing (HLB is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las, resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm compared to those of Brij 35 (4.34 mm and Amp solution (2.83 mm alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB.

  6. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing.

    Science.gov (United States)

    Yang, Chuanyu; Powell, Charles A; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB. PMID:26207823

  7. Postharvest of ‘Fuerte’ and ‘Hass’ avocados: physical and chemical characteristics, damages and control of diseases/ Pós-colheita de abacates ‘Fuerte’ e ‘Hass’: características físicas e químicas, danos e controle de doenças

    Directory of Open Access Journals (Sweden)

    Maria Cecília Arruda

    Full Text Available Postharvest disease is considered an important cause of avocado depreciation during its commercialization. This work aimed to evaluate the postharvest damages and the physical chemical characteristics of avocados ‘Fuerte’ and ‘Hass’, processed at the packinghouse, and to evaluate the effect of products for postharvest disease control. The characteristics skin color, firmness, titratable acidity and soluble solids content and the incidence of the postharvest damages were evaluated periodically in avocados sampled in three different stages in a packinghouse (arrival, pallet and processed fruits after storage for 30 days at 5ºC. For diseases control, ‘Hass’ avocado were treated by immersion with the following products: azoxystrobin, benzalkonium chloride, chlorine dioxide, Ecolife®, sodium hypochlorite, imazalil, prochloraz and thiabendazole. In general, the highest physical chemical changes were observed in fruits collected at their arrival to the packinghouse and in processed fruits after stored for 30 days at 15 days of storage at 25°C. The rots incidence was 56,7% in ‘Fuerte’ and 75,7% in ‘Hass’. Lower incidence of rots was observed in fruits sampled at the pallet and a higher incidence in the processed fruits, after refrigerated storage. Anthracnose was the most important disease in both cultivars. The mechanical injuries increased with the processing stages; however, they did not influence the incidence of the rots. Procloraz and imazalil were the most efficient fungicides in reducing the incidence of rots. Doença pós-colheita é considerada uma importante causa de desvalorização do abacate por ocasião da comercialização. Este trabalho objetivou avaliar os danos pós-colheita e as características físicas e químicas de abacates ‘Fuerte’ e ‘Hass’, beneficiados em packinghouse, e o efeito de produtos no controle pós-colheita das podridões. As características cor da casca, firmeza, acidez titulável e s

  8. Potential Nutritional Benefits of Current Citrus Consumption

    OpenAIRE

    Tami Turner; Burri, Betty J.

    2013-01-01

    Citrus contains nutrients and phytochemicals that may be beneficial for health. We collected citrus production and consumption data and estimated the amount of these compounds that are consumed. We then compared the amounts of citrus and citrus-derived compounds used in studies that suggest a health benefit to the amounts typically found in citrus. Data is scarce, but suggests that citrus consumption might improve indices of antioxidant status, and possibly cardiovascular health and insulin s...

  9. Potential Nutritional Benefits of Current Citrus Consumption

    Directory of Open Access Journals (Sweden)

    Tami Turner

    2013-03-01

    Full Text Available Citrus contains nutrients and phytochemicals that may be beneficial for health. We collected citrus production and consumption data and estimated the amount of these compounds that are consumed. We then compared the amounts of citrus and citrus-derived compounds used in studies that suggest a health benefit to the amounts typically found in citrus. Data is scarce, but suggests that citrus consumption might improve indices of antioxidant status, and possibly cardiovascular health and insulin sensitivity.

  10. Disinfection of Citrus Storage Room by Fumigation with Two Plants and Chemical Product Deccofenato Pot against the Viability of Penicillium Spp Spores

    OpenAIRE

    M. C. Elbouchtaoui; L. M. Idrissi Hassani

    2014-01-01

    Citrus fruits are subject to many postharvest phytopathogenic fungi that cause severe economic losses. The most attacks are mainly due the genus Penicillium spp. The treatment of these fungi uses a lot of chemicals that negatively affect environment and human health. Our study aims to test the antifungal activity by fumigation of two plants and a new chemical pesticide at the station Agrumar Souss, Ait Melloul. Plants and pesticide Deccofenato pot were used as fumigation in or...

  11. Evaluation of low-volume sprayers used in asian citrus Psyllid control applications

    Science.gov (United States)

    The Asian citrus psyllid (Diaphorina citri Kumayama, Sternorrhyncha: Psyllidae) is a detrimental pest to citrus crops when it serves as a vector of the pathogen that causes greening (huanglongbing, or HLB). Transmission of this disease causes mottling, chlorosis, dieback and reductions in both frui...

  12. Evaluation of Quantitative Real-Time PCR Assays for Detection of Citrus Greening

    Science.gov (United States)

    Citrus huanglongbing (HLB), or citrus greening, is a serious and industry-limiting disease. Preliminary diagnoses can be made through visual symptoms, and greater certainty can be achieved through quantitative real-time PCR (qPCR). Several qPCR procedures are available including those by designed by...

  13. Acoustic signals in the courtship of male and female Asian citrus psyllids

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama, was discovered in Broward County, Florida in 1998, and has since spread through most of the state. It is an important vector of Huanglongbing, an economically devastating disease of citrus; consequently, researchers and regulators are trying to d...

  14. Viability of ‘Candidatus Liberibacter asiaticus’ prolonged by addition of citrus juice to culture medium

    Science.gov (United States)

    Huanglongbing, or citrus greening disease, is associated with infection by the phloem-limited bacterium ‘Candidatus Liberibacter asiaticus’ (LAS). Infection with LAS, vectored by the Asian citrus psyllid (Diaphorina citri), is incurable; therefore, knowledge regarding LAS biology and pathogenesis is...

  15. Transmission and Propagation of ‘Candidatus Liberibacter asiaticus’ by Grafting with Individual Citrus Leaves

    Science.gov (United States)

    Huanglongbing (HLB) is a chronic, progressive decline disease in citrus associated with systemic infection by the bacterium Candidatus Liberibacter asiaticus (CLas). Transmission in the field is by the Asian citrus psyllid (ACP), Diaphorina citri, Kuwayama. Experimental propagation of CLas is done c...

  16. Cryopreservation of Citrus seeds via dehydration and direct immersion in liquid nitrogen

    Science.gov (United States)

    Citrus germplasm is conventionally conserved in clonal orchards and greenhouses, where it is subjected to potential losses due to pests, diseases and climatic hazards. In recent years, many studies reported preservation of germplasm in the genus Citrus. As a result, effective freezing protocols have...

  17. Use of nootkatone as a senescence indicator for Rouge La Toma Cv. grapefruit (Citrus paradisi Macf.).

    Science.gov (United States)

    Biolatto, Andrea; Sancho, Ana M; Cantet, Rodolfo J C; Güemes, Daniel R; Pensel, Norma A

    2002-08-14

    The objective of this research was to study the usefulness of nootkatone as a senescence indicator for Rouge La Toma cv. grapefruit (Citrus paradisi Macf.), simulating different treatments that included the normal postharvest handling of citrus fruits: temperature conditioning, cold storage, shipment periods to overseas markets such as Japan and the U.S., marketing conditions, and storage at nonchilling temperature (control treatments). The highest nootkatone levels, determined by GLC-MS analyses, were detected in fruits subjected to control treatments. No significant differences were observed in nootkatone levels between treatments either with or without temperature conditioning prior to the start of the cold storage. Levels of nootkatone increased throughout time for all assayed treatments. The linear regressions of nootkatone levels showed correlation coefficients of 0.80 and 0.83 with storage time (29 and 42 days, respectively). Therefore, nootkatone appears to be a good indicator of senescence for Rouge La Toma grapefruit. PMID:12166965

  18. Postharvest biology and technology of ornamentals

    Science.gov (United States)

    The relatively brief postharvest life of most cut flowers and potted flowering plants can be extended by a range of technologies. Studies have shown that vase life is negatively correlated with respiration after harvest, so prompt cooling to the lowest safe storage temperature is a key to long-dist...

  19. Strawberry breeding selections for postharvest fruit decay

    Science.gov (United States)

    Fruit from the annual replicated yield assessments for the USDA-ARS strawberry (Fragaria ×ananassa Duchesne ex Rozier) breeding program at Beltsville, MD in 2010 were evaluated for postharvest decay development after storage at 5 °C. A statistically significant correlation between percentage decay o...

  20. Pathogen infection drives patterns of nutrient resorption in citrus plants.

    Science.gov (United States)

    Cao, Jirong; Cheng, Chunzhen; Yang, Junjie; Wang, Qibing

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen 'Candidatus Liberibacter asiaticus' grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of 'Ca. L. asiaticus' infection on nitrogen (N) and phosphorus (P) concentrations and resorption in different citrus species (i.e. Citrus reticulata, Citrus limon and Citrus maxima). HLB-pathogen infection had distinctive impacts on nutrient resorption in different species. P resorption efficiency substantially decreased in infected C. reticulata plants relative to the healthy plants in summer, which may account for the marked decrease in the average fruit yield. P resorption was more efficient in infected C. limon plants than in the healthy plants. However, for C. maxima plants, HLB had no significant effects on N:P ratio in live leaves and resorption efficiency as well as on fruit yield. Keeping efficient internal nutrient cycling can be a strategy of citrus species being tolerant to HLB. PMID:26419510

  1. The push-pull strategy for citrus psyllid control.

    Science.gov (United States)

    Yan, Huaxue; Zeng, Jiwu; Zhong, Guangyan

    2015-07-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the only natural vector of Candidatus Liberibacter asiaticus that causes citrus huanglongbing (HLB), a most destructive disease of citrus. Currently, no remedial therapy exists for the disease, and so effective control of ACP is very important in curbing the transmission of the disease. The push-pull strategy should be thoroughly explored as an approach to ACP management. This mini-review summarises the current progress towards more effective repellent and attractant chemicals through investigating known repellent and attractive plants. Interactions between ACP and its host plants are also addressed, with emphasis on the possible involvement of the host biochemicals in attracting the insect. Potential ways to increase the effectiveness of the pull-push strategy are briefly discussed. It is expected that the pull-push strategy will be gradually developed following more extensive research. PMID:25256398

  2. Infection and decontamination of citrus-canker-inoculated leaf surfaces

    Science.gov (United States)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida and continues to spread. Personnel and equipment decontamination is practiced in both disease-endemic and disease-free areas to reduce the risk of bacterial spread by man or machinery. We used grapefruit leaf su...

  3. Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

    Directory of Open Access Journals (Sweden)

    Neelam Mallick

    2016-01-01

    Full Text Available Objective: Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypolipidemic effects of C. sinensis and C. paradisi in rats receiving diet rich in cholesterol. Materials and Methods: All rats were divided into 11 groups each comprising 10 animals: Normal control group and hyperlipidemic control. C. sinensis treated three groups, C. paradisi treated three groups, C. sinensis and C. paradisi combination treated two groups, and group treated atorvastatin. All rats in the respective groups were treated orally with sterile water, juices, and standard drug for 8 weeks and lipid profile was estimated at the end of dosing. Results: Cholesterol, triglycerides (TGs, and low-density lipoprotein (LDL were decreased at all the three doses of C. sinensis and C. paradisi but rise in high-density lipoprotein (HDL was only significant at 8 ml/kg, and 0.3 ml/kg, respectively. Animals received the combination doses of C. sinensis and C. paradisi also showed a highly significant fall in cholesterol, LDL, and TGs, however HDL level was significantly elevated by SPJ-2 combination. Conclusion: Results suggest that C. sinensis and C. paradisi possess antihyperlipidemic activity due to phytochemicals and other essential nutrients, hence may serve as cardioprotective by preventing thrombosis.

  4. Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

    Science.gov (United States)

    Mallick, Neelam; Khan, Rafeeq Alam

    2016-01-01

    Objective: Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypolipidemic effects of C. sinensis and C. paradisi in rats receiving diet rich in cholesterol. Materials and Methods: All rats were divided into 11 groups each comprising 10 animals: Normal control group and hyperlipidemic control. C. sinensis treated three groups, C. paradisi treated three groups, C. sinensis and C. paradisi combination treated two groups, and group treated atorvastatin. All rats in the respective groups were treated orally with sterile water, juices, and standard drug for 8 weeks and lipid profile was estimated at the end of dosing. Results: Cholesterol, triglycerides (TGs), and low-density lipoprotein (LDL) were decreased at all the three doses of C. sinensis and C. paradisi but rise in high-density lipoprotein (HDL) was only significant at 8 ml/kg, and 0.3 ml/kg, respectively. Animals received the combination doses of C. sinensis and C. paradisi also showed a highly significant fall in cholesterol, LDL, and TGs, however HDL level was significantly elevated by SPJ-2 combination. Conclusion: Results suggest that C. sinensis and C. paradisi possess antihyperlipidemic activity due to phytochemicals and other essential nutrients, hence may serve as cardioprotective by preventing thrombosis. PMID:27134462

  5. Phytochemical analysis and radical scavenging profile of juices of Citrus sinensis, Citrus anrantifolia, and Citrus limonum

    OpenAIRE

    Rauf, Abdur; Uddin, Ghias; Ali, Jawad

    2014-01-01

    Background The aim of the current investigation was to identify bioactive secondary metabolites including phenols, tannins, flavonoids, terpinedes, and steroids and compare the phytochemical analysis and antioxidant profile of the juice extracted from the fruits of Citrus sinensis, Citrus anrantifolia, and Citrus limonum. Results Phytochemical screening is important for the isolation of new, novel, and rare secondary metabolites before bulk extraction. Phytochemical analysis of the desired pl...

  6. Huanglongbing: An overview of a complex pathosystem ravaging the world's citrus.

    Science.gov (United States)

    da Graça, John V; Douhan, Greg W; Halbert, Susan E; Keremane, Manjunath L; Lee, Richard F; Vidalakis, Georgios; Zhao, Hongwei

    2016-04-01

    Citrus huanglongbing (HLB) has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role. This review is intended to provide an overview of the importance of HLB to a wider audience of plant biologists. Recent advances on host-pathogen interactions, population genetics and vectoring of the causal agent are discussed. PMID:26466921

  7. Huanglongbing:An overview of a complex pathosystem ravaging the world’s citrus

    Institute of Scientific and Technical Information of China (English)

    John V da Graa; Greg W Douhan; Susan E Halbert; Manjunath L Keremane; Richard F Lee; Georgios Vidalakis; Hongwei Zhao

    2016-01-01

    Citrus huanglongbing (HLB) has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role. This review is intended to provide an overview of the importance of HLB to a wider audience of plant biologists. Recent advances on host-pathogen interactions, population genetics and vectoring of the causal agent are discussed.

  8. Valuing Catastrophic Citrus Losses

    OpenAIRE

    Adams, Damian C.; Kilmer, Richard L.; Moss, Charles B.; Schmitz, Andrew

    2004-01-01

    Courts are often required to estimate changes in welfare to agricultural operations from catastrophic events. For example, courts must assign damages in lawsuits, such as with pesticide drift cases, or determine "just compensation" when the government takes private land for public use, as with the removal of dairy farms from environmentally sensitive land or destruction of canker-contaminated citrus trees. In economics, the traditional method of quantifying producer losses is estimating chang...

  9. A relational database of post-harvest fish losses

    OpenAIRE

    Smith, M. C.; Venn, J.; Cheke, R.A.; Ward, A. R.

    1997-01-01

    The article describes FISHLOSS, a database of post-harvest fish losses devised by the Natural Resources Institute (NRI), UK. The database contains 450 records of post-harvest fish losses from 150 sources. The majority of the estimates are shelf-life estimates. Designed to be a reference for people studying post-harvest fish losses, it draws attention to areas requiring future research to identify significant losses and the factors which cause them. All researchers and users are encouraged to ...

  10. Nitrogen and post-harvest yellowing of Brussels sprouts

    OpenAIRE

    Everaarts, A.P.

    2000-01-01

    A study was made of the effect of a late nitrogen application on post-harvest yellowing of Brussels sprouts. Application of nitrogen, whether as granular fertilizer or as a lower amount sprayed over the crop in a watery solution, increased the nitrogen concentration in the outer leaves of the sprouts, but this did not result in less post-harvest yellowing. Size of the sprouts and moment of harvest, however, strongly influenced post-harvest yellowing.

  11. Review of the Status of Irradiation Effects on Citrus Fruits

    International Nuclear Information System (INIS)

    The United States fresh-market spoilage losses valued at the 1959-1963 retail prices were estimated for oranges and grapefruit to be $8.4 and $5.4 million, respectively. Stem-end rots and green and blue molds cause the greatest post-harvest decay losses to citrus. No single radiation dose can be given that will be the minimum required for protecting citrus fruits against spoilage. Radiation doses required for retarding old or established infections are higher than for the retardation of incipient infections. The flux, as well as the dose of gamma radiation influences the control of infections. Fresh citrus fruits undergo metabolic changes which ultimately lead to senescence. Some of these changes include varied activities in the levels of respiration, organic acids, sugars, pectic substances and color. In many respects the loss of cellular vitality in senescence resembles the effects of radiation injury. Irradiation causes changes in the pectic components of fruits. In general, an increase occurs in the water and ammonium oxalate-soluble fractions and a decrease occurs in the sodium hydroxide-soluble fraction. A large increase of water-soluble pectin is found in the juice extracted from irradiated fruits. Apparently this increases results from movement of the water-soluble pectin from other parts of the fruit. A marked increase in the viscosity of the juice results. Peel injury is sometimes found following irradiation and storage of the fruit. The per centage of fruit showing peel injury, and the severity of the injury, increase the higher the storage temperature and the longer the storage duration. Oranges and grapefruit may be irradiated with doses of up to 200 krad without any appreciable deleterious effects on organoleptic qualities. (author)

  12. Citrus fruits as a treasure trove of active natural metabolites that potentially provide benefits for human health

    OpenAIRE

    Lv, Xinmiao; Zhao, Siyu; Ning, Zhangchi; Zeng, Honglian; Shu, Yisong; Tao, Ou; Xiao, Cheng; Cheng LU; Liu, Yuanyan

    2015-01-01

    Citrus fruits, which are cultivated worldwide, have been recognized as some of the most high-consumption fruits in terms of energy, nutrients and health supplements. What is more, a number of these fruits have been used as traditional medicinal herbs to cure diseases in several Asian countries. Numerous studies have focused on Citrus secondary metabolites as well as bioactivities and have been intended to develop new chemotherapeutic or complementary medicine in recent decades. Citrus-derived...

  13. Guidelines for Selection of Tissues for Electron Microscopy Confirmation of Candidatus Liberibacter spp. in Huanglongbing-affected Citrus

    OpenAIRE

    Achor, Diann; Davis, Craig L.; Brlansky, Ronald H.; Folimonova, Svetlana Y.

    2014-01-01

    Polymerase chain reaction (PCR) with the pathogen-specific primers and electron microscopy are the two techniques of choice that have been used for detection and identification of Candidatus Liberibacter spp. in the Huanglongbing (HLB)-affected citrus. Due to the low population and uneven distribution of Liberibacter in the diseased citrus trees finding the bacteria with transmission electron microscopy has been a challenge. Work with samples from HLB-affected citrus during the past 5 years h...

  14. CONTROL OF POSTHARVEST TOMATO ROT BY SPORE SUSPENSION AND ANTIFUNGAL METABOLITES OF TRICHODERMA HARZIANUM

    OpenAIRE

    El-Katatny, Momein H.; Abeer S. Emam

    2012-01-01

    Rot of cherry tomato (Lycopersicon esculentum) fruits caused by several fungal pathogens is a detrimental disease leading to substantial yield loses worldwide. Alternaria isolates were the most common fungal species isolated from healthy or rotten fruits. Trichoderma harzianum spore suspension and culture filtrate were tested for their antagonistic activity on controlling tomato fruit rot. T. harzianum isolates suppressed or interfered with the growth of different postharvest tomato fungal pa...

  15. Integrated management of causal agents of postharvest fruit rot of apple

    OpenAIRE

    Mila Grahovac; Dušanka Inđić; Brankica Tanović; Sanja Lazić; Slavica Vuković; Jovana Hrustić; Sonja Gvozdenac

    2011-01-01

    One of the major causes of poor quality and fruit loss (during storage and transport) are diseases caused by phytopathogenic fungi. Economic losses which are the consequence of the phytopathogenic fungus activity after harvest exceed the losses in the field. The most important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. ex Fr., Penicillium expansum (Lk.) Thom., Cryptosporiopsis curvispora (Peck.) Grem., Colletotrichum gloeospori...

  16. Plant extracts for controlling the post-harvest anthracnose of banana fruit

    OpenAIRE

    M.E.S Cruz; K.R.F. Schwan-Estrada; E. Clemente; A.T. Itako; J.R. Stangarlin; M.J.S. Cruz

    2013-01-01

    In banana, fruit rot is incited by Colletotrichum musae which has been the most serious post-harvest disease of immature and mature fruit. The usual control by fungicides prohibited in many countries reduces their commercial value. Therefore, two experiments were conducted to evaluate the antimicrobial activity of alternative products to the synthetic fungicides. First, berries naturally infected by anthracnose were immersed into Azadirachta indica and citric extracts at 2 and 4% (v/v) for 3 ...

  17. Thermal control of some post-harvest rot pathogens of Irish potato (solanum tuberosum l.)

    OpenAIRE

    Salami Olusola Abiodun; Popoola Omololu Olumide

    2007-01-01

    Thermal control effect on the incidence of some post-harvest rot pathogens of Solanum tuberosum (potato) was investigated in this study. Three cultivars of potato tuber whose local names are, Patiska, Mai Bawondoya and Nicola were used for the study. Five pathogenic fungi viz: Botryodiplodia theobromae, Fusarium redolens, Fusarium oxysporum, Penicillium sp. and Rhizopus oryzae associated with post harvest storage rot of root-tubers, were isolated from diseased potatoes. Among the three specie...

  18. PCR assays for diagnosis of postharvest fruit rots and early detection of Phacidiopycnis washingtonensis and Sphaeropsis pyriputrescens in apple fruit

    Science.gov (United States)

    Speck rot caused by Phacidiopycnis washingtonensis and Sphaeropsis rot caused by Sphaeropsis pyriputrescens are two recently reported postharvest diseases of apple. Fruit infection by the pathogens occurs in the orchard, but symptoms develop after harvest and are similar to that of gray mold caused...

  19. PCR assays for diagnosis of postharvest fruit rots and early detection of Phacidiopycnis washingtonensis and Sphaeropsis pyriputrescens in apple fruit

    Science.gov (United States)

    Speck rot caused by Phacidiopycnis washingtonensis and Sphaeropsis rot caused by Sphaeropsis pyriputrescens are two recently reported postharvest diseases of apple. Infection of fruit by the pathogens occurs in the orchard, but symptoms develop after harvest and are similar to that of gray mold caus...

  20. PROPOLIS EXTRACT IN POSTHARVEST CONSERVATION BANANA ' PRATA'

    OpenAIRE

    FLÁVIA REGINA PASSOS; FABRÍCIA QUEIROZ MENDES; MARIANA CRIVELARI DA CUNHA; MARIANA TEIXEIRA PIGOZZI; ANDRÉ MUNDSTOCK XAVIER DE CARVALHO

    2016-01-01

    ABSTRACT In the present work were evaluated the effects of propolis coatings of various botanical sources on quality traits of bananas cv. Prata (Musa sapientum L.) stored at room temperature. ´Prata´ bananas were selected and submitted to five postharvest treatments: four coatings applied by immersion in propolis extracts at a concentration of 2.5% (w/v) and a control (without coating). Propolis extracts were applied as 1) a wild type aqueous propolis extract, 2) a wild type hydroalcoholic ...

  1. Roadmapping for improving cocoa postharvest management

    OpenAIRE

    Adriana del Pilar Sánchez Vargas; Óscar Fernando Castellanos Domínguez; Karen Patricia Domínguez Martínez

    2010-01-01

    This article presents the methodology and results which led to preparing post-harvesting technological development strategies for cocoa management which emerged from identifying problems such as deficient cocoa quality and insufficient fermentation of the beans according to international market requirements as shown in the poor technological development in Colombia’s main co-coa producing areas. This situation led to using a technological management tool such as roadmapping orientated towards...

  2. Soil Applied Systemic Insecticides for Control of Asian citrus psyllid in Newly Planted Citrus Trees

    OpenAIRE

    Stansly, Phil; Kostyk, Barry

    2014-01-01

    Orchard renewal is a special challenge where HLB is endemic.  Young trees are especially susceptible to the disease and continuously attractive to the psyllid vector due to frequent flushing.  Heavy reliance is placed on systemic insecticides to protect young trees.  However, all presently labeled for citrus are neonicotinoids (IRAC Group 4a) making resistance likely and the long term viability of this strategy questionable.  Rotation partners are needed to forestall selection for resistance....

  3. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses.

    Science.gov (United States)

    Piazza, Ainelén; Zimaro, Tamara; Garavaglia, Betiana S; Ficarra, Florencia A; Thomas, Ludivine; Marondedze, Claudius; Feil, Regina; Lunn, John E; Gehring, Chris; Ottado, Jorgelina; Gottig, Natalia

    2015-05-01

    Xanthomonas citri subsp. citri (Xcc) is a bacterial pathogen that causes citrus canker in susceptible Citrus spp. The Xcc genome contains genes encoding enzymes from three separate pathways of trehalose biosynthesis. Expression of genes encoding trehalose-6-phosphate synthase (otsA) and trehalose phosphatase (otsB) was highly induced during canker development, suggesting that the two-step pathway of trehalose biosynthesis via trehalose-6-phosphate has a function in pathogenesis. This pathway was eliminated from the bacterium by deletion of the otsA gene. The resulting XccΔotsA mutant produced less trehalose than the wild-type strain, was less resistant to salt and oxidative stresses, and was less able to colonize plant tissues. Gene expression and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant's metabolism than the wild-type strain. These results suggested that trehalose of bacterial origin, synthesized via the otsA-otsB pathway, in Xcc, plays a role in modifying the host plant's metabolism to its own advantage but is also perceived by the plant as a sign of pathogen attack. Thus, trehalose biosynthesis has both positive and negative consequences for Xcc. On the one hand, it enables this bacterial pathogen to survive in the inhospitable environment of the leaf surface before infection and exploit the host plant's resources after infection, but on the other hand, it is a tell-tale sign of the pathogen's presence that triggers the plant to defend itself against infection. PMID:25770587

  4. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

    KAUST Repository

    Piazza, A.

    2015-03-14

    Xanthomonas citri subsp. citri (Xcc) is a bacterial pathogen that causes citrus canker in susceptible Citrus spp. The Xcc genome contains genes encoding enzymes from three separate pathways of trehalose biosynthesis. Expression of genes encoding trehalose-6-phosphate synthase (otsA) and trehalose phosphatase (otsB) was highly induced during canker development, suggesting that the two-step pathway of trehalose biosynthesis via trehalose-6-phosphate has a function in pathogenesis. This pathway was eliminated from the bacterium by deletion of the otsA gene. The resulting XccΔotsA mutant produced less trehalose than the wild-type strain, was less resistant to salt and oxidative stresses, and was less able to colonize plant tissues. Gene expression and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant\\'s metabolism than the wild-type strain. These results suggested that trehalose of bacterial origin, synthesized via the otsA-otsB pathway, in Xcc, plays a role in modifying the host plant\\'s metabolism to its own advantage but is also perceived by the plant as a sign of pathogen attack. Thus, trehalose biosynthesis has both positive and negative consequences for Xcc. On the one hand, it enables this bacterial pathogen to survive in the inhospitable environment of the leaf surface before infection and exploit the host plant\\'s resources after infection, but on the other hand, it is a tell-tale sign of the pathogen\\'s presence that triggers the plant to defend itself against infection. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  5. The effect of a minor constituent of essential oil from Citrus aurantium: the role of β-myrcene in preventing peptic ulcer disease.

    Science.gov (United States)

    Bonamin, Flavia; Moraes, Thiago M; Dos Santos, Raquel C; Kushima, Hélio; Faria, Felipe M; Silva, Marcos A; Junior, Ivan V; Nogueira, Leonardo; Bauab, Tais M; Souza Brito, Alba R M; da Rocha, Lucia R M; Hiruma-Lima, Clélia A

    2014-04-01

    The monoterpene β-myrcene has been widely used in cosmetics, food and beverages, and it is normally found in essential oil from citrus fruit. The aim of this study was to investigate the anti-ulcer effects of β-myrcene on experimental models of ulcers that are induced by ethanol, NSAIDs (non-steroidal anti-inflammatory drugs), stress, Helicobacter pylori, ischaemia-reperfusion injury (I/R) and cysteamine in order to compare with the essential oil of Citrus aurantium and its major compound limonene. The results indicate that the oral administration of β-myrcene at a dose of 7.50mg/kg has important anti-ulcer activity with significantly decreased gastric and duodenal lesions as well as increased gastric mucus production. The results showed treatment with β-myrcene caused a significant increase in mucosal malondialdehyde level (MDA), an important index of oxidative tissue damage. The β-myrcene was also endowed with marked enhancement of antioxidant enzyme activity from GR system as evidenced by the decreased activity of superoxide dismutase (SOD) and increased levels of glutathione peroxidase (GPx), glutathione reductase (GR), and total glutathione in gastric tissue. Our results also shown that treatment with β-myrcene is not involved with thioredoxin reductase (TrxR) activity. Our results reveal, for the first time, the importance of β-myrcene as an inhibitor of gastric and duodenal ulcers and demonstrate that an increase in the levels of gastric mucosa defence factors is involved in the anti-ulcer activity of β-myrcene. PMID:24480520

  6. Efficiency of a yeast-based formulation for the biocontrol of postharvest anthracnose of papayas

    Directory of Open Access Journals (Sweden)

    Jaqueline Rabelo de Lima

    2014-09-01

    Full Text Available To identify formulations of biological agents that enable survival, stability and a good surface distribution of the antagonistic agent, studies that test different application vehicles are necessary. The efficiency of two killer yeasts, Wickerhamomyces anomalus (strain 422 and Meyerozyma guilliermondii (strain 443, associated with five different application vehicles, was assessed for the protection of postharvest papayas. In this study, after 90 days of incubation at 4ºC, W. anomalus (strain 422 and M. guilliermondii (strain 443 were viable with all application vehicles tested. Fruits treated with different formulations (yeasts + application vehicles had a decreased severity of disease (by at least 30% compared with untreated fruits. The treatment with W. anomalus (strain 422 + 2% starch lowered disease occurrence by 48.3%. The most efficient treatments using M. guilliermondii (strain 443 were those with 2% gelatin or 2% liquid carnauba wax, both of which reduced anthracnose by 50% in postharvest papayas. Electron micrographs of the surface tissues of the treated fruits showed that all application vehicles provided excellent adhesion of the yeast to the surface. Formulations based on starch (2%, gelatin (2% and carnauba wax (2% were the most efficient at controlling fungal diseases in postharvest papayas.

  7. Effect of Exogenous Nitric Oxide on Development of Fruits and Vegetables Postharvest Disease Penicillium expansum%外源一氧化氮对果蔬采后病害Penicillium expansum发育的影响

    Institute of Scientific and Technical Information of China (English)

    赖童飞; 刘毅; 任梦; 赖利宇; 周婷

    2013-01-01

    Penicillium expansum是果蔬采后主要的病原真菌,对果蔬的贮藏具有极大的危害,寻找有效的防治方法具有重要的意义.本研究对苹果(Malus domestica)青霉病菌进行了分离及rDNA-ITS法鉴定,确定为P.expansum;利用不同浓度的外源一氧化氮(NO)处理病菌,通过孢子萌发率、芽管长度、菌丝扩展速度等指标以及苹果接种实验,研究了外源NO与P.expansum发育及致病力的关系,并通过进行胞内活性氧水平、蛋白质羰基化、丙二醛(MDA)及ATP含量的检测,对NO的作用机理进行了初步的探索.结果表明,外源NO可以显著抑制P.expansum的发育,且浓度越高抑制作用越强,其抑菌机理可能是通过诱导P.expansum胞内活性氧积累引起氧化损伤.本研究为果蔬采后病原菌的防治提供了新的思路.%Penicillium expansum is a major postharvest pathogen and quite harmful to fruit and vegetable preservation. Therefore, it is necessary to search for an effective control method. In this study, we isolated a P. expansum from naturally infected apples (Malus domestica) and identified it by rDNA-ITS method. The relationship between exogenous nitre oxide (NO) with different concentrations and growth or pathogenicity of P. expansum were evaluated via assessment of germination ratio, germ tube length, mycelium extension speed, and inoculation experiment of apple. In addition, by determining level of reactive oxygen species, carbonylated proteins, and evaluating the content of malondialdehyde (MDA) and ATP, the possible inhibitory mechanism of exogenous NO on P. expansum was explored preliminarily. The results indicated that exogenous NO could inhibit the growth of P. expansum and the behavior was dose-dependent. It was speculated that the inhibitory effect came from accumulation of reactive oxygen species, which led to oxidative damages. This study provides a new approach to control postharvest horticulture pathogens potentially of fruit and

  8. Podridão basal pós-colheita do coco verde no estado do Ceará Post-harvest basal rot of coconut fruits in the State of Ceará, Brazil

    OpenAIRE

    Francisco M. P Viana; FRANCISCO C.O. FREIRE; Beatriz M Barguil; Ricardo E Alves; ANTONIO A. SANTOS; JOSÉ E. CARDOSO; Julio C. Vidal

    2002-01-01

    A new post-harvest disease of coconut (Cocos nucifera) was recently detected in fruits exported to European countries. The main symptoms are the blacking and cracking of basal parts of the fruits. Water oozing may occurs as the infection progresses. The fungus Lasiodiplodia theobromae has been frequently isolated from the lesions. Inoculation tests proved that this pathogen is the causal agent of the coconut fruit basal rot. This is the first occurrence of this post-harvest disease in Brazil.

  9. Induced mutations in citrus

    International Nuclear Information System (INIS)

    Full text: Parthenocarpic tendency is an important prerequisite for successful induction of seedlessness in breeding and especially in mutation breeding. A gene for asynapsis and accompanying seedless fruit has been found by us in inbred progeny of cv. 'Wilking'. Using budwood irradiation by gamma rays, seedless mutants of 'Eureka' and 'Villafranca' lemon (original clone of the latter has 25 seeds) and 'Minneola' tangelo have been obtained. Ovule sterility of the three mutants is nearly complete, with some pollen fertility still remaining. A semi-compact mutant of Shamouti orange has been obtained by irradiation. A programme for inducing seedlessness in easy peeling citrus varieties and selections has been initiated. (author)

  10. Insecticide sprays, natural enemy assemblages and predation on Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae).

    Science.gov (United States)

    Monzo, C; Qureshi, J A; Stansly, P A

    2014-10-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is considered a key citrus pest due to its role as vector of 'huanglongbing' (HLB) or citrus greening, probably the most economically damaging disease of citrus. Insecticidal control of the vector is still considered a cornerstone of HLB management to prevent infection and to reduce reinoculation of infected trees. The severity of HLB has driven implementation of intensive insecticide programs against ACP with unknown side effects on beneficial arthropod fauna in citrus agroecosystems. We evaluated effects of calendar sprays directed against this pest on natural enemy assemblages and used exclusion to estimate mortality they imposed on ACP populations in citrus groves. Predator exclusion techniques were used on nascent colonies of D. citri in replicated large untreated and sprayed plots of citrus during the four major flushing periods over 2 years. Population of spiders, arboreal ants and ladybeetles were independently assessed. Monthly sprays of recommended insecticides for control of ACP, adversely affected natural enemy populations resulting in reduced predation on ACP immature stages, especially during the critical late winter/early spring flush. Consequently, projected growth rates of the ACP population were greatest where natural enemies had been adversely affected by insecticides. Whereas, this result does not obviate the need for insecticidal control of ACP, it does indicate that even a selective regimen of sprays can impose as yet undetermined costs in terms of reduced biological control of this and probably other citrus pests. PMID:24830653

  11. Amino acids implicated in plant defense are higher in Candidatus Liberibacter asiaticus-tolerant citrus varieties.

    Science.gov (United States)

    Killiny, Nabil; Hijaz, Faraj

    2016-04-01

    Citrus Huanglongbing (HLB), also known as citrus greening, has been threatening the citrus industry since the early 1900's and up to this date there are no effective cures for this disease. Field observations and greenhouse controlled studies demonstrated that some citrus genotypes are more tolerant to Candidatus Liberibacter asiaticus (CLas) pathogen than others. However, the mechanisms underpinning tolerance has not been determined yet. The phloem sap composition of CLas-tolerant and sensitive citrus varieties was studied to identify metabolites that could be responsible for their tolerance to CLas. The citrus phloem sap was collected by centrifugation and was analyzed with gas chromatography-mass spectrometry after methyl chloroformate derivatization. Thirty-three metabolites were detected in the phloem sap of the studied varieties: twenty 20 amino acids, eight 8 organic acids, and five 5 fatty acids. Interestingly, the levels of most amino acids, especially those implicated in plantdefense to pathogens such as phenylalanine, tyrosine, tryptophan, lysine, and asparagine were higher in tolerant varieties. Although the level of organic acids varied between cultivars, this variation was not correlated with citrus resistance to CLas and could be cultivar specific. The fatty acids were found in trace amounts and in most cases their levels were not significantly different among varieties. Better understanding of the mechanisms underpinning citrus tolerance to CLas will help in developing economically tolerant varieties. PMID:27057814

  12. The science, development, and commercialization of postharvest biocontrol

    Science.gov (United States)

    Postharvest biological control agents as a viable alternative to the use of synthetic chemicals have been the focus of considerable research for the last 30 years by many scientists and several commercial companies worldwide. Several antagonists of postharvest pathogens have been identified and tes...

  13. Insecticidal Suppression of Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae) Vector of Huanglongbing Pathogens

    OpenAIRE

    Jawwad A Qureshi; Kostyk, Barry C.; Stansly, Philip A.

    2014-01-01

    Diaphorina citri vectors pathogens that cause ‘huanglongbing’ or citrus greening disease which poses a serious threat to citrus production worldwide. Vector suppression is critical to reduce disease spread. Efficacy is a main concern when choosing an insecticide. Insecticidal treatments of 49 products or 44 active ingredients (a.i) labeled or experimental were field tested between 2005–2013 as foliar sprays (250 treatments, 39 a.i) or soil applications (47 treatments, 9 a.i) to control D. cit...

  14. Integrated Management of Causal Agents of Postharvest Fruit Rot of Apple

    Directory of Open Access Journals (Sweden)

    Mila Grahovac

    2011-01-01

    Full Text Available One of the major causes of poor quality and fruit loss (during storage and transportare diseases caused by phytopathogenic fungi. Economic losses which are the consequenceof the phytopathogenic fungus activity after harvest exceed the losses in the field.Themost important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. exFr., Penicillium expansum (Lk. Thom., Cryptosporiopsis curvispora (Peck. Grem., Colletotrichumgloeosporioides (Penz. Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata(Fr. Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles. Wollenw., Stemphyliumbotryosum Wallr. The use of available protection technologies can significantly reducelosses caused by pathogens in storage. The concept of integrated pest management (IPMin apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot,using cultural, physical, biological and chemical measures, to minimize economic, healthand risks to consumers and environment, is presented in the paper.

  15. Citrus greening detection using airborne hyperspectral and multispectral imaging techniques

    Science.gov (United States)

    Hyperspectral imaging can provide unique spectral signatures for diseased vegetation. Airborne multispectral and hyperspectral imaging can be used to detect potentially infected trees over a large area for rapid detection of infected zones. This paper proposes a method to detect the citrus greening...

  16. Chitosan controls postharvest anthracnose in bell pepper by activating defense-related enzymes.

    Science.gov (United States)

    Edirisinghe, Madushani; Ali, Asgar; Maqbool, Mehdi; Alderson, Peter G

    2014-12-01

    Anthracnose, a postharvest disease caused by the fungus Colletotrichum capsici is the most devastating disease of bell pepper that causes great economic losses especially in tropical climates. Therefore, the objective of this study was to evaluate the antifungal properties of chitosan (low molecular weight from crab shell, Mw: 50 kDa and 75-85 % deacetylated) against anthracnose by inducing defense-related enzymes. The concentrations of 0, 0.5, 1.0, 1.5 and 2.0 % chitosan were used to control the fungus in vitro and postharvest. There was a reduction in C. capsici mycelial growth and the highest chitosan concentration (2.0 %) reduced the growth by 70 % after 7 days incubation. In germination test, the concentration of 1.5 and 2.0 % chitosan reduced spore germination in C. capsici between 80 % and 84 %, respectively. In postharvest trial the concentration of 1.5 % decreased the anthracnose severity in pepper fruit by approximately 76 % after 28 days of storage (10 ± 1 °C; 80 % RH). For enzymatic activities, the concentration of 1.5 and 2.0 % chitosan increased the polyphenol oxidase (PPO), peroxidase (POD) and total phenolics in inoculated bell pepper during storage. Based on these results, the chitosan presents antifungal properties against C. capsici, as well as potential to induce resistance on bell pepper. PMID:25477684

  17. In Vitro and In Vivo Antibacterial Activity of Some Organic and Inorganic Salts Against Asiatic Citrus Canker Agent Xanthomonas Citri Subsp. Citri

    OpenAIRE

    Vahideh Hasabi; Hossein Askari; Seyed Mehdi Alavi; Masood Soltani Najafabadi

    2014-01-01

    Asiatic citrus canker caused by Xanthomonas citri subsp. citri is becoming a disease of high economic impact, affecting all types of important citrus crops. In this study, the potential antibacterial activity of ten organic and inorganic salts on X. citri subsp. citri and on citrus canker disease development was evaluated. Among the salt compounds, copper, iron and zinc inorganic salts particularly zinc (with the highest diameter of inhibition, the lowest MIC and MBC values and the highest ba...

  18. Asian Citrus Psyllid Expression Profiles Suggest Candidatus Liberibacter Asiaticus-Mediated Alteration of Adult Nutrition and Metabolism, and of Nymphal Development and Immunity

    OpenAIRE

    Vyas, Meenal; Tonja W. Fisher; He, Ruifeng; Nelson, William; Yin, Guohua; Joseph M. Cicero; Willer, Mark; Kim, Ryan; Kramer, Robin; Greg A. May; John A. Crow; Soderlund, Carol A.; Gang, David R.; Brown, Judith K.

    2015-01-01

    The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is the insect vector of the fastidious bacterium Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus greening disease, or Huanglongbing (HLB). The widespread invasiveness of the psyllid vector and HLB in citrus trees worldwide has underscored the need for non-traditional approaches to manage the disease. One tenable solution is through the deployment of RNA interference technology to silence prote...

  19. Detection of Liberibacter asiaticus in a single infected Asian citrus psyllid adult or nymph: Impact of dilution with clean Asian citrus psyllids (Diaphorina citri) during extraction

    OpenAIRE

    LeVesque, Cynthia; Kumagai, Lucita; Bloomquist, Cheryl; Keremane, Manjunath; Lee, Richard; Kunta, Madhurababu; da Graça, John V.; Vidalakis, Georgious; Lin, Hong; Morgan, John; Hall, David G.; Polek, MaryLou

    2014-01-01

    Now that the presence of Huanglongbing (HLB) has been confirmed in California, protecting the state’s citrus industry through early detection of disease is essential in curtailing its spread. Because ‘Candidatus Liberibacter asiaticus’ (Las), the putative causal agent of HLB, accumulates in its vector, the Asian citrus psyllid (ACP), Diaphorina citri, Kuwayama, accurate testing of the insect is vital. Due to the fact that insect secondary metabolites interfere with downstream applications (1,...

  20. Deciphering the bacterial microbiome of citrus plants in response to ‘Candidatus Liberibacter asiaticus’-infection and antibiotic treatment

    Science.gov (United States)

    Huanglongbing (HLB), the most devastating citrus disease worldwide, is vectored by phloem-feeding insects, and the pathogen in the USA is Candidatus Liberibacter asiaticus (Las). The bacterial microbiome of citrus after Las-infection and treatments with ampicillin (Amp) and gentamicin (Gm) was chara...

  1. THE ENDOPHYTE CURTOBACTERIUM FLACCUMFACIENS REDUCES SYMPTOMS CAUSED BY XYLELLA FASTIDIOSA IN CATHARANTHUS ROSEUSAN ENDOPHYTIC BACTERIUM FROM CITRUS

    Science.gov (United States)

    Citrus variegated chlorosis (CVC) is a disease of sweet orange (Citrus sinensis (L.)) caused by Xylella fastidiosa subsp. pauca, a phytopathogenic bacterium that can infect all sweet orange cultivars. Sweet orange trees are sometimes observed to be infected by Xylella fastidiosa without showing seve...

  2. Desenvolvimento de um sistema de apoio à decisão para a diagnose de doenças, pragas e distúrbios abióticos dos citros Development of a decision support system for the diagnosis of citrus diseases, pests, and abiotic factors

    Directory of Open Access Journals (Sweden)

    Cleilson do Nascimento Uchôa

    2010-06-01

    Full Text Available A preocupação com a diagnose dos problemas que afetam as plantas cítricas proporcionou ao longo dos anos o acúmulo de conhecimento, que precisava ser organizado e divulgado de forma eficiente e rápida. Dessa forma, objetivou-se com esse trabalho construir uma base de conhecimentos para diagnóstico de doenças bióticas e abióticas dos citros, desenvolver e implementar o sistema de apoio à decisão (SAD e avaliar o sistema. O SAD foi construído utilizando a ferramenta 'Borland Delphi' versão 5. Foram formuladas 562 perguntas, 322 regras e anexadas fotografias para facilitar o diagnóstico de 34 doenças, 40 pragas e 34 distúrbios abióticos dos citros. A avaliação do SAD foi dividida em verificação e validação. Na verificação, o SAD foi submetido a uma análise por meio de questionário a 5 especialistas em citros. A validação do programa foi realizada com quatro grupos, de diferentes níveis de conhecimento (10 pessoas/grupo, tentando diagnosticar corretamente. Obteve-se um acerto de 45,6% dos usuários e 93,6% do SAD. O sistema foi denominado Dr. Citrus (protótipo com registro no INPI n° 014070009188.The concern about the diagnosis of problems affecting citrus led to an accumulation of knowledge over the years. However, such accumulated knowledge needed to be organized and efficiently disseminated. Thus, the aims of this work were to build a knowledge basis for the diagnosis of abiotic and biotic citrus diseases to develop and implement a Decision Support System (DSS and to test and evaluate this system. DSS was built by using the tool 'Borland Delphi' version 5. A total of 562 questions were formulated, including 322 rules, besides photographs to help in the diagnosis of 34 diseases, 40 pests and 34 abiotics disturbances in citrus. DSS evolution was divided into verification and validation. In the verification phase, DSS was analyzed by means of a questionnaire applied to citrus specialists. The program validation phase

  3. Exposure to Guava Affects Citrus Olfactory Cues and Attractiveness to Diaphorina citri (Hemiptera: Psyllidae).

    Science.gov (United States)

    Barman, Jagadish Chandra; Campbell, Stuart A; Zeng, Xinnian

    2016-06-01

    Intercropping can reduce agricultural pest incidence, and represents an important sustainable alternative to conventional pest control methods. Understanding the ecological mechanisms for intercropping could help optimize its use, particularly in tropical systems which present a large number of intercropping possibilities. Citrus is threatened worldwide by greening disease (huanglongbing, HLB) vectored by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). Control of HLB and citrus psyllid can be partially achieved through intercropping with guava, Psidium guajava L., but the mechanisms remain unclear. We tested the hypothesis that guava olfactory cues affect psyllid behavior by altering the attractiveness of citrus through plant-plant interactions. In choice and no-choice cage experiments, psyllid settlement was reduced on citrus shoots that had been exposed to guava shoot odors for at least 2 h. In Y-tube olfactometer experiments, psyllids oriented to odors of unexposed, compared with guava-exposed, citrus shoots. These behavioral results indicate that a mechanism for the success of guava intercropping for sustainable, ecological disease management may be the indirect effect of guava on citrus attractiveness. PMID:27247354

  4. Metabolite signature of candidatus liberibacter asiaticus infection in two citrus varieties

    OpenAIRE

    Chin, EL; Mishchuk, DO; Breksa, AP; Slupsky, CM

    2014-01-01

    Huanglongbing (HLB), also known as Citrus Greening Disease, is caused by the bacterium 'Candidatus Liberibacter asiaticus' (CLas) and is a serious threat to the citrus industry. To understand the effect of CLas infection on the citrus metabolome, juice from healthy (n = 18), HLB-asymptomatic (n = 18), and HLB-symptomatic Hamlin (n = 18), as well as from healthy (n = 18) and HLB-symptomatic (n = 18) Valencia sweet oranges (from southern and eastern Florida) were evaluated using 1H NMR-based me...

  5. Postharvest characteristics of two cultivars of cauliflower

    Directory of Open Access Journals (Sweden)

    Adenilson Mroginski de Souza

    2010-06-01

    Full Text Available The cauliflower has a great economic importance, especially for small producers, and it turns out to be a profitable crop in small areas. However, at postharvest period it is difficult to store it at a given room temperature due to sweating and a heavy breathing process, which leads to a discoloration of the inflorescence. Thus, the current study aimed to characterize the postharvest storage of cauliflower hybrids Snow Mystique and Graffiti kept at room temperature corresponding to an air temperature of 20 ± 2oC and a relative humidity (RH of 75%. Evaluations were made every three days during a period of 12 days of storage. The parameters studied were percentage of weight loss in fresh weight terms, firmness of stem, soluble solids, pH and measurable acidity. By evaluating the results, it was concluded that the cauliflower is not supposed to be stored at an air temperature of 20 ± 2oC and a 75% RH for more than three days, since the inflorescence presented a high water loss through the transpiration process under the environmental conditions in study.

  6. Studies on the postharvest physiology and storage of citrus fruit, (8)

    International Nuclear Information System (INIS)

    Metabolism of acid and sugar of mandarin fruit after harvest was investigated. Each 0.1 μ Ci of citrate-1.5-14C(pH 3.49), glucose-1-14C (pH 7.0, G-1-14C) and glucose-6-14C(pH 7.0, G-6-14C) are injected into segments of the mandarin fruit through the peel, and metabolism was measured by the tracing method. The injected citrate-1,5-14C was decarboxylated immediately. One third out of the injected amount is discharged as 14C out of the fruit through 10 days after injection. On the contrary, the rate metabolism of G-1-14C and G-6-14C were comparatively slow. The amount of discharged 14CO2 was 6.5% and 6.3% of the total amount through 50 days respectively. Their rate of decarboxylation was faster than that of G-1-14C. It was suggested that the injected glucose was decomposed through the Hexose monophosphate pathway and then decomposed through the Embden-Meyerhof-Parnas pathway gradually. The 14C injected into sarcocarp was metabolized to sugar, amino acid, protein and pectin at a high speed, and the existence of acid was 50% or less after 10 days. On the contrary, the metabolism of glucose-14C was slow, and about 80% was left in the neutral section after 50 days. In the soluble section of the fruit, the transfer from glucose to acid and amino acid was 20% after 50 days. The conclusion is that the rate of turnover of citric acid in mandarin fruit can be considerably high, even after harvest. (Iwakiri, K.)

  7. Inhibitory effect of some spice essential oils on Penicillium digitatum causing postharvest rot in citrus

    Directory of Open Access Journals (Sweden)

    Akgül, Attila

    2000-08-01

    Full Text Available In this study to control blue mould caused by Penicillium digitatum, essential oil of cumin was applied with filter paper discs of 6 mm diameter which were soaked in 0,04 ml oil and vapour effect inhibited completely mycelial growth and spore germination of pathogen in vitro. When filter paper discs soaked in essential oils of black thyme, dill, coriander and rosemary were placed on the culture medium (PDA, they had no effect on the mycelial growth. Their vapour effect inhibited mycelial growth of pathogen 85.8%, 82.8%, 80% and 71.4% respectively. Dill and rosemary oils also prevented mycelial colour.En este estudio para controlar las manchas azules causadas por Penicillium digitatum, se aplicó aceite esencial de comino en discos de papel de filtro de 6 mm de diámetro, los cuales fueron empapados en 0,04 ml de aceite y su vapor inhibió completamente el crecimiento micelar y la germinación de esporas del patógeno in vitro. Cuando los discos de papel de filtro empapados en aceites esenciales de tomillo, eneldo, culantro y romero se colocaron sobre el medio de cultivo (PDA, no se observó efecto sobre el crecimiento micelar. Los efectos de sus vapores inhibieron el crecimiento micelar de patógenos en un 85,8%, 82,8%, 80% y 71,4% respectivamente. Los aceites de eneldo y romero también evitaron la aparición del color micelar.

  8. Report of postharvest rot of kiwifruit in Korea caused by Sclerotinia sclerotiorum.

    Science.gov (United States)

    Lee, Jung Han; Kwon, Young Ho; Kwack, Yong-Bum; Kwak, Youn-Sig

    2015-08-01

    In May 2014, sclerotinia rot symptoms caused by Sclerotinia sclerotiorum were observed on stored kiwifruit in Jinju, South Korea. The symptoms appeared as soft, water-soaked lesions on fruit covered with a white mycelium. The morphological characteristics and the internal transcribed spacer sequences of rRNA of the pathogen isolated from the sclerotinia rot showed it to be S. sclerotiorum. This was confirmed by performing a pathogenicity test with pure cultures of S. sclerotiorum and by reisolating S. sclerotiorum from artificially inoculated kiwifruits. Our results should help promote a better understanding of the diseases that affect kiwifruit and improve practices for postharvest disease control in the kiwifruit industry. PMID:25996522

  9. Chitosan controls postharvest anthracnose in bell pepper by activating defense-related enzymes

    OpenAIRE

    Edirisinghe, Madushani; Ali, Asgar; Maqbool, Mehdi; Alderson, Peter G.

    2012-01-01

    Anthracnose, a postharvest disease caused by the fungus Colletotrichum capsici is the most devastating disease of bell pepper that causes great economic losses especially in tropical climates. Therefore, the objective of this study was to evaluate the antifungal properties of chitosan (low molecular weight from crab shell, Mw: 50 kDa and 75–85 % deacetylated) against anthracnose by inducing defense-related enzymes. The concentrations of 0, 0.5, 1.0, 1.5 and 2.0 % chitosan were used to control...

  10. A transcriptomic approach highlights induction of secondary metabolism in citrus fruit in response to Penicillium digitatum infection

    Directory of Open Access Journals (Sweden)

    González-Candelas Luis

    2010-08-01

    Full Text Available Abstract Background Postharvest losses of citrus fruit due to green mold decay, caused by the fungus Penicillium digitaum, have a considerable economic impact. However, little is known about the molecular processes underlying the response of citrus fruit to P. digitatum. Results Here we describe the construction of a subtracted cDNA library enriched in citrus genes preferentially expressed in response to pathogen infection followed by cDNA macroarray hybridization to investigate gene expression during the early stages of colonization of the fruit's peel by P. digitatum. Sequence annotation of clones from the subtracted cDNA library revealed that induction of secondary and amino acid metabolisms constitutes the major response of citrus fruits to P. digitatum infection. Macroarray hybridization analysis was conducted with RNA from either control, wounded, ethylene treated or P. digitatum infected fruit. Results indicate an extensive overlap in the response triggered by the three treatments, but also demonstrated specific patterns of gene expression in response to each stimulus. Collectively our data indicate a significant presence of isoprenoid, alkaloid and phenylpropanoid biosynthetic genes in the transcriptomic response of citrus fruits to P. digitatum infection. About half of the genes that are up-regulated in response to pathogen infection are also induced by ethylene, but many examples of ethylene-independent gene regulation were also found. Two notable examples of this regulation pattern are the genes showing homology to a caffeine synthase and a berberine bridge enzyme, two proteins involved in alkaloid biosynthesis, which are among the most induced genes upon P. digitatum infection but are not responsive to ethylene. Conclusions This study provided the first global picture of the gene expression changes in citrus fruit in response to P. digitatum infection, emphasizing differences and commonalities with those triggered by wounding or

  11. Anti-inflammatory effects of Citrus sinensis L., Citrus paradisi L. and their combinations.

    Science.gov (United States)

    Khan, Rafeeq Alam; Mallick, Neelam; Feroz, Zeeshan

    2016-05-01

    Citrus bioflavonoids embrace a wide group of phenolic compounds effecting the production and scavenging of reactive oxygen species and the processes relating free radical-mediated injury. Keeping in view of the antioxidant and anti-inflammatory properties of Citrus sinensis and Citrus paradisi, present study was undertaken to explore the effects of C. sinensis (orange juice) and C. paradisi (grapefruit juice) at three different doses alone and their two combinations with the objective to examine the effects of these compounds in an experimental model of rat colitis induced by trinitrobenzenesulphonic acid (TNBS). Hence biochemical parameters e.g. myeloperoxidase, alkaline phosphatase, C-reactive protein (CRP) and glutathione were assessed. Data entry and analysis was accomplished by Statistical Package for the Social Sciences version 17 and was presented as mean ± S.E.M with 95% confidence interval. Present result shows that these juices, mainly C. paradisi, may be efficacious for the management of inflammatory bowel disease. In acute colitis model, C. paradise encouraged a decrease in the extension of the lesion escorted by a decrease in the occurrence of diarrhea and reinstatement of the glutathione content. Related effects were produced by the administration of C. sinensis, which also prevented the myeloperoxidase and alkaline phosphatase actions in acute intestinal inflammatory process. The effect of the citrus juices on the inflammatory process may be associated to their antioxidant and anti-inflammatory properties, as revealed in present investigation. The favorable effects exerted were demonstrated both by histological and biochemical changes and were related with a progress in the colonic oxidative status. PMID:27166529

  12. CIBMAN: Database exploring Citrus biodiversity of Manipur

    OpenAIRE

    Sanabam, Rakesh; Somkuwar, Bharat Gopalrao; Thingnam, Gourshyam; Moirangthem, Sila; Handique, Pratap Jyoti; Huidrom, Sunitibala

    2012-01-01

    The rich wealth of Citrus genetic resources makes India to enjoy a remarkable position in the “Citrus belt of the world”. We have developed CIBMAN, a unique database on Citrus biodiversity of Manipur which comprises 33 accessions collected through extensive survey for more than three years. CIBMAN provides integrated access to Citrus species through sophisticated web interface which has following capabilities a) morphological details, b) socio-economic details, c) taxonomic details and d) geo...

  13. Citrus breeding, genetics and genomics in Japan

    OpenAIRE

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional br...

  14. 薰衣草精油对樱桃番茄采后黑斑病的抑制活性%Control of black rot disease in postharvest cherry tomato with lavender oil

    Institute of Scientific and Technical Information of China (English)

    任雪艳; 梁卓; 王慧敏; 闫帆; 魏玉荣; 孔庆军

    2014-01-01

    This experiment was conducted to study the inhibitory effect and action mode of lavender oil against black rot in postharvest cherry tomato caused by Alternaria alternata by means of fumigation and direct contact. Lavender oil fumi-gation with the dosage of 5 μl per petri dish or direct contact at 400 μl/L could inhibit the growth of A. alternata complete-ly. The incidences of black rot were reduced by 54% and 60% in post harvest cherry tomatoes fumigated with 100 μl/L lavender oil and directly contacted with 500 μl/L lavender oil respectively. An inhibitory effect of short-time lavender oil treatment was shown on A. alternata while a lethal effect of long-time lavender oil treatment was exhibited.%为薰衣草精油用于防治樱桃番茄采后黑斑病提供依据,研究了薰衣草精油熏蒸和直接接触对病原真菌链格孢( Alternaria alternata)的抑制活性及作用方式。结果表明,在培养基培养试验中,每皿5μl的薰衣草精油熏蒸即可完全抑制病原菌的生长;当400μl/L薰衣草精油直接接触链格孢病原菌时,可完全抑制病原菌的生长。在薰衣草精油对樱桃番茄果实采后黑斑病抑制效果试验中发现,100μl/L精油熏蒸处理果实时,处理组果实发病率比对照组降低54%,用500μl/L精油直接处理果实时,处理组果实发病率则比对照组降低60%。在薰衣草精油对病原真菌链格孢作用方式试验中,薰衣草精油作用时间短时,对链格孢病原菌生长有抑制作用,薰衣草精油作用时间长时(5 d和7 d)对链格孢病原菌有致死效应。

  15. Effect of Liberibacter infection (Huanglongbing disease) of citrus on orange fruit physiology and fruit/fruit juice quality: chemical and physical analyses

    Science.gov (United States)

    Huanglongbing (HLB) or greening disease was discovered in Florida several years ago and has since spread throughout the state. The disease is correlated to the presence of a gram-negative bacteria, Candididatus Liberibacter asiaticus (Las). This disease is not feasible to eradicate, thus, the indus...

  16. Soil Micronutrients and Citrus Growth

    Institute of Scientific and Technical Information of China (English)

    OUYANGTAO

    1993-01-01

    By using nutritional diagnosis of citrus leaves and determining soil micronutrients,the relationship between soil micronutrients and citrus growth in southern China has been studied.Studies showed that there was a significant positive correlation between available micronutrients (such as Zn,Mo,Cu)in the soil and the corresponding nutrients in citrus leaves.Thus,one can roughly learn of the sufficiency or deficiency of certain nutrients in soils by analyzing citrus leaves.Rational spray of Zn B or Mo fertilizer not only improved citrus yields but also increased the total sugar of Satsuma mandarin and of Xinhui orange by 2.9 and 17.2% respectively compared with the control.Spraying Mo fertilizer increased the vitamin C content of Satsuma mandarin juice by 4.7%-8.4%,maturated fruits 7-10 days earlier and gave the peel a brighter color.The ultramicroscopic characteristics of Zn-deficient citrus leaves were investigated under an electron microscope.Results showed that the Zn-deficient leaf cell was characterized mainly by poor cytoplasm,endoplasmic reticula and ribosomes and by big starch grains in the chloroplast.As a result of spraying Zn fertilizer the structure of the cell returned to normal,the cytoplasm became rich and the amount of chloroplast increased.There also appeared a great deal of multiform endoplasmic reticula,thus promoting the photosynthesis of Zn-deficient plants.This provides a cytologico-theoretical basis for fertilization of high-yielding citrus trees.

  17. Citrus Limonoids: Analysis, Bioactivity, and Biomedical Prospects

    Science.gov (United States)

    This publication is a review of the chemistry, biochemistry and bioactivity of limonoids occurring in citrus. The review chronologically relates the evolution of research in citrus limonoids beginning with their association with bitterness development in citrus juices. The chemical and biochemical...

  18. Phytophthora parasitica transcriptome, a new concept in the understanding of the citrus gummosis

    OpenAIRE

    Daniel D. Rosa; Magnólia A. Campos; Maria Luisa P.N. Targon; De Souza, Alessandra A.

    2007-01-01

    Due to the economic importance of gummosis disease for the citriculture, studies on P. parasitica-Citrus interaction comprise a significant part in the Brazilian Citrus genome data bank (CitEST). Among them, two cDNA libraries constructed from two different growth conditions of the P. parasitica pathogen are included which has generated the PP/CitEST database (CitEST - Center APTA Citros Sylvio Moreira/IAC- Millennium Institute). Through this genomic approach and clustering analyses the follo...

  19. An in silico analysis of the key genes involved in flavonoid biosynthesis in Citrus sinensis

    OpenAIRE

    Adriano R. Lucheta; Ana Carla O. Silva-Pinhati; Ana Carolina Basílio-Palmieri; Irving J. Berger; Juliana Freitas-Astúa; Mariângela Cristofani

    2007-01-01

    Citrus species are known by their high content of phenolic compounds, including a wide range of flavonoids. In plants, these compounds are involved in protection against biotic and abiotic stresses, cell structure, UV protection, attraction of pollinators and seed dispersal. In humans, flavonoid consumption has been related to increasing overall health and fighting some important diseases. The goals of this study were to identify expressed sequence tags (EST) in Citrus sinensis (L.) Osbeck co...

  20. ‘Candidatus Liberibacter asiaticus’, Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids

    OpenAIRE

    Canales, Eduardo; Coll, Yamilet; Hernández, Ingrid; Portieles, Roxana; Rodríguez García, Mayra; López, Yunior; Aranguren, Miguel; Alonso, Eugenio; Delgado, Roger; Luis, Maritza; Batista, Lochy; Paredes, Camilo; Rodríguez, Meilyn; Pujol, Merardo; Ochagavia, María Elena

    2016-01-01

    Huanglongbing (HLB) constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, ‘Candidatus Liberibacter asiaticus’. The bacterial titers were reduced after treatme...

  1. Preliminary Research on Soil Conditioner Mediated Citrus Huanglongbing Mitigation in the Field

    OpenAIRE

    Xu, M. R.; Liang, M. D.; Zheng, Z.; Zhu, Q.; Chen, J C.; Deng, X. L.

    2014-01-01

    Huanglongbing (HLB, yellow shoot disease) is devastating citrus production worldwide. No effective control measure is currently available. In China, management of HLB through nutrient applications was raised in the past and the interest is renewed recently. In this study, the efficacy of a soil conditioner on different ages of huanglongbing (HLB)-affected citrus trees was evaluated at 3 orchards in Sihui and at different months post treatment in Longmen, Guangdong province. Two species, Shata...

  2. The Genetic Structure of an Invasive Pest, the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae)

    OpenAIRE

    Guidolin, Aline S.; Fresia, Pablo; Cônsoli, Fernando L.

    2014-01-01

    The Asian citrus psyllid Diaphorina citri is currently the major threat to the citrus industry as it is the vector of Candidatus Liberibacter, the causal agent of huanglongbing disease (HLB). D. citri is native to Asia and now colonizes the Americas. Although it has been known in some countries for a long time, invasion routes remain undetermined. There are no efficient control methods for the HLB despite the intensive management tools currently in use. We investigated the genetic variability...

  3. Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata

    OpenAIRE

    Beloti, Vitor Hugo; Alves, Gustavo Rodrigues; Araújo, Diogo Feliciano Dias; Picoli, Mateus Manara; Moral, Rafael de Andrade; Demétrio, Clarice Garcia Borges; Yamamoto, Pedro Takao

    2015-01-01

    Huanglongbing (HLB) is a disease associated with the bacteria “Candidatus Liberibacter spp.” and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston), the main agent for biological control of D. citri. This study as...

  4. Analysis of 13000 unique Citrus clusters associated with fruit quality, production and salinity tolerance

    OpenAIRE

    Dossat Carole; Ollitrault Patrick; Courtois Brigitte; Argout Xavier; Legaz Francisco; Götz Stefan; Iglesias Domingo J; Brumos Javier; Soler Guillermo; de Andres Fernando; Alós Enriqueta; Agustí Javier; Tadeo Francisco; Cercos Manuel; Colmenero Jose M

    2007-01-01

    Abstract Background Improvement of Citrus, the most economically important fruit crop in the world, is extremely slow and inherently costly because of the long-term nature of tree breeding and an unusual combination of reproductive characteristics. Aside from disease resistance, major commercial traits in Citrus are improved fruit quality, higher yield and tolerance to environmental stresses, especially salinity. Results A normalized full length and 9 standard cDNA libraries were generated, r...

  5. Drinking Citrus Fruit Juice Inhibits Vascular Remodeling in Cuff-Induced Vascular Injury Mouse Model

    OpenAIRE

    Ohnishi, Arika; Asayama, Rie; Mogi, Masaki; Nakaoka, Hirotomo; Kan-no, Harumi; Tsukuda, Kana; Chisaka, Toshiyuki; Wang, Xiao-li; Bai, Hui-Yu; Shan, Bao-Shuai; Kukida, Masayoshi; Iwanami, Jun; Horiuchi, Masatsugu

    2015-01-01

    Citrus fruits are thought to have inhibitory effects on oxidative stress, thereby attenuating the onset and progression of cancer and cardiovascular disease; however, there are few reports assessing their effect on vascular remodeling. Here, we investigated the effect of drinking the juice of two different citrus fruits on vascular neointima formation using a cuff-induced vascular injury mouse model. Male C57BL6 mice were divided into five groups as follows: 1) Control (water) (C), 2) 10% Cit...

  6. Developing an understanding of cross-protection by Citrus tristeza virus

    Directory of Open Access Journals (Sweden)

    Svetlana Y Folimonova

    2013-04-01

    Full Text Available Citrus tristeza virus (CTV causes two citrus diseases that have caused devastating losses in global citrus production. The first disease is quick decline of trees propagated on the sour orange rootstock. The second disease is stem pitting, which severely affects a number of economically important citrus varieties regardless of the rootstock used and results in reduced tree growth and vigor as well as in reduced fruit size and quality. Both diseases continue to invade new areas. While quick decline could be effectively managed by the use of resistant and/or tolerant rootstocks, the only means to protect commercial citrus against endemic stem pitting isolates of CTV has been cross-protection with mild isolates of the virus. In some citrus areas cross-protection has been successful and allowed production of certain citrus cultivars despite the presence of severe stem pitting isolates in those regions. However, many other attempts to find isolates that would provide sustained protection against aggressive isolates of the virus had failed. In general, there has been no understanding why some mild isolates were effective and others failed to protect. We have been working on the mechanism of cross-protection by CTV. Recent considerable progress has significantly advanced our understanding of how cross-protection may work in the citrus/CTV pathosystem. As we demonstrated, only isolates that belong to the same strain of the virus cross protect against each other, while isolates from different strains do not. We believe that the results of our research could now make finding protecting isolates relatively straightforward. This review discusses some of the history of CTV cross-protection along with the recent findings and our ‘recipe’ for selection of protecting isolates.

  7. Metabolic Interplay between the Asian Citrus Psyllid and Its Profftella Symbiont: An Achilles' Heel of the Citrus Greening Insect Vector.

    Directory of Open Access Journals (Sweden)

    John S Ramsey

    Full Text Available 'Candidatus Liberibacter asiaticus' (CLas, the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including 'Candidatus Profftella armatura', are likely to impact transmission of CLas. We used quantitative mass spectrometry to compare the proteomes of CLas(+ and CLas(- populations of D. citri, and found that proteins involved in polyketide biosynthesis by the endosymbiont Profftella were up-regulated in CLas(+ insects. Mass spectrometry analysis of the Profftella polyketide diaphorin in D. citri metabolite extracts revealed the presence of a novel diaphorin-related polyketide and the ratio of these two polyketides was changed in CLas(+ insects. Insect proteins differentially expressed between CLas(+ and CLas(- D. citri included defense and immunity proteins, proteins involved in energy storage and utilization, and proteins involved in endocytosis, cellular adhesion, and cytoskeletal remodeling which are associated with microbial invasion of host cells. Insight into the metabolic interdependence between the insect vector, its endosymbionts, and the citrus greening pathogen reveals novel opportunities for control of this disease, which is currently having a devastating impact on citrus production worldwide.

  8. Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii

    OpenAIRE

    Nociti Letícia A; Rodrigues Neto Julio; Leite Rui P; Nishiyama Milton Y; Laia Marcelo L; Kitajima Elliot W.; Jones Jeffrey B; Gimenez Daniele F; Furlan Luiz R; Ferro Maria I; Ferraz André L; Facincani Agda P; de Souza Robson F; de Oliveira Julio C; de Moraes Fabrício E

    2010-01-01

    Abstract Background Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. R...

  9. Visualization of ‘Candidatus Liberibacter asiaticus’ Cells in Citrus Seed Coats with Fluorescence In Situ Hybridization and Transmission Electron Microscopy

    OpenAIRE

    Hilf, M E; Sims, K. R.; Folimonova, S. Y.; Achor, D. S.

    2014-01-01

    ‘Candidatus Liberibacter asiaticus’ is bacterium implicated as the causal agent of the economically damaging disease of citrus called huanglongbing (HLB).  The bacterium is spread by movement of infected citrus propagation material and by the Asian citrus psyllid, Diaphorina citri Kuwayama.  Seed transmission is a possible additional route of dissemination for the pathogen.  Some published studies on seed transmission found abundant bacterial DNA in seed coats but no infections of germinated ...

  10. Synthesis results from eight years of field testing insecticides against Asian citrus psyllid Diaphorina citri vector of huanglongbing: Considerations and Implications

    OpenAIRE

    Qureshi, Jawwad A.; Kostyk, Barry C; Stansly, Philip A.

    2014-01-01

    Diaphorina citri also known as Asian citrus psyllid (ACP) vectors Candidatus Liberibacter asiaticus, causal organism of the Asian “huanglongbing” or citrus greening disease and therefore needs to be managed effectively.  Forty-three insecticides containing 39 active ingredients (a.i) recommended or experimental were tested during the growing season in foliar sprays (171 treatments, 35 a.i) targeted at flushing trees and soil applications (26 treatments, 6 a.i) to control ACP in citrus between...

  11. In-vitro evaluation of bioactive compounds, anti-oxidant, lipid peroxidation and lipoxygenase inhibitory potential of Citrus karna L. peel extract

    OpenAIRE

    Singh, Jagdeep; Sood, Shailja; Muthuraman, Arunachalam

    2011-01-01

    Many medicinal plants have been studied for their antioxidant and their pharmacological activity. Citrus species were well documented as potential antioxidant based therapy for cancer, inflammation, heart disease. Citrus seeds and peels have been shown to possess high antioxidant activity. Therefore, the present study to explore the antioxidant and lipid peroxidation & lipoxygenase inhibitory action of Citrus karna peel extracts were undertaken. Extraction was performed with different solvent...

  12. History and Diversity of Citrus leprosis virus Recorded in Herbarium Specimens.

    Science.gov (United States)

    Hartung, John S; Roy, Avijit; Fu, Shimin; Shao, Jonathan; Schneider, William L; Brlansky, Ronald H

    2015-09-01

    Leprosis refers to two diseases of citrus that present similar necrotic local lesions, often surrounded by chlorotic haloes on citrus. Two distinct viruses are associated with this disease, one that produces particles primarily in the nucleus of infected plant cells (Citrus leprosis virus nuclear type [CiLV-N]; Dichorhavirus) and another type that produces particles in the cytoplasm of infected plant cells (Citrus leprosis virus cytoplasmic type [CiLV-C]; Cilevirus). Both forms are transmitted by Brevipalpid mites and have bipartite, single-stranded, RNA genomes. CiLV-C and CiLV-N are present in South and Central America and as far north as parts of Mexico. Although leprosis disease was originally described from Florida, it disappeared from there in the 1960s. The United States Department of Agriculture-Agricultural Research Service maintains preserved citrus specimens identified at inspection stations 50 or more years ago with symptoms of citrus leprosis. We isolated RNA from these samples and performed degradome sequencing. We obtained nearly full-length genome sequences of both a typical CiLV-C isolate intercepted from Argentina in 1967 and a distinct CiLV-N isolate obtained in Florida in 1948. The latter is a novel form of CiLV-N, not known to exist anywhere in the world today. We have also documented the previously unreported presence of CiLV-N in Mexico in the mid-20th century. PMID:25961338

  13. Postharvest biochemical and textural characteristics of sh2 sweetcorn cobs

    OpenAIRE

    Smyrniotaki, Mari

    2011-01-01

    The determination of storage conditions leading to optimum quality attributes and extended postharvest life of sweetcorn is essential. The increased consumption and consequently the need for greater consumer satisfaction have resulted in the introduction of supersweet sweetcorn. The present study, aimed to report on the effects of various postharvest factors on biochemical and texture-related characteristics of supersweet sweetcorn cultivars as current knowledge is still incomp...

  14. OPTIMAL POST-HARVEST GRAINS STORAGE BY RISK AVERSE FARMERS

    OpenAIRE

    Lai, Jing-Yi; Myers, Robert J.; Hanson, Steven D.

    2001-01-01

    Most previous research on post-harvest grain storage by farmers has assumed risk-neutral behavior and/or made restrictive assumptions about underlying price probability distributions. In this study we solve the optimal post-harvest storage problem for a risk averse farmer under more general assumptions about underlying price distributions. The resulting model is applied to Michigan corn farmers and results show that, contrary to the sell all-or-nothing risk-neutral rule, risk averse farmers w...

  15. Managing postharvest innovation: a review of developments and trends

    OpenAIRE

    Batterink, M.H.; Omta, S.W.F.; Wubben, E.F.M.

    2005-01-01

    Purpose of the review: With the fast developments in technologies, combined with increased global competition and changing customer demands, innovation is increasingly seen as a means for sustainable growth. This paper reviews literature on the management of innovation and the most prominent findings from postharvest innovation practices. Main findings: Three areas of postharvest innovation were identified: product innovation, enablers for fresh foods and quality improvements and netchain inn...

  16. Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates

    OpenAIRE

    Oikeh, Ehigbai I.; Omoregie, Ehimwenma S; Oviasogie, Faith E.; Oriakhi, Kelly

    2015-01-01

    Abstract The search for new antimicrobial compounds is ongoing. Its importance cannot be overemphasized in an era of emerging resistant pathogenic organisms. This study therefore investigated the phytochemical composition and antioxidant and antimicrobial activities of different citrus juice concentrates. Fruit juices of Citrus tangerine (tangerine), Citrus paradisi (grape), Citrus limon (lemon), and Citrus aurantifolia (lime) were evaluated. Antimicrobial activities against five bacterial an...

  17. Citrus fruits as a treasure trove of active natural metabolites that potentially provide benefits for human health.

    Science.gov (United States)

    Lv, Xinmiao; Zhao, Siyu; Ning, Zhangchi; Zeng, Honglian; Shu, Yisong; Tao, Ou; Xiao, Cheng; Lu, Cheng; Liu, Yuanyan

    2015-01-01

    Citrus fruits, which are cultivated worldwide, have been recognized as some of the most high-consumption fruits in terms of energy, nutrients and health supplements. What is more, a number of these fruits have been used as traditional medicinal herbs to cure diseases in several Asian countries. Numerous studies have focused on Citrus secondary metabolites as well as bioactivities and have been intended to develop new chemotherapeutic or complementary medicine in recent decades. Citrus-derived secondary metabolites, including flavonoids, alkaloids, limonoids, coumarins, carotenoids, phenolic acids and essential oils, are of vital importance to human health due to their active properties. These characteristics include anti-oxidative, anti-inflammatory, anti-cancer, as well as cardiovascular protective effects, neuroprotective effects, etc. This review summarizes the global distribution and taxonomy, numerous secondary metabolites and bioactivities of Citrus fruits to provide a reference for further study. Flavonoids as characteristic bioactive metabolites in Citrus fruits are mainly introduced. PMID:26705419

  18. Effectivity of Kaffir lime (Citrus hystrix, Nasnaran Mandarin (Citrus amblycarpa, and Pomelo (Citrus maxima Leaf Extract Against Aedes aegypti Larvae

    Directory of Open Access Journals (Sweden)

    Hebert Adrianto

    2014-03-01

    Full Text Available The used of chemicals as larvicidal may causing resistance, health problem, and environment problem. Leaf extracts of Citrus as biolarvicidal against Aedes aegypti larvae can be used as an alternative larvicidal. The aims of this study is to find out the species of Citrus in the study sample, which is the most effective as biolarvicidal. This study was conducted using nested experiment design, with six treatments and five replicates. Larvae mortality was observed after 24 and 48 hours. Then, data were analyzed by probit. The results of this study show that (1 the LC95 value after 24 hours of exposure of leaf extracts of Citrus hystrix, Citrus amblycarpa, and Citrus maxima, were each 3,176 ppm; 4,174 ppm; and 6,369 ppm. (2 the LC95 value after 48 hours of exposure of leaf extracts of Citrus hystrix, Citrus amblycarpa, and Citrus maxima, were each 2,499 ppm; 3,256 ppm; and 4,886 ppm. (3 leaf extract of Citrus hystrix is the most effective among others as biolarvicidal against Aedes aegypti larvae. Leaf extract of Citrus hystrix can be used as alternative biolarvicidal.

  19. Effect of gamma irradiation and its convergent treatment for control of postharvest Botrytis cinerea of cut roses

    Science.gov (United States)

    Chu, Eun-Hee; Shin, Eun-Jung; Park, Hae-Jun; Jeong, Rae-Dong

    2015-10-01

    Postharvest diseases cause considerable losses to harvested crops. Among them, gray mold (Botrytis cinerea) is a major problem of exporting to cut rose flowers into Korea. Irradiation treatment is an alternative to phytosanitary purposes and a useful nonchemical approach to the control of postharvest diseases. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against B. cinerea on cut rose varieties, 'Shooting Star' and 'Babe'. The irradiating dose required to reduce the population by 90%, D10, was 0.99 kGy. Gamma irradiation showed complete inhibition of spore germination and mycelial growth of B. cinerea, especially 4.0 kGy in vitro. Antifungal activity of gamma irradiation on rose B. cinerea is a dose-dependent manner. A significant phytotoxicity such as bent neck in cut rose quality was shown from gamma irradiation at over 0.4 kGy (pcontrol the postharvest diseases in cut rose flowers, and will provide a promising technology for horticulture products for exportation.

  20. Study of packing lines for stone fruits and citrus using two instrumented spheres in some cooperatives in the region of Murcia (Spain).

    OpenAIRE

    Ruiz-Altisent, Margarita; Garcia, F.; Riquelme Ballestero, F.; Barreiro Elorza, Pilar

    1996-01-01

    Two instrumented spheres IS 100 were used to evaluate the quality of post-harvest operations. Results obtained from measurements made with both IS (8.8 cm 0 and 6.2 cm 0) show significant differences. Both IS measure the same values of the same variables for soft materials, but not for hard surfaces. Four packing lines belonging to different cooperatives of the region of Murcia (two for stone fruits and two for citrus) were tested. IS values obtained in transfers belonging to the tested lines...

  1. Effectiveness of Phenolic Compounds against Citrus Green Mould

    OpenAIRE

    Sanzani, Simona M.; Leonardo Schena; Antonio Ippolito

    2014-01-01

    Stored citrus fruit suffer huge losses because of the development of green mould caused by Penicillium digitatum. Usually synthetic fungicides are employed to control this disease, but their use is facing some obstacles, such public concern about possible adverse effects on human and environmental health and the development of resistant pathogen populations. In the present study quercetin, scopoletin and scoparone—phenolic compounds present in several agricultural commodities and associated w...

  2. Evaluation of Citrus Fibers as a Tablet Excipient

    OpenAIRE

    Cespi, Marco; Bonacucina, Giulia; Roberts, Matthew; Hanson, Samuel; Jones, Stephen; Makevica, Elina; Casettari, Luca; Palmieri, Giovanni Filippo

    2013-01-01

    The consumption of fibers is associated with many health benefits, such as a reduction of cardiovascular and gastrointestinal diseases, control of body weight, and prevention of diabetes. Despite the widespread use of fiber supplements such as capsules or tablets, there is an almost complete lack of information concerning the technological properties of functional fibers used in nutraceutical formulations. The aim of this work was to characterize the technological properties of citrus fibers ...

  3. Pathogen infection drives patterns of nutrient resorption in citrus plants

    OpenAIRE

    Jirong Cao; Chunzhen Cheng; Junjie Yang; Qibing Wang

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen ‘Candidatus Liberibacter asiaticus’ grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of ‘Ca. L. asiaticus’ infection on nit...

  4. 78 FR 8435 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus Hybrids and Fortunella

    Science.gov (United States)

    2013-02-06

    ... Animal and Plant Health Inspection Service 7 CFR Part 319 RIN 0579-AD59 Importation of Fresh Citrus Fruit From Uruguay, Including Citrus Hybrids and Fortunella spp., Into the Continental United States AGENCY.... australis. \\2\\...

  5. Enhancing Florida strawberry shelf life using peroxiacetic acid pre-harvest treatments and postharvest edible coatings

    Science.gov (United States)

    Strawberry is an important fruit crop in Florida. Yearly losses can be attributed to pre- and postharvest decay caused by Botrytis cinerea, and postharvest decay due primarily to Rhizopus stolonifer. Postharvest applications of edible coatings and sanitizers were tested. Among them, a medium-dens...

  6. Characterization of a recombinant Cathepsin B-Like cysteine peptidase from Diaphorina citri Kuwayama (Hemiptera: Liviidae): A putative target control of citrus huanglongbing

    Science.gov (United States)

    Huanglongbing (HLB) is one of the most destructive disease affecting citrus plants. The causal agent is associated with the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas) spread by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Among the control strategies for H...

  7. 76 FR 23449 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Science.gov (United States)

    2011-04-27

    ... 22, 2007 and effective on March 16, 2007 (72 FR 13423-13428, Docket No. APHIS-2007-0032) that....aphis.usda.gov/plant_health/plant_pest_info/citrus/index.shtml . We believe that the procedures set... effective on June 17, 2010 (75 FR 34322-34336, Docket No. APHIS- 2008-0015).\\4\\ Several commenters on...

  8. 75 FR 34322 - Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations

    Science.gov (United States)

    2010-06-17

    ... Animal and Plant Health Inspection Service 7 CFR Parts 301 and 305 RIN 0579-AC85 Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations AGENCY: Animal and Plant Health... African citrus psyllid is not present in the United States. The Animal and Plant Health Inspection...

  9. Acquisition, Replication and Inoculation of Candidatus Liberibacter asiaticus following Various Acquisition Periods on Huanglongbing-Infected Citrus by Nymphs and Adults of the Asian Citrus Psyllid.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available The Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae, is the primary vector of Candidatus Liberibacter asiaticus (Las implicated as causative agent of citrus huanglongbing (citrus greening, currently the most serious citrus disease worldwide. Las is transmitted by D. citri in a persistent-circulative manner, but the question of replication of this bacterium in its psyllid vector has not been resolved. Thus, we studied the effects of the acquisition access period (AAP by nymphs and adults of D. citri on Las acquisition, multiplication and inoculation/transmission. D. citri nymphs or adults (previously non-exposed to Las were caged on Las-infected citrus plants for an AAP of 1, 7 or 14 days. These 'Las-exposed' psyllids were then transferred weekly to healthy citrus or orange jasmine plants, and sampled via quantitative polymerase chain reaction (qPCR analysis 1-42 days post-first access to diseased plants (padp; all tested nymphs became adults 7-14 days padp. Our results indicate that following 1 or 7 day AAP as nymphs 49-59% of Las-exposed psyllids became Las-infected (qPCR-positive, whereas only 8-29% of the psyllids were infected following 1-14 day AAP as adults. Q-PCR analysis also indicated that Las titer in the Las-exposed psyllids (relative to that of the psyllid S20 ribosomal protein gene was: 1 significantly higher, and increasing at a faster rate, following Las acquisition as nymphs compared to that following Las acquisition as adults; 2 higher as post-acquisition time of psyllids on healthy plants increased reaching a peak at 14-28 days padp for nymphs and 21-35 days padp for adults, with Las titer decreasing or fluctuating after that; 3 higher with longer AAP on infected plants, especially with acquisition as adults. Our results strongly suggest that Las multiplies in both nymphs and adults of D. citri but attains much higher levels in a shorter period of time post-acquisition when acquired by nymphs than when acquired by

  10. Botanicals, selective insecticides, and predators to control Diaphorina citri (Hemiptera: Liviidae) in citrus orchards.

    Science.gov (United States)

    Khan, Azhar A; Afzal, Muhammad; Qureshi, Jawwad A; Khan, Arif M; Raza, Abubakar M

    2014-12-01

    The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama vectors pathogens that cause huanglongbing (HLB) or citrus greening devastating and economically important disease present in most citrus growing regions. Young citrus shoots are required for psyllid reproduction and development. During winter citrus trees produce little or no new growth. Overwintering adults reproduce in spring on newly emerging shoots also attractive to other pests and beneficial insects. Botanicals and relatively selective insecticides could help to conserve beneficial insects and reduce pest resistance to insecticides. Sprays of Azadirachtin (Neem), Tropane (Datura), Spirotetramat, Spinetoram, and broad-spectrum Imidacloprid were evaluated to control ACP in spring and summer on 10-year-old "Kinow" Citrus reticulata Blanco trees producing new growth. Psyllid populations were high averaging 5-9 nymphs or adults per sample before treatment application. Nymphs or adults were significantly reduced to 0.5-1.5 per sample in all treatments for 3 weeks, average 61%-83% reduction. No significant reduction in ladybeetles Adalia bipunctata, Aneglei scardoni, Cheilomenes sexmaculata, and Coccinella septempunctata was observed. Syrphids, spiders and green lacewings were reduced in treated trees except with Tropane. Studies are warranted to assess impact of these predators on ACP and interaction with insecticides. Observed reduction in ACP populations may not be enough considering its reproductive potential and role in the spread of HLB. Follow-up sprays may be required to achieve additional suppression using rotations of different insecticides. PMID:25205398

  11. Irradiation for international trade in agricultural products: The case of citrus fruit

    International Nuclear Information System (INIS)

    The paper analyses the influence of irradiation techniques on the Uruguayan market and their repercussions on international trade, with emphasis on the important and steadily growing citrus sector. This growth of citrus cultivation in Uruguay has been based on increasing international trade, and therefore producers and exporters have shown particular interest in the plant protection requirements which the European Economic Community (EEC) may adopt to govern the import of citrus fruit into its area. Over the past few years, the sector has become a net exporter, increasing its turnover from one harvest to the next. However, it is currently facing problems caused by the citrus plant disease known as canker, which is caused by a bacterium (Xanthomonas campestris, pv citri). The EEC is considering plant protection measures which could close its market to Uruguayan citrus fruit. Likewise, the North American market does not accept fruit from regions affected by canker. It is intended to treat fruit ready for export (wax-treated and packed) by irradiation at 0.7 kGy, combined with heat treatment for 5 min at 50 deg. C at the first rinsing stage during packing. Citrus fruit irradiation thus appears as an alternative treatment which would solve the problem by allowing a quality product to be offered on the foreign market, thereby improving commercial prospects as well as avoiding non-tariff barriers. (author). 9 refs, 1 tab

  12. Signaling pathways in a Citrus EST database

    OpenAIRE

    Angela Mehta; Marilia Santos Silva; Simone Guidetti-Gonzalez; Helaine Carrer; Marco Aurélio Takita; Natália F. Martins

    2007-01-01

    Citrus spp. are economically important crops, which in Brazil are grown mainly in the State of São Paulo. Citrus cultures are attacked by several pathogens, causing severe yield losses. In order to better understand this culture, the Millenium Project (IAC Cordeirópolis) was launched in order to sequence Citrus ESTs (expressed sequence tags) from different tissues, including leaf, bark, fruit, root and flower. Plants were submitted to biotic and abiotic stresses and investigated under differe...

  13. Antimicrobial Compounds to Combat Citrus Huanglongbing

    OpenAIRE

    Zhang, Muqing; Guo, Ying; Powell, Charles A.; Duan, Yongping

    2014-01-01

    Citrus Huanglongbing (HLB) is associated with the fastidious bacterium,Candidatus Liberibacter, (Las) that is transmitted by a phloem-feeding insect (Citrus Psyllid). An ideal solution to combat citrus HLB is to completely eliminate the bacteria after a single course of the chemotherapy, either active directly on the bacteria or indirectly through induction of host defense compounds. Twenty-seven antimicrobial compounds were screened to test for in vivo activities against HLB bacterium while ...

  14. The aconitate hydratase family from Citrus

    OpenAIRE

    Cercos Manuel; Talon Manuel; Soler Guillermo; Terol Javier

    2010-01-01

    Abstract Background Research on citrus fruit ripening has received considerable attention because of the importance of citrus fruits for the human diet. Organic acids are among the main determinants of taste and organoleptic quality of fruits and hence the control of fruit acidity loss has a strong economical relevance. In citrus, organic acids accumulate in the juice sac cells of developing fruits and are catabolized thereafter during ripening. Aconitase, that transforms citrate to isocitrat...

  15. CONTROL OF POSTHARVEST TOMATO ROT BY SPORE SUSPENSION AND ANTIFUNGAL METABOLITES OF TRICHODERMA HARZIANUM

    Directory of Open Access Journals (Sweden)

    Momein H. El-Katatny

    2012-06-01

    Full Text Available Rot of cherry tomato (Lycopersicon esculentum fruits caused by several fungal pathogens is a detrimental disease leading to substantial yield loses worldwide. Alternaria isolates were the most common fungal species isolated from healthy or rotten fruits. Trichoderma harzianum spore suspension and culture filtrate were tested for their antagonistic activity on controlling tomato fruit rot. T. harzianum isolates suppressed or interfered with the growth of different postharvest tomato fungal pathogens albeit at different degrees. Their culture filtrate inhibited pathogen spore germination possibly due to the released extracellular diffusible metabolite(s. Besides, aberrant morphology of conidia was observed with deformation of hyphal tips. Furthermore, the resulting mycelia appeared desiccated with coagulated protoplasm leading to complete collapse of protoplasm in presence of T. harzianum culture filtrate. Application of T. harzianum spores to tomato fruits decreased disease severity significantly with the most profound effect at higher spore concentrations (108 cells per ml. Similarly, culture filtrate of T. harzianum prevented pathogen spore germination on the surface of tomato fruits leading to decreased incidence of rot symptoms at high culture filtrate concentrations. This work provides strong evidence that T. harzianum is a competent antagonist and its spore suspension and culture filtrate can be used efficiently to control postharvest tomato rot.

  16. Bionomics of Asian Citrus Psyllid (Hemiptera: Liviidae) Associated with Orange Jasmine Hedges in Southeast Central Florida, with Special Reference to Biological Control by Tamarixia radiata.

    Science.gov (United States)

    Hall, David G; Rohrig, Eric

    2015-06-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama, is an important pest in Florida because it transmits bacteria responsible for citrus huanglongbing disease. In addition to infesting citrus, orange jasmine (Murraya exotica L.) is one of Asian citrus psyllid's preferred host plants and is widely grown as an ornamental hedge. We report on Asian citrus psyllid bionomics over three years at five urban plantings of orange jasmine and on biological control of Asian citrus psyllid by a parasitoid Tamarixia radiata (Waterston). T. radiata had been released in Florida shortly after Asian citrus psyllid was first found, and the parasitoid was known to be established at each planting. Additionally, three new T. radiata haplotypes were released every 3 wk at three plantings during the first study year (one haplotype per planting, over all releases an average of 17 parasitoids per linear meter of hedge); all three haplotypes were released at a fourth planting beginning midway through the study (over all releases, an average combined total of 202 parasitoids per linear meter of hedge). Asian citrus psyllid populations were present year-round at each planting, often at large levels. Such plantings may pose risk to commercial citrus as Asian citrus psyllid reservoirs. Releases of the new haplotypes did not cause any measurable reduction in Asian citrus psyllid population levels during the study, and ironically percentage parasitism was generally highest at a planting where no releases were made. Higher release rates might have been more effective. The probability is discussed that repetitive pruning of orange jasmine reduced the full potential of T. radiata against Asian citrus psyllid in this study. PMID:26470246

  17. Stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the Asian citrus psyllid Diaphorina citri, vector of citrus huanglongbing bacterium.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri (Hemiptera: Psyllidae, is the primary vector of the phloem-limited bacterium Candidatus Liberibacter asiaticus (LAS associated with huanglongbing (HLB, citrus greening, considered the world's most serious disease of citrus. Stylet morphometrics of ACP nymphs and adults were studied in relation to citrus vein structure and to their putative (histologically verified feeding sites on Valencia orange leaves. ACP nymphs preferred to settle and feed on the lower (abaxial side of young leaves either on secondary veins or on the sides of the midrib, whereas adults preferred to settle and feed on the upper (adaxial or lower secondary veins of young or old leaves. Early instar nymphs can reach and probe the phloem probably because the distance to the phloem is considerably shorter in younger than in mature leaves, and is shorter from the sides of the midrib compared to that from the center. Additionally, the thick-walled 'fibrous ring' (sclerenchyma around the phloem, which may act as a barrier to ACP stylet penetration into the phloem, is more prominent in older than in younger leaves and in the center than on the sides of the midrib. The majority (80-90% of the salivary sheath termini produced by ACP nymphs and adults that reached a vascular bundle were associated with the phloem, whereas only 10-20% were associated with xylem vessels. Ultrastructural studies on ACP stylets and LAS-infected leaves suggested that the width of the maxillary food canal in first instar nymphs is wide enough for LAS bacteria to traverse during food ingestion (and LAS acquisition. However, the width of the maxillary salivary canal in these nymphs may not be wide enough to accommodate LAS bacteria during salivation (and LAS inoculation into host plants. This may explain the inability of early instar nymphs to transmit LAS/HLB in earlier reports.

  18. Antibacterial activity of Citrus limonum fruit juice extract.

    Science.gov (United States)

    Okeke, Malachy Ifeanyi; Okoli, Arinze Stanley; Eze, Edith Nneka; Ekwume, Grace Chinwe; Okosa, Evangelin Uchena; Iroegbu, Christian Ukwuoma

    2015-09-01

    The fruit juice extract of Citrus limonum was investigated for antibacterial activity. The antibacterial activity of the extract on ten strains of bacteria was determined by both agar well diffusion and macro-broth dilution methods. The extract was variously bacteriostatic and bactericidal against Bacillussubtilis ATCC 6051, Staphylococcus aureus ATCC 12600, Escherichia coli ATCC 11775, Pseudomonas aeruginosa ATCC 10145 as well as locally isolated clinical strains of the above bacteria and Salmonella kintambo (Human: 13, 23: mt:-), Salmonella typhi and Proteus sp. The MICs ranged from 0.78 mg/ml to 50mg/ml; MBCs, 25.0mg/ml to >100mg/ml and MBC/MIC ratios 2.0 to >16.0. These results provide scientific justification for the medicinal use of Citrus limonum fruit juice by Nigerian herbalists in the treatment of diseases in which strains of the test organisms have been implicated as etiologic agents. PMID:26408878

  19. Extension of Small-Scale Postharvest Horticulture Technologies—A Model Training and Services Center

    OpenAIRE

    Lisa Kitinoja; Diane M. Barrett

    2015-01-01

    A pilot Postharvest Training and Services Center (PTSC) was launched in October 2012 in Arusha, Tanzania as part of a United States Agency for International Development (USAID) funded project. The five key components of the PTSC are (1) training of postharvest trainers, (2) postharvest training and demonstrations for local small-scale clientele, (3) adaptive research, (4) postharvest services, and (5) retail sales of postharvest tools and supplies. During the years of 2011–2012, a one year ...

  20. In Vitro and In Vivo Antibacterial Activity of Some Organic and Inorganic Salts Against Asiatic Citrus Canker Agent Xanthomonas Citri Subsp. Citri

    Directory of Open Access Journals (Sweden)

    Vahideh Hasabi

    2014-06-01

    Full Text Available Asiatic citrus canker caused by Xanthomonas citri subsp. citri is becoming a disease of high economic impact, affecting all types of important citrus crops. In this study, the potential antibacterial activity of ten organic and inorganic salts on X. citri subsp. citri and on citrus canker disease development was evaluated. Among the salt compounds, copper, iron and zinc inorganic salts particularly zinc (with the highest diameter of inhibition, the lowest MIC and MBC values and the highest bacterial growth inhibitory effect had direct antibacterial activity and strongly reduced the development of canker disease and bacterial population of lime plants.

  1. Green synthesis of gold nanoparticles using Citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) aqueous extract and its characterization

    Science.gov (United States)

    Sujitha, Mohanan V.; Kannan, Soundarapandian

    2013-02-01

    This study reports the biological synthesis of gold nanoparticles by the reduction of HAuCl4 by using citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) juice extract as the reducing and stabilizing agent. A various shape and size of gold nanoparticles were formed when the ratio of the reactants were altered with respect to 1.0 mM chloroauric acid solution. The gold nanoparticles obtained were characterized by UV-visible spectra, transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM studies showed the particles to be of various shapes and sizes and particle size ranges from 15 to 80 nm. Selected-area electron diffraction (SAED) pattern confirmed fcc phase and crystallinity of the particles. The X-ray diffraction analysis revealed the distinctive facets (1 1 1, 2 0 0, 2 2 0 and 2 2 2 planes) of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size for colloid gp3 of C. limon, C. reticulata and C. sinensis are 32.2 nm, 43.4 nm and 56.7 nm respectively. The DLS graph showed that the particles size was larger and more polydispersed compared to the one observed by TEM due to the fact that the measured size also includes the bio-organic compounds enveloping the core of the Au NPs. Zeta potential value for gold nanoparticles obtained from colloid gp3 of C. limon, C. reticulata and C. sinensis are -45.9, -37.9 and -31.4 respectively indicating the stability of the synthesized nanoparticles. Herein we propose a novel, previously unexploited method for the biological syntheses of polymorphic gold nanoparticles with potent biological applications.

  2. Vector Control and Foliar Nutrition for Management of Huanglongbing in Florida Citrus

    OpenAIRE

    Stansly, Philip A.; Arevalo, H. Alejandro; Jawwad A Qureshi; Jones, Moneen M.; Hendricks, Katherine; Roberts, Pamela D.; Roka, Fritz M.

    2014-01-01

    Huanglongbing (HLB) or citrus greening is a bacterial disease vectored by the Asian citrus psyllid (ACP) and causing mottled leaves, tree decline, and yield loss.  Vector control and foliar nutrition are widely employed in Florida and elsewhere to respectively slow the spread of HLB and mitigate debilitating effects of the disease.  A replicated field study was conducted in a 5.4-ha commercial block of young ‘Valencia’ orange trees through four harvests employing a factorial design to evaluat...

  3. Comparison of two aerial imaging platforms for identification of Huanglongbing-infected citrus trees

    DEFF Research Database (Denmark)

    Garcia Ruiz, Francisco Jose; Sankaran, Sindhuja; Maja, Joe Mari;

    2013-01-01

    Huanglongbing (HLB) or citrus greening disease is one of the most important diseases affecting citrus orchards in Florida and other parts of the world. The first critical step for a successful control of HLB is its detection and diagnosis. Spectroscopy has proven to yield reliable results for its...... machine (SVM) with kernel resulted in better performance than other methods such as SVM (linear), linear discriminant analysis and quadratic discriminant analysis. Thus, high-resolution aerial sensing has good prospect for the detection of HLB-infected trees....

  4. Digital Gene Expression Analysis of Ponkan Mandarin (Citrus reticulata Blanco in Response to Asia Citrus Psyllid-Vectored Huanglongbing Infection

    Directory of Open Access Journals (Sweden)

    Yun Zhong

    2016-07-01

    Full Text Available Citrus Huanglongbing (HLB, the most destructive citrus disease, can be transmitted by psyllids and diseased budwoods. Although the final symptoms of the two main HLB transmission ways were similar and hard to distinguish, the host responses might be different. In this study, the global gene changes in leaves of ponkan (Citrus reticulata mandarin trees following psyllid-transmission of HLB were analyzed at the early symptomatic stage (13 weeks post inoculation, wpi and late symptomatic stage (26 wpi using digital gene expression (DGE profiling. At 13 wpi, 2452 genes were downregulated while only 604 genes were upregulated in HLB infected ponkan leaves but no pathway enrichment was identified. Gene function analysis showed impairment in defense at the early stage of infection. At late stage of 26 wpi, however, differentially expressed genes (DEGs involved in carbohydrate metabolism, plant defense, hormone signaling, secondary metabolism, transcription regulation were overwhelmingly upregulated, indicating that the defense reactions were eventually activated. The results indicated that HLB bacterial infection significantly influenced ponkan gene expression, and a delayed response of the host to the fast growing bacteria might be responsible for its failure in fighting against the bacteria.

  5. RATIONAL TECHNOLOGIES OF SUNFLOWER SEEDS POST-HARVEST PROCESSING

    Directory of Open Access Journals (Sweden)

    Priporov I. E.

    2015-10-01

    Full Text Available The aim of the research is the determination of rational technology of post-harvest treatment of seeds of sunflower. Existing technologies that are implemented in grain cleaning units and complexes for the preparation of seed material type GCM (Voronezhselmash, "Polyma" (Belarus and others perform seed treatment by sequential processing on all cleaning machines. Return at any point not provided, it is necessary to conduct repeated handling throughout the chain of cars that leads to the reduction of seed yield, decreased performance and increased injury to seed. Research Institute of oil crops designed container technology in universal seed cleaning complex, eliminates these disadvantages and allows finishing the processing of seed material at the time of matching seeds with the requirements of GOST at any stage. In seed output pneumatic sorting machines MOS-9N, which is seed cleaning complex that contained diseased seeds that differ from healthy seeds by color and lowered their quality. To improve the quality of seed material was applied photoelectron separator F 5.1, followed by separation of sunflower seeds on the dimension fraction (Ø7-Ø8 mm, Ø8-Ø9мм. In the result of the research container technology with subsequent fractionation of sunflower seeds on the separator at the final stage of their processing improves the yield of highly certified seeds from 92.90 to 93.20 % compared 91,20 % (without fractionation and reduce the content of their departure from 68,83 to 65,60 % compared 85,52 % (without fractionation depending on size fraction

  6. Determination of the Presence of Huanglongbing in Seeds and Movement of the Pathogen in Citrus reticulata

    Directory of Open Access Journals (Sweden)

    Hajivand Shokrollah

    2009-01-01

    Full Text Available Problem statement: Huanglongbing (HLB also known as citrus greening disease is a fastidious phloem-inhabiting bacterium in the genus Candidatus Liberibacter. Using universal primers, the 16S ribosomal DNA sequence of three strains of the bacterium were obtained by PCR. However there is very little information on seed transmission and HLB pathogen movement to find a way for control or reduce the severity of HLB on the field. The study was conducted to detect HLB pathogen in seeds of Citrus, to determine pathogen movement in citrus seedling after infection and to detect the HLB pathogen in citrus roots. Approach: Seeds of Citrus reticulata cv. Limau Madu were collected from infected orchard and were germinated in screenhouse condition. The seeds of Citrus reticlata cv. L. Madu were planted in screenhouse too for HLB pathogen movement and HLB detection in roots. The seedlings were inoculated using infected grafting methods. Results: HLB was not amplified in new seedlings after germination. HLB moved slowly reaching up to 1.5 cm after 2 weeks, 1.5-4.5 cm after eight weeks and detected on 4.5-9 cm after 14 weeks below the grafting area. HLB was also detected up to 9-15 cm after 16 weeks, 15-24 cm after twenty weeks, 24-28.5 cm after 22 weeks and 28.5-30 cm after 24 weeks below the grafting area. Conclusion: Base on conventional PCR test, HLB disease in citrus is not seed borne and it can reach to the roots 26 weeks after inoculation.

  7. PROPOLIS EXTRACT IN POSTHARVEST CONSERVATION BANANA ' PRATA'

    Directory of Open Access Journals (Sweden)

    FLÁVIA REGINA PASSOS

    2016-01-01

    Full Text Available ABSTRACT In the present work were evaluated the effects of propolis coatings of various botanical sources on quality traits of bananas cv. Prata (Musa sapientum L. stored at room temperature. ´Prata´ bananas were selected and submitted to five postharvest treatments: four coatings applied by immersion in propolis extracts at a concentration of 2.5% (w/v and a control (without coating. Propolis extracts were applied as 1 a wild type aqueous propolis extract, 2 a wild type hydroalcoholic propolis extract, 3 a rosemary green type hydroalcoholic propolis extract and 4 a red type hydroalcoholic propolis extract. The bananas were evaluated at three-day intervals along 12 days for fresh weight losses, flesh firmness, soluble solids (SS, titratable acidity (TA, the ratio SS/TA and pH. Sensory analyses were performed after three and six days of storage by 55 not trained panelists designed for acceptability. At the end of the twelve-day storage period, bananas coated either with the rosemary green hydroalcoholic extract or with the aqueous extract presented lower fresh weight losses in comparison to the bananas of the control treatment. No differences were determined in relation to flesh firmness and along the storage period TA values decreased and pH values increased in bananas of all treatments. SS contents increased towards the end of the storage period that, consequently, contributed to increases in the SS/TA ratio. The most significant increase in SS/TA ratio was determined in bananas coated with the red type hydroalcoholic extract. Taste panelists did not detect significant differences amongst coated and not coated cv. Prata bananas up to six days of storage.

  8. Selected Activities of Citrus Maxima Merr. Fruits on Human Endothelial Cells: Enhancing Cell Migration and Delaying Cellular Aging

    OpenAIRE

    Paiwan Buachan; Linda Chularojmontri; Wattanapitayakul, Suvara K.

    2014-01-01

    Endothelial injury and damage as well as accumulated reactive oxygen species (ROS) in aging play a significant role in the development of cardiovascular disease (CVD). Recent studies show an association of high citrus fruit intake with a lower risk of CVD and stroke but the mechanisms involved are not fully understood. This study investigated the effects of pummelo (Citrus maxima Merr. var. Tubtim Siam, CM) fruit extract on human umbilical vein endothelial cell (HUVECs) migration and aging. T...

  9. Citrus reticulata’s Peels Modulate Blood Cholesterol Profile and IncreaseBone Density of Ovariectomized Rats

    OpenAIRE

    Rosa Adelina; Maria Dwi Supriyati; Dwi Ana Nawangsari; Riris I Jenie; Edy Meiyanto

    2015-01-01

    Hormon Replacement Therapy is a common therapy for estrogen deficiency but in other side it will increase the risk of cardiovascular disease. Another alternative therapy which relatively more safe is using phytoestrogen. The Citrus reticulata’s peel contain flavanone and polimethoxyflavone which are suspected to give estrogenic effect, therefore it is potential to be used as phytoestrogen.The purpose of this study was to examine the estrogenic effect of Citrus reticulata’s...

  10. Increases in ‘Candidatus Liberibacter asiaticus’ viability and investigations of biofilm-like structures in citrus juice medium

    OpenAIRE

    Parker, J. K.; Wisotsky, S. R.; Hilf, M E; Sims, K. R.; Cobine, P. A.; de la Fuente, L.

    2014-01-01

    Huanglongbing disease of citrus, associated with infection by the bacterium ‘Candidatus Liberibacter asiaticus’ (LAS), has spread rapidly in the US since 2005. Attempts to culture LAS in vitro have not yielded a consistently reproducible culture method; therefore, obtaining knowledge about the infection process is difficult. To determine conditions which sustain LAS viability, LAS inoculum obtained from seeds of fruit from infected pomelo trees (Citrus grandis ‘Mato Buntan’) was added to diff...

  11. Geographic Distribution of Habitat, Development, and Population Growth Rates of the Asian Citrus Psyllid, Diaphorina citri, in Mexico

    OpenAIRE

    López-Collado, José; Isabel López-Arroyo, J.; Robles-García, Pedro L.; Márquez-Santos, Magdalena

    2013-01-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is an introduced pest in Mexico and a vector of huanglongbing, a lethal citrus disease. Estimations of the habitat distribution and population growth rates of D. citri are required to establish regional and areawide management strategies and can be used as a pest risk analysis tools. In this study, the habitat distribution of D. citri in Mexico was computed with MaxEnt, an inductive, machine-learning program that uses...

  12. Convenient Detection of the Citrus Greening (Huanglongbing) Bacterium ‘Candidatus Liberibacter asiaticus’ by Direct PCR from the Midrib Extract

    OpenAIRE

    Fujikawa, Takashi; Miyata, Shin-ichi; Iwanami, Toru

    2013-01-01

    A phloem-limited bacterium, ‘Candidatus Liberibacter asiaticus’ (Las) is a major pathogen of citrus greening (huanglongbing), one of the most destructive citrus diseases worldwide. The rapid identification and culling of infected trees and budwoods in quarantine are the most important control measures. DNA amplification including conventional polymerase chain reaction (PCR) has commonly been used for rapid detection and identification. However, long and laborious procedures for DNA extraction...

  13. Complex history of admixture during citrus domestication revealed by genome analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wu, G. Albert; Prochnik, Simon; Jenkins, Jerry; Salse, Jerome; Hellsten, Uffe; Murat, Florent; Perrier, Xavier; Ruiz, Manuel; Scalabrin, Simone; Terol, Javier; Takita, Marco Aur& #233; lio,; Labadie, Karine; Poulain, Julie; Couloux, Arnaud; Jabbari, Kamel; Cattonaro, Federica; Fabbro, Cristian Del; Pinosio, Sara; Zuccolo, Andrea; Chapman, Jarrod; Grimwood, Jane; Tadeo, Francisco; Estornell, Leandro H.; Mu?oz-Sanz, Juan V.; Ibanez, Victoria; Herrero-Ortega, Amparo; Aleza, Pablo; P& #233; rez, Juli& #225; n P& #233; rez,; Ramon, Daniel; Brunel, Dominique; Luro, Francois; Chen, Chunxian; Farmerie, William G.; Desany, Brian; Kodira, Chinnappa; Mohiuddin, Mohammed; Harkins, Tim; Fredrikson, Karin; Burns, Paul; Lomsadze, Alexandre; Borodovsky, Mark; Reforgiato, Giuseppe; Freitas-Astua, Juliana; Quetier, Francis; Navarro, Luis; Roose, Mikeal; Wincker, Patrick; Schmutz, Jeremy; Morgante, Michele; Machado, Marcos Antonio; Talon, Manuel; Jaillon, Olivier; Ollitrault, Patrick; Gmitter, Frederick; Rokhsar, Daniel

    2014-06-30

    vulnerable to disease outbreaks, including citrus greening disease (also known as Huanglongbing) that is rapidly spreading throughout the world's major citrus producing regions1. Understanding the population genomics and domestication of citrus will enable strategies for improvements to citrus including resistance to greening and other diseases. The domestication and distribution of edible citrus types began several thousand years ago in Southeast Asia and spread globally following ancient land and sea routes. The lineages that gave rise to most modern cultivated varieties, however, are lost in undocumented antiquity, and their identities remain controversial2, 3. Several features of Citrus biology and cultivation make deciphering these origins difficult. Cultivated varieties are typically propagated clonally by grafting and through asexual seed production (apomixis via nucellar polyembryony) to maintain desirable combinations of traits (Fig. 1). Thus many important cultivar groups have characteristic basic genotypes that presumably arose through interspecific hybridization and/or successive introgressive hybridizations of wild ancestral species. These domestication events predated the global expansion of citrus cultivation by hundreds or perhaps thousands of years, with no record of the domestication process. Diversity within such groups arises through accumulated somatic mutations, generally without sexual recombination, either as limb sports on trees or variants among apomictic seedling progeny. Two wild species are believed to have contributed to domesticated pummelos, mandarins and oranges. Based on morphology and genetic markers, pummelos have generally been identified with the wild species C. maxima (Burm.) Merrill that is indigenous to Southeast Asia. Although mandarins are similarly widely identified with the species C. reticulata Blanco 4-6, wild populations of C. reticulata have not been definitively described. Various authors have taken dif

  14. 7 CFR 319.56-38 - Citrus from Chile.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata Blanco), and tangerines (Citrus reticulata Blanco) may be imported into the United States from Chile,...

  15. Effect of blending Huanglongbing (HLB) disease affected orange juice with juice from healthy oranges on flavor quality

    Science.gov (United States)

    Huanglongbing, or citrus greening disease, has been a concern for the citrus industry as it progressively damages and ultimately kills citrus trees. While this disease does not affect human health, it is associated with bitter off-flavor for orange juice. The objective of this study was to determine...

  16. Cryopreservation and Cryotherapy of Citrus Cultivars

    Science.gov (United States)

    Long-term conservation of Citrus clones can be accomplished by cryopreservation. Shoot tips will survive liquid nitrogen exposure and storage when appropriately desiccated and treated with cryoprotectant solutions. In our research, vegetative Citrus budwood is shipped from Riverside to Fort Collin...

  17. Differences in Stylet Sheath Occurrence and the Fibrous Ring (Sclerenchyma) between xCitroncirus Plants Relatively Resistant or Susceptible to Adults of the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae)

    OpenAIRE

    Ammar, El-Desouky; Richardson, Matthew L.; Abdo, Zaid; David G Hall; Shatters, Robert G

    2014-01-01

    The Asian citrus psyllid (ACP, Diaphorina citri, Hemiptera: Liviidae), is the principal vector of the phloem-limited bacteria strongly associated with huanglongbing (HLB), the world’s most serious disease of citrus. Host plant resistance may provide an environmentally safe and sustainable method of controlling ACP and/or HLB. Two xCitroncirus accessions (hybrids of Poncirus trifoliata and Citrus spp.), that are relatively resistant (UN-3881) or relatively susceptible (Troyer-1459) to ACP adul...

  18. Screening, identification of antagonistic yeast and its biocontrol efficacy against green mold caused by Penicillium digitotum of citrus fruit%柑橘采后绿霉病生防酵母菌的筛选、鉴定及其生防效果研究

    Institute of Scientific and Technical Information of China (English)

    耿鹏; 张彦博; 胡美英; 陈少华; 瞿菲

    2011-01-01

    [Objective]The study focused on isolating and characterizing yeast with abilities to control diseases of citrus fruits, to provide an alternative strategy to control postharvest disease of citrus fruits.[Method]An antagonistic yeast HP-10 was preliminarily identified as Kluyveromyces marsianus based on physiological-biochemical characteristics and the similarity analysis of its 18S rDNA sequence.The efficacy of HP-10 to Penicilluium digitatum in vitro and in vivo was studied by PDB trials and wounding inoculation.[Result]The spore germination of P.digitatum was significantly inhibited by the yeast cell suspensions in the tests on potato dextrose broth (PDB).High efficacy was achieved when fruits were treated with suspension of HP-10 at l08 CFU/mL.Disease incidence was reduced by 84.45% compared with control after 2 days incubation.When antagonistic yeat K.marxianus was treated at a concentration of 108 CFU/mL under 25 ℃ for 2 days,the decay incidence occured by 6.67% and lesion diameter 2.14 mm,while the conrol fruits had 93.33% disease incidence and 53.31 mm lesion diameter.[Conclusion]It was suggested that HP-10 had a great potential to control green mold of citrus fruit,and can be used as a new strategy for the biocontrol of postharvest diseases.%[目的]筛选能有效防治柑橘采后绿霉病菌(Penicillium digitatum)的拮抗酵母菌,为柑橘的采后保鲜提供参考.[方法]从园艺果园采集不同的水果样品,用稀释平板法分离筛选生防酵母菌株,并进行鉴定;采用PDB液体培养试验和刺伤接种的方法,研究不同浓度酵母菌悬浮液对离体和活体柑橘绿霉病菌的防治效果.[结果]获得1株拮抗酵母菌HP-10,结合生理生化特性及18S rDNA序列同源性分析,将其鉴定为马克斯克鲁维酵母(Kluyveromyces marxianus).离体和活体抑菌试验表明,菌株HP-10悬浮液能有效抑制绿霉病菌孢子的萌发;用108 CFU/mL HP-10悬浮液处理病原菌孢子时,其萌发率仅为3

  19. Assessment of the efficiency of essential oils in the preservation of postharvest papaya in an antimicrobial packaging system Avaliação da eficiência de óleos essenciais na preservação pós-colheita de mamão mediante um sistema de embalagem antimicrobiana

    OpenAIRE

    Paula Judith Perez Espitia; Nilda de Fátima Ferreira Soares; Laura Costa Moreira Botti; Nathália Ramos de Melo; Olinto Liparini Pereira; Washington Azevêdo da Silva

    2012-01-01

    Rot and damage caused by post-harvest phytopathogenic fungi affect fruit quality. Essential oils (EO) are considered as an alternative to fungicides. Postharvest diseases of fruits may also be controlled by the bagging approach and the use of antimicrobial packaging. Based on the beneficial properties of EO and the concepts of bagging and antimicrobial packaging, this study aimed to develop sachets containing EO to be used as part of an antimicrobial packaging system. The activities of oregan...

  20. Sugarcane postharvest residue management in a temperate climate

    Science.gov (United States)

    Full retention of sugarcane (interspecific hybrids of Saccharum spp.) post-harvest residue often reduces subsequent ratoon crop yields in Louisiana. Experiments were conducted to determine the effects of different removal methods and removal timings on sugarcane growth and yield and to determine if...

  1. Evaluating strawberry breeding selections for post-harvest fruit decay

    Science.gov (United States)

    The annual replicated yield assessments for the USDA-ARS strawberry breeding effort at Beltsville, MD, 2007 and 2008, were used to develop a method of assessing each genotype’s post-harvest decay. Detectability of statistical differences between genotypes was improved by treating harvest × plot comb...

  2. Postharvest quality of cut roses following electron-beam irradiation

    International Nuclear Information System (INIS)

    Cut Rosa x hybrida L. 'Royalty' flowers were used to determine the efficacy of electron-beam irradiation for increasing postharvest quality and decreasing petal infection by Botrytis cinerea Pers. In an experiment for determining the injury threshold, roses received electron-beam irradiation of 0, 0.5, 1, 2, and 4 kGy. Irradiation dosages greater than or equal to 4 kGy caused necrosis on petal tissue and decreased postharvest life at 20 degrees C. In a second experiment to evaluate postharvest quality, roses were irradiated at 0, 0.25, 0.5, 0.75, and 1 kGy. Dosages of 0.25 and 0.5 kGy slowed the rate of flower bud opening for 2 days but did not decrease postharvest quality when compared with nonirradiated roses. Roses that received irradiation dosages of 0.75 and 1 kGy showed unacceptable quality. In a third experiment, roses that had or had not been inoculated with B. cinerea were irradiated at 0, 0.25, 0.5, and 0.75 kGy. Irradiation did not control B. cinerea populations, and rose quality decreased as dosage increased. In a fourth experiment to determine the effect of irradiation on B. cinerea, conidia on water-agar plates exposed to dosages less than or equal to 1, 2, and 4 kGy germinated at rates of approximately 90%, 33%, and 2%, respectively, within 24 h

  3. Óleos essenciais no controle pós-colheita de Colletotrichum gloeosporioides em mamão Essential oils on postharvest control of Colletotrichum gloeosporioides in papaya fruit

    Directory of Open Access Journals (Sweden)

    P.R. Carnelossi

    2009-01-01

    Full Text Available Os subprodutos de plantas medicinais têm sido estudados como uma alternativa para o controle de doenças de plantas visando amenizar e/ou reduzir o uso abusivo de agrotóxicos, principalmente em condições pós-colheita. Assim, este trabalho teve como objetivo avaliar, in vitro e in vivo, o controle de Colletotrichum gloeosporioides, agente causal da antracnose do mamão em pós-colheita, por óleos essenciais (OEs de Cymbopogon citratus, Eucalyptus citriodora, Mentha arvensis e Artemisia dracunculus. Para inibição do crescimento micelial in vitro, os OEs foram incorporados ao BDA (Batata-dextrose-ágar tendo-se observado a inibição total ou parcial do crescimento micelial e da esporulação deste fitopatógeno, dependendo do óleo essencial utilizado. No ensaio in vivo utilizaram-se os OEs de C. citratus (1% e E. citriodora (1%. A inoculação com o fitopatógeno foi concomitante e 24 h após os tratamentos alternativos, que foram: óleos essenciais de C. citratus e de E. citriodora (1% e biomassa cítrica (150 mL 100 L-1 (Ecolife®. Os parâmetros avaliados foram severidade da doença, redução da massa, diâmetro, comprimento final dos frutos, pH e a concentração de sólidos solúveis totais (ºBrix. Pode-se observar que, no controle da doença, os frutos tratados e imediatamente inoculados com o fitopatógenos apresentaram maior AACPD (Área Abaixo da Curva do Progresso da Doença. Porém, frutos tratados e inoculados 24 h após os tratamentos apresentaram maior controle da doença, confirmando o potencial dos óleos essenciais testados no presente trabalho.The products from medicinal plants have been studied as an alternative in the control of plant diseases in order to mitigate and / or reduce pesticide abuse mainly in postharvest. Thus, the present study aimed to evaluate, in vitro and in vivo, the control of Colletotrichum gloeosporioides, the causative agent of papaya anthracnose, in postharvest using essential oils (EOs of

  4. Comparative Studies of Various Phytonutrients in Citrus Fruits

    Directory of Open Access Journals (Sweden)

    S. Ali

    2014-06-01

    Full Text Available The current piece of research was undertaken to investigate the phytochemicals constituents such as carbohydrates, proteins, alkaloids, anthraquinone, glycosides, Saponin, glycosides, steroid, cyanogenetic glycosides, tannins, phlobotannins, saponins, terpenoids, cardiac glycosides, etc in the species of citrus genus (Citrus sinensis, Citrus reticulate Blanco, Citrus aurantium L. All these plants were collected locally. Qualitative analysis of these phytochemicals was performed. All three types of citrus are rich with phytochemicals. Quantitative screenings is in progress in our lab.

  5. Determinants of Yam Postharvest Management in the Zabzugu District of Northern Ghana

    Directory of Open Access Journals (Sweden)

    Isaac Gershon Kodwo Ansah

    2016-01-01

    Full Text Available Postharvest loss reduction has received attention in many policy documents across nations to ensure global food security, particularly in developing countries. Many researchers have examined various options for reducing postharvest losses. We contribute our quota to this scientific discourse by using a different approach. We argue that the human element of managing postharvest loss is central and therefore poses the question of what are the characteristics of the farmer who manages postharvest losses better. We examine this question by using a cross section of yam farmers in the Zabzugu district in Northern Ghana and generate a proportional variable called postharvest management, which measures how effective a farmer works to reduce storage losses. We then use a fractional logistic regression model to examine the determinants of postharvest management. A significant result is that subsistence farmers manage postharvest losses better than commercial farmers. Characteristically, the farmer who effectively manages postharvest losses is a young, subsistence farmer, living in or close to a district capital with fewer household members, has attained formal education, and produces more yam. Efforts to reduce postharvest losses require the provision of access roads to remote towns or providing effective storage techniques and training on postharvest management practices.

  6. Clues into the metagenome of huanglongbing infected citrus by analysis of ancillary sequences from Ion Torrent whole genome Candidatus Liberibacter asiaticus sequencing

    Science.gov (United States)

    Huanglongbing (HLB) is a globally devastating disease of citrus. Presently, three etiological agents are associated with HLB and include; Candidatus Liberibacter asiaticus (CLas), Candidatus Liberibacter americanus; and Candidatus Liberibacter africanus. Attempts to determine alternate (non-Liberi...

  7. Accumulation of the sesquiterpenes nootkatone and valencene by callus cultures of Citrus paradisi, Citrus limonia and Citrus aurantium.

    Science.gov (United States)

    Del Río, J A; Ortuño, A; Puig, D G; Iborra, J L; Sabater, F

    1991-10-01

    The production of the sesquiterpenes nootkatone and valencene by callus cultures of Citrus species is described. The levels of these compounds were examined by gas chromatography-mass spectrometry and their yields were compared with the amounts found in mature fruits. A simultaneous increase and decrease in the levels of nootkatone and valencene, respectively, were observed with the aging of callus cultures of Citrus paradisi. These results suggest that valencene might be a possible precursor of nootkatone in this species. The high level of nootkatone detected in 9-month-old callus cultures of Citrus paradisi might be associated with the corresponding cell morphological changes observed. PMID:24221735

  8. Signaling pathways in a Citrus EST database

    Directory of Open Access Journals (Sweden)

    Angela Mehta

    2007-01-01

    Full Text Available Citrus spp. are economically important crops, which in Brazil are grown mainly in the State of São Paulo. Citrus cultures are attacked by several pathogens, causing severe yield losses. In order to better understand this culture, the Millenium Project (IAC Cordeirópolis was launched in order to sequence Citrus ESTs (expressed sequence tags from different tissues, including leaf, bark, fruit, root and flower. Plants were submitted to biotic and abiotic stresses and investigated under different development stages (adult vs. juvenile. Several cDNA libraries were constructed and the sequences obtained formed the Citrus ESTs database with almost 200,000 sequences. Searches were performed in the Citrus database to investigate the presence of different signaling pathway components. Several of the genes involved in the signaling of sugar, calcium, cytokinin, plant hormones, inositol phosphate, MAPKinase and COP9 were found in the citrus genome and are discussed in this paper. The results obtained may indicate that similar mechanisms described in other plants, such as Arabidopsis, occur in citrus. Further experimental studies must be conducted in order to understand the different signaling pathways present.

  9. Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers*

    OpenAIRE

    Wang, Rui; Shi, Xue-gen; Wei, You-zhang; Yang, Xiao-e; Uoti, Juhani

    2006-01-01

    Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to study the effects of compound fertilizers on their yields and quality. In the citrus experiment, application of compound fertilizers increased available P, K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg...

  10. Huanglongbing in Texas: Report on the first detections in commercial citrus

    OpenAIRE

    da Graça, J. V.; Kunta, M.; Sétamou, M.; Rascoe, J.; Li, W.; Nakhla, M. K.; Salas, B.; Bartels, D. W.

    2015-01-01

    Huanglongbing (HLB), also known as citrus greening, is a destructive citrus disease associated with 3 α-proteobacteria species of Candidatus Liberibacter. The first report of HLB in the USA was from Florida in 2005 and Ca. L. asiaticus (Las) is the only species currently confirmed in the USA. In January 2012, a Valencia sweet orange tree in a commercial orchard in San Juan, Texas, tested positive for Las by real-time and conventional PCR assays and by the sequence of its partial 16S rRNA gene...

  11. The complete chloroplast genome sequence of Citrus sinensis (L.) Osbeck var 'Ridge Pineapple': organization and phylogenetic relationships to other angiosperms

    OpenAIRE

    Jansen Robert K; Lee Seung-Bum; Singh Nameirakpam D; Bausher Michael G; Daniell Henry

    2006-01-01

    Abstract Background The production of Citrus, the largest fruit crop of international economic value, has recently been imperiled due to the introduction of the bacterial disease Citrus canker. No significant improvements have been made to combat this disease by plant breeding and nuclear transgenic approaches. Chloroplast genetic engineering has a number of advantages over nuclear transformation; it not only increases transgene expression but also facilitates transgene containment, which is ...

  12. Field validation of a greenhouse demonstration of phytohormone-mediated restoration of naturally infected HLB citrus in Florida, Texas and Jamaica

    OpenAIRE

    Woodward, R.; Stoller, J. H.; Liptay, A.; Alvarado, V.

    2014-01-01

    A model system based on restoration of the physiological phytohormone balance in the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las) infected citrus (orange, mercot, tangelo and grapefruit) was evaluated in the field at Ft Meade, FL, Weslaco, TX and Kingston, Jamaica.  We hypothesize that development of Citrus Greening Disease or Huanglongbing (HLB), is the result of the release of latent infection precipitated by phloem blockage, root disease and the demise of the mevalonate...

  13. Comparison of Potato and Asian Citrus Psyllid Adult and Nymph Transcriptomes Identified Vector Transcripts with Potential Involvement in Circulative, Propagative Liberibacter Transmission

    OpenAIRE

    Tonja W. Fisher; Meenal Vyas; Ruifeng He; William Nelson; Joseph M. Cicero; Mark Willer; Ryan Kim; Robin Kramer; Greg A. May; John A. Crow; Soderlund, Carol A.; Gang, David R.; Brown, Judith K.

    2014-01-01

    The potato psyllid (PoP) Bactericera cockerelli (Sulc) and Asian citrus psyllid (ACP) Diaphorina citri Kuwayama are the insect vectors of the fastidious plant pathogen, Candidatus Liberibacter solanacearum (CLso) and Ca. L. asiaticus (CLas), respectively. CLso causes Zebra chip disease of potato and vein-greening in solanaceous species, whereas, CLas causes citrus greening disease. The reliance on insecticides for vector management to reduce pathogen transmission has increased interest in alt...

  14. Evaluating Sustainable Competitive Advantages in Brazilian and U.S. Processed Citrus Supply Chains: An Application of Porter’s Diamond Framework

    OpenAIRE

    Sterns, James A.; Thomas H. Spreen

    2010-01-01

    The processed citrus industries of Sao Paulo, Brazil and Florida, United States collectively account for over 80 percent of world orange juice production. In recent years, both industries have been confronted with serious plant disease outbreaks. Porter’s Diamond framework is used to assess the strenghts and weakness of the processed citrus industry in each country to confront the combined challenge of effectively combating these diseases while maintaining market competitiveness. Althou...

  15. Description of the airflow produced by an air-assisted sprayer during pesticide applications to citrus

    Directory of Open Access Journals (Sweden)

    Ramon Salcedo

    2015-06-01

    Full Text Available Atmospheric drift of plant protection products is considered a major source of air pollution during pesticide applications. Citrus protection against pests and diseases usually requires application of these products using air-blast sprayers. Many authors have emphasized the influence of vegetation on the risk of spray drift. The aim of this work was to describe in detail how the airflow from an air-blast sprayer behaves when it reaches citrus trees and, in particular, the effect that the tree canopy has on this flow. Tests were conducted at a commercial citrus orchard with conventional machinery, placed parallel to a row of trees. Air velocity and direction was measured using a 3D ultrasonic anemometer in 225 points situated in three parallel planes perpendicular to the equipment. The stability of the airflow at each measuring point was studied and the mean velocities were graphically represented. Two vortexes, one behind the canopy, and another over the tree, have been deducted and never been reported before. Both may have an important influence on the trajectories of the sprayed droplets and, as a consequence, on the way in which plant protection products are diffused into the atmosphere. Observed turbulence intensities were higher than in similar experiments conducted in other tree crops, which may be attributable to the higher air volume generated by the machinery used for citrus protection and to the higher foliage density of citrus orchards.

  16. Citrus plant nutritional profile in relation to huanglongbing prevalence in Pakistan

    International Nuclear Information System (INIS)

    Citrus is an important fruit crop in Pakistan that requires proper crop nutrition and disease management strategies as it is a tree crop and withstands harsh seasonal conditions for decades. Huanglongbing (HLB) is a century old, devastating disease of citrus caused by phloem limiting bacteria of the alpha-proteobacteria subdivision. As disease has no known cure, so, effective prevention methods are useful in crop management. Improper crop nutrition impairs plant genetic resistance to invasive pathogens, decreases yield and reduces productive life of the plant. In this study we selected 116 citrus trees from 43 orchard of Punjab for a nutritional assessment. All the trees were showing HLB symptoms and were subjected to NPK and Zn analysis as well as molecular detection of Candidatus L. asiaticus, the pathogen associated with HLB. Nitrogen and Zn were significantly higher (P=0.05) in HLB infected trees. Out of 48 diseased trees, 19, 43 and 27 were deficient in nitrogen, phosphorous and potash, respectively. Our study concludes that there is no relationship between nutritional deficiency status and HLB incidence in citrus; however, nutritional treatments may help in stress relief to infected plants. (author)

  17. An update on the effect of citrus greening on flavor and taste of orange juice

    Science.gov (United States)

    There have been some anecdotal reports that Huanglongbing (HLB) or citrus greening disease, recently introduced in Florida, may impart off flavor to orange juice. It is of interest to the processing industry to determine what affect fruit from trees of various stages of infection would have on proce...

  18. Microbial Production of Pectin from Citrus Peel

    OpenAIRE

    Sakai, Takuo; Okushima, Minoru

    1980-01-01

    A new method for the production of pectin from citrus peel was developed. For this purpose, a microorganism which produces a protopectin-solubilizing enzyme was isolated and identified as a variety of Trichosporon penicillatum. The most suitable conditions for the pectin production were determined as follows. Citrus (Citrus unshiu) peel was suspended in water (1:2, wt/vol), the organism was added, and fermentation proceeded over 15 to 20 h at 30°C. During the fermentation, the pectin in the p...

  19. An in silico analysis of the key genes involved in flavonoid biosynthesis in Citrus sinensis

    Directory of Open Access Journals (Sweden)

    Adriano R. Lucheta

    2007-01-01

    Full Text Available Citrus species are known by their high content of phenolic compounds, including a wide range of flavonoids. In plants, these compounds are involved in protection against biotic and abiotic stresses, cell structure, UV protection, attraction of pollinators and seed dispersal. In humans, flavonoid consumption has been related to increasing overall health and fighting some important diseases. The goals of this study were to identify expressed sequence tags (EST in Citrus sinensis (L. Osbeck corresponding to genes involved in general phenylpropanoid biosynthesis and the key genes involved in the main flavonoids pathways (flavanones, flavones, flavonols, leucoanthocyanidins, anthocyanins and isoflavonoids. A thorough analysis of all related putative genes from the Citrus EST (CitEST database revealed several interesting aspects associated to these pathways and brought novel information with promising usefulness for both basic and biotechnological applications.

  20. AHP choice in cocoa post-harvest technology for small-scale farmers

    OpenAIRE

    Lenin Vera-Montenegro; Amparo Baviera-Puig; Jose-Maria Garcia-Alvarez-Coque

    2014-01-01

    Ensuring that the post-harvest process yields good quality cocoa is a relevant research question. However, the literature currently lacks detailed studies of producers’ criteria for post-harvest technology selection. There is therefore a need for research that examines technology choice based on several criteria. This is the aim of our paper. We defined a cocoa post-harvest technology selection model to assist small producers in Ecuador. To do so, we employed the Analytical Hierarchy Process ...

  1. Principles of Designing and Implementing Agricultural Extension Programs for Reducing Post-harvest Loss

    OpenAIRE

    Paul E. McNamara; Joyous S. Tata

    2015-01-01

    Post-harvest losses represent a significant threat to food security and farmer incomes worldwide. It is an inefficiency in the global food production system that is avoidable. In deducing principles of designing and implementing agricultural extension programs to reduce post-harvest losses, valuable lessons can be gleaned from the handful of previous extension projects and programs addressing post-harvest loss. Abstracting principles from previous experiences and using this to inform future p...

  2. Green Synthesis and Biological Activities of Gold Nanoparticles Functionalized with Citrus reticulata, Citrus aurantium, Citrus sinensis and Citrus grandis

    International Nuclear Information System (INIS)

    In the present study, gold nanoparticles (GNPs) were prepared at boiling temperature (90-95 degree C) by treating gold ions with Citrus fruit extracts. The effect of mixing ratios of the reactants and concentration of gold hydrochloride was studied. In the standardization process, 10/sup -3/ M solution of HAuCl/sub 4/.3H/sub 2/O was reacted with fruit extracts for half an hour at 90-95 degree C in different ratios. GNPs were characterized by UV-Vis spectroscopy (UV-Vis) and atomic force microscopy (AFM). Their stability was evaluated against varying pH solutions and volumes of sodium chloride along with metals and antibiotics sensing ability. The gold nanoparticles were tested for antibacterial and antifungal activities against various pathogenic strains. The UV-Vis spectra of gold nanoparticles gave surface plasmon resonance at about 540 nm while the AFM images revealed the particle size within the range of 70-100 nm. GNPs showed remarkable stability in varying pH solutions and salt volumes as well as high detection ability towards cobalt, copper, ceftriaxone and penicillin. Moreover, the GNPs possessed moderate antibacterial and good antifungal activity. These results concluded that the Citrus fruit extracts can be utilized for large scale synthesis of cost-effective nanoparticles which may have compatibility for biomedical and pharmaceutical applications. (author)

  3. Effectivity of Kaffir lime (Citrus hystrix), Nasnaran Mandarin (Citrus amblycarpa), and Pomelo (Citrus maxima) Leaf Extract Against Aedes aegypti Larvae

    OpenAIRE

    Hebert Adrianto; Subagyo Yotopranoto; Hamidah

    2014-01-01

    The used of chemicals as larvicidal may causing resistance, health problem, and environment problem. Leaf extracts of Citrus as biolarvicidal against Aedes aegypti larvae can be used as an alternative larvicidal. The aims of this study is to find out the species of Citrus in the study sample, which is the most effective as biolarvicidal. This study was conducted using nested experiment design, with six treatments and five replicates. Larvae mortality was observed after 24 and 48 hours. Then, ...

  4. Analysis of 13000 unique Citrus clusters associated with fruit quality, production and salinity tolerance

    Directory of Open Access Journals (Sweden)

    Dossat Carole

    2007-01-01

    Full Text Available Abstract Background Improvement of Citrus, the most economically important fruit crop in the world, is extremely slow and inherently costly because of the long-term nature of tree breeding and an unusual combination of reproductive characteristics. Aside from disease resistance, major commercial traits in Citrus are improved fruit quality, higher yield and tolerance to environmental stresses, especially salinity. Results A normalized full length and 9 standard cDNA libraries were generated, representing particular treatments and tissues from selected varieties (Citrus clementina and C. sinensis and rootstocks (C. reshni, and C. sinenis × Poncirus trifoliata differing in fruit quality, resistance to abscission, and tolerance to salinity. The goal of this work was to provide a large expressed sequence tag (EST collection enriched with transcripts related to these well appreciated agronomical traits. Towards this end, more than 54000 ESTs derived from these libraries were analyzed and annotated. Assembly of 52626 useful sequences generated 15664 putative transcription units distributed in 7120 contigs, and 8544 singletons. BLAST annotation produced significant hits for more than 80% of the hypothetical transcription units and suggested that 647 of these might be Citrus specific unigenes. The unigene set, composed of ~13000 putative different transcripts, including more than 5000 novel Citrus genes, was assigned with putative functions based on similarity, GO annotations and protein domains Conclusion Comparative genomics with Arabidopsis revealed the presence of putative conserved orthologs and single copy genes in Citrus and also the occurrence of both gene duplication events and increased number of genes for specific pathways. In addition, phylogenetic analysis performed on the ammonium transporter family and glycosyl transferase family 20 suggested the existence of Citrus paralogs. Analysis of the Citrus gene space showed that the most

  5. Analysis of 13000 unique Citrus clusters associated with fruit quality, production and salinity tolerance

    Science.gov (United States)

    Terol, Javier; Conesa, Ana; Colmenero, Jose M; Cercos, Manuel; Tadeo, Francisco; Agustí, Javier; Alós, Enriqueta; Andres, Fernando; Soler, Guillermo; Brumos, Javier; Iglesias, Domingo J; Götz, Stefan; Legaz, Francisco; Argout, Xavier; Courtois, Brigitte; Ollitrault, Patrick; Dossat, Carole; Wincker, Patrick; Morillon, Raphael; Talon, Manuel

    2007-01-01

    Background Improvement of Citrus, the most economically important fruit crop in the world, is extremely slow and inherently costly because of the long-term nature of tree breeding and an unusual combination of reproductive characteristics. Aside from disease resistance, major commercial traits in Citrus are improved fruit quality, higher yield and tolerance to environmental stresses, especially salinity. Results A normalized full length and 9 standard cDNA libraries were generated, representing particular treatments and tissues from selected varieties (Citrus clementina and C. sinensis) and rootstocks (C. reshni, and C. sinenis × Poncirus trifoliata) differing in fruit quality, resistance to abscission, and tolerance to salinity. The goal of this work was to provide a large expressed sequence tag (EST) collection enriched with transcripts related to these well appreciated agronomical traits. Towards this end, more than 54000 ESTs derived from these libraries were analyzed and annotated. Assembly of 52626 useful sequences generated 15664 putative transcription units distributed in 7120 contigs, and 8544 singletons. BLAST annotation produced significant hits for more than 80% of the hypothetical transcription units and suggested that 647 of these might be Citrus specific unigenes. The unigene set, composed of ~13000 putative different transcripts, including more than 5000 novel Citrus genes, was assigned with putative functions based on similarity, GO annotations and protein domains Conclusion Comparative genomics with Arabidopsis revealed the presence of putative conserved orthologs and single copy genes in Citrus and also the occurrence of both gene duplication events and increased number of genes for specific pathways. In addition, phylogenetic analysis performed on the ammonium transporter family and glycosyl transferase family 20 suggested the existence of Citrus paralogs. Analysis of the Citrus gene space showed that the most important metabolic pathways known

  6. 2004 SWFWMD Citrus County Lidar Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata record describes the ortho & LIDAR mapping of Citrus County, FL. The mapping consists of LIDAR data collection, contour generation, and production...

  7. Infection Density Dynamics of the Citrus Greening Bacterium “Candidatus Liberibacter asiaticus” in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants

    Science.gov (United States)

    Ukuda-Hosokawa, Rie; Sadoyama, Yasutsune; Kishaba, Misaki; Kuriwada, Takashi; Anbutsu, Hisashi

    2015-01-01

    Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, “Candidatus Liberibacter asiaticus,” and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of “Ca. Liberibacter asiaticus” in field populations of D. citri with experiments using field-collected insects to address how “Ca. Liberibacter asiaticus” infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from “Ca. Liberibacter asiaticus”-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were “Ca. Liberibacter asiaticus” positive. The infections were systemic across head-thorax and abdomen, ranging from 103 to 107 bacteria per insect. In spring, the infection densities were low in March, at ∼103 bacteria per insect, increasing up to 106 to 107 bacteria per insect in April and May, and decreasing to 105 to 106 bacteria per insect in late May, whereas the infection densities were constantly ∼106 to 107 bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with “Ca. Liberibacter asiaticus” infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected “Ca. Liberibacter asiaticus”-infected insects suggested that (i) “Ca. Liberibacter asiaticus”-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼106 bacteria per insect) of “Ca. Liberibacter asiaticus” density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits “Ca. Liberibacter asiaticus” to citrus plants in a stochastic manner. These

  8. Infection Density Dynamics of the Citrus Greening Bacterium "Candidatus Liberibacter asiaticus" in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants.

    Science.gov (United States)

    Ukuda-Hosokawa, Rie; Sadoyama, Yasutsune; Kishaba, Misaki; Kuriwada, Takashi; Anbutsu, Hisashi; Fukatsu, Takema

    2015-06-01

    Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, "Candidatus Liberibacter asiaticus," and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of "Ca. Liberibacter asiaticus" in field populations of D. citri with experiments using field-collected insects to address how "Ca. Liberibacter asiaticus" infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from "Ca. Liberibacter asiaticus"-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were "Ca. Liberibacter asiaticus" positive. The infections were systemic across head-thorax and abdomen, ranging from 10(3) to 10(7) bacteria per insect. In spring, the infection densities were low in March, at ∼ 10(3) bacteria per insect, increasing up to 10(6) to 10(7) bacteria per insect in April and May, and decreasing to 10(5) to 10(6) bacteria per insect in late May, whereas the infection densities were constantly ∼ 10(6) to 10(7) bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with "Ca. Liberibacter asiaticus" infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected "Ca. Liberibacter asiaticus"-infected insects suggested that (i) "Ca. Liberibacter asiaticus"-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼ 10(6) bacteria per insect) of "Ca. Liberibacter asiaticus" density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits "Ca. Liberibacter asiaticus" to citrus plants in a stochastic manner. These findings provide

  9. The aconitate hydratase family from Citrus

    Directory of Open Access Journals (Sweden)

    Cercos Manuel

    2010-10-01

    Full Text Available Abstract Background Research on citrus fruit ripening has received considerable attention because of the importance of citrus fruits for the human diet. Organic acids are among the main determinants of taste and organoleptic quality of fruits and hence the control of fruit acidity loss has a strong economical relevance. In citrus, organic acids accumulate in the juice sac cells of developing fruits and are catabolized thereafter during ripening. Aconitase, that transforms citrate to isocitrate, is the first step of citric acid catabolism and a major component of the citrate utilization machinery. In this work, the citrus aconitase gene family was first characterized and a phylogenetic analysis was then carried out in order to understand the evolutionary history of this family in plants. Gene expression analyses of the citrus aconitase family were subsequently performed in several acidic and acidless genotypes to elucidate their involvement in acid homeostasis. Results Analysis of 460,000 citrus ESTs, followed by sequencing of complete cDNA clones, identified in citrus 3 transcription units coding for putatively active aconitate hydratase proteins, named as CcAco1, CcAco2 and CcAco3. A phylogenetic study carried on the Aco family in 14 plant species, shows the presence of 5 Aco subfamilies, and that the ancestor of monocot and dicot species shared at least one Aco gene. Real-time RT-PCR expression analyses of the three aconitase citrus genes were performed in pulp tissues along fruit development in acidic and acidless citrus varieties such as mandarins, oranges and lemons. While CcAco3 expression was always low, CcAco1 and CcAco2 genes were generally induced during the rapid phase of fruit growth along with the maximum in acidity and the beginning of the acid reduction. Two exceptions to this general pattern were found: 1 Clemenules mandarin failed inducing CcAco2 although acid levels were rapidly reduced; and 2 the acidless "Sucreña" orange

  10. Tomatoes for processing in the 90's: Postharvest handling.

    OpenAIRE

    Ruiz-Altisent, Margarita; Rodriguez del Rincón, Angel

    1990-01-01

    Processing tomato industry has a high potential in Spain. Variety testing and mechanization studies and applications have been performed during the last 15 years. Many factors affect the quality and product losses during post-harvest handling which may be classified as: main or external factors: those related to the systems, procedures and devices; and fruit factors: those related to fruit properties. A research project is being carried on in the area of Vegas del Guadiana (Badajoz, Spain) to...

  11. Thermal control of some post-harvest rot pathogens of Irish potato (solanum tuberosum l.

    Directory of Open Access Journals (Sweden)

    Salami Olusola Abiodun

    2007-01-01

    Full Text Available Thermal control effect on the incidence of some post-harvest rot pathogens of Solanum tuberosum (potato was investigated in this study. Three cultivars of potato tuber whose local names are, Patiska, Mai Bawondoya and Nicola were used for the study. Five pathogenic fungi viz: Botryodiplodia theobromae, Fusarium redolens, Fusarium oxysporum, Penicillium sp. and Rhizopus oryzae associated with post harvest storage rot of root-tubers, were isolated from diseased potatoes. Among the three species of potatoes used in the study, Patiska was found most resistant followed by Mai Bawondoya, while Nicola was the least resistant. Increase in substrate (i.e. soluble starch or CMC concentration enhanced a proportional increase in mycelial growth and in the amount of extracellular enzymes produced. Some of these test pathogens were found to produce cell wall degrading enzymes (i.e. amylase and cellulase. Preferential utilization of carbohydrate sources was established in this study based on the growth of test pathogens. Growth on potato broth medium was highest followed by growth on Cocoyam and Sweet potato broth media and least on Cassava broth medium. Growth of the test pathogens on carbohydrate sources was found at variant. The use of hot water treatment at different temperatures was found to significantly reduce post-harvest fungal populations on the surface of root-tubers. The efficacy of blanching in hot water at 60˚C was significantly higher than that of blanching in hot water at other temperatures. The control method adopted in this study showed that the problems of potatoes’ rot disease in storage (especially by the peasant farmers can be eradicated by thermal treatments without reducing the quality of the Irish tuber.

  12. Potential of Cerbera odollam as a bio-fungicide for post-harvest pathogen Penicilium digitatum

    Science.gov (United States)

    Singh, Harbant; Yin-Chu, Sue; Al-Samarrai, Ghassan; Syarhabil, Muhammad

    2015-05-01

    Postharvest diseases due to fungal infection contribute to economic losses in agriculture industry during storage, transportation or in the market. Penicillium digitatum is one of the common pathogen responsible for the postharvest rot in fruits. This disease is currently being controlled by synthetic fungicides such as Guazatine and Imazalil. However, heavy use of fungicides has resulted in environmental pollution, such as residue in fruit that expose a significant risk to human health. Therefore, there is a strong need to develop alternatives to synthetic fungicide to raise customer confidence. In the current research, different concentrations (500 to 3000 ppm) of ethanol extract of Cerbera odollam or commonly known as Pong-pong were compared with Neem and the controls (Positive control/Guazatine; Negative control/DMSO) for the anti-fungicide activity in PDA media contained in 10 cm diameter Petri dishes, using a modification of Ruch and Worf's method. The toxicity (Lc50) of the C.odollam extract was determined by Brine-shrimp test (BST). The results of the research indicated that crude extraction from C.odollam showed the highest inhibition rate (93%) and smallest colony diameter (0.63 cm) at 3000 ppm in vitro compared with Neem (inhibition rate: 88%; colony diameter: 1.33 cm) and control (Positive control/Guazatine inhibition rate: 79%, colony diameter: 1.9 cm; Negative control/DMSO inhibition rate: 0%, colony diameter: 9.2 cm). C.odollam recorded Lc50 value of 5 µg/ml which is safe but to be used with caution (unsafe level: below 2 µg/ml). The above anti-microbial activity and toxicity value results indicate that C.odollam has a potential of being a future bio-fungicide that could be employed as an alternative to synthetic fungicide.

  13. Characterization of the Asian Citrus Psyllid Transcriptome

    OpenAIRE

    Reese, Justin; Christenson, Matthew K.; Leng, Nan; Saha, Surya; Cantarel, Brandi; Lindeberg, Magdalen; Tamborindeguy, Cecilia; MacCarthy, Justin; Weaver, Daniel; Trease, Andrew J.; Ready, Steven V.; Davis, Vincent M.; McCormick, Courtney; Haudenschild, Christian; Han, Shunsheng

    2014-01-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is a vector for the causative agents of Huanglongbing, which threatens citrus production worldwide. This study reports and discusses the first D. citri transcriptomes, encompassing the three main life stages of D. citri, egg, nymph and adult. The transcriptomes were annotated using Gene Ontology (GO) and insecticide-related genes within each life stage were identified to aid the development of future D. citri insectici...

  14. Post-harvest handling and storage of mangoes - an overview

    International Nuclear Information System (INIS)

    Mango fruit is an important agricultural commodity in the global trade and economy of its producing countries. Of late, there is a growing demand for the traditional varieties of mango in the Western markets. However, it is yet to realize its maximum potential as a tradable commodity due to its localized production and its potential markets located across the globe. Post-harvest losses in mangoes have been estimated in the range of 25 to 40% from harvesting to consumption stage. If proper methods of harvesting, handling, transportation and storage are adopted, such losses could be minimized. Hence, to tap its potential to the fullest, there is a need to adopt technologies and strategies to ensure a longer post-harvest shelf-life and longer transportation times. There are several technologies, like low temperature and other associated technologies such as controlled atmosphere (CA)/modified atmosphere (MA) storage, hypobaric storage, irradiated storage and storage in chemicals and by coatings. It is also essential that post-harvest operations like grading, packaging and precooling are adopted, to enhance the efficiency of the preservation techniques. Before adopting any of the preservation techniques, it is necessary to evaluate the relative merits and constraints of the respective technologies and adopt the most appropriate technology based on its techno-economic feasibility. In this paper different techniques for handling and storage of mangoes have been critically reviewed and discussed. (author)

  15. Phyllosticta citriasiana sp nov., the cause of Citrus tan spot of Citrus maxima in Asia

    NARCIS (Netherlands)

    Wulandari, N.F.; To-anun, C.; Hyde, K.D.; Duong, L.M.; de Gruyter, J.; Meffert, J.P.; Groenewald, J.Z.; Crous, P.W.

    2009-01-01

    Guignardia citricarpa, the causal agent of Citrus Black Spot, is subject to phytosanitary legislation in the European Union and the U.S.A. This species is frequently confused with G. mangiferae, which is a non-pathogenic, and is commonly isolated as an endophyte from citrus fruits and a wide range o

  16. Phyllosticta citriasiana sp. nov., the cause of Citrus tan spot of Citrus maxima in Asia

    NARCIS (Netherlands)

    Wulandari, N.F.; To-anun, C.; Hyde, K.D.; Duong, L.M.; Gruyter, de J.; Meffert, J.P.; Groenewald, J.Z.; Crous, P.W.

    2009-01-01

    Guignardia citricarpa, the causal agent of Citrus Black Spot, is subject to phytosanitary legislation in the European Union and the U.S.A. This species is frequently confused with G. mangiferae, which is a non-pathogenic, and is commonly isolated as an endophyte from citrus fruits and a wide range o

  17. Detection of non-typhoid Salmonella infection by citrus and citrus extracts in Lao PDR

    Institute of Scientific and Technical Information of China (English)

    Yutaka Midorikawa; Satoshi Nakamura; Rattanaphone Phetsouvanh; Manivanh Vongsouvaht; Kaoru Midorikawa

    2010-01-01

    Objective: To know the current state of non-typhoid Salmonella infection in Laos. To examine the usefulness of new screening methods for Salmonella using citrus. Methods: Non-typhoidSalmonella infection of person in Lao PDR was studied in this research (2004-2009). The site was Vientiane capital city in 2004. Research from rural villages locating suburb of Vientiane during 2005-2008 was carried out. Rural villages in Attapu province where ethnic minorities were living was searched for this study in 2009. During this research, to detect Salmonella strain, a new method using citrus and citrus extract named MY phenomenon that observing black ring (MIDO ring) on DHL agar was tried. The slice lemon and lime were used for this trial in 2004. After 2005, disk of ascorbic acid and citric acid were used for the device instead of citrus fruits itself. Results: During this research, 65 of 272 human samples (23.9%) were infected with non-typhoid Salmonella. Conclusions: During this study, the method using citrus and citrus extracts was accepted for the detection of Salmonella. This study shows that with citrus and citrus extract, detection of Salmonella is possible using only DHL media. Results suggest that infectious rate of non-typhoid Salmonella was high.

  18. Evaluation of natural colorants and their application on citrus fruit as alternatives to citrus red II

    Science.gov (United States)

    The poor peel color of some varieties of oranges and the hybrids, especially for early season fruits, is caused by the subtropical climate of Florida, and has resulted in the use of a red dye on the peel to improve fruit appearance and marketability. Citrus Red II (CR2), the commercial citrus color ...

  19. The effects of inter-crop cultivation Between rows of citrus crop on spreading of Guignardia citricarpa Ascospores and in the citrus black spot occurrence

    Directory of Open Access Journals (Sweden)

    José Antonio Miranda Bellotte

    2013-03-01

    Full Text Available This study highlighted the effect of planting coast-cross grass and forage peanut cv. Amarilis between rows of Natal oranges on spreading of Guignardia citricarpa ascospores and consequent citrus black spot control. Treatments evaluated were: 1- conventional cultivation, free of fungicides; 2- conventional cultivation, using protective fungicides; 3- inter-crop cultivation of coast-cross grass between rows of citrus crops and; 4- inter-cropping cultivation of forage peanut between the rows of citrus crops. Quest Volumetric Spore SystemTM traps were set in order to determine the number of ascospores released. A total of 33 inspections were conducted weekly, from the end of August until early September the following year. A diagrammatic scale was used to determine the severity of the disease as well as the percentage of fruits having a commercial standard. The coast-cross grass was more effective in reducing the number of ascospores produced, whose average statistics were lower than in the conventional treatments, free-fungicides. The inter-crop and conventional cultivation method coupled with fungicide treatment was more effective in reducing the severity of citrus black spot symptoms, and differs statistically from the fungicide-free control method. These methods also resulted in a higher percentage of fruits of a commercial standard, ranging from the 89% through the 91% percentile, and the cultivation, free of fungicides, fell within the 73%.

  20. The Composition, Antioxidant and Antibacterial Activities of Cold-Pressed and Distilled Essential Oils of Citrus paradisi and Citrus grandis (L.) Osbeck

    Science.gov (United States)

    Ou, Ming-Chiu; Liu, Yi-Hsin; Sun, Yung-Wei; Chan, Chin-Feng

    2015-01-01

    The chemical composition and functional activities of cold-pressed and water distilled peel essential oils of Citrus paradisi (C. paradisi) and Citrus grandis (L.) Osbeck (C. grandis) were investigated in present study. Yields of cold-pressed oils were much higher than those of distilled oils. Limonene was the primary ingredient of essential oils of C. paradisi (cold 92.83%; distilled 96.06%) and C. grandis (cold 32.63%; distilled 55.74%). In addition, C. grandis oils obtained were rich in oxygenated or nitrogenated compounds which may be involved in reducing cardiovascular diseases or enhancing sleep effectiveness. The order of free radical scavenging activities of 4 citrus oils was distilled C. paradisi oil > cold-pressed C. paradisi oil > distilled C. grandis oil > cold-pressed C. grandis oil. Cold-pressed C. grandis oil exhibited the lowest activity in all antioxidative assays. The order of antimicrobial activities of 4 citrus oils was distilled C. grandis oil, cold-pressed C. paradisi oil > distilled C. paradisi oil > cold-pressed C. paradisi oil. Surprisingly, distilled C. grandis oil exhibited better antimicrobial activities than distilled C. paradisi oil, especially against Escherichia coli and Salmonella enterica subsp. The results also indicated that the antimicrobial activities of essential oils may not relate to their antioxidative activities. PMID:26681970

  1. The Composition, Antioxidant and Antibacterial Activities of Cold-Pressed and Distilled Essential Oils of Citrus paradisi and Citrus grandis (L.) Osbeck.

    Science.gov (United States)

    Ou, Ming-Chiu; Liu, Yi-Hsin; Sun, Yung-Wei; Chan, Chin-Feng

    2015-01-01

    The chemical composition and functional activities of cold-pressed and water distilled peel essential oils of Citrus paradisi (C. paradisi) and Citrus grandis (L.) Osbeck (C. grandis) were investigated in present study. Yields of cold-pressed oils were much higher than those of distilled oils. Limonene was the primary ingredient of essential oils of C. paradisi (cold 92.83%; distilled 96.06%) and C. grandis (cold 32.63%; distilled 55.74%). In addition, C. grandis oils obtained were rich in oxygenated or nitrogenated compounds which may be involved in reducing cardiovascular diseases or enhancing sleep effectiveness. The order of free radical scavenging activities of 4 citrus oils was distilled C. paradisi oil > cold-pressed C. paradisi oil > distilled C. grandis oil > cold-pressed C. grandis oil. Cold-pressed C. grandis oil exhibited the lowest activity in all antioxidative assays. The order of antimicrobial activities of 4 citrus oils was distilled C. grandis oil, cold-pressed C. paradisi oil > distilled C. paradisi oil > cold-pressed C. paradisi oil. Surprisingly, distilled C. grandis oil exhibited better antimicrobial activities than distilled C. paradisi oil, especially against Escherichia coli and Salmonella enterica subsp. The results also indicated that the antimicrobial activities of essential oils may not relate to their antioxidative activities. PMID:26681970

  2. The Composition, Antioxidant and Antibacterial Activities of Cold-Pressed and Distilled Essential Oils of Citrus paradisi and Citrus grandis (L. Osbeck

    Directory of Open Access Journals (Sweden)

    Ming-Chiu Ou

    2015-01-01

    Full Text Available The chemical composition and functional activities of cold-pressed and water distilled peel essential oils of Citrus paradisi (C. paradisi and Citrus grandis (L. Osbeck (C. grandis were investigated in present study. Yields of cold-pressed oils were much higher than those of distilled oils. Limonene was the primary ingredient of essential oils of C. paradisi (cold 92.83%; distilled 96.06% and C. grandis (cold 32.63%; distilled 55.74%. In addition, C. grandis oils obtained were rich in oxygenated or nitrogenated compounds which may be involved in reducing cardiovascular diseases or enhancing sleep effectiveness. The order of free radical scavenging activities of 4 citrus oils was distilled C. paradisi oil > cold-pressed C. paradisi oil > distilled C. grandis oil > cold-pressed C. grandis oil. Cold-pressed C. grandis oil exhibited the lowest activity in all antioxidative assays. The order of antimicrobial activities of 4 citrus oils was distilled C. grandis oil, cold-pressed C. paradisi oil > distilled C. paradisi oil > cold-pressed C. paradisi oil. Surprisingly, distilled C. grandis oil exhibited better antimicrobial activities than distilled C. paradisi oil, especially against Escherichia coli and Salmonella enterica subsp. The results also indicated that the antimicrobial activities of essential oils may not relate to their antioxidative activities.

  3. Fighting HLB with Citrus tristeza virus (CTV): Heterogeneity in the genome ends of CTV is an important consideration

    Science.gov (United States)

    As California prepares for a potential showdown with Huanglongbing (HLB), contemporary disease control strategies that use low inputs, yet produce high value control, are needed to manage the disease. With biotechnology, Citrus tristeza virus (CTV) may be developed into a tool for protection or trea...

  4. Deciphering the Bacterial Microbiome in Huanglongbing-Affected Citrus Treated with Thermotherapy and Sulfonamide Antibiotics.

    Science.gov (United States)

    Yang, Chuanyu; Powell, Charles A; Duan, Yongping; Shatters, Robert; Fang, Jingping; Zhang, Muqing

    2016-01-01

    Huanglongbing (HLB) is a serious citrus disease that threatens the citrus industry. In previous studies, sulfonamide antibiotics and heat treatment suppressed 'Candidatus Liberibacter asiaticus' (Las), but did not completely eliminate the Las. Furthermore, there are few reports studying the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics. In this study, combinations of heat (45°C or 40°C) and sulfonamide treatment (sulfathiazole sodium-STZ, or sulfadimethoxine sodium-SDX) were applied to HLB-affected citrus. The bacterial microbiome of HLB-affected citrus following thermotherapy and/or chemotherapy was characterized by PhyloChipTMG3-based metagenomics. Our results showed that the combination of thermotherapy at 45°C and chemotherapy with STZ and SDX was more effective against HLB than thermotherapy alone, chemotherapy alone, or a combination of thermotherapy at 40°C and chemotherapy. The PhyloChipTMG3-based results indicated that 311 empirical Operational Taxonomic Units (eOTUs) were detected in 26 phyla. Cyanobacteria (18.01%) were dominant after thermo-chemotherapy. Thermotherapy at 45°C decreased eOTUs (64.43%) in leaf samples, compared with thermotherapy at 40°C (73.96%) or without thermotherapy (90.68%) and it also reduced bacterial family biodiversity. The eOTU in phylum Proteobacteria was reduced significantly and eOTU_28, representing "Candidatus Liberibacter," was not detected following thermotherapy at 45°C. Following antibiotic treatment with SDX and STZ, there was enhanced abundance of specific eOTUs belonging to the families Streptomycetaceae, Desulfobacteraceae, Chitinophagaceae, and Xanthomonadaceae, which may be implicated in increased resistance to plant pathogens. Our study further develops an integrated strategy for combating HLB, and also provides new insight into the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics. PMID:27171468

  5. Deciphering the Bacterial Microbiome in Huanglongbing-Affected Citrus Treated with Thermotherapy and Sulfonamide Antibiotics.

    Directory of Open Access Journals (Sweden)

    Chuanyu Yang

    Full Text Available Huanglongbing (HLB is a serious citrus disease that threatens the citrus industry. In previous studies, sulfonamide antibiotics and heat treatment suppressed 'Candidatus Liberibacter asiaticus' (Las, but did not completely eliminate the Las. Furthermore, there are few reports studying the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics. In this study, combinations of heat (45°C or 40°C and sulfonamide treatment (sulfathiazole sodium-STZ, or sulfadimethoxine sodium-SDX were applied to HLB-affected citrus. The bacterial microbiome of HLB-affected citrus following thermotherapy and/or chemotherapy was characterized by PhyloChipTMG3-based metagenomics. Our results showed that the combination of thermotherapy at 45°C and chemotherapy with STZ and SDX was more effective against HLB than thermotherapy alone, chemotherapy alone, or a combination of thermotherapy at 40°C and chemotherapy. The PhyloChipTMG3-based results indicated that 311 empirical Operational Taxonomic Units (eOTUs were detected in 26 phyla. Cyanobacteria (18.01% were dominant after thermo-chemotherapy. Thermotherapy at 45°C decreased eOTUs (64.43% in leaf samples, compared with thermotherapy at 40°C (73.96% or without thermotherapy (90.68% and it also reduced bacterial family biodiversity. The eOTU in phylum Proteobacteria was reduced significantly and eOTU_28, representing "Candidatus Liberibacter," was not detected following thermotherapy at 45°C. Following antibiotic treatment with SDX and STZ, there was enhanced abundance of specific eOTUs belonging to the families Streptomycetaceae, Desulfobacteraceae, Chitinophagaceae, and Xanthomonadaceae, which may be implicated in increased resistance to plant pathogens. Our study further develops an integrated strategy for combating HLB, and also provides new insight into the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics.

  6. Deciphering the Bacterial Microbiome in Huanglongbing-Affected Citrus Treated with Thermotherapy and Sulfonamide Antibiotics

    Science.gov (United States)

    Powell, Charles A.; Duan, Yongping; Shatters, Robert; Fang, Jingping; Zhang, Muqing

    2016-01-01

    Huanglongbing (HLB) is a serious citrus disease that threatens the citrus industry. In previous studies, sulfonamide antibiotics and heat treatment suppressed ‘Candidatus Liberibacter asiaticus’ (Las), but did not completely eliminate the Las. Furthermore, there are few reports studying the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics. In this study, combinations of heat (45°C or 40°C) and sulfonamide treatment (sulfathiazole sodium–STZ, or sulfadimethoxine sodium—SDX) were applied to HLB-affected citrus. The bacterial microbiome of HLB-affected citrus following thermotherapy and/or chemotherapy was characterized by PhyloChipTMG3-based metagenomics. Our results showed that the combination of thermotherapy at 45°C and chemotherapy with STZ and SDX was more effective against HLB than thermotherapy alone, chemotherapy alone, or a combination of thermotherapy at 40°C and chemotherapy. The PhyloChipTMG3-based results indicated that 311 empirical Operational Taxonomic Units (eOTUs) were detected in 26 phyla. Cyanobacteria (18.01%) were dominant after thermo-chemotherapy. Thermotherapy at 45°C decreased eOTUs (64.43%) in leaf samples, compared with thermotherapy at 40°C (73.96%) or without thermotherapy (90.68%) and it also reduced bacterial family biodiversity. The eOTU in phylum Proteobacteria was reduced significantly and eOTU_28, representing “Candidatus Liberibacter,” was not detected following thermotherapy at 45°C. Following antibiotic treatment with SDX and STZ, there was enhanced abundance of specific eOTUs belonging to the families Streptomycetaceae, Desulfobacteraceae, Chitinophagaceae, and Xanthomonadaceae, which may be implicated in increased resistance to plant pathogens. Our study further develops an integrated strategy for combating HLB, and also provides new insight into the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics. PMID:27171468

  7. Citrus nobiletin suppresses inducible nitric oxide synthase gene expression in interleukin-1β-treated hepatocytes

    International Nuclear Information System (INIS)

    Highlights: •Nobiletin is a polymethoxylated flavone that is abundant in citrus peels. •Nobiletin is a major constituent of the Citrus unshiu peel extract. •Nobiletin suppresses induction of NO and reduces iNOS expression in hepatocytes. •Nobiletin reduces the iNOS promoter activity and the DNA-binding activity of NF-κB. -- Abstract: Background: Nobiletin is a polymethoxylated flavone that is abundant in the peels of citrus fruits, such as Citrus unshiu (Satsuma mandarin) and Citrus sinensis. The dried peels of C. unshiu (chinpi) have been included in several formulae of Japanese Kampo medicines. Nobiletin may suppress the induction of inducible nitric oxide synthase (iNOS), which synthesizes the inflammatory mediator nitric oxide (NO) in hepatocytes. Methods: A C. unshiu peel (CUP) extract was prepared. Primary cultured rat hepatocytes were treated with the CUP extract or nobiletin in the presence of interleukin 1β (IL-1β), which induces iNOS expression. NO production and iNOS gene expression were analyzed. Results: High-performance liquid chromatography analyses revealed that the nobiletin content in the CUP extract was 0.14%. Nobiletin dose-dependently reduced the NO levels and decreased iNOS expression at the protein, mRNA and antisense transcript levels. Flavone, which does not contain any methoxy groups, also suppressed iNOS induction. Nobiletin reduced the transcriptional activity of iNOS promoter-luciferase constructs and the DNA-binding activity of nuclear factor κB (NF-κB) in the nuclei. Conclusions: The suppression of iNOS induction by nobiletin suggests that nobiletin may be responsible for the anti-inflammatory effects of citrus peels and have a therapeutic potential for liver diseases

  8. Citrus nobiletin suppresses inducible nitric oxide synthase gene expression in interleukin-1β-treated hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Yoshigai, Emi [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Machida, Toru [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okuyama, Tetsuya [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Mori, Masatoshi; Murase, Hiromitsu; Yamanishi, Ryota [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okumura, Tadayoshi [Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga (Japan); Department of Surgery, Kansai Medical University, Hirakata, Osaka (Japan); Ikeya, Yukinobu [Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga (Japan); Nishino, Hoyoku [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Department of Biochemistry, Kyoto Prefectural University of Medicine, Kyoto (Japan); Nishizawa, Mikio, E-mail: nishizaw@sk.ritsumei.ac.jp [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan)

    2013-09-13

    Highlights: •Nobiletin is a polymethoxylated flavone that is abundant in citrus peels. •Nobiletin is a major constituent of the Citrus unshiu peel extract. •Nobiletin suppresses induction of NO and reduces iNOS expression in hepatocytes. •Nobiletin reduces the iNOS promoter activity and the DNA-binding activity of NF-κB. -- Abstract: Background: Nobiletin is a polymethoxylated flavone that is abundant in the peels of citrus fruits, such as Citrus unshiu (Satsuma mandarin) and Citrus sinensis. The dried peels of C. unshiu (chinpi) have been included in several formulae of Japanese Kampo medicines. Nobiletin may suppress the induction of inducible nitric oxide synthase (iNOS), which synthesizes the inflammatory mediator nitric oxide (NO) in hepatocytes. Methods: A C. unshiu peel (CUP) extract was prepared. Primary cultured rat hepatocytes were treated with the CUP extract or nobiletin in the presence of interleukin 1β (IL-1β), which induces iNOS expression. NO production and iNOS gene expression were analyzed. Results: High-performance liquid chromatography analyses revealed that the nobiletin content in the CUP extract was 0.14%. Nobiletin dose-dependently reduced the NO levels and decreased iNOS expression at the protein, mRNA and antisense transcript levels. Flavone, which does not contain any methoxy groups, also suppressed iNOS induction. Nobiletin reduced the transcriptional activity of iNOS promoter-luciferase constructs and the DNA-binding activity of nuclear factor κB (NF-κB) in the nuclei. Conclusions: The suppression of iNOS induction by nobiletin suggests that nobiletin may be responsible for the anti-inflammatory effects of citrus peels and have a therapeutic potential for liver diseases.

  9. Maturity and Postharvest Performance of US Early Pride Seedless Mandarins

    Science.gov (United States)

    This article describes efforts underway at the US Horticultural Laboratory, Ft. Pierce, FL to develop seedless versions of seedy, but otherwise high quality citrus scions. Two approaches for development of seedless scions are discussed: 1) irradiation which has resulted in the release of 'US Seedle...

  10. Dietary citrus pulp reduces lipid oxidation in lamb meat

    OpenAIRE

    Inserra, L.; Priolo, A.; L. Biondi; Lanza, M.; Bognanno, M.; Gravador, R.; Luciano, G.

    2014-01-01

    This study investigated the effect of replacing cereal concentrateswith high levels of dried citrus pulp in the diet on lamb meat oxidative stability. Over 56 days, lambs were fed a barley-based concentrate (Control) or concentrates inwhich 24% and 35% dried citrus pulpwere included to partially replace barley (Citrus 24% and Citrus 35%, respectively). Meat was aged under vacuum for 4 days and subsequently stored aerobically at 4 °C. The Control diet increased the redness, yellowness and satu...

  11. Whitefly Pest Species (Homoptera: Aleyrodidae) on Citrus Trees

    OpenAIRE

    Katja Žanić; Sonja Kačić; Miro Katalinić

    2000-01-01

    Today, the Citrus whitefly, Dialeurodes citri (Ashmead), is a very important pest on all Citrus species throughout the citrus growing areas in Croatia. It causes direct damage by sucking the plant juice from the leaves. Furthermore, immatures excrete honeydew that stimulates sooy mold. The presence of sooty mold on contaminated leaves interferes with the photosynthesis of plants. Citrus fruits coated by sooty mold lose its market value. Because Dialeurodes citri is poorly known in Croatia, th...

  12. Selection efficiency for raspberry postharvest shelf life affected by storage temperature and harvest season

    Science.gov (United States)

    Improved postharvest quality is an important goal for fresh-market raspberry breeding programs. To determine if warm or cold storage following harvest would better facilitate the breeding selection process for the assessment of postharvest decay and bleed, pesticide-free fruit from cultivars and bre...

  13. Extension of Small-Scale Postharvest Horticulture Technologies—A Model Training and Services Center

    Directory of Open Access Journals (Sweden)

    Lisa Kitinoja

    2015-07-01

    Full Text Available A pilot Postharvest Training and Services Center (PTSC was launched in October 2012 in Arusha, Tanzania as part of a United States Agency for International Development (USAID funded project. The five key components of the PTSC are (1 training of postharvest trainers, (2 postharvest training and demonstrations for local small-scale clientele, (3 adaptive research, (4 postharvest services, and (5 retail sales of postharvest tools and supplies. During the years of 2011–2012, a one year e-learning program was provided to 36 young horticultural professionals from seven Sub-Saharan African countries. These postharvest specialists went on to train more than 13,000 local farmers, extension workers, food processors, and marketers in their home countries in the year following completion of their course. Evaluators found that these specialists had trained an additional 9300 people by November 2014. When asked about adoption by their local trainees, 79% reported examples of their trainees using improved postharvest practices. From 2012–2013, the project supported 30 multi-day training programs, and the evaluation found that many of the improved practices being promoted were adopted by the trainees and led to increased earnings. Three PTSC components still require attention. Research activities initiated during the project are incomplete, and successful sales of postharvest goods and services will require commitment and improved partnering.

  14. Metabolomics analysis of postharvest ripening heterogeneity of ‘Hass' avocadoes

    NARCIS (Netherlands)

    Pedreschi, R.; Munoz, P.; Robledo, P.; Becerra, C.; Defilippi, B.G.; Eekelen, van H.D.L.M.; Mumm, R.; Westra, E.H.; Vos, de R.C.H.

    2014-01-01

    The complex physiology of ‘Hass’ avocado renders its postharvest ripening heterogeneous and unpre-dictable. Several approaches have previously been undertaken to broaden our understanding of the causesof this postharvest ripening heterogeneity but without much success. In this study, a fruit biopsy

  15. Salmonella surveillance and control at post-harvest in the Belgian pork meat chain.

    Science.gov (United States)

    Delhalle, L; Saegerman, C; Farnir, F; Korsak, N; Maes, D; Messens, W; De Sadeleer, L; De Zutter, L; Daube, G

    2009-05-01

    Salmonella remains the primary cause of reported bacterial food borne disease outbreaks in Belgium. Pork and pork products are recognized as one of the major sources of human salmonellosis. In contrast with the primary production and slaughterhouse phases of the pork meat production chain, only a few studies have focussed on the post-harvest stages. The goal of this study was to evaluate Salmonella and Escherichia coli contamination at the Belgian post-harvest stages. E. coli counts were estimated in order to evaluate the levels of faecal contamination. The results of bacteriological analysis from seven cutting plants, four meat-mincing plants and the four largest Belgian retailers were collected from official and self-monitoring controls. The prevalence of Salmonella in the cutting plants and meat-mincing plants ranged from 0% to 50%. The most frequently isolated serotype was Salmonella typhimurium. The prevalence in minced meat at retail level ranged from 0.3% to 4.3%. The levels of Salmonella contamination estimated from semi-quantitative analysis of data relating to carcasses, cuts of meat and minced meat were equal to -3.40+/-2.04 log CFU/cm(2), -2.64+/-1.76 log CFU/g and -2.35+/-1.09 log CFU/g, respectively. The E. coli results in meat cuts and minced meat ranged from 0.21+/-0.50 to 1.23+/-0.89 log CFU/g and from 1.33+/-0.58 to 2.78+/-0.43 log CFU/g, respectively. The results showed that faecal contamination still needs to be reduced, especially in specific individual plants. PMID:19269567

  16. Characterizing the citrus variety Carrizo genome through 454 shotgun sequencing

    Science.gov (United States)

    Citrus production is of global importance both in economic impact and significance to nutrition. The number of natural citrus species appears extremely limited. The genome size is small (haploid approximately 367 Mb), arranged on 18 chromosomes. The citrus variety Carrizo, generated by a ‘Washingt...

  17. Evaluation of natural colorants and their application on citrus fruit

    Science.gov (United States)

    Warm temperatures can often result in poor peel color of some citrus varieties, especially early in the harvest season. Under these conditions, Florida oranges, temples, tangelos, and K-Early citrus fruit are allowed to be treated with Citrus Red No.2 (CR2) to help produce a more acceptable peel col...

  18. Thirty years of citrus tristeza virus observations in Peru

    Science.gov (United States)

    The Peruvian citrus industry was devastated by epidemics of Citrus tristeza virus (CTV) decline (CTV-D) on sour orange rootstock between 1950 and 1965 and CTV stem pitting (SP) between 1965 and 1985. CTV-SP debilitates citrus and fruit production regardless of rootstock. Control of CTV-SP by mild st...

  19. Efficacy of plant-derived pesticides in the control of myco-induced postharvest rots of tubers and agricultural products: A review

    Directory of Open Access Journals (Sweden)

    D. N. Enyiukwu

    2014-02-01

    Full Text Available The most important losses in agricultural production which involve the greatest costs on the farm economy occur postharvest. It is estimated that worldwide between 10 and 40% losses of agricultural produce occur postharvest. Losses are more severe in developing than developed nations of the world. Several species of fungi and in some cases bacteria participate in postharvest deterioration and rots of tubers and agro-produce. These include species of Aspergillus, Fusarium, Colletotrichum, Macrophomina, Penicillium and Rhizopus amongst several others. In a bid to control these storage diseases several control techniques including physical, biological, and chemical and in recent times plant-based pesticides are employed. Chemical control has been identified as the most popular and most effective means of controlling plant diseases. However, it is being de-emphasized due largely to mammalian toxicity occasioned by chemical residues in crops. This in addition to many other demerits on ecological health and build-up of pathogens’ resistance to some of the most effective fungicides have prompted search for alternatives. Recently in plant pathology many tropical plants are being screened for fungitoxic properties. This review presents highlights of the different control techniques and emphasized the efficacy of plant-based pesticides for control of myco-induced storage rots of tubers and agricultural products in the tropics.

  20. Effective antibiotics against 'Candidatus Liberibacter asiaticus' in HLB-affected citrus plants identified via the graft-based evaluation.

    Directory of Open Access Journals (Sweden)

    Muqing Zhang

    Full Text Available Citrus huanglongbing (HLB, caused by three species of fastidious, phloem-limited 'Candidatus Liberibacter', is one of the most destructive diseases of citrus worldwide. To date, there is no established cure for this century-old and yet, newly emerging disease. As a potential control strategy for citrus HLB, 31 antibiotics were screened for effectiveness and phytotoxicity using the optimized graft-based screening system with 'Candidatus Liberibacter asiaticus' (Las-infected citrus scions. Actidione and Oxytetracycline were the most phytotoxic to citrus with less than 10% of scions surviving and growing; therefore, this data was not used in additional analyses. Results of principal component (PCA and hierarchical clustering analyses (HCA demonstrated that 29 antibiotics were clustered into 3 groups: highly effective, partly effective, and not effective. In spite of different modes of actions, a number of antibiotics such as, Ampicillin, Carbenicillin, Penicillin, Cefalexin, Rifampicin and Sulfadimethoxine were all highly effective in eliminating or suppressing Candidatus Liberibacter asiaticus indicated by both the lowest Las infection rate and titers of the treated scions and inoculated rootstock. The non-effective group, including 11 antibiotics alone with three controls, such as Amikacin, Cinoxacin, Gentamicin, Kasugamycin, Lincomycin, Neomycin, Polymixin B and Tobramycin, did not eliminate or suppress Las in the tested concentrations, resulting in plants with increased titers of Las. The other 12 antibiotics partly eliminated or suppressed Las in the treated and graft-inoculated plants. The effective and non-phytotoxic antibiotics could be potential candidates for control of citrus HLB, either for the rescue of infected citrus germplasm or for restricted field application.

  1. Effects of Chitin and Its Derivative Chitosan on Postharvest Decay of Fruits: A Review

    Directory of Open Access Journals (Sweden)

    Weimin Liu

    2011-01-01

    Full Text Available Considerable economic losses to harvested fruits are caused by postharvest fungal decay during transportation and storage, which can be significantly controlled by synthetic fungicides. However, considering public concern over pesticide residues in food and the environment, there is a need for safer alternatives for the control of postharvest decay to substitute synthetic fungicides. As the second most abundant biopolymer renewable source in nature, chitin and its derivative chitosan are widely used in controlling postharvest decay of fruits. This review aims to introduce the effect of chitin and chitosan on postharvest decay in fruits and the possible modes of action involved. We found most of the actions discussed in these researches rest on physiological mechanisms. All of the mechanisms are summarized to lay the groundwork for further studies which should focus on the molecular mechanisms of chitin and chitosan in controlling postharvest decay of fruits.

  2. Effect of Cyantraniliprole, a Novel Insecticide, on the Inoculation of Candidatus Liberibacter Asiaticus Associated with Citrus Huanglongbing by the Asian Citrus Psyllid (Hemiptera: Liviidae).

    Science.gov (United States)

    Ammar, El-Desouky; Hall, David G; Alvarez, Juan M

    2015-04-01

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is the principal vector of 'Candidatus Liberibacter asiaticus' (CLas) associated with huanglongbing (HLB), the most serious citrus disease worldwide. New control measures including pesticides are urgently needed to combat HLB, especially to protect young or newly planted citrus trees from CLas-inoculation by vector psyllids. Here, we tested CLas-inoculation by D. citri adults (CLas-exposed, reared on infected plants) by feeding them for 7 d on excised healthy citrus leaves with dry residues of cyantraniliprole (Exirel), a novel insecticide, in comparison with fenpropathrin (Danitol 2.4EC), an insecticide commonly used against D. citri. Fewer adults settled (putatively feeding or probing) on leaves treated with cyantraniliprole than those treated with fenpropathrin or water controls. Also, psyllid adults died at a slower rate on leaves treated with cyantraniliprole than those treated with fenpropathrin, although the final cumulative mortality did not differ between the two treatments. In quantitative real-time polymerase chain reaction tests, 59.0-65.3% of the CLas-exposed psyllid adults were proven to be CLas-positive. Inoculation rates of CLas (using 10 adults per leaf) into untreated healthy citrus leaves (47.5-85%) were significantly higher than rates into leaves treated with cyantraniliprole or fenpropathrin (2.5-12.5%). Reduced inoculation rates to leaves treated with cyantraniliprole probably occurred as a result of reduced feeding or probing by D. citri. The excised leaf assay method, which took only a few weeks compared with up to a year or longer using whole plants, can be an effective tool for testing the effect of new pesticides or other treatments in reducing CLas inoculation or transmission by psyllid vectors. PMID:26470150

  3. Clues into the metagenome of Huanglongbing infected Citrus by analysis of ancillary sequences from Ion Torrent whole genome Candidatus Liberibacter asiaticus sequencing

    OpenAIRE

    Morgan, J K; Shatters, R. G.; Stover, E; Duan, Y. P.; Moore, G. A.; Powell, C A; Jarra-Cavieres, A.; Clark, S

    2014-01-01

    Huanglongbing (HLB) is a globally devastating disease of citrus.  Presently, three etiological agents are associated with HLB and include; Candidatus Liberibacter asiaticus (CLas), Candidatus Liberibacter americanus; and Candidatus Liberibacter africanus.  Attempts to determine alternate (non-Liberibacter) associated etiological agents of HLB have been performed, namely by metagenomic analyses with HLB phenotypic citrus of phloem tissue isolated from bark [1] and whole leaf midribs [2].  Thes...

  4. Innate and Conditioned Responses to Chemosensory and Visual Cues in Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae), Vector of Huanglongbing Pathogens

    OpenAIRE

    Joseph M. Patt; Dara Stockton; Meikle, William G; Mamoudou Sétamou; Agenor Mafra-Neto; Adamczyk, John J.

    2014-01-01

    Asian citrus psyllid (Diaphorina citri) transmits Huanglongbing, a devastating disease that threatens citrus trees worldwide. A better understanding of the psyllid’s host-plant selection process may lead to the development of more efficient means of monitoring it and predicting its movements. Since behavioral adaptations, such as associative learning, may facilitate recognition of suitable host-plants, we examined whether adult D. citri could be conditioned to visual and chemosensory stimuli ...

  5. Evidence of Recombinant Citrus tristezavirus Isolate Occurring in Acid Lime cv. Pant Lemon Orchard in Uttarakhand Terai Region of Northern Himalaya in India

    OpenAIRE

    Singh, Jaywant Kumar; Tarafdar, Avijit; Sharma, Susheel Kumar; Biswas, Kajal Kumar

    2012-01-01

    The present study for the first time describes biological and molecular characterization of Citrus tristeza virus (CTV) occurring in the Terai area of Uttarakhand State in Northern Himalaya region of India. Direct antigen coated-ELISA and reverse transcriptase-polymerase chain reaction (RT-PCR) detected the CTV infection in Acid lime cv. Pant lemon (Citrus aurantifolia) orchards of Pantnagar with an estimated disease incidence of 16.6–20.5 %. To know the biological and genetic properties, an ...

  6. Biological control of toxigenic citrus and papaya-rotting fungi by Streptomyces violascens MT7 and its extracellular metabolites.

    Science.gov (United States)

    Choudhary, Bharti; Nagpure, Anand; Gupta, Rajinder K

    2015-12-01

    An Indian indigenous, Loktak Lake soil isolate Streptomyces violascens MT7 was assessed for its biocontrol potential both in vitro and in vivo against toxigenic fruit-rotting fungi. Strain MT7 exhibited broad-spectrum antifungal activity against various pathogenic postharvest fungi of citrus and papaya. In shake-flask fermentation, antagonist S. violascens MT7 highly produced extracellular antifungal metabolites in early stationary growth phase in glucose-yeast extract-malt extract (M93) broth. Both extracellular culture fluid (ECF) and its n-butanol extract showed significant broad-spectrum fungal mycelial inhibition of several tested fruit-rotting fungi. Antifungal metabolite was found to be heat stable, nonpeptidic, and polyene type antibiotic. The lowest minimum inhibitory concentration (MIC) of n-butanol extract against Colletotrichum gloeosporioides MTCC 9664 and Aspergillus niger MTCC 281 was 0.0312 and 0.0625 mg/ml, respectively. Purification of n-butanol extract through silica gel chromatography resulted in partial purification of bioactive metabolite and the TLC autobiography revealed the presence of single antifungal metabolite with Rf value of 0.755. In vivo bioassays demonstrated the biocontrol potential of tested biocontrol agents on fruit-rotting fungi. Use of cell suspension of S. violascens MT7, extracellular metabolite(s), and n-butanol extract significantly (p < 0.05) reduced sour-rot development on Citrus reticulata Blanco (oranges) and soft-rot development on papaya fruits. Therefore, these results strongly suggest a high potential for application of S. violascens MT7 and its extracellular metabolites as an effective eco-friendly alternative to synthetic fungicides for controlling toxigenic citrus and papaya-rotting fungi. PMID:26214840

  7. Does citrus leaf miner impair hydraulics and fitness of citrus host plants?

    Science.gov (United States)

    Raimondo, Fabio; Trifilò, Patrizia; Gullo, Maria A Lo

    2013-12-01

    Gas exchange and hydraulic features were measured in leaves of three different Citrus species (Citrus aurantium L., Citrus limon L., Citrus  ×  paradisii Macfad) infested by Phyllocnistis citrella Staiton, with the aim to quantify the impact of this pest on leaf hydraulics and, ultimately, on plant fitness. Infested leaves were characterized by the presence on the leaf blade of typical snake-shaped mines and, in some cases, of a crumpled leaf blade. Light microscopy showed that leaf crumpling was induced by damage to the cuticular layer. In all three Citrus species examined: (a) the degree of infestation did not exceed 10% of the total surface area of infested plants; (b) control and infested leaves showed similar values of minimum diurnal leaf water potential, leaf hydraulic conductance and functional vein density; and (c) maximum diurnal values of stomatal conductance to water vapour, transpiration rate and photosynthetic rate (An) were similar in both control leaves and the green areas of infested leaves. A strong reduction of An was recorded only in mined leaf areas. Our data suggest that infestation with P. citrella does not cause conspicuous plant productivity reductions in young Citrus plants, at least not in the three Citrus species studied here. PMID:24319027

  8. 海洋放线菌A3202的分离鉴定及其对柑橘采后病害的防效%Isolation and identification of marine actinomyces A3202 and its control efficacy against postharvest citrus diseases

    Institute of Scientific and Technical Information of China (English)

    鹿连明; 杜丹超; 程保平; 胡秀荣; 陈国庆

    2014-01-01

    为获得用于防治柑橘采后病害的海洋放线菌,以柑橘青霉病菌Penicillium italicum、柑橘绿霉病菌P.digitatum和柑橘炭疽病菌Colletotrichum gloeosporioides为指示菌,对分离到的25株海洋放线菌进行筛选.通过平板对峙法测定拮抗菌株的抑菌谱,并测定其发酵产物粗提物对柑橘果实采后病害的防效,根据形态特征、培养特征、生理生化特征及16S rDNA序列对其进行鉴定.结果表明,分离自鳞笠藤壶Tetraclita squamosa的菌株A3202对3种指示菌均具有强抑菌活性,对供试13种植物病原菌的菌丝生长具有不同程度的抑制作用,尤其对柑橘青霉病菌和柑橘绿霉病菌的抑制作用最强,抑菌带宽度分别可达2.33±0.05 cm和2.32±0.10cm.该菌株800 mg/L粗提物溶液对接种后7d的柑橘青霉病、柑橘绿霉病和柑橘炭疽病的相对防效均可达100%.初步鉴定该菌株为放线菌中的米修链霉菌Streptomyces misionensis.

  9. Evaluation of natural colorants and their application on citrus fruit as alternatives to Citrus Red No. 2

    Science.gov (United States)

    Warm field temperatures can often result in poor peel color of some citrus varieties, especially early in the harvest season. Under these conditions, Florida oranges, temples, tangelos, and K-Early citrus fruit are allowed to be treated with Citrus Red No.2 (CR2) to help produce a more acceptable pe...

  10. Foliar application of biofilm formation-inhibiting compounds enhances control of citrus canker caused by Xanthomonas citri subsp. citri.

    Science.gov (United States)

    Li, Jinyun; Wang, Nian

    2014-02-01

    Citrus canker caused by the bacterium Xanthomonas citri subsp. citri is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of X. citri subsp. citri on host leaves. In this study, we assessed the hypothesis that small molecules inhibiting biofilm formation reduce X. citri subsp. citri infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by X. citri subsp. citri on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in X. citri subsp. citri. In laboratory experiments, planktonic and biofilm cells of X. citri subsp. citri treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated. In greenhouse assays, D-leucine and IAN applied alone or combined with copper reduced both the number of canker lesions and bacterial populations of X. citri subsp. citri on citrus host leaves. This study provides the basis for the use of foliar-applied biofilm inhibitors for the control of citrus canker alone or combined with copper-based bactericides. PMID:23901828

  11. Seed transmission of Candidatus Liberibacter asiaticus in periwinkle and dodder resulted in low bacterial titer and very mild disease in periwinkle

    Science.gov (United States)

    Canadidatus Liberibacter asiaticus (Las) is the most widely-distributed of three species of Liberibacter that are associated with citrus Huanglongbing (HLB), a lethal disease of citrus worldwide. In addition to citrus, periwinkle (Catharanthus roseus) and dodder (Cuscuta pentagona) are two experime...

  12. Inhibitory effect of some spice essential oils on Penicillium digitatum causing postharvest rot in citrus

    OpenAIRE

    Akgül, Attila; Özcan, Musa; Yigit, Fahri

    2000-01-01

    In this study to control blue mould caused by Penicillium digitatum, essential oil of cumin was applied with filter paper discs of 6 mm diameter which were soaked in 0,04 ml oil and vapour effect inhibited completely mycelial growth and spore germination of pathogen in vitro. When filter paper discs soaked in essential oils of black thyme, dill, coriander and rosemary were placed on the culture medium (PDA), they had no effect on the mycelial growth. Their vapour effect inhibited mycelial gro...

  13. Past and future of a century old Citrus tristeza virus collectionA California citrus germplasm tale

    Directory of Open Access Journals (Sweden)

    Jinbo eWang

    2013-12-01

    Full Text Available Citrus tristeza virus (CTV isolates collected from citrus germplasm, dooryard and field trees in California from 1914 have been maintained in planta under quarantine in the Citrus Clonal Protection Program (CCPP, Riverside, California. This collection, therefore, represents populations of CTV isolates obtained over time and space in California. To determine CTV genetic diversity in this context, genotypes of CTV isolates from the CCPP collection were characterized using multiple molecular markers (MMM. Genotypes T30, VT, and T36 were found at high frequencies with T30 and T30+VT genotypes being the most abundant. The MMM analysis did not identify T3 and B165/T68 genotypes; however, biological and phylogenetic analysis suggested some relationships of CCPP CTV isolates with these two genotypes. Phylogenetic analysis of the CTV coat protein gene sequences classified the tested isolates into seven distinct clades. Five clades were in association with the standard CTV genotypes T30, T36, T3, VT, and B165/T68. The remaining two identified clades were not related to any standard CTV genotypes. Spatiotemporal analysis indicated a trend of reduced genotype and phylogenetic diversity as well as virulence from southern California at early (1907-1957 in comparison to that of central California isolates collected from later (1957-2009 time periods. CTV biological characterization also indicated a reduced number and less virulent stem pitting (SP CTV isolates compared to seedling yellows isolates introduced to California. This data provides a historical insight of the introduction, movement, and genetic diversity of CTV in California and provides genetic and biological information useful for CTV quarantine, eradication, and disease management strategies such as CTV-SP cross protection.

  14. Postharvest technologies for mangosteen (Garcinia mangostana L.) conservation

    OpenAIRE

    Maria Fernanda Pontes Penteado Moretzsohn de Castro; Valéria Delgado de Almeida Anjos; Ana Carolina Bortolossi Rezende; Eliane Aparecida Benato; Silvia Regina de Toledo Valentini

    2012-01-01

    The application of technologies to extend the postharvest life of mangosteen fruit was studied and compared to storage at 25 °C/70-75%R.H (25 °C control treatment). The fruits were packed in expanded polystyrene (EPS) trays (5 fruits/tray). Five treatments were carried out at 13 °C/ 90-95% RH: application of carnauba wax coating, lecithin + CMC (carboxymethyl cellulose) coating, 50 µm LDPE (low density polyethylene) film coating, 13 µm PVC (Polyvinyl chloride), and non-coated sample (13 °C co...

  15. Post-harvest losses of fish in the tropics

    OpenAIRE

    Ames, Geoff; Clucas, Ivor; Paul, Susan Scott

    1991-01-01

    Huge quantities of fish are lost after capture. This is an enormous waste of food, especially in the Third World, where much fish production is on a small scale, and where high temperatures make spoilage much more rapid. The situation is increasingly serious, at a time when the world's demand for fish is increasing, yet fishery resources are already under very heavy pressure. This publication seeks to explain just what the 'post-harvest' losses are, and the steps which can be taken to reduce ...

  16. Hyperspectral reflectance imaging for detecting citrus canker based on dual-band ratio image classification method

    Science.gov (United States)

    Li, Jiangbo; Rao, Xiuqin; Guo, Junxian; Ying, Yibin

    2010-10-01

    Citrus are one of the major fruit produced in China. Most of this production is exported to Europe for fresh consumption, where consumers increasingly demand best quality. Citrus canker is one of the most devastating diseases that threaten peel of most commercial citrus varieties. The aim of this research was to investigate the potential of using hyperspectral imaging technique for detecting canker lesions on citrus fruit. Navel oranges with cankerous, normal and various common diseased skin conditions including wind scar, thrips scarring, scale insect, dehiscent fruit, phytotoxicity, heterochromatic stripe, and insect damage were studied. The imaging system (400-1000 nm) was established to acquire reflectance images from samples. Region of interest (ROI) spectral feature of various diseased peel areas was analyzed and characteristic wavebands (630, 685, and 720 nm) were extracted. The dual-band reflectance ratio (such as Q720/685) algorithm was performed on the hyperspectral images of navel oranges for differentiating canker from normal fruit skin and other surface diseases. The overall classification success rate was 96.84% regardless of the presence of other confounding diseases. The presented processing approach overcame the presence of stem/navel on navel oranges that typically has been a problematic source for false positives in the detection of defects. Because of the limited sample size, delineation of an optimal detection scheme is beyond the scope of the current study. However, the results showed that two-band ratio (Q685/630) along with the use of a simple threshold value segmentation method for discriminating canker on navel oranges from other peel diseases may be feasible.

  17. Plant extracts for controlling the post-harvest anthracnose of banana fruit

    Directory of Open Access Journals (Sweden)

    M.E.S. Cruz

    2013-01-01

    Full Text Available In banana, fruit rot is incited by Colletotrichum musae which has been the most serious post-harvest disease of immature and mature fruit. The usual control by fungicides prohibited in many countries reduces their commercial value. Therefore, two experiments were conducted to evaluate the antimicrobial activity of alternative products to the synthetic fungicides. First, berries naturally infected by anthracnose were immersed into Azadirachta indica and citric extracts at 2 and 4% (v/v for 3 minutes and stored for 11 days under environmental conditions. Next, other berries were immersed into essential oil emulsions of Allium sativum, Copaifera langsdorfii, Cinnamomum zeylanicum and Eugenia caryophyllata at 5% for 3 minutes but stored for 11 days. Berries immersed into distilled water were used as control-treatments. The percentage of disease incidence observed in the control-treatment was similar to the ones observed in the extract of A. indica at 2%. The control-treatment showed disease severity of 75.13% and the percentage of disease control was 20.85%. Fruit immersed into distilled water presented less effectiveness than the ones immersed into citric extracts, which promoted the highest effectiveness. Citric extract at 4% was the most efficient treatment because the disease incidence was 19.44%, the disease severity was 9.34% and the disease control was 90.16%. Less severity and, consequently, more disease control were achieved by immersing the berries into the emulsion of essential oil of A. sativum, followed by treatments with C. langsdorfii, E. caryophyllata and C. zeylanicum.

  18. Efeito dos compostos naturais bioativos na conservação pós-colheita de frutos de mangueira cv. Tommy Atkins Effects of bioactive natural compounds on the postharvest conservation of mango fruits cv. Tommy Atkins

    Directory of Open Access Journals (Sweden)

    Maria Julia da Silva Cruz

    2010-04-01

    Full Text Available A antracnose causa severos danos na pós-colheita de manga. Como o controle químico tem demonstrado desvantagens, o potencial uso de óleos essenciais para o controle de fitopatógenos tem sido uma alternativa. Neste trabalho, objetvou-se avaliar a eficácia de produtos alternativos no controle da antracnose e na conservação de mangas (Mangifera indica cv. Tommy Atkins tratado com bicarbonato de sódio diluído em água destilada, na concentração de 3% (v/v, via imersão. Como tratamento, foram utilizados os óleos essenciais de Origanum majorana, Citrus sinensis, Cymbopogon citratus e Eucalyptus citriodora, via fumigação, na dosagem de 1000 μL e água destilada via fumigação; todos por 3 minutos. Frutos da Unidade CEASA-Maringá/PR, selecionados, pesados em balança semianalítica, desinfetados em imersão por 3 minutos em solução de hipoclorito de sódio a 0,5% (v/v; foram submetidos aos tratamentos, permanecendo sob condições ambientes (26 ± 2ºC e UR 90 ± 5%. Exceto o tratamento com Citrus sinensis, que proporcionou um pH maior do que a testemunha, diferindo significativamente dos demais tratamentos que elevaram a variável. A redução da acidez em todos os tratamentos e aumentos dos sólidos solúveis totais nos frutos, sendo que o tratamento com bicarbonato de sódio proporcionou 14,42 ºBrix. O número de frutos com antracnose foi menor no tratamento com Citrus sinensis e este diferiu dos demais comprovando o efeito de espécies do gênero Citrus como antifúngicos. O uso de óleos essenciais como o de Citrus sinensis controlou a antracnose e manteve a qualidade dos frutos.The anthracnose causes severe damages to the mango post-harvest. As chemical control has shown disadvantages, the potential of use of essential oils has been an alternative for the phytopathogen control. The objective of the present work was to evaluate the efficacy of alternative products in the anthracnose control and in the conservation of mangos

  19. Noninvasive maturity detection of citrus with machine vision

    Science.gov (United States)

    Ying, Yibin; Xu, Zhenggang; Fu, Xiaping; Liu, Yande

    2004-03-01

    A computer vision system was established to explore a method for citrus maturity detection. The surface color information and the ratio of total soluble solid to titratable acid (TSS/TA) were used as maturity indexes of citrus. The spectral reflectance properties with different color were measured by UV-240 ultraviolet and visible spectrophotometer. The biggest discrepancy of gray levels between citrus pixels and background pixels was in blue component image by image background segmentation. Dynamic threshold method for background segmentation had best result in blue component image. Methods for citrus image color description were studied. The citrus spectral reflectance experiments showed that green surface and saffron surface of citrus were of highest spectral reflectance at the wavelength of 700nm, the difference between them reached to maximum, about 53%, and the image acquired at this wavelength was of more color information for maturity detection. A triple-layer feed forward network was established to map citrus maturity from the hue frequency sequence by the mean of artificial neural network. After training, the network mapper was used to detect the maturity of the test sample set, which was composed of 252 Weizhang citrus with different maturity. The identification accuracy of mature citrus reached 79.1%, that of immature citrus was 63.6%, and the mean identification accuracy was 77.8%. This study suggested that it is feasible to detect citrus maturity non-invasively by using the computer vision system and hue frequency sequence method.

  20. Next generation haplotyping to decipher nuclear genomic interspecific admixture in Citrus species: analysis of chromosome 2

    OpenAIRE

    Curk, Franck; Ancillo, Gema; Garcia-Lor, Andres; Luro, François; Perrier, Xavier; Jacquemoud-Collet, Jean-Pierre; Navarro, Luis; Ollitrault, Patrick

    2014-01-01

    Background The most economically important Citrus species originated by natural interspecific hybridization between four ancestral taxa (Citrus reticulata, Citrus maxima, Citrus medica, and Citrus micrantha) and from limited subsequent interspecific recombination as a result of apomixis and vegetative propagation. Such reticulate evolution coupled with vegetative propagation results in mosaic genomes with large chromosome fragments from the basic taxa in frequent interspecific heterozygosity....

  1. 7 CFR 457.107 - Florida citrus fruit crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ... of the following: (1) Citrus I—Early and mid-season oranges; (2) Citrus II—Late oranges juice; (3) Citrus III—Grapefruit for which freeze damage will be adjusted on a juice basis; (4) Citrus IV—Tangelos...; or (2) The following juice content, if acceptable records are not furnished: (i) Citrus I—52...

  2. Genome-wide identification of sweet orange (Citrus sinensis histone modification gene families and their expression analysis during the fruit development and fruit-blue mold infection process

    Directory of Open Access Journals (Sweden)

    Jidi eXu

    2015-08-01

    Full Text Available In eukaryotes, histone acetylation and methylation have been known to be involved in regulating diverse developmental processes and plant defense. These histone modification events are controlled by a series of histone modification gene families. To date, there is no study regarding genome-wide characterization of histone modification related genes in citrus species. Based on the two recent sequenced sweet orange genome databases, a total of 136 CsHMs (Citrus sinensis histone modification genes, including 47 CsHMTs (histone methyltransferase genes, 23 CsHDMs (histone demethylase genes, 50 CsHATs (histone acetyltransferase genes, and 16 CsHDACs (histone deacetylase genes were identified. These genes were categorized to 11 gene families. A comprehensive analysis of these 11 gene families was performed with chromosome locations, phylogenetic comparison, gene structures and conserved domain compositions of proteins. In order to gain an insight into the potential roles of these genes in citrus fruit development, 42 CsHMs with high mRNA abundance in fruit tissues were selected to further analyze their expression profiles at six stages of fruit development. Interestingly, a numbers of genes were expressed highly in flesh of ripening fruit and some of them showed the increasing expression levels along with the fruit development. Furthermore, we analyzed the expression patterns of all 136 CsHMs response to the infection of blue mold (Penicillium digitatum, which is the most devastating pathogen in citrus postharvest process. The results indicated that 20 of them showed the strong alterations of their expression levels during the fruit-pathogen infection. In conclusion, this study presents a comprehensive analysis of the histone modification gene families in sweet orange and further elucidates their behaviors during the fruit development and the blue mold infection responses.

  3. Genome-wide identification of sweet orange (Citrus sinensis) histone modification gene families and their expression analysis during the fruit development and fruit-blue mold infection process.

    Science.gov (United States)

    Xu, Jidi; Xu, Haidan; Liu, Yuanlong; Wang, Xia; Xu, Qiang; Deng, Xiuxin

    2015-01-01

    In eukaryotes, histone acetylation and methylation have been known to be involved in regulating diverse developmental processes and plant defense. These histone modification events are controlled by a series of histone modification gene families. To date, there is no study regarding genome-wide characterization of histone modification related genes in citrus species. Based on the two recent sequenced sweet orange genome databases, a total of 136 CsHMs (Citrus sinensis histone modification genes), including 47 CsHMTs (histone methyltransferase genes), 23 CsHDMs (histone demethylase genes), 50 CsHATs (histone acetyltransferase genes), and 16 CsHDACs (histone deacetylase genes) were identified. These genes were categorized to 11 gene families. A comprehensive analysis of these 11 gene families was performed with chromosome locations, phylogenetic comparison, gene structures, and conserved domain compositions of proteins. In order to gain an insight into the potential roles of these genes in citrus fruit development, 42 CsHMs with high mRNA abundance in fruit tissues were selected to further analyze their expression profiles at six stages of fruit development. Interestingly, a numbers of genes were expressed highly in flesh of ripening fruit and some of them showed the increasing expression levels along with the fruit development. Furthermore, we analyzed the expression patterns of all 136 CsHMs response to the infection of blue mold (Penicillium digitatum), which is the most devastating pathogen in citrus post-harvest process. The results indicated that 20 of them showed the strong alterations of their expression levels during the fruit-pathogen infection. In conclusion, this study presents a comprehensive analysis of the histone modification gene families in sweet orange and further elucidates their behaviors during the fruit development and the blue mold infection responses. PMID:26300904

  4. Detection of Anomalies in Citrus Leaves Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Sankaran, Sindhuja; Ehsani, Reza; Morgan, Kelly T

    2015-08-01

    Nutrient assessment and management are important to maintain productivity in citrus orchards. In this study, laser-induced breakdown spectroscopy (LIBS) was applied for rapid and real-time detection of citrus anomalies. Laser-induced breakdown spectroscopy spectra were collected from citrus leaves with anomalies such as diseases (Huanglongbing, citrus canker) and nutrient deficiencies (iron, manganese, magnesium, zinc), and compared with those of healthy leaves. Baseline correction, wavelet multivariate denoising, and normalization techniques were applied to the LIBS spectra before analysis. After spectral pre-processing, features were extracted using principal component analysis and classified using two models, quadratic discriminant analysis and support vector machine (SVM). The SVM resulted in a high average classification accuracy of 97.5%, with high average canker classification accuracy (96.5%). LIBS peak analysis indicated that high intensities at 229.7, 247.9, 280.3, 393.5, 397.0, and 769.8 nm were observed of 11 peaks found in all the samples. Future studies using controlled experiments with variable nutrient applications are required for quantification of foliar nutrients by using LIBS-based sensing. PMID:26163130

  5. Metabolite signature of Candidatus Liberibacter asiaticus infection in two citrus varieties.

    Science.gov (United States)

    Chin, Elizabeth L; Mishchuk, Darya O; Breksa, Andrew P; Slupsky, Carolyn M

    2014-07-16

    Huanglongbing (HLB), also known as Citrus Greening Disease, is caused by the bacterium 'Candidatus Liberibacter asiaticus' (CLas) and is a serious threat to the citrus industry. To understand the effect of CLas infection on the citrus metabolome, juice from healthy (n = 18), HLB-asymptomatic (n = 18), and HLB-symptomatic Hamlin (n = 18), as well as from healthy (n = 18) and HLB-symptomatic (n = 18) Valencia sweet oranges (from southern and eastern Florida) were evaluated using (1)H NMR-based metabolomics. Differences in the concentration of several metabolites including phenylalanine, histidine, limonin, and synephrine between control or asymptomatic fruit and symptomatic fruit were observed regardless of the citrus variety or location. There were no clear differences between the metabolite profiles of Hamlin fruits classified by PCR as asymptomatic and control, suggesting that some of the control fruit may have been infected. Taken together, these data indicate that infection due to CLas presents a strong metabolic response that is observed across different cultivars and regions, suggesting the potential for generation of metabolite-based biomarkers of CLas infection. PMID:24959841

  6. Odorants for Surveillance and Control of the Asian Citrus Psyllid (Diaphorina citri)

    Science.gov (United States)

    Coutinho-Abreu, Iliano V.; Forster, Lisa; Guda, Tom; Ray, Anandasankar

    2014-01-01

    Background The Asian Citrus Psyllid (ACP), Diaphorina citri, can transmit the bacterium Candidatus Liberibacter while feeding on citrus flush shoots. This bacterium causes Huanglongbing (HLB), a major disease of citrus cultivation worldwide necessitating the development of new tools for ACP surveillance and control. The olfactory system of ACP is sensitive to variety of odorants released by citrus plants and offers an opportunity to develop new attractants and repellents. Results In this study, we performed single-unit electrophysiology to identify odorants that are strong activators, inhibitors, and prolonged activators of ACP odorant receptor neurons (ORNs). We identified a suite of odorants that activated the ORNs with high specificity and sensitivity, which may be useful in eliciting behavior such as attraction. In separate experiments, we also identified odorants that evoked prolonged ORN responses and antagonistic odorants able to suppress neuronal responses to activators, both of which can be useful in lowering attraction to hosts. In field trials, we tested the electrophysiologically identified activating odorants and identified a 3-odor blend that enhances trap catches by ∼230%. Conclusion These findings provide a set of odorants that can be used to develop affordable and safe odor-based surveillance and masking strategies for this dangerous pest insect. PMID:25347318

  7. Characterization of Basidiomycetes associated with wood rot of citrus in southern Italy.

    Science.gov (United States)

    Roccotelli, Angela; Schena, Leonardo; Sanzani, Simona M; Cacciola, Santa O; Mosca, Saveria; Faedda, Roberto; Ippolito, Antonio; di San Lio, Gaetano Magnano

    2014-08-01

    The characterization of Basidiomycetes associated with wood rots in commercial citrus orchards in southern Italy revealed that both white and brown rot fungi are implicated in this disease. Fomitiporia mediterranea was the most prevalent species causing a white rot, followed by Fomitopsis sp. which, by contrast, was associated with brown rot wood decay. Furthermore, Phellinus spp. and other nonidentified basidiomycetous fungi showing genetic affinity with the genera Phellinus and Coniophora were occasionally isolated. Artificial inoculations on lemon (Citrus limon) branches showed a faster wood colonization by Fomitopsis sp. compared with F. mediterranea, indicating that the former species as a potentially serious pathogen of citrus trees. The analysis of F. mediterranea internal transcribed spacer (ITS) sequences revealed a high level of genetic variability, with 13 genotypes which were both homozygous (6 genotypes) and heterozygous (7 genotypes). The presence of heterozygous genomes based on ITS sequences has never been reported before for F. mediterranea. This, together with the high frequency of basidiomata on infected wood, unambiguously confirms the outcrossing nature of reproduction in F. mediterranea and the primary role of basidiospores in the dissemination of inoculum. Similarly, high genetic variability was observed analyzing Fomitopsis sp. Because basidiomata of this fungus have not been observed on citrus trees, it can be hypothesized that basidiospores are produced on alternative host plants. PMID:24502208

  8. Odorants for surveillance and control of the Asian Citrus Psyllid (Diaphorina citri.

    Directory of Open Access Journals (Sweden)

    Iliano V Coutinho-Abreu

    Full Text Available BACKGROUND: The Asian Citrus Psyllid (ACP, Diaphorina citri, can transmit the bacterium Candidatus Liberibacter while feeding on citrus flush shoots. This bacterium causes Huanglongbing (HLB, a major disease of citrus cultivation worldwide necessitating the development of new tools for ACP surveillance and control. The olfactory system of ACP is sensitive to variety of odorants released by citrus plants and offers an opportunity to develop new attractants and repellents. RESULTS: In this study, we performed single-unit electrophysiology to identify odorants that are strong activators, inhibitors, and prolonged activators of ACP odorant receptor neurons (ORNs. We identified a suite of odorants that activated the ORNs with high specificity and sensitivity, which may be useful in eliciting behavior such as attraction. In separate experiments, we also identified odorants that evoked prolonged ORN responses and antagonistic odorants able to suppress neuronal responses to activators, both of which can be useful in lowering attraction to hosts. In field trials, we tested the electrophysiologically identified activating odorants and identified a 3-odor blend that enhances trap catches by ∼230%. CONCLUSION: These findings provide a set of odorants that can be used to develop affordable and safe odor-based surveillance and masking strategies for this dangerous pest insect.

  9. Expression profile of oxidative and antioxidative stress enzymes based on ESTs approach of citrus

    Directory of Open Access Journals (Sweden)

    Luis Antonio Peroni

    2007-01-01

    Full Text Available Plants not only evolve but also reduce oxygen in photosynthesis. An inevitable consequence of this normal process is the production of reactive oxygen species (ROS. Plants are adequately protected by the presence of multiple antioxidative enzymes in the cytosol and also in the different cell organelles such as chloroplasts, mitochondria, and peroxisomes. Traditionally, ROS were considered to be only a toxic byproduct of aerobic metabolism. However, recently it has become apparent that plants actively produce these molecules which may control many different physiological processes such as abiotic and biotic stress response, pathogen defense and systemic signaling. The search results using the Citrus Genome Program in Brazil (CitEST for oxidative stress and the antioxidant enzyme system in Citrus Sinensis variety ‘Pera IAC’ indicated that the multiple ROS-scavenging enzymes were expressed throughout all citrus tissues. The analyses demonstrated the ubiquitous expression of metallothioneins, probably indicating a constitutive expression pattern. Oxalate oxidase has been identified as the most abundant expressed gene in developing fruits, which suggests a specific function in the ripening of citrus fruit. Moreover, infected leaves with Xylella fastidiosa and Leprosis citri showed a massive change in their ROS gene expression profile which may indicate that the suppression of ROS detoxifying mechanisms may be involved in the induction of the diseases.

  10. Phytophthora parasitica transcriptome, a new concept in the understanding of the citrus gummosis

    Directory of Open Access Journals (Sweden)

    Daniel D. Rosa

    2007-01-01

    Full Text Available Due to the economic importance of gummosis disease for the citriculture, studies on P. parasitica-Citrus interaction comprise a significant part in the Brazilian Citrus genome data bank (CitEST. Among them, two cDNA libraries constructed from two different growth conditions of the P. parasitica pathogen are included which has generated the PP/CitEST database (CitEST - Center APTA Citros Sylvio Moreira/IAC- Millennium Institute. Through this genomic approach and clustering analyses the following has been observed: out of a total of 13,285 available in the Phytophthora parasitica database, a group of 4,567 clusters was formed, comprising 2,649 singlets and 1,918 contigs. Out of a total of 4,567 possible genes, only 2,651 clusters were categorized; among them, only 4.3% shared sequence similarities with pathogenicity factors and defense. Some of these possible genes (103 corresponding to 421 ESTs, were characterized by phylogenetic analysis and discussed. A comparison made with the COGEME database has shown homology which may be part of an evolutionary pathogenicity pathway present in Phytophthora and also in other fungi. Many of the genes which were identified here, which may encode proteins associated to mechanisms of citrus gummosis pathogenicity, represent only one facet of the pathogen-host Phytophthora - Citrus interaction.

  11. Phytochemistry and biological activity of Spanish Citrus fruits.

    Science.gov (United States)

    Gironés-Vilaplana, Amadeo; Moreno, Diego A; García-Viguera, Cristina

    2014-04-01

    The evaluation of the potential inhibitory activity on α-glucosidase and pancreatic lipase by Citrus spp. fruits of Spanish origin (lemon, orange, grapefruit, lime, and mandarin) together with the evaluation of their phytochemical content and antioxidant capacity (DPPH˙, ORACFL, ABTS(+), FRAP and O2˙(-)) aiming for new applications of the fruits in nutrition and health was carried out. As far as we are aware, the presence of 3-O-caffeoylferuoylquinic acid and two hydrated feruloylquinic acids in orange and the presence of 3,5-diferuoylquinic acid in grapefruit have been reported for the first time. Although grapefruit showed higher contents of phytochemicals such as flavanones and vitamin C, lemon and lime showed higher potential for inhibitory effects on lipase, and lime also showed the best results for in vitro α-glucosidase inhibition. On the other hand, higher antioxidant capacity was reported for grapefruit, lemon and lime, which correlated well with their phytochemical composition. Based on the results, it could be concluded that Citrus fruits are of great value for nutrition and treatment of diet-related diseases such as obesity and diabetes, and consequently, a new field of interest in the food industry regarding new bioactive ingredients would be considered. PMID:24563112

  12. Isolation of Xylella fastidiosa from Citrus sinensis (L) Osb. And Vitis vinifera and study of genetic diversity in Costa Rica

    International Nuclear Information System (INIS)

    Xylella fastidiosa is a plant pathogenic bacterium that causes diseases in different crops. Symptoms similar to those caused by citrus variegated chlorosis (CVC) were observed in sweet orange trees which served as shade and fences in coffee plantations in Costa Rica, in 2002. A total of 35 citrus trees and 24 vines from eight different districts and 3 respectively were evaluated by 'double antibody sandwich enzyme-linked immunosorbent assay' (DASELISA), resulting in 21 citrus and 19 positive vid. From four citrus trees and six of vines, were obtained six isolates and seven isolates respectively in solid medium, whose morphological and biochemical characteristics coincided with those reported in the literature as characteristic of X. fastidiosa. The identity of the isolates is confirmed by the chain polymerase reaction (PCR) using primers 272-1/272-2int and RST31/RST33. Three isolates from Grecia (Alajuela Province) amplified a band of 500pb using specific primers 272-2int/CVC-1 for strains of X. fastidiosa that cause CVC. The genetic variability of isolates from each other in comparison with isolates of coffee in Costa Rica, U.S. grapes and citrus in Brazil have been studied using techniques of random amplification polymorphism DNA (RAPD) and length polymorphisms of restriction fragments (RFLPs) of the products obtained with primers int/272-2int JB-1/JB-2 and 272-1. The results showed a clear separation between citrus isolates of Costa Rica; and, an association of three of them with the strains of citrus in Brasil. Also, an association between strains of coffee of Costa Rica with grape vines in the U.S. An association of molecular analysis confirmed the data variance. (author)

  13. Biogenic emissions from Citrus species in California

    Science.gov (United States)

    Fares, Silvano; Gentner, Drew R.; Park, Jeong-Hoo; Ormeno, Elena; Karlik, John; Goldstein, Allen H.

    2011-09-01

    Biogenic Volatile Organic Compounds (BVOC) emitted from plants are the dominant source of reduced carbon chemicals to the atmosphere and are important precursors to the photochemical production of ozone and secondary organic aerosols. Considering the extensive land used for agriculture, cultivated Citrus plantations may play an important role in the chemistry of the atmosphere especially in regions such as the Central Valley of California. Moreover, the BVOC emissions from Citrus species have not been characterized in detail and more species-specific inputs for regional models of BVOC emissions are needed. In this study, we measured the physiological parameters and emissions of the most relevant BVOC (oxygenated compounds, monoterpenes, and sesquiterpenes) for four predominant Citrus species planted in California ( Citrus sinensis var. 'Parent Navel', Citrus limon var. 'Meyer', Citrus reticulata var. 'W. Murcott' and 'Clementine'). We used two analytical techniques to measure a full range of BVOC emitted: Proton Transfer Reaction Mass Spectrometry (PTR-MS) and gas chromatography with mass spectrometry. Methanol, followed by acetone and acetaldehyde, were the dominant BVOC emitted from lemon and mandarin trees (basal emission rates up to 300 ng(C) g(DW) -1 h -1), while oxygenated monoterpenes, monoterpenes, and sesquiterpenes were the main BVOC emitted from orange trees (basal emission rates up to = 2500 ng(C) g(DW) -1 h -1). Light and temperature-dependent algorithms were better predictors of methanol, acetaldehyde, acetone, isoprene and monoterpenes for all the Citrus species. Whereas, temperature-dependent algorithms were better predictors of oxygenated monoterpenes, and sesquiterpenes. We observed that flowering increased emissions from orange trees by an order of magnitude with the bulk of BVOC emissions being comprised of monoterpenes, sesquiterpenes, and oxygenated monoterpenes. Chemical speciation of BVOC emissions show that the various classes of terpene

  14. Identification and functional analysis of Penicillium digitatum genes putatively involved in virulence towards citrus fruit.

    Science.gov (United States)

    López-Pérez, Mario; Ballester, Ana-Rosa; González-Candelas, Luis

    2015-04-01

    The fungus Penicillium digitatum, the causal agent of green mould rot, is the most destructive post-harvest pathogen of citrus fruit in Mediterranean regions. In order to identify P. digitatum genes up-regulated during the infection of oranges that may constitute putative virulence factors, we followed a polymerase chain reaction (PCR)-based suppression subtractive hybridization and cDNA macroarray hybridization approach. The origin of expressed sequence tags (ESTs) was determined by comparison against the available genome sequences of both organisms. Genes coding for fungal proteases and plant cell wall-degrading enzymes represent the largest categories in the subtracted cDNA library. Northern blot analysis of a selection of P. digitatum genes, including those coding for proteases, cell wall-related enzymes, redox homoeostasis and detoxification processes, confirmed their up-regulation at varying time points during the infection process. Agrobacterium tumefaciens-mediated transformation was used to generate knockout mutants for two genes encoding a pectin lyase (Pnl1) and a naphthalene dioxygenase (Ndo1). Two independent P. digitatum Δndo1 mutants were as virulent as the wild-type. However, the two Δpnl1 mutants analysed were less virulent than the parental strain or an ectopic transformant. Together, these results provide a significant advance in our understanding of the putative determinants of the virulence mechanisms of P. digitatum. PMID:25099378

  15. Use of micellar liquid chromatography for rapid monitoring of fungicides post harvest applied to citrus wastewater.

    Science.gov (United States)

    Peris-Vicente, Juan; Marzo-Mas, Ana; Roca-Genovés, Pasqual; Carda-Broch, Samuel; Esteve-Romero, Josep

    2016-04-01

    A method based on micellar liquid chromatography has been developed to simultaneously monitor four pesticides largely post-harvest applied to citrus: thiabendazole, pyrimethanil, o-phenylphenol and imazalil. Water samples were filtered and directly injected without other treatment, thus avoiding extraction steps. The composition of the mobile phase was optimized using a chemometrical approach to achieve and excellent resolution to 0.07mol/L SDS/5%, V/V 1-pentanol buffered at pH3. Mobile phase run through a C18 column at 1mL/min at room temperature. The detection was performing by UV-Visible absorbance using a wavelength program: 0-10min, 305nm (for thiabendazole); 10-12; 265nm (for pyrimethanil) and 12-18, 220nm (o-phenylphenol and imazalil). The developed method was validated following the guidelines of the US Environmental Protection Agency in terms of: quantitation range, (0.5-4 to 15μg/mL), linearity (r(2)>0.9995), sensitivity (LOD, 0.18-1.4μg/mL), precision (<9.2%), trueness (93.9%-103.7%), and ruggedness (<9.9%). It was found that the fungicides remain up to eight days in surface water at outdoor conditions. The method was used to screen the presence of the analytes in several waste water samples, and was proved to be useful in routine analysis. PMID:27090721

  16. Use of bacillus subtilis strains to inhibit postharvest pathogenic fungi

    International Nuclear Information System (INIS)

    An isolate (87) of the bacillus subtilis strains isolated from cold stored citrus fruit 13 proved to inhibit the growth in vitro of the penicillium italicum used in the experiment (from 50.6% to 92.2%) and to inhibit botrytis cinerea (from 65.3% to 95.9%). A further test, superimposing on plates containing PDA strains Nos. 13, 173, and 160, totally inhibited the fungi. Tested in vivo on artificially bruised oranges, they significantly inhibited two fungi

  17. Impacts of Horticultural Mineral Oils and Two Insecticide Practices on Population Fluctuation of Diaphorina citri and Spread of Huanglongbing in a Citrus Orchard in Sarawak

    Directory of Open Access Journals (Sweden)

    Stephen Chan Teck Leong

    2012-01-01

    Full Text Available Aspects of the incidence and spread of the citrus disease huanglongbing (HLB in relation to the vector Diaphorina citri population fluctuation were studied from January 1999 to December 2001 seasons in a 0.8 ha citrus orchard at Jemukan (1° 33′N, 110° 41′E, Southwest Sarawak in Malaysia. In relation to insecticide and horticultural mineral oils (HMOs use, levels of HLB infection rose quite rapidly over the next 3 years in the unsprayed control and less rapidly in the other treatments such as imidacloprid, nC24HMO, and triazophos/cypermethrin/chlorpyrifos. Levels of HLB as determined by Polymerase Chain Reaction (PCR were 42.2%, 9.4%, 11.4%, and 22.7%, respectively. The effects of nC24HMO and conventional pesticides on the citrus psyllid population and parasitoids in citrus orchard were also determined.

  18. Antimycotic Activity and Genotoxic Evaluation of Citrus sinensis and Citrus latifolia Essential Oils

    OpenAIRE

    Ruiz-Pérez, Nancy J.; González-Ávila, Marisela; Sánchez-Navarrete, Jaime; Toscano-Garibay, Julia D.; Moreno-Eutimio, Mario A.; Sandoval-Hernández, Teresa; Arriaga-Alba, Myriam

    2016-01-01

    The aim of this study was to evaluate the antifungal activity of essential oils (EOs) of Citrus sinensis (C. sinensis) and Citrus latifolia (C. latifolia) against five Candida species: Candida albicans, Candida tropicalis, Candida glabrata, Candida lusitaniae and Candida guilliermondii; and perform its genotoxic evaluation. The EOs of C. sinensis and C. latifolia were obtained from the peel by hydro-distillation. The major components determined by GC-MS were in C. sinensis, d-limonene (96%) a...

  19. Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; SHI Xue-gen; WEI You-zhang; YANG Xiao-e; UOTI Juhani

    2006-01-01

    Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to studythe effects of compound fertilizers on their yieldsand quality. In the citrus experiment, application of compound fertilizers increased available P,K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51, 0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea.Optimal rates of compound fertilizers were recommended for both crops.

  20. Chemical composition, antioxidant and antimicrobial activities of citrus jambhiri lush and citrus reticulata blanco essential oils

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the time interval in which we can get maximum concentration of essential oil from the peels of Citrus jambhiri Lush and Citrus reticulata Blanco, to determine the composition of peel oils and to evaluate the antioxidant and antimicrobial activity of extracted oils. It was observed that in case of Citrus jambhiri Lush maximum oil yield (I %) was obtained when fruits were immature (during October). As the fruit samples got matured, the oil yield decreased. In December the oil yield decreased to 0.2 %. In case of Citrus reticulata Blanco maximum oil yield (0.189 %) was obtained during the last week of January. Chemical analysis of essential oils showed that limonene was the most abundant compound (86 %-93 %) followed by alpha terpinene (2 %-4.5 %), beta-pinene(1 0/0-2 %) and nerol (0.5 %-1.5 %). The radical scavenging and antioxidant activities of essential oils were determined by DPPH and linoleic acid test. The essential oil of Citrus jambhiri Lush inhibited the oxidation of linoleic acid by 54.98 % and that of Citrus reticulata Blanco inhibited by 49.98 %. Moreover, the essential oils also showed antimicrobial activities against the tested microorganisms. (author)

  1. Follow-up of the fate of imazalil from post-harvest lemon surface treatment to a baking experiment.

    Science.gov (United States)

    Vass, Andrea; Korpics, Evelin; Dernovics, Mihály

    2015-01-01

    Imazalil is one of the most widespread fungicides used for the post-harvest treatment of citrus species. The separate use of peel during food preparation and processing may hitherto concentrate most of the imazalil into food products, where specific maximum residue limits hardly exist for this fungicide. In order to monitor comprehensively the path of imazalil, our study covered the monitoring of the efficiency of several washing treatments, the comparison of operative and related sample preparation methods for the lemon samples, the validation of a sample preparation technique for a fatty cake matrix, the preparation of a model cake sample made separately either with imazalil containing lemon peel or with imazalil spiking, the monitoring of imazalil degradation into α-(2,4-dichlorophenyl)-1H-imidazole-1-ethanol because of the baking process, and finally the mass balance of imazalil throughout the washing experiments and the baking process. Quantification of imazalil was carried out with an LC-ESI-MS/MS set-up, while LC-QTOF was used for the monitoring of imazalil degradation. Concerning the washing, none of the addressed five washing protocols could remove more than 30% of imazalil from the surface of the lemon samples. The study revealed a significant difference between the extraction efficiency of imazalil by the EN 15662:2008 and AOAC 2007.1 methods, with the advantage of the former. The use of the model cake sample helped to validate a modified version of the EN 15662:2008 method that included a freeze-out step to efficiently recover imazalil (>90%) from the fatty cake matrix. The degradation of imazalil during the baking process was significantly higher when this analyte was spiked into the cake matrix than in the case of preparing the cake with imazalil-containing lemon peel (52% vs. 22%). This observation calls the attention to the careful evaluation of pesticide stability data that are based on solution spiking experiments. PMID:26365625

  2. Modelling the effect of an alternative host population on the spread of citrus Huanglongbing

    Science.gov (United States)

    d'A. Vilamiu, Raphael G.; Ternes, Sonia; Laranjeira, Francisco F.; de C. Santos, Tâmara T.

    2013-10-01

    The objective of this work was to model the spread of citrus Huanglongbing (HLB) considering the presence of a population of alternative hosts (Murraya paniculata). We developed a compartmental deterministic mathematical model for representing the dynamics of HLB disease in a citrus orchard, including delays in the latency and incubation phases of the disease in the plants and a delay period on the nymphal stage of Diaphorina citri, the insect vector of HLB in Brazil. The results of numerical simulations indicate that alternative hosts should not play a crucial role on HLB dynamics considering a typical scenario for the Recôncavo Baiano region in Brazil . Also, the current policy of removing symptomatic plants every three months should not be expected to significantly hinder HLB spread.

  3. A graft-based chemotherapy method for screening effective molecules and rescuing Huanglongbing (HLB)-affected citrus plants

    Science.gov (United States)

    Huanglongbing (HLB), the most devastating disease of citrus worldwide, is associated with three species of fastidious and phloem-limited a-Proteobacteria in the genus of ‘Candidatus Liberibacter’. We previously reported a regeneration-based chemical screening system using periwinkle cuttings. In ...

  4. Performance of 'Valencia' Orange (Citrus sinensis [L.] Osbeck) on 17 rootstocks in a trial severely affected by huanglongbing

    Science.gov (United States)

    Valencia orange (Citrus sinensis L. Osbeck) was grown on 17 rootstocks through seven years of age and the first four harvest seasons in a central Florida field trial severely affected by huanglongbing (HLB) disease. All trees in the trial had huanglongbing symptoms and were shown by Polymerase chain...

  5. Differentiation of citrus Hop stunt viroid variants by real-time RT-PCR and high resolution melting analysis

    Science.gov (United States)

    Viroids are small, infectious, single-stranded RNA molecules that cause several important citrus diseases. Viroids are transmitted primarily in budwood, however, spread can also occur mechanically on pruning equipment, budding knives, hedging and topping equipment. Exocortis and cachexia are two we...

  6. Postharvest Application of Some Essential Oils for Controlling Gray and Blue Moulds of Apple Fruits

    Directory of Open Access Journals (Sweden)

    Faten M. Abd-El- Latif

    2016-01-01

    Full Text Available Worldwide gray mould caused by Botrytis cinerea and blue mould caused by Penicillium spp. are the most important diseases attacking apple fruit during storage. Evaluating the effects of some essential oils i.e., eucalyptus, lemongrass and thyme on linear growth and spore germination of pathogenic fungi. Moreover, their efficacy on gray and blue moulds incidence of apple fruits was tested. All treatments significantly reduced the linear growth and spore germination of both tested fungi. Essential oils of eucalyptus, lemongrass and thyme at a concentration of 0.6 and 0.8% completely inhibit the linear growth and spore germination of B. cinerea and Penicillium sp. except that lemongrass at 0.6%. Sterilized water containing essential oils of eucalyptus, lemon grass and thyme at different concentrations, i.e., 0.0, 0.6 and 0.8% (v/v were tested to study their effect against gray and blue mould incidence of apple fruits. Results indicated that all treatments significantly reduced the disease incidence and rotted part tissue (Disease severity. The most effective treatment was eucalyptus and thyme at 0.8%, which reduced the disease incidence more than 83.8 and 82.7% and rotted part tissue by 85.9 and 88.5% for gray and blue moulds, respectively. The highest reduction was obtained with eucalyptus and thyme at concentrations of 0.6% and lemongrass at 0.8% which reduced both diseases incidence and rotted part tissue more than 74.0 and 75.8%, respectively. Meanwhile, other treatments showed moderate effect. It could be suggested that essential oils could make them an excellent treatment for controlling postharvest diseases of apple fruits.

  7. Asian citrus psyllid - biology and seasonal ecology

    Science.gov (United States)

    The seasonal ecology of Diaphorina citri was investigated in a non-irrigated citrus grove of mature orange trees beginning January 2005 in east central Florida. No insecticides were applied during the study. Predators including lady beetles, lacewings and syrphid flies were observed during the stud...

  8. Digital PCR for detection of citrus pathogens

    Science.gov (United States)

    Citrus trees are often infected with multiple pathogens of economic importance, especially those with insect or mite vectors. Real-time/quantitative PCR (qPCR) has been used for high-throughput detection and relative quantification of pathogens; however, target reference or standards are required. I...

  9. Founder lines for improved citrus biotechnology

    Science.gov (United States)

    This article discusses the research needed to develop the RMCE strategy and molecular assays for site-specific recombinases as tools for genome manipulation. Explanation of genetic engineering used to generate transgenic citrus plants to exhibit a novel phenotype, but not to contain the recombinase...

  10. Rootstock-scion interaction affecting citrus response to CTV infection: a proteomic view.

    Science.gov (United States)

    Laino, Paolo; Russo, Maria P; Guardo, Maria; Reforgiato-Recupero, Giuseppe; Valè, Giampiero; Cattivelli, Luigi; Moliterni, Vita M C

    2016-04-01

    Citrus tristeza virus (CTV) is the causal agent of various diseases with dramatic effects on citrus crops worldwide. Most Citrus species, grown on their own roots, are symptomless hosts for many CTV isolates. However, depending on different scion-rootstock combination, CTV infection should result in distinct syndromes, being 'tristeza' the more severe one, leading to a complete decline of the susceptible plants in a few weeks. Transcriptomic analyses revealed several genes involved either in defense response, or systemic acquired resistance, as well as transcription factors and components of the phosphorylation cascades, to be differentially regulated during CTV infection in Citrus aurantifolia species. To date little is known about the molecular mechanism of this host-pathogen interaction, and about the rootstock effect on citrus response to CTV infection. In this work, the response to CTV infection has been investigated in tolerant and susceptible scion-rootstock combinations by two-dimensional gel electrophoresis (2DE). A total of 125 protein spots have been found to be differently accumulated and/or phosphorylated between the two rootstock combinations. Downregulation in tolerant plants upon CTV infection was detected for proteins involved in reactive oxygen species (ROS) scavenging and defense response, suggesting a probable acclimation response able to minimize the systemic effects of virus infection. Some of these proteins resulted to be modulated also in absence of virus infection, revealing a rootstock effect on scion proteome modulation. Moreover, the phospho-modulation of proteins involved in ROS scavenging and defense response, further supports their involvement either in scion-rootstock crosstalk or in the establishment of tolerance/susceptibility to CTV infection. PMID:26459956

  11. Drinking citrus fruit juice inhibits vascular remodeling in cuff-induced vascular injury mouse model.

    Directory of Open Access Journals (Sweden)

    Arika Ohnishi

    Full Text Available Citrus fruits are thought to have inhibitory effects on oxidative stress, thereby attenuating the onset and progression of cancer and cardiovascular disease; however, there are few reports assessing their effect on vascular remodeling. Here, we investigated the effect of drinking the juice of two different citrus fruits on vascular neointima formation using a cuff-induced vascular injury mouse model. Male C57BL6 mice were divided into five groups as follows: 1 Control (water (C, 2 10% Citrus unshiu (CU juice (CU10, 3 40% CU juice (CU40, 4 10% Citrus iyo (CI juice (CI10, and 5 40% CI juice (CI40. After drinking them for 2 weeks from 8 weeks of age, cuff injury was induced by polyethylene cuff placement around the femoral artery. Neointima formation was significantly attenuated in CU40, CI10 and CI40 compared with C; however, no remarkable preventive effect was observed in CU10. The increases in levels of various inflammatory markers including cytokines such as monocyte chemotactic protein-1, interleukin-6 (IL-6, IL-1β, and tumor necrosis factor-α in response to vascular injury did not differ significantly between C, CU10 and CI10. The increases in cell proliferation and superoxide anion production were markedly attenuated in CI10, but not in CU10 compared with C. The increase in phosphorylated ERK expression was markedly attenuated both in CU10 and CI10 without significant difference between CU10 and CI10. Accumulation of immune cells did not differ between CU10 and CI10. These results indicate that drinking citrus fruit juice attenuates vascular remodeling partly via a reduction of oxidative stress. Interestingly, the preventive efficacy on neointima formation was stronger in CI than in CU at least in part due to more prominent inhibitory effects on oxidative stress by CI.

  12. Drinking citrus fruit juice inhibits vascular remodeling in cuff-induced vascular injury mouse model.

    Science.gov (United States)

    Ohnishi, Arika; Asayama, Rie; Mogi, Masaki; Nakaoka, Hirotomo; Kan-No, Harumi; Tsukuda, Kana; Chisaka, Toshiyuki; Wang, Xiao-Li; Bai, Hui-Yu; Shan, Bao-Shuai; Kukida, Masayoshi; Iwanami, Jun; Horiuchi, Masatsugu

    2015-01-01

    Citrus fruits are thought to have inhibitory effects on oxidative stress, thereby attenuating the onset and progression of cancer and cardiovascular disease; however, there are few reports assessing their effect on vascular remodeling. Here, we investigated the effect of drinking the juice of two different citrus fruits on vascular neointima formation using a cuff-induced vascular injury mouse model. Male C57BL6 mice were divided into five groups as follows: 1) Control (water) (C), 2) 10% Citrus unshiu (CU) juice (CU10), 3) 40% CU juice (CU40), 4) 10% Citrus iyo (CI) juice (CI10), and 5) 40% CI juice (CI40). After drinking them for 2 weeks from 8 weeks of age, cuff injury was induced by polyethylene cuff placement around the femoral artery. Neointima formation was significantly attenuated in CU40, CI10 and CI40 compared with C; however, no remarkable preventive effect was observed in CU10. The increases in levels of various inflammatory markers including cytokines such as monocyte chemotactic protein-1, interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α in response to vascular injury did not differ significantly between C, CU10 and CI10. The increases in cell proliferation and superoxide anion production were markedly attenuated in CI10, but not in CU10 compared with C. The increase in phosphorylated ERK expression was markedly attenuated both in CU10 and CI10 without significant difference between CU10 and CI10. Accumulation of immune cells did not differ between CU10 and CI10. These results indicate that drinking citrus fruit juice attenuates vascular remodeling partly via a reduction of oxidative stress. Interestingly, the preventive efficacy on neointima formation was stronger in CI than in CU at least in part due to more prominent inhibitory effects on oxidative stress by CI. PMID:25692290

  13. Reduction of Legionella spp. in water and in soil by a citrus plant extract vapor.

    Science.gov (United States)

    Laird, Katie; Kurzbach, Elena; Score, Jodie; Tejpal, Jyoti; Chi Tangyie, George; Phillips, Carol

    2014-10-01

    Legionnaires' disease is a severe form of pneumonia caused by Legionella spp., organisms often isolated from environmental sources, including soil and water. Legionella spp. are capable of replicating intracellularly within free-living protozoa, and once this has occurred, Legionella is particularly resistant to disinfectants. Citrus essential oil (EO) vapors are effective antimicrobials against a range of microorganisms, with reductions of 5 log cells ml(-1) on a variety of surfaces. The aim of this investigation was to assess the efficacy of a citrus EO vapor against Legionella spp. in water and in soil systems. Reductions of viable cells of Legionella pneumophila, Legionella longbeachae, Legionella bozemanii, and an intra-amoebal culture of Legionella pneumophila (water system only) were assessed in soil and in water after exposure to a citrus EO vapor at concentrations ranging from 3.75 mg/liter air to 15g/liter air. Antimicrobial efficacy via different delivery systems (passive and active sintering of the vapor) was determined in water, and gas chromatography-mass spectrometry (GC-MS) analysis of the antimicrobial components (linalool, citral, and β-pinene) was conducted. There was up to a 5-log cells ml(-1) reduction in Legionella spp. in soil after exposure to the citrus EO vapors (15 mg/liter air). The most susceptible strain in water was L. pneumophila, with a 4-log cells ml(-1) reduction after 24 h via sintering (15 g/liter air). Sintering the vapor through water increased the presence of the antimicrobial components, with a 61% increase of linalool. Therefore, the appropriate method of delivery of an antimicrobial citrus EO vapor may go some way in controlling Legionella spp. from environmental sources. PMID:25063652

  14. Colonization of Seeds of Citrus Rootstock Varieties by ‘Candidatus Liberibacter asiaticus’

    OpenAIRE

    Hilf, Mark E.

    2014-01-01

    Huanglongbing (HLB) is a disease of citrus associated with a systemic infection by the α-proteobacterium ‘Candidatus Liberibacter asiaticus’.  Infection of an individual tree can occur via psyllids (Diaphorina citri Kuwayama) carrying the bacterium or if the tree is propagated from infected budwood.  Seed transmission is another possible mode of dissemination of the pathogen.  Rootstock varieties are propagated from seed so we assessed the seed transmission among eighteen rootstock varieties ...

  15. Genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens

    OpenAIRE

    Li, Wenbin; Song, Qijian; Brlansky, Ronald H.; Hartung, John S.

    2007-01-01

    Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) was first documented in India and Java in the mid 19th century. Since that time, the known distribution of the disease has steadily increased. Concurrent with the dispersion of the pathogen, the diversity of described strains continues to increase, with novel strains appearing in Saudi Arabia, Iran, and Florida in the last decade. Herbarium specimens of infected plants provide an historical record documenting both ...

  16. Soft Rot on Citrus unshiu Caused by Rhizopus oryzae in Korea

    OpenAIRE

    Jin-Hyeuk Kwon; Jinwoo Kim; Jae-Wook Hyun; Yong Hwan Lee; Hong-Sik Shim

    2011-01-01

    Soft rot caused by Rhizopus oryzae occurred on unshiu orange (Citrus unshiu Marc.) sampled from commercial markets in Jinju, Korea, 2010. The first symptom of soft rot on orange is a water-soaked appearance of the affected tissue. The infected parts later disintegrated into a mushy mass of disorganized cells followed by rapid softening of the diseased tissue. The lesion on orange was rapidly softened and rotted, then became brown or dark brown. Optimum temperature for mycelial growth of the c...

  17. Relative susceptibility of citrus genotypes to fruit rot caused by Ceratocystis radicicola in Iran

    OpenAIRE

    Mohammad R Mirzaee; Mojtaba Mohammadi; Ali Azari Nasrabad

    2009-01-01

    Several citrus genotypes were evaluated for their relative susceptibility to the new lemon fruit rot pathogen, Ceratocystis radicicola. Wounded detached fruits were inoculated ten days before normal harvest by placing on the wound site a droplet of distilled water followed by a mycelial plug of one-week-old culture. Inoculated fruits were ranked for their relative susceptibility to the pathogen by determining disease severity based on mean lesion size. Using Duncan's multiple range test, citr...

  18. Reduction of Legionella spp. in Water and in Soil by a Citrus Plant Extract Vapor

    OpenAIRE

    Laird, Katie; Kurzbach, Elena; Score, Jodie; Tejpal, Jyoti; Chi Tangyie, George; Phillips, Carol

    2014-01-01

    Legionnaires' disease is a severe form of pneumonia caused by Legionella spp., organisms often isolated from environmental sources, including soil and water. Legionella spp. are capable of replicating intracellularly within free-living protozoa, and once this has occurred, Legionella is particularly resistant to disinfectants. Citrus essential oil (EO) vapors are effective antimicrobials against a range of microorganisms, with reductions of 5 log cells ml−1 on a variety of surfaces. The aim o...

  19. Protective effect of Bacillus amyloliquefaciens against infections of Citrus aurantium seedlings by Phoma tracheiphila.

    Science.gov (United States)

    Kalai-Grami, L; Ben Slimane, I; Mnari-Hattab, M; Rezgui, S; Aouani, M A; Hajlaoui, M R; Limam, F

    2014-02-01

    Isolate TEB1 an antagonistic endophytic bacterium, obtained from citrus leaves and identified as Bacillus amyloliquefaciens by 16S rDNA sequencing, was used for the biological control of mal secco disease of Citrus aurantium seedlings caused by the mitosporic fungus Phoma tracheiphila. The isolate TEB1 exhibited a good in vitro activity against P. tracheiphila in dual cultures as well as with the well diffusion method. C. aurantium seedlings watered with a suspension of TEB1 cells showed a reduction of 53.61 and 48.63% in disease severity and incidence, respectively. A PCR test with specific primers was performed 365 days after inoculation and P. tracheiphila was detected along the whole stem in inoculated control plant while no amplification product was obtained in TEB1 treated seedlings. Molecular analysis of TEB1 revealed a positive amplification of fenD and ituC genes responsible of the biosynthesis of fengycin and iturin lipopeptides, respectively. Moreover, observations by optical microscope showed that TEB1 reduced by 55% the germination of P. tracheiphila conidia and exhibited a marked effect on mycelia structure. Data suggest that lipopeptides produced by the bacterium interact with the cytoplasmic membrane of the fungus causing pore formation. TEB1 appears a potential candidate for the biological control of citrus mal secco disease. PMID:23990072

  20. Slight Fermentation with Lactobacillus fermentium Improves the Taste (Sugar:Acid Ratio) of Citrus (Citrus reticulata cv. chachiensis) Juice.

    Science.gov (United States)

    Yu, Yuanshan; Xiao, Gengsheng; Xu, Yujuan; Wu, Jijun; Fu, Manqin; Wen, Jing

    2015-11-01

    The aim of this study was to evaluate the hypothesis that fermentation with Lactobacillus fermentium, which can metabolize citric acid, could be applied in improving the taste (sugar:acid ratio) of citrus juice. During fermentation, the strain of L. fermentium can preferentially utilize citric acid of citrus (Citrus reticulata cv. Chachiensis) juice to support the growth without the consumption of sugar. After 6 h of fermentation with L. fermentium at 30 °C, the sugar:acid ratio of citrus juice increased to 22:1 from 12:1, which resulted in that the hedonic scores of sweetness, acidity and overall acceptability of fermented-pasteurized citrus juice were higher than the unfermented-pasteurized citrus juice. Compared with unfermented-pasteurized citrus juice, the ORAC value and total amino acid showed a reduction, and no significant change (P > 0.05) in the L*, a*, b*, total soluble phenolics and ascorbic acid (Vc) content in the fermented-pasteurized citrus juice was observed as compared with unfermented-pasteurized citrus juice. Hence, slight fermentation with L. fermentium can be used for improving the taste (sugar:acid ratio) of citrus juice with the well retaining of quality. PMID:26447635

  1. The effect of ionizing irradiation on the postharvest quality of vegetables

    International Nuclear Information System (INIS)

    The widespread adoption of irradiation as a postharvest treatment must depend on superior performances with regard to product quality, economics, safety both during application and of the final product, and finally consumer acceptance

  2. Recent advances in development of ultralow oxygen treatment for postharvest pest control on perishable commodities.

    Science.gov (United States)

    Several controlled atmosphere treatments with ultralow oxygen (ULO treatments) have been developed for postharvest pest control on different types of perishable products. Complete control of green peach aphid (Myzus persicae), sweetpotato whitefly (Bemisia sp.), twopotted spider mite (Tetranychus u...

  3. Effect of gamma irradiation and its convergent treatment for control of postharvest Botrytis cinerea of cut roses

    International Nuclear Information System (INIS)

    Postharvest diseases cause considerable losses to harvested crops. Among them, gray mold (Botrytis cinerea) is a major problem of exporting to cut rose flowers into Korea. Irradiation treatment is an alternative to phytosanitary purposes and a useful nonchemical approach to the control of postharvest diseases. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against B. cinerea on cut rose varieties, ‘Shooting Star’ and ‘Babe’. The irradiating dose required to reduce the population by 90%, D10, was 0.99 kGy. Gamma irradiation showed complete inhibition of spore germination and mycelial growth of B. cinerea, especially 4.0 kGy in vitro. Antifungal activity of gamma irradiation on rose B. cinerea is a dose-dependent manner. A significant phytotoxicity such as bent neck in cut rose quality was shown from gamma irradiation at over 0.4 kGy (p<0.05) in both varieties. Although there is no significant difference in both varieties for fresh weight, in the case of flower rate, ‘Babe’ shows more sensitivity than ‘Shooting Star’. In vivo assays demonstrated that established doses in in vitro, over 4 kGy, could completely inactive fungal pathogens, but such high doses can cause severe flowers damage. Thus, to eliminate negative impact on their quality, gamma irradiation was evaluated at lower doses in combination with an eco-friendly chemical, sodium dichloroisocyanurate (NaDCC) to examine the inhibition of B. cinerea. Intriguingly, only the combined treatment with 0.2 kGy of gamma irradiation and 70 ppm of NaDCC exhibited significant synergistic antifungal activity against blue mold decay in both varieties. Together, these results suggest that a synergistic effect of the combined treatment with gamma irradiation and NaDCC can be efficiently used to control the postharvest diseases in cut rose flowers, and will provide a promising technology for horticulture products for exportation. - Highlights: • Gamma irradiation and Na

  4. In vitro xanthine oxidase inhibitory activity of leaves, fruits and peel extracts of Citrus aurantium, Citrus limetta and Citrus limon

    Directory of Open Access Journals (Sweden)

    Muthiah PL

    2012-07-01

    Full Text Available Aim of the study: To evaluate the in vitro xanthine oxidase inhibitory activity of the extract of leaves, fruits and peel of Citrus aurantium, Citrus limetta and Citrus limon.   Materials and Methods: Xanthine oxidase inhibitory activity was assayed spectrophotometrically under aerobic conditions and the degree of enzyme inhibition was determined by measuring the increase in absorbance at 295nm associated with uric acid formation.   Results: Among the extracts tested, the C.limetta peel extract exhibited highest potency of xanthine oxidase inhibition (IC50 40.16±0.88μg/ml. This was followed by C.aurantium peel (IC50 51.50±2.05μg/ml, C.limon peel (IC50 64.90±1.24μg/ml, C.aurantium leaf (IC5073.50±1.26μg/ml, C.limetta leaf (IC50 74.83±2.42μg/ml, C.limon leaf (IC50 76.83±2.02μg/ml, C.limetta fruit (IC50 95.16±0.60μg/ml extracts compared with the IC50 value of standard allopurinol was 6.6μg/ml.   Conclusion: Recent findings show that the occurrence of gout is increasing worldwide, possibly due to the changes in dietary habits like intake of food rich in nucleic acids, such as meat, sea foods, etc. Xanthine oxidase inhibitors such as allopurinol is the drug of choice, however it has been observed more side effects.  An alternative to allopurinol is the use of medicinal plants, We thus began our program to look for xanthine oxidase inhibitors of phytochemical origin. In conclusion, the study suggests that the leaves and peel extracts of Citrus aurantium, Citrus limetta and Citrus limon possess xanthine oxidase inhibitory activity that might be helpful in preventing or slowing the progress of gout and related disorders.

  5. Effects of Chitin and Its Derivative Chitosan on Postharvest Decay of Fruits: A Review

    OpenAIRE

    Weimin Liu; Hongyin Zhang; Renping Li

    2011-01-01

    Considerable economic losses to harvested fruits are caused by postharvest fungal decay during transportation and storage, which can be significantly controlled by synthetic fungicides. However, considering public concern over pesticide residues in food and the environment, there is a need for safer alternatives for the control of postharvest decay to substitute synthetic fungicides. As the second most abundant biopolymer renewable source in nature, chitin and its derivative chitosan are wide...

  6. Effects of Post-Harvest Treatment Requirements on the Markets for Oysters

    OpenAIRE

    Muth, Mary K.; Karns, Shawn A.; Anderson, Donald W.; Brian C. Murray

    2002-01-01

    Because of public health concerns, regulators are considering requiring post-harvest treatment of halfshell and shucked oysters by wholesalers and processors. Two recently developed post-harvest treatment technologies may actually reduce the costs of producing shucked oysters, but would increase the costs of halfshell oysters. An interregional model of the wholesale oyster industry is developed to estimate the effects of treatment requirements on prices, output, and employment. If post-harves...

  7. CHANGES OF CRUDE PROTEIN CONTENT IN MALTING BARLEY INFLUENCED BY POSTHARVEST RIPENING

    OpenAIRE

    M. LÍŠKOVÁ; H FRANČÁKOVÁ; J. MAREČEK

    2011-01-01

    Aim of this experiment was to investigate to what extent post-harvest ripening and growing locality influenced changes of crude protein content in malting barley and values of Kolbach index in malt. Results revealed that already in the sixth week after harvest, amount of crude protein decreased and amount of Kolbach index increased, due to post-harvest ripening. Moreover climatic conditions during vegetation and harvest as well as the growing locality significantly influenced (P<0.001) the...

  8. Post-harvest loss in Sub-Saharan Africa -- what do farmers say ?

    OpenAIRE

    Kaminski, Jonathan; Christiaensen, Luc

    2014-01-01

    The 2007-2008 global food crisis has renewed interest in post-harvest loss, but estimates remain scarce, especially in Sub-Saharan Africa. This paper uses self-reported measures from nationally representative household surveys in Malawi, Uganda, and Tanzania. Overall, on-farm post-harvest loss adds to 1.4-5.9 percent of the national maize harvest, substantially lower than the Food and Agri...

  9. Effect of Calcium Chloride and Cooling on Post-Harvest Brussels Cabbage (Brassica Oleracea L.)

    OpenAIRE

    Alfonso Rincón Pérez; Helber Enrique Balaguera-López; Pedro José Almanza-Merchán

    2014-01-01

    In recent years, the demand of crucifers has increased and particularly of Brussels sprouts (Brassica genus, species Brassica oleracea L.); mainly due to their functional properties; however, this vegetable is perishable and with inadequate techniques in postharvest handling, considerable losses are generated. The objective of this research was to determine the effect of calcium chloride and cooling on postharvest behavior of Brussels sprouts. A completely randomized design was performed, tre...

  10. Post-harvest conservation of organic strawberries coated with cassava starch and chitosan

    OpenAIRE

    Raquel P Campos; Angela Kwiatkowski; Edmar Clemente

    2011-01-01

    The strawberry is as non-climacteric fruit, but has a high post-harvest respiration rate, which leads to a rapid deterioration at room temperature. This study aimed to evaluate the application of biodegradable coating on postharvest conservation of organic strawberries, cv. Camarosa, packed in plastic hinged boxes and stored at 10ºC. The treatments consisted of: a) control; b) 2% cassava starch; c) 1% chitosan; and d) 2% cassava starch + 1% chitosan. Physical and chemical characteristics of f...

  11. Effect of Carboxymethyl Cellulose and Alginate Coating Combined with Brewer Yeast on Postharvest Grape Preservation

    OpenAIRE

    Zhang Shaoying; Ren Yinzhe

    2013-01-01

    The effect of carboxymethyl cellulose and alginate coating combined with brewer yeast on postharvest grape preservation was investigated. The postharvest grapes were coated with 2% of alginate and 3% of carboxymethyl cellulose combined with 1.5×109 CFU/mL of brewer yeast. The combined treatment samples showed good sensory character on day 13 compared with control samples or only coated samples. The increase of weight loss and decrease of total soluble solids of combined treatment grapes were ...

  12. Economic Analysis of Post-harvest Losses in Marketing of Vegetables in Uttarakhand

    OpenAIRE

    Sharma, Gaurav; Singh, S.P.

    2011-01-01

    The study has examined the nature and extent of post-harvest losses in vegetable supply chain in the Kumaon division of Uttarakhand. Multistage cluster sampling has been used for selection of 80 vegetable growers, 40 farmers from the hilly region and 40 farmers from the bhabhar region. The sample has also included 25 market functionaries. Twelve major vegetables have been selected for the study. The maximum aggregate post-harvest losses have been found in tomato, followed by potato, brinjal, ...

  13. Good Postharvest-handling Application of Corn in Supporting Food Self-Sufficiency in Indonesia

    OpenAIRE

    Zainal

    2015-01-01

    Corn is one of potential commodity to support food self-sufficiency in Indonesia. Some regions use corn as alternative food substituting rice. The corn production tend to increase every year. However, the quality is still low because of poor postharvest-handling. The objective of this research was to compare the corn quality from different postharvest-handling between farmers and the good handling method. The observed parameters were the moisture, the damage grain, the broken grain, and the a...

  14. An Antifungal Role of Hydrogen Sulfide on the Postharvest Pathogens Aspergillus niger and Penicillium italicum

    OpenAIRE

    Liu-Hui Fu; Kang-Di Hu; Lan-Ying Hu; Yan-Hong Li; Liang-Bin Hu; Hong Yan; Yong-Sheng Liu; Hua Zhang

    2014-01-01

    In this research, the antifungal role of hydrogen sulfide (H2S) on the postharvest pathogens Aspergillus niger and Penicillium italicum growing on fruits and under culture conditions on defined media was investigated. Our results show that H2S, released by sodium hydrosulfide (NaHS) effectively reduced the postharvest decay of fruits induced by A. niger and P. italicum. Furthermore, H2S inhibited spore germination, germ tube elongation, mycelial growth, and produced abnormal mycelial contract...

  15. INFLUENCE OF SALINITY ON CITRUS: A REVIEW PAPER

    Directory of Open Access Journals (Sweden)

    ADNAN Al-Yassin

    2005-04-01

    Full Text Available Due to the rapid expansion of irrigated agriculture, effi cient use of the limited water resources in arid and semi-arid regions is becoming more and more vital. However, water salinity is a major problem due to its negative infl uence on the yields of many crops. It reduces citrus trees’ growth and causes physiological disorders. Primarily salt-stress lowers net CO2 assimilation, stomatal conductance, and water potential of citrus tree leaves, in addition to accumulation of excessive concentration of Chloride or Sodium in leaves. A great deal of research indicates that citrus have the genetic potential to be salt-sensitive; however inheritance studies in citrus are scarce. In this paper the adverse of effects of salinity on physiological aspects of citrus are reviewed. The review summarizes the prevailing state of knowledge about the responses and tolerance of citrus trees to salinity.

  16. Genetic Diversity and Population Differentiation of the Causal Agent of Citrus Black Spot in Brazil

    OpenAIRE

    Ester Wickert; Antonio de Goes; Andressa Souza; Eliana Gertrudes de Macedo Lemos

    2012-01-01

    One of the most important diseases that affect sweet orange orchards in Brazil is the Citrus Black Spot that is caused by the fungus Guignardia citricarpa. This disease causes irreparable losses due to the premature falling of fruit, as well as its severe effects on the epidermis of ripe fruit that renders them unacceptable at the fresh fruit markets. Despite the fact that the fungus and the disease are well studied, little is known about the genetic diversity and the structure of the fungi p...

  17. Citrus Genetic Resources Grown on the Ryukyu Islands, Japan

    OpenAIRE

    Yamamoto, Masashi; ヤマモト, マサシ; 山本, 雅史

    2014-01-01

    The Ryukyu Islands are located southwest part of Japan. Various local citrus are grown in this subtropical region. Since there are large geographical and climatic differences between the Ryukyu Islands and the main islands (Honshu, Kyushu, and Shikoku) of Japan, there are unique local citrus genetic resources on the Ryukyu Islands. Shiikuwasha (Citrus depressa) is an indigenous mandarin species in this region. This species is clearly distinguished from the mandarin grown in China and India ba...

  18. Synergy and Other Interactions between Polymethoxyflavones from Citrus Byproducts

    OpenAIRE

    Benito F. García; Ascensión Torres; Francisco A. Macías

    2015-01-01

    The citrus by-products released from citrus processing plants may contain high levels of potentially bioactive compounds such as flavonoids, which are a widely distributed group of polyphenolic compounds with health-related properties based on their antioxidant activity. In the study reported here, the potential bioactivities and antioxidant activities of extracts, fractions and compounds from citrus by-products were evaluated along with the chemical interactions of binary mixtures of compoun...

  19. Mechanisms of sexual polyploidization and inheritance in triploid citrus populations

    OpenAIRE

    CUENCA IBÁÑEZ, JOSÉ

    2013-01-01

    Citrus is the main fruit crop in the world and Spain is the 6th producer and the major exporter for the fresh fruit market. Seedlessness is one of the most important fruit quality traits for this market since consumers do not accept seedy fruits. Recovery of triploid hybrids has become an important breeding strategy to develop new seedless citrus varieties and several of them have been already released from citrus breeding programs worldwide. Despite the undisputable importance of polyploidy ...

  20. Citrus blackfly in Florida: Eradication or bio-control?

    OpenAIRE

    Tefertiller, Kenneth R.; McKee, Vernon C.; Perry, Vernon G.

    1991-01-01

    The citrus blackfly (CBF) invaded south Florida in January 1976. It was considered by scientists to be a major threat to the Florida citrus industry located in the central part of the state. The CBF was successfully contained in a 1000 square mile tri-county quarantined area surrounding Ft. Lauderdale for several months before breaking out to an area near the commercial citrus production area. During this time federal and state research agencies were evaluating a bio-control approach involvin...