Behavioral responses of male Diaphorina citri (Hemiptera: Liviidae) to mating communication signals from vibration traps in citrus (Sapindales: Rutaceae) trees

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The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors the bacterium causing citrus greening disease, which has devastated citrus production worldwide wherever it has been introduced. To help monitor and target D citri populations in commercial groves, thereby facilitating more effective manag...

Land cover classification of VHR airborne images for citrus grove identification

Science.gov (United States)

Amorós López, J.; Izquierdo Verdiguier, E.; Gómez Chova, L.; Muñoz Marí, J.; Rodríguez Barreiro, J. Z.; Camps Valls, G.; Calpe Maravilla, J.

Managing land resources using remote sensing techniques is becoming a common practice. However, data analysis procedures should satisfy the high accuracy levels demanded by users (public or private companies and governments) in order to be extensively used. This paper presents a multi-stage classification scheme to update the citrus Geographical Information System (GIS) of the Comunidad Valenciana region (Spain). Spain is the first citrus fruit producer in Europe and the fourth in the world. In particular, citrus fruits represent 67% of the agricultural production in this region, with a total production of 4.24 million tons (campaign 2006-2007). The citrus GIS inventory, created in 2001, needs to be regularly updated in order to monitor changes quickly enough, and allow appropriate policy making and citrus production forecasting. Automatic methods are proposed in this work to facilitate this update, whose processing scheme is summarized as follows. First, an object-oriented feature extraction process is carried out for each cadastral parcel from very high spatial resolution aerial images (0.5 m). Next, several automatic classifiers (decision trees, artificial neural networks, and support vector machines) are trained and combined to improve the final classification accuracy. Finally, the citrus GIS is automatically updated if a high enough level of confidence, based on the agreement between classifiers, is achieved. This is the case for 85% of the parcels and accuracy results exceed 94%. The remaining parcels are classified by expert photo-interpreters in order to guarantee the high accuracy demanded by policy makers.

An Ecoinformatics Approach to Field-Scale Evaluation of Insecticide Effects in California Citrus: Are Citrus Thrips and Citrus Red Mite Induced Pests?

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Livingston, George; Hack, Lindsey; Steinmann, Kimberly P; Grafton-Cardwell, Elizabeth E; Rosenheim, Jay A

2018-05-28

Experimental approaches to studying the consequences of pesticide use, including impacts on beneficial insects, are vital; however, they can be limited in scale and realism. We show that an ecoinformatics approach that leverages existing data on pesticides, pests, and beneficials across multiple fields can provide complementary insights. We do this using a multi-year dataset (2002-2013) on pesticide applications and density estimates of two pests, citrus thrips (Scirtothrips citri (Moulton [Thysanoptera: Thripidae])) and citrus red mites (Panonychus citri McGregor [Acari: Tetranychidae]), and a natural enemy (Euseius spp. predatory mites) collected from citrus groves in the San Joaquin Valley of California. Using correlative analyses, we investigated the long-term consequences of pesticide use on S. citri and P. citri population densities to evaluate the hypothesis that the pest status of these species is largely due to the disruption of natural biological control-i.e., these are induced pests. We also evaluated short-term pesticide efficacy (suppression of citrus thrips and citrus red mite populations immediately post-application) and asked if it was correlated with the suppression of Euseius predator populations. Although the short-term efficacy of different pesticides varied significantly, our dataset does not suggest that the use of citrus pesticides suppressed Euseius densities or worsened pest problems. We also find that there is no general trade-off between pesticide efficacy and pesticide risk to Eusieus, such that highly effective and minimally disruptive compounds were available to citrus growers during the studied time period.

H NMR analyses of Citrus macrophylla subjected to Asian citrus psyllid (Diaphorina citri Kuwayama) feeding

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The Asian citrus psyllid (ACP) is a phloem feeding insect that can host and transmit the bacterium Candidatus Liberibacter asiaticus (CLas), which is the putative causative agent of the economically important citrus disease, Huanglongbing (HLB). ACP are widespread in Florida, and are spreading in Ca...

Saving Citrus: Does the Next Generation See GM Science as a Solution?

Science.gov (United States)

Rumble, Joy N.; Ruth, Taylor K.; Owens, Courtney T.; Lamm, Alexa J.; Taylor, Melissa R.; Ellis, Jason D.

2016-01-01

Citrus is one of Florida's most prominent commodities, providing 66% of the total United States' value for oranges. Florida's citrus production decreased 21% in 2014 from the previous season, partly due to the disease citrus greening. The science of genetic modification (GM) is one of the most promising solutions to the problem. However, a…

Implementation evaluation of a culturally competent eye injury prevention program for citrus workers in a Florida migrant community.

Science.gov (United States)

Luque, John S; Monaghan, Paul; Contreras, Ricardo B; August, Euna; Baldwin, Julie A; Bryant, Carol A; McDermott, Robert J

2007-01-01

The Partnership for Citrus Worker Health (PCWH) is a coalition that connects academic institutions, public health agencies, industry and community-based organizations for implementation of an eye safety pilot project with citrus workers using the Camp Health Aide (CHA) model. This project was an implementation evaluation of an eye safety curriculum using modeling and peer-to-peer education among Mexican migrant citrus workers in a southwest Florida community to increase positive perceptions toward the use of safety eyewear and reduce occupational eye injuries. CHAs have been employed and trained in eye safety and health during harvesting seasons since 2004. Field observations, focus group interviews, and written questionnaires assessed program implementation and initial outcomes. There was an increase in positive perceptions toward use of safety eyewear between 2004 and 2005. Evaluation of training suggested ways to improve the curriculum. The modest literacy level of the CHAs necessitated some redesign of the curriculum and its implementation (e.g., introduction of and more reliance on use of training posters). PCWH benefited by extensive documentation of the training and supervision, a pilot project that demonstrated the potential effectiveness of CHAs, and having a well-defined target population of citrus workers (n = 427). Future research can rigorously test the effectiveness of CHAs in reducing eye injuries among citrus workers.

Water Quality and Evaluation of Pesticides in Lakes in the Ridge Citrus Region of Central Florida

Science.gov (United States)

Choquette, Anne F.; Kroening, Sharon E.

2009-01-01

Water chemistry, including major inorganic constituents, nutrients, and pesticide compounds, was compared between seven lakes surrounded by citrus agriculture and an undeveloped lake on the Lake Wales Ridge (herein referred to as the Ridge) in central Florida. The region has been recognized for its vulnerability to the leaching of agricultural chemicals into the subsurface due to factors including soils, climate, and land use. About 40 percent of Florida's citrus cultivation occurs in 'ridge citrus' areas characterized by sandy well drained soils, with the remainder in 'flatwoods citrus' characterized by high water tables and poorly drained soils. The lakes on the Ridge are typically flow-through lakes that exchange water with adjacent and underlying aquifer systems. This study is the first to evaluate the occurrence of pesticides in lakes on the Ridge, and also represents one of the first monitoring efforts nationally to focus on regional-scale assessment of current-use pesticides in small- to moderate-sized lakes (5 to 393 acres). The samples were collected between December 2003 and September 2005. The lakes in citrus areas contained elevated concentrations of major inorganic constituents (including alkalinity, total dissolved solids, calcium, magnesium, sodium, potassium, chloride, and sulfate), total nitrogen, pH, and pesticides compared to the undeveloped lake. Nitrate (as N) and total nitrogen concentrations were typically elevated in the citrus lakes, with maximum values of 4.70 and 5.19 mg/L (milligrams per liter), respectively. Elevated concentrations of potassium, nitrate, and other inorganic constituents in the citrus lakes likely reflect inputs from the surficial ground-water system that originated predominantly from agricultural fertilizers, soil amendments, and inorganic pesticides. A total of 20 pesticide compounds were detected in the lakes, of which 12 compounds exceeded the standardized reporting level of 0.06 ug/L (microgram per liter). Those

Quantitative distribution of 'Candidatus Liberibacter asiaticus' in citrus plants with citrus huanglongbing.

Science.gov (United States)

Li, Wenbin; Levy, Laurene; Hartung, John S

2009-02-01

Citrus huanglongbing (HLB), or greening disease, is strongly associated with any of three nonculturable gram-negative bacteria belonging to 'Candidatus Liberibacter spp.' 'Ca. Liberibacter spp.' are transmitted by citrus psyllids to all commercial cultivars of citrus. The diseases can be lethal to citrus and have recently become widespread in both São Paulo, Brazil, and Florida, United States, the locations of the largest citrus industries in the world. Asiatic HLB, the form of the disease found in Florida, is associated with 'Ca. Liberibacter asiaticus' and is the subject of this report. The nonculturable nature of the pathogen has hampered research and little is known about the distribution of 'Ca. L. asiaticus' in infected trees. In this study, we have used a quantitative polymerase chain reaction assay to systematically quantify the distribution of 'Ca. L. asiaticus' genomes in tissues of six species of citrus either identified in the field during survey efforts in Florida or propagated in a greenhouse in Beltsville, MD. The populations of 'Ca. L. asiaticus' inferred from the distribution of 16S rDNA sequences specific for 'Ca. L. asiaticus' in leaf midribs, leaf blades, and bark samples varied by a factor of 1,000 among samples prepared from the six citrus species tested and by a factor of 100 between two sweet orange trees tested. In naturally infected trees, above-ground portions of the tree averaged 10(10) 'Ca. L. asiaticus' genomes per gram of tissue. Similar levels of 'Ca. L. asiaticus' genomes were observed in some but not all root samples from the same plants. In samples taken from greenhouse-inoculated trees, levels of 'Ca. L. asiaticus' genomes varied systematically from 10(4) genomes/g at the graft inoculation site to 10(10) genomes/g in some leaf petioles. Root samples from these trees also contained 'Ca. L. asiaticus' at 10(7) genomes/g. In symptomatic fruit tissues, 'Ca. L. asiaticus' genomes were also readily detected and quantified. The highest

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).

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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. Copyright © 2014. Published by Elsevier B.V.

EFFECTIVENESS OF HUANGLONGBING VECTOR (DIAPHORINA CITRI KUWAYAMA CONTROL IN CITRUS GROWER GROUP BASED IN SAMBAS REGENCY OF WEST KALIMANTAN, INDONESIA

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Supriyanto A.

2017-12-01

Full Text Available The purpose of this study was to determine the effectiveness of Huanglongbing vector control based on Citrus Grower Group recommendation. Studies have been carried out in 2010 in Tebas Sungai village, Sambas district, with 11 tangerine groves owned by growers in the Citrus grower Association of Sambas district. The tangerine grove that been used are, one grower's orchard as a demonstration plot in a particular citrus grower group (orchard I; five other citrus orchards with different ownership at the same citrus grower Group (orchard II, as well as five other citrus orchard with different ownership which each of them spreads over five different citrus grower groups outside the farm demonstration plots (orchard III. The recommendation technology for controlling Huanglongbing vector which applied in this experiment, included bark painting by systemic insecticide of imidacloprid for two each 1.5-month and spray using contact insecticide with dimethoate to the plant crown which application time been alternated after bark painting application. The effectiveness of technology implementation is measured by a decrease psyllid populations found in citrus samples in adult stage, nymphs and eggs that were observed at regular intervals every two weeks during the flushing to the 14th week after the first treatment. The results showed that recommended treatment technology were absolutely proven to reduce Huanglongbing vector population in significant, namely in the orchard I, II, and III respectively at 95.3%, 84.7%, and 72% for stage adult; 97.3 %, 80%, and 100% for stage nymphs; and 98.5%, 100% and 100% for the egg stage.

Field Evaluation of Plant Defense Inducers for the Control of Citrus Huanglongbing.

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Li, Jinyun; Trivedi, Pankaj; Wang, Nian

2016-01-01

Huanglongbing (HLB) is currently the most economically devastating disease of citrus worldwide and no established cure is available. Defense inducing compounds are able to induce plant resistance effective against various pathogens. In this study the effects of various chemical inducers on HLB diseased citrus were evaluated in four groves (three with sweet orange and one with mandarin) in Florida (United States) for two to four consecutive growing seasons. Results have demonstrated that plant defense inducers including β-aminobutyric acid (BABA), 2,1,3-benzothiadiazole (BTH), and 2,6-dichloroisonicotinic acid (INA), individually or in combination, were effective in suppressing progress of HLB disease. Ascorbic acid (AA) and the nonmetabolizable glucose analog 2-deoxy-D-glucose (2-DDG) also exhibited positive control effects on HLB. After three or four applications for each season, the treatments AA (60 to 600 µM), BABA (0.2 to 1.0 mM), BTH (1.0 mM), INA (0.1 mM), 2-DDG (100 µM), BABA (1.0 mM) plus BTH (1.0 mM), BTH (1.0 mM) plus AA (600 µM), and BTH (1.0 mM) plus 2-DDG (100 µM) slowed down the population growth in planta of 'Candidatus Liberibacter asiaticus', the putative pathogen of HLB and reduced HLB disease severity by approximately 15 to 30% compared with the nontreated control, depending on the age and initial HLB severity of infected trees. These treatments also conferred positive effect on fruit yield and quality. Altogether, these findings indicate that plant defense inducers may be a useful strategy for the management of citrus HLB.

76 FR 33641 - Safety Zone; The Pacific Grove Feast of Lanterns, Fireworks Display, Pacific Grove, CA

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2011-06-09

...-AA00 Safety Zone; The Pacific Grove Feast of Lanterns, Fireworks Display, Pacific Grove, CA AGENCY... support of the Pacific Grove Feast of Lanterns Fireworks Display. This safety zone is established to... Purpose Pacific Grove Feast of Lanterns will sponsor the Pacific Grove Feast of Lanterns Fireworks Display...

Potential feedstock sources for ethanol production in Florida

Energy Technology Data Exchange (ETDEWEB)

Rahmani, Mohammad [Univ. of Florida, Gainesville, FL (United States); Hodges, Alan [Univ. of Florida, Gainesville, FL (United States)

2015-10-01

This study presents information on the potential feedstock sources that may be used for ethanol production in Florida. Several potential feedstocks for fuel ethanol production in Florida are discussed, such as, sugarcane, corn, citrus byproducts and sweet sorghum. Other probable impacts need to be analyzed for sugarcane to ethanol production as alternative uses of sugarcane may affect the quantity of sugar production in Florida. While citrus molasses is converted to ethanol as an established process, the cost of ethanol is higher, and the total amount of citrus molasses per year is insignificant. Sorghum cultivars have the potential for ethanol production. However, the agricultural practices for growing sweet sorghum for ethanol have not been established, and the conversion process must be tested and developed at a more expanded level. So far, only corn shipped from other states to Florida has been considered for ethanol production on a commercial scale. The economic feasibility of each of these crops requires further data and technical analysis.

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

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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...

The effect of nutritional spray programs applied to mitigate symptoms of Huanglongbing on fruit drop caused by HLB and citrus canker on ‘Hamlin’ orange trees

OpenAIRE

Roberts, P. D.; Rouse, R. E.; Teems, S. S.; Sytsma, R. E.; Shobert, Z.

2014-01-01

Huanglongbing (HLB) was detected in Florida in 2005 and has reached 100% incidence in certain citrus plantings in southwest Florida. The putative causal agent of HLB in Florida is the bacterium Candidatus Liberibacter asiaticus (CLa).  Citrus canker caused by the bacterium Xanthomonas citri subsp. citri is endemic in Florida.  In 2011 and 2012, fruit drop on young ‘Hamlin’ trees with symptoms of HLB and/or citrus canker was particularly severe, with more than 90% fruit drop recorded. Nutritio...

Imidacloprid soil movement under micro-sprinkler irrigation and soil-drench applications to control Asian citrus psyllid (ACP) and citrus leafminer (CLM).

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Fletcher, Evelyn; Morgan, Kelly T; Qureshi, Jawwad A; Leiva, Jorge A; Nkedi-Kizza, Peter

2018-01-01

Imidacloprid (IM) is used to control the Asian Citrus Psyllid (ACP) and citrus leafminer (CLM), which are related to the spread of huanglongbing (HLB or citrus greening) and citrus canker diseases, respectively. In Florida citrus, imidacloprid is mainly soil-drenched around the trees for proper root uptake and translocation into plant canopy to impact ACP and CLM. The objective of this study was to determine the effect of imidacloprid rate, and irrigate amount on concentration of imidacloprid in the soil following drench application to citrus trees in three age classes. The plots were established at the Southwest Florida Research and Education Center, Immokalee, using a randomized complete-block design for three age classes of trees: one-year-old trees (B1), three to five-year-old trees (B2), and eight-year-old trees (B3). The treatments were a combination of two rates each of imidacloprid (1D, 2D) and micro-sprinkling irrigation (1I, 2I). Imidacloprid and bromide (Br-) used as tracer were applied simultaneously. Soil moisture and concentrations of imidacloprid and Br were monitored using soil cores from hand held augers. Soil moisture content (θV) did not differ under two irrigation rates at any given observation day or depth, except following heavy rainfall events. Br- was lost from the observation depths (0-45 cm) about two weeks after soil-drench. Contrarily, imidacloprid persisted for a much longer time (4-8 weeks) at all soil depths, regardless of treatment combinations. The higher retardation of imidacloprid was related to the predominantly unsaturated conditions of the soil (which in turn reduced soil hydraulic conductivities by orders of magnitude), the imidacloprid sorption on soil organic matter, and the citrus root uptake. Findings of this study are important for citrus growers coping with the citrus greening and citrus canker diseases because they suggest that imidacloprid soil drenches can still be an effective control measure of ACP and CLM, and the

7 CFR 905.149 - Procedure for permitting growers to ship tree run citrus fruit.

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2010-01-01

... Fruit § 905.149 Procedure for permitting growers to ship tree run citrus fruit. (a) Tree run citrus fruit. Tree run citrus fruit as referenced in this section is defined in the Florida Department of... grower shall apply to ship tree run fruit using a Grower Tree Run Certificate Application, furnished by...

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.

Avocado pests in Florida: Not what you expected

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Avocado, Persea americana Mill., is Florida's second most important fruit crop after citrus. Until recently, the complex of spider mite and insect pests that affected avocado in south Florida was under a 20 year Integrated Pest Management (IPM) program. The recent invasion of avocado orchards by a...

Bacterial diversity analysis of Huanglongbing pathogen-infected citrus, using PhyloChip and 16S rRNA gene clone library sequencing

Energy Technology Data Exchange (ETDEWEB)

Shankar Sagaram, U.; DeAngelis, K.M.; Trivedi, P.; Andersen, G.L.; Lu, S.-E.; Wang, N.

2009-03-01

The bacterial diversity associated with citrus leaf midribs was characterized 1 from citrus groves that contained the Huanglongbing (HLB) pathogen, which has yet to be cultivated in vitro. We employed a combination of high-density phylogenetic 16S rDNA microarray and 16S rDNA clone library sequencing to determine the microbial community composition of symptomatic and asymptomatic citrus midribs. Our results revealed that citrus leaf midribs can support a diversity of microbes. PhyloChip analysis indicated that 47 orders of bacteria from 15 phyla were present in the citrus leaf midribs while 20 orders from phyla were observed with the cloning and sequencing method. PhyloChip arrays indicated that nine taxa were significantly more abundant in symptomatic midribs compared to asymptomatic midribs. Candidatus Liberibacter asiaticus (Las) was detected at a very low level in asymptomatic plants, but was over 200 times more abundant in symptomatic plants. The PhyloChip analysis was further verified by sequencing 16S rDNA clone libraries, which indicated the dominance of Las in symptomatic leaves. These data implicate Las as the pathogen responsible for HLB disease. Citrus is the most important commercial fruit crop in Florida. In recent years, citrus Huanglongbing (HLB), also called citrus greening, has severely affected Florida's citrus production and hence has drawn an enormous amount of attention. HLB is one of the most devastating diseases of citrus (6,13), characterized by blotchy mottling with green islands on leaves, as well as stunting, fruit decline, and small, lopsided fruits with poor coloration. The disease tends to be associated with a phloem-limited fastidious {alpha}-proteobacterium given a provisional Candidatus status (Candidatus Liberobacter spp. later changed to Candidatus Liberibacter spp.) in nomenclature (18,25,34). Previous studies indicate that HLB infection causes disorder in the phloem and severely impairs the translocation of assimilates in

First derivative versus absolute spectral reflectance of citrus varieties

Science.gov (United States)

Blazquez, Carlos H.; Nigg, H. N.; Hedley, Lou E.; Ramos, L. E.; Sorrell, R. W.; Simpson, S. E.

1996-06-01

Spectral reflectance measurements from 400 to 800 nm were taken from immature and mature leaves of grapefruit ('McCarty' and 'Rio Red'), 'Minneola' tangelo, 'Satsuma' mandarin, 'Dancy' tangerine, 'Nagami' oval kumquat, and 'Valencia' sweet orange, at the Florida Citrus Arboretum, Division of Plant Industry, Winter Haven, Florida. Immature and mature leaves of 'Minneola' tangelo had greater percent reflectance in the 400 to 800 nm range than the other varieties and leaf ages measured. The slope of the citrus spectral curves in the 800 nm range was not as sharp as conventional spectrometers, but had a much higher reflectance value than those obtained with a DK-2 spectrometer. Statistical analyses of absolute spectral data yielded significant differences between mature and immature leaves and between varieties. First derivative data analyses did not yield significant differences between varieties.

'Psyllid purple’: evidence of behavior-based utilization by the Asian citrus psyllid of a combination of short and long wavelengths

Science.gov (United States)

The Asian citrus psyllid, Diaphorina citri, is the vector of huanglongbing, the most serious disease affecting citrus globally. In Florida alone, D. citri has resulted in billions of dollars of damage and has spread to all the citrus growing regions of North America. The visual behavior of D. citri ...

Repellent Activity of Botanical Oils against Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae).

Science.gov (United States)

Kuhns, Emily H; Martini, Xavier; Hoyte, Angel; Stelinski, Lukasz L

2016-07-14

The Asian citrus psyllid, Diaphorina citri Kuwayama, is the insect vector of the pathogen causing huanglongbing. We selected three botanical oils to evaluate behavioral activity against D. citri. In laboratory olfactometer assays, fir oil was repellent to D. citri females, while litsea and citronella oils elicited no response from D. citri females. In choice settling experiments, D. citri settled almost completely on control plants rather than on plants treated with fir oil at a 9.5 mg/day release rate. Therefore, we conducted field trials to determine if fir oil reduced D. citri densities in citrus groves. We found no repellency of D. citri from sweet orange resets that were treated with fir oil dispensers releasing 10.4 g/day/tree as compared with control plots. However, we found a two-week decrease in populations of D. citri as compared with controls when the deployment rate of these dispensers was doubled. Our results suggest that treatment of citrus with fir oil may have limited activity as a stand-alone management tool for D. citri and would require integration with other management practices.

Birds of sacred groves of northern Kerala, India

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K. M. Jyothi

2015-12-01

Full Text Available Sacred groves are patches of vegetation preserved due to  religious or cultural tradition.  They are protected through spiritual beliefs.  Sacred groves provide an excellent abode to the biodiversity of the region where they are located.   Scientific exploration of fauna from sacred groves of India is few and far between.  The present study was conducted to explore the bird diversity and abundance in 15 selected sacred groves of northern Kerala, eight from Kannur District and seven from Kasargod District each.  A total of 111 bird species were observed belonging to 49 families and 16 orders.  The sacred groves of northern Kerala support many of the ‘forest-birds’ such as the Grey Junglefowl Gallus sonneratii, Asian Fairy-bluebird Irena puella, Tickell’s Blue-flycatcher Cyornis tickelliae, Malabar Trogon Harpactes fasciatus, Heart-spotted Woodpecker Hemicircus canente, Malabar Whistling-Thrush Myophonus horsfieldii, Little Spiderhunter Arachnothera longirostra, etc.  The sacred groves of northern Kerala also support two endemic bird species of the Western Ghats, such as the Malabar Grey Hornbill Ocyceros griseus and Rufous Babbler Turdoides subrufa. Five species of raptors and four owl species were reported from the sacred groves of north Kerala during the present study.  The breeding of the White-bellied Sea-Eagle has been reported at Edayilakadu Kavu, a sacred grove in Kasargod District.  The sacred groves of northern Kerala also supported 17 species of long distant migratory birds.  Thazhe Kavu, recorded the Black-headed Ibis Threskiornis melanocephalus, a Near-Threatened bird according to IUCN. 

Temperature studies with the Asian citrus psyllid, Diaphorina citri: cold hardiness and temperature thresholds for oviposition.

Science.gov (United States)

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 discovered during 2005. Little was known regarding cold hardiness of D. citri, but Florida citrus is occasionally subjected to notable freeze events. Temperature and duration were each significant sources of variation in percent mortality of D. citri subjected to freeze events. Relatively large percentages of adults and nymphs survived after being exposed for several hours to temperatures as low as -5 to -6 °C. Relatively large percentages of eggs hatched after being exposed for several hours to temperatures as low as -8 °C. Research results indicated that adult D. citri become cold acclimated during the winter through exposure to cooler winter temperatures. There was no evidence that eggs became cold acclimated during winter. Cold acclimation in nymphs was not investigated. Research with adult D. citri from laboratory and greenhouse colonies revealed that mild to moderate freeze events were usually nonlethal to the D. citri irrespective of whether they were cold acclimated or not. Upper and lower temperature thresholds for oviposition were investigated because such information may be valuable in explaining the geographic distribution and potential spread of the pest from Florida as well as how cooler winter temperatures might limit population growth. The estimated lower and upper thresholds for oviposition were 16.0 and 41.6 °C, respectively; the estimated temperature of peak oviposition over a 48 h period was 29.6 °C.

Analyses of Mitogenome Sequences Revealed that Asian Citrus Psyllids (Diaphorina citri) from California Were Related to Those from Florida.

Science.gov (United States)

Wu, Fengnian; Kumagai, Luci; Cen, Yijing; Chen, Jianchi; Wallis, Christopher M; Polek, MaryLou; Jiang, Hongyan; Zheng, Zheng; Liang, Guangwen; Deng, Xiaoling

2017-08-31

Asian citrus psyllid (ACP, Diaphorina citri Kuwayama) transmits "Candidatus Liberibacter asiaticus" (CLas), an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB). CLas has recently been found in California. Understanding ACP population diversity is necessary for HLB regulatory practices aimed at reducing CLas spread. In this study, two circular ACP mitogenome sequences from California (mt-CApsy, ~15,027 bp) and Florida (mt-FLpsy, ~15,012 bp), USA, were acquired. Each mitogenome contained 13 protein coding genes, 2 ribosomal RNA and 22 transfer RNA genes, and a control region varying in sizes. The Californian mt-CApsy was identical to the Floridian mt-FLpsy, but different from the mitogenome (mt-GDpsy) of Guangdong, China, in 50 single nucleotide polymorphisms (SNPs). Further analyses were performed on sequences in cox1 and trnAsn regions with 100 ACPs, SNPs in nad1-nad4-nad5 locus through PCR with 252 ACP samples. All results showed the presence of a Chinese ACP cluster (CAC) and an American ACP cluster (AAC). We proposed that ACP in California was likely not introduced from China based on our current ACP collection but somewhere in America. However, more studies with ACP samples from around the world are needed. ACP mitogenome sequence analyses will facilitate ACP population research.

Phytosociological studies of the sacred grove of Kanyakumari district, Tamilnadu, India

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S. Sukumaran

2018-04-01

Full Text Available Sacred groves are forest patches conserved by the local people through religious and cultural practices. These groves are important reservoirs of biodiversity, preserving indigenous plant species and serving as asylum of Rare, Endangered and Threatened (RET species. The present study was carried out in Muppuram coastal sacred grove of Kanyakumari district to reveal the plant diversity, structure and regeneration pattern of trees using quadrate method. About 102 plant species were recorded from the total area (0.2 ha of the grove studied. The vegetation of the grove clearly indicates tropical dry evergreen forest. Malvaceae was the dominant family. Young plant species were dominating than older ones (> 160 cm. To avoid the rapid environmental degradation of the sacred grove, conserving the groves is urgent and it is necessary to conduct more researches on this grove as well as other groves of the district.

77 FR 41709 - Common Crop Insurance Regulations; Florida Citrus Fruit Crop Insurance Provisions

Science.gov (United States)

2012-07-16

... fees from limited resource farmers. FCIC believes this waiver helps to ensure that small entities are... farmers. FCIC is proposing to change the term ``citrus fruit crop'' to ``citrus fruit commodity'' and to.... Abandoned orchards harbor disease and insects, which without proper control measures and remediation efforts...

Whole plant destructive screening for huanglongbing susceptibility with conetainer seedlings exposed to no-choice Asian citrus psyllid inoculation

Science.gov (United States)

Huanglongbing (HLB) is associated with Candidatus Liberibacter asiaticus (Las) and is vectored by the Asian Citrus Psyllid (ACP, Diaphorina citri). HLB is devastating the Florida citrus industry, with production reduced by 60 percent in the last 12 years, and HLB is considered the greatest threat to...

Repellent Activity of Botanical Oils against Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

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Emily H. Kuhns

2016-07-01

Full Text Available The Asian citrus psyllid, Diaphorina citri Kuwayama, is the insect vector of the pathogen causing huanglongbing. We selected three botanical oils to evaluate behavioral activity against D. citri. In laboratory olfactometer assays, fir oil was repellent to D. citri females, while litsea and citronella oils elicited no response from D. citri females. In choice settling experiments, D. citri settled almost completely on control plants rather than on plants treated with fir oil at a 9.5 mg/day release rate. Therefore, we conducted field trials to determine if fir oil reduced D. citri densities in citrus groves. We found no repellency of D. citri from sweet orange resets that were treated with fir oil dispensers releasing 10.4 g/day/tree as compared with control plots. However, we found a two-week decrease in populations of D. citri as compared with controls when the deployment rate of these dispensers was doubled. Our results suggest that treatment of citrus with fir oil may have limited activity as a stand-alone management tool for D. citri and would require integration with other management practices.

Genetic variation of Anastrepha suspensa (Diptera: Tephritidae) in Florida and the Caribbean using microsatellite DNA markers.

Science.gov (United States)

Boykin, Laura M; Shatters, Robert G; Hall, David G; Dean, David; Beerli, Peter

2010-12-01

Anastrepha suspensa (Loew) (Diptera: Tephritidae), the Caribbean fruit fly, is indigenous to Florida and the Greater Antilles where it causes economic losses in fruit crops, including citrus. Because of the geographic separation of many of its native locations and anecdotal descriptions of regional differences in host preferences, there have been questions about the population structure of A. suspensa. Seven DNA microsatellite markers were used to characterize the population genetic structure of A. suspensa, in Florida and the Caribbean from a variety of hosts, including citrus. We genotyped 729 A. suspensa individuals from Florida, Puerto Rico, Cayman Island, Dominican Republic, and Jamaica. The investigated seven loci displayed from 5 to 19 alleles, with expected heterozygosities ranging from 0.05 to 0.83. There were five unique alleles in Florida and three unique alleles in the Caribbean samples; however, no microsatellite alleles were specific to a single host plant. Genetic diversity was analyzed using F(ST) and analysis of molecular variance and revealed low genetic diversity between Florida and Caribbean samples and also between citrus and noncitrus samples. Analyses using migrate revealed there is continuous gene flow between sampling sites in Florida and the Caribbean and among different hosts. These results support previous comparisons based on the mitochondrial cytochrome oxidase I locus indicating there is no genetic differentiation among locations in Florida and the Caribbean and that there is no separation into host races.

Sacred Groves, Spirituality and Sustainable Development in ...

African Journals Online (AJOL)

Since creation, mankind has strived to maintain a positive relationship with nature by preserving and making certain specific trees, water bodies, highlands and other places sacred. The practice of keeping sacred groves is one of the ways which promotes this human, ecological and spiritual connection. These groves ...

Non-phytoseiid Mesostigmata within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants and additional collection records of mites in citrus orchards.

Science.gov (United States)

Childers, Carl C; Ueckermann, Eduard A

2015-03-01

Seven citrus orchards on reduced- to no-pesticide spray programs in central and south central Florida were sampled for non-phytoseiid mesostigmatid mites. Inner and outer canopy leaves, fruits, twigs and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. A total of 431 samples from one or more of 82 vine or ground cover plants were sampled monthly in five of the seven orchards. Two of the seven orchards (Mixon I and II) were on full herbicide programs and vines and ground cover plants were absent. A total of 2,655 mites (26 species) within the families: Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae were identified. A total of 685 mites in the genus Asca (nine species: family Ascidae) were collected from within tree samples, 79 from vine or ground cover plants. Six species of Blattisociidae were collected: Aceodromus convolvuli, Blattisocius dentriticus, B. keegani, Cheiroseius sp. near jamaicensis, Lasioseius athiashenriotae and L. dentatus. A total of 485 Blattisociidae were collected from within tree samples compared with 167 from vine or ground cover plants. Low numbers of Laelapidae and Macrochelidae were collected from within tree samples. One Zygoseius furciger (Pachylaelapidae) was collected from Eleusine indica. Four species of Melicharidae were identified from 34 mites collected from within tree samples and 1,190 from vine or ground cover plants: Proctolaelaps lobatus was the most abundant species with 1,177 specimens collected from seven ground cover plants. One Phorytocarpais fimetorum (Parasitidae) was collected from inner leaves and four from twigs. Species of Ascidae, Blattisociidae, Melicharidae, Laelapidae and Pachylaelapidae were collected from 31 of the 82 vine or ground cover plants sampled, representing only a small fraction of the total number of Phytoseiidae collected from the same plants. Including the

Seasonal nitrogen budgets of mature citrus trees on a sandy entisol

NARCIS (Netherlands)

Morgan, K.; Scholberg, J.M.S.; Obreza, T.; Wheaton, T.

2012-01-01

Approximately 30% of Florida citrus is grown on well-drained Entisols with low nutrient-holding capacity, which are prone to high nitrogen (N) leaching losses. However, increasing application frequency of N-fertilizer via multiple fertigations does not increase crop yield, whereas in agronomic

First report of Cilevirus associated with green ringspot on senescent hibiscus leaves in Tampa, Florida

Science.gov (United States)

The genus Cilevirus includes plant and mite associated viruses with single stranded and positive sense bipartite genomes. The type member of the genus is Citrus leprosis virus, which causes an important disease of citrus in South America, but is not known to occur in Florida. Symptoms of the disea...

Quality Matters: Influences of Citrus Flush Physicochemical Characteristics on Population Dynamics of the Asian Citrus Psyllid (Hemiptera: Liviidae.

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Mamoudou Sétamou

Full Text Available Studies were conducted to relate the influence of the physical characteristics, leaf nutrient content and phloem sap amino acid concentration of citrus flush shoots on the densities of various Diaphorina citri life stages. Adult D. citri preferentially selected young shoots for feeding and numbers of D. citri immatures were positively correlated with flush shoot softness. Young flush shoots had higher concentrations of macro and micro nutrients relative to mature ones and this was associated with higher densities of all D. citri life stages. All D. citri life stages were positively correlated with higher nitrogen-carbon (N:C, nitrogen:sulfur (N:S and nitrogen:calcium (N:Ca ratios in leaf tissue, while densities of adults were negatively related to calcium, manganese and boron levels. Concentrations of total and essential amino acids were highest in phloem sap of young expanding flush shoots in both grapefruit and lemon, but dramatically declined as flush shoots matured. The sulfur-containing amino acids cystine, methionine and taurine occurred only in younger flush shoots. In contrast, cystathionine was only present in phloem sap of mature shoots. These results clearly indicate that young citrus flush shoots are a nutritionally richer diet relative to mature shoots, thus explaining their preference by D. citri for feeding and reproduction. Conversely, tissue hardness and the lower nutritional quality of mature flush shoots may limit oviposition and immature development. The data suggest that both physical characteristics and nutritional composition of flush shoots and their phloem sap are important factors regulating host colonization and behavior of D. citri, and this interaction can impact the dynamics and spread of HLB in citrus groves.

Quality Matters: Influences of Citrus Flush Physicochemical Characteristics on Population Dynamics of the Asian Citrus Psyllid (Hemiptera: Liviidae)

Science.gov (United States)

Simpson, Catherine R.; Alabi, Olufemi J.; Nelson, Shad D.; Telagamsetty, Srilakshmi; Jifon, John L.

2016-01-01

Studies were conducted to relate the influence of the physical characteristics, leaf nutrient content and phloem sap amino acid concentration of citrus flush shoots on the densities of various Diaphorina citri life stages. Adult D. citri preferentially selected young shoots for feeding and numbers of D. citri immatures were positively correlated with flush shoot softness. Young flush shoots had higher concentrations of macro and micro nutrients relative to mature ones and this was associated with higher densities of all D. citri life stages. All D. citri life stages were positively correlated with higher nitrogen-carbon (N:C), nitrogen:sulfur (N:S) and nitrogen:calcium (N:Ca) ratios in leaf tissue, while densities of adults were negatively related to calcium, manganese and boron levels. Concentrations of total and essential amino acids were highest in phloem sap of young expanding flush shoots in both grapefruit and lemon, but dramatically declined as flush shoots matured. The sulfur-containing amino acids cystine, methionine and taurine occurred only in younger flush shoots. In contrast, cystathionine was only present in phloem sap of mature shoots. These results clearly indicate that young citrus flush shoots are a nutritionally richer diet relative to mature shoots, thus explaining their preference by D. citri for feeding and reproduction. Conversely, tissue hardness and the lower nutritional quality of mature flush shoots may limit oviposition and immature development. The data suggest that both physical characteristics and nutritional composition of flush shoots and their phloem sap are important factors regulating host colonization and behavior of D. citri, and this interaction can impact the dynamics and spread of HLB in citrus groves. PMID:28030637

Expression patterns of flowering genes in leaves of 'Pineapple' sweet orange [Citrus sinensis (L.) Osbeck] and pummelo (Citrus grandis Osbeck).

Science.gov (United States)

Pajon, Melanie; Febres, Vicente J; Moore, Gloria A

2017-08-30

In citrus the transition from juvenility to mature phase is marked by the capability of a tree to flower and fruit consistently. The long period of juvenility in citrus severely impedes the use of genetic based strategies to improve fruit quality, disease resistance, and responses to abiotic environmental factors. One of the genes whose expression signals flower development in many plant species is FLOWERING LOCUS T (FT). In this study, gene expression levels of flowering genes CiFT1, CiFT2 and CiFT3 were determined using reverse-transcription quantitative real-time PCR in citrus trees over a 1 year period in Florida. Distinct genotypes of citrus trees of different ages were used. In mature trees of pummelo (Citrus grandis Osbeck) and 'Pineapple' sweet orange (Citrus sinensis (L.) Osbeck) the expression of all three CiFT genes was coordinated and significantly higher in April, after flowering was over, regardless of whether they were in the greenhouse or in the field. Interestingly, immature 'Pineapple' seedlings showed significantly high levels of CiFT3 expression in April and June, while CiFT1 and CiFT2 were highest in June, and hence their expression induction was not simultaneous as in mature plants. In mature citrus trees the induction of CiFTs expression in leaves occurs at the end of spring and after flowering has taken place suggesting it is not associated with dormancy interruption and further flower bud development but is probably involved with shoot apex differentiation and flower bud determination. CiFTs were also seasonally induced in immature seedlings, indicating that additional factors must be suppressing flowering induction and their expression has other functions.

Evaluating Sustainable Competitive Advantages in Brazilian and U.S. Processed Citrus Supply Chains: An Application of Porter’s Diamond Framework

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James A. Sterns

2010-05-01

Full Text Available 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. Although Sao Paulo and Florida produce a similar product, the Porter’s Diamond framework reveals that there are significant diffences in the organizational structure of the two industries. The article concludes with an analysis of how these differences will impact each industry’s ability to sustain its global leadership in the international processed citrus market.

Zero-inflated beta regression model for leaf citrus canker incidence in orange genotypes grafted onto different rootstocks

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Oilson Alberto Gonzatto Junior

2017-06-01

Full Text Available Data with excess zeros are frequently found in practice, and the recommended analysis is to use models that adequately address the counting of zero observations. In this study, the Zero Inflated Beta Regression Model (BeZI was used on experimental data to describe the mean incidence of leaf citrus canker in orange groves under the influence of genotype and rootstocks of origin. Based on the model, it was possible to quantify the odds that a null observation to mean incidence comes from a particular plant according to genotype and rootstock, and estimate its expected value according to this combination. Laranja Caipira rootstock proved to be the most resistant to leaf citrus canker as well as Limão Cravo proved to be the most fragile. The Ipiguá IAC, Arapongas, EEL and Olímpia genotypes have statistically equivalent chances.

Evaluation of the effects of light source and plant materials in psyllid trapping levels in the traps for citrus shipping containers

Science.gov (United States)

The Asian citrus psyllid (ACP), the principle vector for Huanglongbing (HLB), has been reported to be transported in truckloads of oranges in Florida. Citrus, especially Key limes and lemons, are shipped to the U.S. from Mexican states that are heavily infested with HLB and live, infected psyllids c...

Geographical Assessment of Sacred Groves in Bolpur Sub-division ...

African Journals Online (AJOL)

Dr Osondu

area). Methodology. A total 41 different Sacred Groves in Bolpur sub- division area were randomly ... as breeding sites for some animals and recreational facilities. Groves of Bolpur ..... Cockroach(Periplaneta anericane),Black bee. Reptiles.

Genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens.

Science.gov (United States)

Li, Wenbin; Song, Qijian; Brlansky, Ronald H; Hartung, John S

2007-11-20

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 the geographic distribution and genetic diversity of the pathogen in the past. However, no method was available to assess the genetic diversity within these herbarium samples. We have developed a method, insertion event scanning (IES), and applied the method to characterize the diversity present within CBC populations documented as herbarium specimens over the past century. IES is based on the specific amplification of junction fragments that define insertion events. The potential for IES in current forensic applications is demonstrated by finding an exact match of pathogen genotypes preserved in herbarium specimens from Japan and Florida, demonstrating the source of the original outbreak of citrus canker in Florida in 1911. IES is a very sensitive technique for differentiating bacterial strains and can be applied to any of the several hundred bacteria for which full genomic sequence data are available.

The effect of urban waste compost applied in a vineyard, olive grove and orange grove on soil proprieties in Mediterranean environment

Science.gov (United States)

Novara, Agata; Gristina, Luciano; Bono, Giuseppe; Guaitoli, Fabio; Pasciuta, Giuseppe; Santoro, Antonino

2013-04-01

The application to soil of compost produced from urban wastes not only could improve the soil properties but also could be a solution for disposal of large quantities of different refuses. Knowledge on compost characteristic, soil properties as well as on mineral crop nutrition are important to proper management of fertilization with compost and to understanding the impact on C and N dynamics in field. We present the results of soil physical and chemical changes after the application of urban waste compost in three different orchards (vineyard, olive grove, and orange grove) in Mediterranean environment (Sicily). The compost was applied on November 2010 and samples were collected 1 month after application for two years. Soil pH, carbon content, weight of soil aggregate fractions, nitrate content were examined during the trial, comparing with adjacent no fertilized plot. The application of compost caused a decrease in soil organic carbon stock of 14% and 28% after two years in vineyard and orange grove, respectively, while a significant increase under olive grove was registered. Nitrate monitoring showed for all crops high content of Nitrate for most of the year that involved SOC stock depletion. This was not observed in olive grove, where soil received further C input thanks to soil management with cover crop. In two years of observations there were no significant change in soil physic properties.

Compatibility of Isaria fumosorosea (Hypocreales: Cordycipitaceae Blastospores with Agricultural Chemicals Used for Management of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

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Pasco B. Avery

2013-11-01

Full Text Available Biorational insecticides are being increasingly emphasized for inclusion in integrated pest management programs for invasive insects. The entomopathogenic fungus, Isaria fumosorosea, can be used to help manage the Asian citrus psyllid with minimal impact on beneficial arthropods, but its effectiveness may be compromised by agrochemicals used to control concurrent arthropod pests and diseases. We evaluated the compatibility of I. fumosorosea blastospores with a range of spray oils and copper-based fungicides registered for use in citrus groves. Results of laboratory and greenhouse tests showed a range of responses of the fungus to the different materials, including compatibility and incompatibility. Overall, I. fumosorosea growth in vitro was reduced least by petroleum-based materials and most by botanical oils and borax, and some of the copper-based fungicides, suggesting that tank mixing of I. fumosorosea with these latter products should be avoided. However, equivalent negative effects of test materials on fungal pathogenicity were not always observed in tests with adult psyllids. We hypothesize that some oils enhanced adherence of blastospores to the insect cuticle, overcoming negative impacts on germination. Our data show that care should be taken in selecting appropriate agrochemicals for tank-mixing with commercial formulations of entomopathogenic fungi for management of citrus pests. The prospects of using I. fumosorosea for managing the invasive Asian citrus psyllid and other citrus pests are discussed.

Nonlinear models for describing the Citrus Variegated Chlorosis in groves of two counties at northwestern Paraná state, Brazil = Modelo não-linear para a curva de progresso de incidência da Clorose Variegada dos Citros (CVC em dois municípios da região noroeste do Estado do Paraná

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Clara Matiko Ueda

2010-10-01

Full Text Available In Brazil, the production of sweet oranges has been threatened by the Citrus Variegated Chlorosis (CVC incited by the gram-negative bacterium Xylella fastidiosa (Wells. Commercial citrus groves in two counties at the Northwestern Paraná state were evaluated to estimate the disease progression by using parameterizations of nonlinear models. Groves of Citrus sinensis Osbeck, variety “Pêra”, “Valência”, “Natal” and “Folha Murcha” had all the plants evaluated for the presence of disease symptoms. Thereafter, different parameterizations of the Logistic and Gompertz models were fitted to these data. The goodness of fit was evaluated by the intrinsic (IN and parameter-effects (PE curvatures of Bates and Watts, the bias of Box and the Hougaard measures of skewness. In Loanda, the best model was the Fermi-Dirac, and in Nova Esperança the data were best fitted to the parameterization L5, which is also a parameterization from the Logistic model.A citricultura é afetada por diversas doenças, dentre as quais a Clorose Variegada dos Citros (CVC causada pela bactéria Xylella fastidiosa (Wells. Para a região noroeste do Estado do Paraná, onde foi avaliada a CVC, propõe-se encontrar modelos não-lineares de curvas de progresso de incidência da CVC que representem o percentual de plantas acometidas pela doença. Para avaliar o comprometimento dos pomares com relação à doença, foram escolhidos pomares comerciais em dois municípios, onde foi determinada a proporção de plantas doentes. Foram selecionados talhões de laranja doce (Citrus sinensis Osbeck nas variedades “Pêra”, “Valência”, “Natal” e “Folha Murcha” e a avaliação de todas as plantas do talhão foi realizada visualmente em relação à presença ou à ausência de sintomas de CVC. Para estimar o modelo que melhor se ajustou aos dados de progresso da proporção da doença em cada talhão, foram considerados modelos não-lineares decrescimento sigmoidal

Inventory of drainage wells and potential sources of contaminants to drainage-well inflow in Southwest Orlando, Orange County, Florida

Science.gov (United States)

Taylor, George Fred

1993-01-01

Potential sources of contaminants that could pose a threat to drainage-well inflow and to water in the Floridan aquifer system in southwest Orlando, Florida, were studied between October and December 1990. Drainage wells and public-supply wells were inventoried in a 14-square-mile area, and available data on land use and activities within each drainage well basin were tabulated. Three public-supply wells (tapping the Lower Floridan aquifer) and 38 drainage wells (open to the Upper Floridan aquifer) were located in 17 drainage basins within the study area. The primary sources of drainage-well inflow are lake overflow, street runoff, seepage from the surficial aquifer system, and process-wastewater disposal. Drainage-well inflow from a variety of ares, including resi- dential, commercial, undeveloped, paved, and industrial areas, are potential sources of con- taminants. The four general types of possible contaminants to drainage-well inflow are inorganic chemicals, organic compounds, turbidity, and microbiological contaminants. Potential contami- nant sources include plant nurseries, citrus groves, parking lots, plating companies, auto- motive repair shops, and most commonly, lake- overflow water. Drainage wells provide a pathway for contaminants to enter the Upper Floridan aquifer and there is a potential for contaminants to move downward from the Upper Floridan to the Lower Floridan aquifer.

Sexual behavior and diel activity of citrus fruit borer Ecdytolopha aurantiana.

Science.gov (United States)

Bento, J M; Parra, J R; Vilela, E F; Walder, J M; Leal, W S

2001-10-01

Males and virgin females of the citrus fruit borer Ecdytolopha aurantiana Lima, displayed two flight peaks during a 24-hr period, one at dawn and the other at dusk in an orange grove near Gavião Peixoto, São Paulo, Brazil. During the day, when temperatures were highest and relative humidity lowest, most individuals rested on leaves in the lower and middle crown. Moths rapidly moved higher in the crown after sunset, and many were observed flying above the tree canopy. This behavior was mainly associated with mating. Males and virgin females marked with fluorescent powder of different colors were observed in the dark with the aid of a black light. Mating was observed only in the upper crown of citrus trees from 6:00 to 9:00 PM, with a peak (64%) between 7:00 and 8:00 PM. Males of E. aurantiana were captured in traps baited either with virgin females or female extracts, suggesting the use of a long-range sex pheromone. At close distance (1-2 cm), males and females displayed a short-range communication behavior, with males exposing hairpencils and vibrating their wings. Females were frequently stimulated to contact the body of a male before copulation. The mean duration of copulation was 1 hr 40 min.

Technological Advances in Huanglongbing (HLB or Citrus Greening Disease Management

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Krishna Prasad Paudyal

2015-12-01

Full Text Available Huanglongbing (HLB, previously citrus greening disease, is the most destructive of citrus species causing major threat to the world citrus industry. The disease was reported from China in 1919 and now known to occur in more than 40 different countries of Asia, Africa, South and North America. Three species of gram negative bacterium namely Candidatus Liberibacter asiaticus, Candidatus Liberibacter africanus and Candidatus Liberibacter americanus are the casual organisms of HLB, respectively prevailing in the continent of Asia, Africa and South America. It is one of the most extensively researched subjects in citriculture world. HLB was detected in 2004 and 2005, respectively in San Paulo of Brazil and Florida of USA: the two leading citrus production hub of the world causing huge economic loss within 5 years of first detection. Since then research on HLB detection and management was further accelerated in American continents. This paper presents the scientific advancement made on detection, spread, economic losses caused by HLB in different parts of the world and controlling management strategies. Remarkable achievements have been made on HLB detection techniques including iodine test, qPCR and more recently in spectroscopy. While efforts are being made to develop resistance varieties using conventional and biotechnological tools management strategy which includes reduction of inoculums source, vector control and replant with disease-free planting materials still remains major option for HLB control. Citrus intercropping with guava have shown promising results for vector reduction.

Resistance Management for Asian Citrus Psyllid, Diaphorina citri Kuwayama, in Florida.

Science.gov (United States)

Chen, Xue Dong; Stelinski, Lukasz L

2017-09-20

The Asian citrus psyllid, Diaphorina citri Kuwayma, is one of the most important pests in citrus production. The objective of this study was to evaluate D. citri resistance management with three insecticide rotations and compare them with no rotation and an untreated check. The different insecticides (modes of action) tested were: dimethoate, imidacloprid, diflubenzuron, abamectin 3% + thiamethoxam 13.9%, and fenpropathrin. Eggs, nymph, and adult psyllids were counted weekly. Five insecticide applications were made in 2016. Insecticide susceptibility was determined by direct comparison with a laboratory susceptible population and field populations before and after all treatments were applied. Rankings of eggs, nymphs, and adults counted in treated plots were significantly lower than in the untreated control plots after each application. Initially, the resistance ratio (RR 50 ) for each rotation model, as compared with laboratory susceptible strain and the field population before application, was less than 5.76 and 4.31, respectively. However, after five applications with dimethoate, the RR 50 using the laboratory and pre-treatment field populations was 42.34 and 34.74, respectively. Our results indicate that effectively rotating modes of action can delay and/or prevent development of insecticide resistance in populations of D. citri .

Production, soil erosion and economic failure in new citrus plantations in Eastern Spain

Science.gov (United States)

Giménez Morera, Antonio; Carles membrado, Joan; Cerdà, Artemi; Ángel González Peñaloza, Félix

2013-04-01

Eastern Spain has been worldwide well known by the high quality citrus production (Piqueras, 2012). During the last century, the export of València's oranges contributed to a high income in Spain albeit during the last decade the revenues for the small farmers were short (Bono, 2010). The orange agricultural specialization in València begun at the end of the eighteenth century in the town of Carcaixent, close to the Xúquer river, where the first commercial orange groves were planted. This was due to the climatic conditions (no frosts) and the traditional flood irrigation systems. The orange trade was not important until the second half of the nineteenth century, due to a combination of factors: i) the increasing demand of oranges from the United Kingdom, first, and then from Germany, France and other north-european industrialized countries; ii) the highly productive capacity of the Valencian soil thanks to its mild weather and irrigated fields; iii) the open mindedness of Valencian farmers towards innovation; and, iv) the developemnt of a railways network which made it possible to bring the oranges into the shipment ports (Bono, 2010; Piqueras, 2012). The Valencian orange trade knew its peak during the period 1925-1930 but later it experienced an economic crisis because of wars (both in Spain and Europe) and did not recover until the 1960's (Piqueras, 1999; Bono, 2010). After Spain's EEC (European Economic Community) membership (1986) and the creation of EU (1993) Valencian citrus sector grew: new orange groves were planted, new commercial varieties (especially mandarins) were promoted, and exports increased. Nevertheless, nowadays Valencian orange sector suffers from a structural problem: the small farm size and the lack of a good commercial network of distribution. But in spite of the current crisis, the orange groves' impact on landscape is still huge in Valencia, since it creates a thick forest of orange trees stretching not only the floodplains but also

A Preliminary Assessment of Ethiopian Sacred Grove Status at the Landscape and Ecosystem Scales.

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Alemaheyu Wassie Eshete

2013-04-01

Full Text Available The northern Ethiopian landscape is dotted with small patches of church forests that are religious centers for the Ethiopian Orthodox Tewahido Church (EOTC. These sacred groves are what remain of the once vast tropical Afromontane dry forest. Herein we review the landscape pattern of sacred groves in the Amhara region of Ethiopia, and their local scale nutrient status at two sites, Zahara and Debresena. A total of 1,488 sacred groves were inventoried within the study area, yielding an overall density of one sacred grove for every twenty square kilometers. Sacred groves averaged a little over five hectares and were separated from one another by more than two kilometers. At the local scale we found that soil carbon and nitrogen stocks have decreased significantly between the forest interior and the clearing indicating decreased soil fertility. Together our data indicate that these sacred groves are vulnerable to loss because of their small average size, isolation from seed sources, and decreasing soil status.

Resistance Management for Asian Citrus Psyllid, Diaphorina citri Kuwayama, in Florida

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Xue Dong Chen

2017-09-01

Full Text Available The Asian citrus psyllid, Diaphorina citri Kuwayma, is one of the most important pests in citrus production. The objective of this study was to evaluate D. citri resistance management with three insecticide rotations and compare them with no rotation and an untreated check. The different insecticides (modes of action tested were: dimethoate, imidacloprid, diflubenzuron, abamectin 3% + thiamethoxam 13.9%, and fenpropathrin. Eggs, nymph, and adult psyllids were counted weekly. Five insecticide applications were made in 2016. Insecticide susceptibility was determined by direct comparison with a laboratory susceptible population and field populations before and after all treatments were applied. Rankings of eggs, nymphs, and adults counted in treated plots were significantly lower than in the untreated control plots after each application. Initially, the resistance ratio (RR50 for each rotation model, as compared with laboratory susceptible strain and the field population before application, was less than 5.76 and 4.31, respectively. However, after five applications with dimethoate, the RR50 using the laboratory and pre-treatment field populations was 42.34 and 34.74, respectively. Our results indicate that effectively rotating modes of action can delay and/or prevent development of insecticide resistance in populations of D. citri.

Hydrogen cyanamide on citrus: preliminary data on phytotoxicity and influence on flush in potted and field trees

Science.gov (United States)

Bloom in individual citrus trees typically continues for more than a month in south Florida, with even greater bloom duration within most orchard blocks because of variation in bloom timing between trees. Prolonged bloom contributes to variable fruit maturity as harvest approaches and increases seve...

Agricultural irrigated land-use inventory for Polk County, Florida, 2016

Science.gov (United States)

Marella, Richard L.; Berry, Darbi; Dixon, Joann F.

2017-08-16

An accurate inventory of irrigated crop acreage is not available at the level of resolution needed to better estimate agricultural water use or to project future water demands in many Florida counties. A detailed digital map and summary of irrigated acreage was developed for Polk County, Florida, during the 2016 growing season. This cooperative project between the U.S. Geological Survey and the Office of Agricultural Water Policy of the Florida Department of Agriculture and Consumer Services is part of an effort to improve estimates of water use and projections of future demands across all counties in the State. The irrigated areas were delineated by using land-use data provided by the Florida Department of Agriculture and Consumer Services, along with information obtained from the South and Southwest Florida Water Management Districts consumptive water-use permits. Delineations were field verified between April and December 2016. Attribute data such as crop type, primary water source, and type of irrigation system were assigned to the irrigated areas.The results of this inventory and field verification indicate that during the 2016 growing seasons (spring, summer, fall, and winter), an estimated 88,652 acres were irrigated within Polk County. Of the total field-verified crops, 83,995 acres were in citrus; 2,893 acres were in other non-citrus fruit crops (blueberries, grapes, peaches, and strawberries); 621 acres were in row crops (primarily beans and watermelons); 1,117 acres were in nursery (container and tree farms) and sod production; and 26 acres were in field crops including hay and pasture. Of the total inventoried irrigated acreage within Polk County, 98 percent (86,566 acres) was in the Southwest Florida Water Management District, and the remaining 2 percent (2,086 acres) was in the South Florida Water Management District.About 85,788 acres (96.8 percent of the acreage inventoried) were irrigated by a microirrigation system, including drip, bubblers, and

"Forest Grove School District v. T.A.": The Supreme Court and Unilateral Private Placements

Science.gov (United States)

Yell, Mitchell L.; Katsiyannis, Antonis; Collins, Terri S.

2010-01-01

On June 22, 2009, the U.S. Supreme Court issued its decision in the case "Forest Grove School District v. T.A." (hereafter "Forest Grove"). In "Forest Grove," the High Court answered the question of whether the parents of students with disabilities are entitled to reimbursement for the costs associated with placing…

Guava SSR analysis: Diversity assessment and similarity to accessions associated with reducing citrus greening in Vietnam

Science.gov (United States)

The guava (Psidium guajava) is an evergreen tree in the Myrtaceae, native to tropical America. It is grown throughout the tropics and subtropics of the world, and is used as a fresh fruit and processed into juice, jelly and paste. Recent introduction of citrus greening (huanglongbing) into Florida...

Water Use in Florida, 2005 and Trends 1950-2005

Science.gov (United States)

Marella, Richard L.

2008-01-01

Water is among Florida's most valued resources. The State has more than 1,700 streams and rivers, 7,800 freshwater lakes, 700 springs, 11 million acres of wetlands, and underlying aquifers yielding quantities of freshwater necessary for both human and environmental needs (Fernald and Purdum, 1998). Although renewable, these water resources are finite, and continued growth in population, tourism, and agriculture will place increased demands on these water supplies. The permanent population of Florida in 2005 totaled 17.9 million, ranking fourth in the Nation (University of Florida, 2006); nearly 86 million tourists visited the State (Orlando Business Journal, 2006). In 2005, Florida harvested two-thirds of the total citrus production in the United States and ranked fifth in the Nation net farm income (Florida Department of Agriculture and Consumer Services, 2006). Freshwater is vital for sustaining Florida's population, economy, and agricultural production. Accurate estimates reflecting water use and trends in Florida are compiled in 5-year intervals by the U.S. Geological Survey (USGS) in cooperation with the Florida Department of Environmental Protection (FDEP) and the Northwest Florida, St. Johns River, South Florida, Southwest Florida, and Suwannee River Water Management Districts (Marella, 2004). This coordinated effort provides the necessary data and information for planning future water needs and resource management. The purpose of this fact sheet is to present the highlights of water use in Florida for 2005 along with some significant trends in withdrawals since 1950.

Final work plan : environmental site investigation at Sylvan Grove, Kansas.

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M. (Environmental Science Division)

2012-07-15

In 1998, carbon tetrachloride was found above the maximum contaminant level (MCL) of 5 {micro}g/L in groundwater from one private livestock well at Sylvan Grove, Kansas, by the Kansas Department of Health and Environment (KDHE). The 1998 KDHE sampling was conducted under the U.S. Department of Agriculture (USDA) private well sampling program. The Commodity Credit Corporation (CCC), a USDA agency, operated a grain storage facility in Sylvan Grove from 1954 to1966. Carbon tetrachloride is the contaminant of primary concern at sites associated with former CCC/USDA grain storage operations. Sylvan Grove is located in western Lincoln County, approximately 60 mi west of Salina (Figure 1.1). To determine whether the former CCC/USDA facility at Sylvan Grove is a potential contaminant source and its possible relationship to the contamination in groundwater, the CCC/USDA has agreed to conduct an investigation, in accordance with the Intergovernmental Agreement between the KDHE and the Farm Service Agency (FSA) of the USDA. This Work Plan presents historical data related to previous investigations, grain storage operations, local private wells and public water supply (PWS) wells, and local geologic and hydrogeologic conditions at Sylvan Grove. The findings from a review of all available documents are discussed in Section 2. On the basis of the analyses of historical data, the following specific technical objectives are proposed for the site investigation at Sylvan Grove: (1) Evaluate the potential source of carbon tetrachloride at the former CCC/USDA facility; (2) Determine the relationship of potential contamination (if present) at the former CCC/USDA facility to contamination identified in 1998 in groundwater samples from one private well to the west; and (3) Delineate the extent of potential contamination associated with the former CCC/USDA facility. The detailed scope of work is outlined in Section 3. The results of the proposed work will provide the basis for determining

Status of the Caribbean fruit fly, Anastrepha suspensa (Loew), sterile insect technique programme in the state of Florida, USA - November 1996

International Nuclear Information System (INIS)

Holler, T.C.; Harris, D.L.; Burns, R.E.

1999-01-01

Status of the Caribbean fruit fly, Anastrepha suspensa, Loew, sterile insect technique program in the state of Florida, USA - November 1996. Application of sterilization techniques to Anastrepha suspensa in Florida was conducted as early as 1970 in Key West. In 1988-1990, releases of sterile flies were made in a 20 km 2 urban area in southwestern Florida adjacent to commercial citrus. With the intent to integrate a sterile insect technique system within a fly-free management program for the caribfly, additional tests are being conducted both within a major citrus production area and in an isolated urban location of the mid to lower Florida peninsula. Tests at the former site measures the synergistic effect of augmenting sterile fly releases with parasitoids, whereas the latter studies will define the efficacy of reduced numbers of sterile flies released per acre than is standard in medfly and medfly eradication and suppression programs. Discussed here is the progress of an ongoing project to measure the benefits of SIT as it applies to caribfly export protocols. (author)

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

Science.gov (United States)

2011-04-27

... for all germplasm and budwood destined for propagation in nurseries within the State, construction and... movement of citrus nursery stock is considered to be a high-risk pathway for citrus canker and citrus..., we did not initiate rulemaking at that time to establish such a systems approach. Rather, we decided...

Qualidade física do solo sob sistemas de preparo e cobertura morta em pomar de laranja Soil physical quality under planting and mulching systems in an orange grove

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Jonez Fidalski

2009-01-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito de preparo do solo e de cobertura morta sobre a qualidade física de um Latossolo, em um pomar de laranja 'Pêra'. O experimento foi instalado em Paranavaí, PR, em área com Brachiaria brizantha. O delineamento foi o de blocos ao acaso, em parcelas subsubdivididas, com 12 tratamentos e 4 repetições. Nas parcelas foram estudados os sistemas plantio direto, preparo em faixas e preparo convencional; nas subparcelas, os manejos com e sem cobertura morta, na linha das plantas de laranjeira 'Pêra'; e nas subsubparcelas, os porta-enxertos Citrus limonia Osb. e Citrus reshni Hort. ex Tan. Foram coletadas amostras de solo nas linhas das plantas, sob o rodado e no entrerrodado do trator, para quantificação de densidade, macroporosidade e microporosidade. O plantio direto de laranja em pastagem manteve a qualidade física do solo nas linhas das plantas, no entrerrodado e sob o rodado. O preparo convencional comprometeu a qualidade física do solo sob o rodado. A qualidade física do solo foi favorecida pelo menor revolvimento do solo, resultante do plantio direto ou do preparo em faixas, e pelo manejo da cobertura morta nas linhas das plantas, após o plantio das laranjeiras.The objective of this work was to evaluate the effects of planting and mulching systems on the soil physical quality of a Typic Haplorthox (Rhodic Ferralsol, in a grove cultivated with orange cultivar Pêra. The experiment was established in Paranavaí, PR, Brazil, in a field dominated by the forage grass Brachiaria brizantha. The experiment had a randomized complete block split-split plot design, with 12 treatments and 4 replicates. The main plots were no-tillage, strip-tillage, and conventional tillage systems; in the split plots, systems with or without mulching in plant rows were evaluated; and in the split-split plots, the root stocks Citrus limonia Osb. and Citrus reshni Hort. ex Tan. were evaluated. Soil samples were collected

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

Science.gov (United States)

2013-10-24

... that seed transmission may occur. The pathogen can also be transmitted by two insect vectors in the... by the Secretary prior to movement. Citrus canker is a plant disease that is caused by a complex of....75-6. Citrus greening, also known as Huanglongbing disease of citrus, is considered to be one of the...

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...

Evaluation of Antibacterial Activities of Citrus limon, Citrus reticulata, and Citrus grandis Against Pathogenic Bacteria

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Sholeh Saeb

2016-11-01

Full Text Available Background: Microorganisms resistant to most antibiotics are rapidly spreading, and there is an urgent and continuous need for novel antimicrobial compounds. The genus Citrus belongs to the family Rutaceae has many biologically active secondary metabolites. Objectives: The purpose of this study was to evaluate antimicrobial activity of essential oil and extract of Lemon (Citrus limon, Mandarin (Citrus reticulata and Pummelo (Citrus grandis against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Salmonella typhi. Materials and Methods: The fresh Citrus leaves were shade-dried and powdered. Antimicrobial metabolites were extracted from them by 80% methanol for extract and using a Clevenger-type apparatus for essential oil. Eight different concentrations of the each leaf extract and essential oil were prepared. The antimicrobial susceptibility assay of Citrus leaves metabolites were subjected against four bacterial strains by agar disc diffusion and E-test method. Results: In this study, minimum inhibitory concentrations (MIC of different Citrus leaf extracts were determined against all four food-borne pathogens. The C. grandis leaf essential oil had potent antimicrobial activity against all four pathogens, and the C. limon leaf essential oil was effective on Gram-positive bacteria. S. typhi was resistant against two leaves essential oils. Conclusions: The results showed that there was no antimicrobial activity effect in all extracts on tested bacteria. In this study, the antibacterial effect of essential oil of Citrus leaves on four strains of pathogenic microorganisms was confirmed. The C. grandis leaf essential oil had the most powerful antimicrobial properties, suggesting its potential application as natural preservative in foods or an effective medicine against different pathogenic microbes. Key words: Antibacterial activity, E-test, Citr

Tests with VHR images for the identification of olive trees and other fruit trees in the European Union

Science.gov (United States)

Masson, Josiane; Soille, Pierre; Mueller, Rick

2004-10-01

In the context of the Common Agricultural Policy (CAP) there is a strong interest of the European Commission for counting and individually locating fruit trees. An automatic counting algorithm developed by the JRC (OLICOUNT) was used in the past for olive trees only, on 1m black and white orthophotos but with limits in case of young trees or irregular groves. This study investigates the improvement of fruit tree identification using VHR images on a large set of data in three test sites, one in Creta (Greece; one in the south-east of France with a majority of olive trees and associated fruit trees, and the last one in Florida on citrus trees. OLICOUNT was compared with two other automatic tree counting, applications, one using the CRISP software on citrus trees and the other completely automatic based on regional minima (morphological image analysis). Additional investigation was undertaken to refine the methods. This paper describes the automatic methods and presents the results derived from the tests.

Fortuitous establishment of Ageniaspis citricola (Hymenoptera: Encyrtidae) in Jamaica on the citrus leafminer (Lepidoptera: Gracillariidae)

International Nuclear Information System (INIS)

Hoy, M.A.; Jeyaprakash, A.; Clarke-Harris, D.

2007-01-01

These data indicate that the population of A. citricola in Jamaica probably originated from the Australian (Thailand), rather than from the Taiwan, population. This is consistent with what is currently known about the origin of the established Ageniaspis population in Florida (Alvarez 2000). It is not known when, or how, A. citricola arrived in Jamaica, although the CLM was detected there in 1994. The fortuitous establishment of A. citricolaon the CLM in Jamaica is not the only such establishment of a natural enemy discovered during this 2004 survey of citrus. The parasitoid Lipolexis oregmae Gahan (Hymenoptera: Aphidiidae) was found attacking the brown citrus aphid, Toxoptera citricida Kirkaldy (Hemiptera: Aphididae) (Hoy et al., unpublished data), and the eulophid parasitoid Tamarixia radiata Waterston was found attacking the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). The fact that 3 natural enemies of 3 invasive citrus pests were found in Jamaica, none of which were purposefully imported and released, suggests that pest-infested citrus trees were imported into Jamaica without going through appropriate quarantine procedures. Because each pest arrived at different times, the parasitoids probably arrived at different times, as well. This indicates that an analysis is needed to identify the critical control points within those services in Jamaica that support border protection, and that procedures may require strengthening. (author)

Assessing the Effects of Climate Variability on Orange Yield in Florida to Reduce Production Forecast Errors

Science.gov (United States)

Concha Larrauri, P.

2015-12-01

Orange production in Florida has experienced a decline over the past decade. Hurricanes in 2004 and 2005 greatly affected production, almost to the same degree as strong freezes that occurred in the 1980's. The spread of the citrus greening disease after the hurricanes has also contributed to a reduction in orange production in Florida. The occurrence of hurricanes and diseases cannot easily be predicted but the additional effects of climate on orange yield can be studied and incorporated into existing production forecasts that are based on physical surveys, such as the October Citrus forecast issued every year by the USDA. Specific climate variables ocurring before and after the October forecast is issued can have impacts on flowering, orange drop rates, growth, and maturation, and can contribute to the forecast error. Here we present a methodology to incorporate local climate variables to predict the USDA's orange production forecast error, and we study the local effects of climate on yield in different counties in Florida. This information can aid farmers to gain an insight on what is to be expected during the orange production cycle, and can help supply chain managers to better plan their strategy.

Compatibility and Efficacy of Isaria fumosorosea with Horticultural Oils for Mitigation of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

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Vivek Kumar

2017-10-01

Full Text Available Horticultural oils are an important component of integrated management programs of several phytophagous arthropods and pathogens affecting fruit, ornamentals and vegetables in greenhouse and field production systems. Although effective against the target pest, their incompatibility with biological control agents can compromise efforts to develop eco-friendly management programs for important agricultural pests. In this study, we assessed the in vitro effect of selected refined petroleum oils used in citrus and other horticultural crops with a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea (PFR-97 under laboratory conditions. Further, we used leaf disk bioassays to evaluate the combined efficacy of petroleum oils and I. fumosorosea against the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae, a major pest of citrus in the United States. All five petroleum oil treatments (Orchex, Sun Pure, Conoco Blend -1, Conoco Blend -2, and JMS were compatible with I. fumosorosea blastospores, as none of them were found to affect I. fumosorosea colony-forming units and radial fungal growth measured at 3, 6, 9, and 12 days post-inoculation. All mixed treatments performed better than I. fumosorosea alone against D. citri, where the highest mean survival time of D. citri was 12.5 ± 0.7 days. No significant differences in D. citri survival time and I. fumosorosea growth (fungal development index on dead cadavers, which is important for determining their horizontal transmission, were observed when mixed with Orchex, Sun Pure, Conoco Blend -2, and JMS. Results indicated that horticultural oils in combination with I. fumosorosea could offer citrus growers an alternative treatment for integrating into their current management programs while battling against D. citri in citrus production systems. Due to their eco-friendly, broad-spectrum effect, it could provide control against various citrus pests, while also encouraging the

Compatibility and Efficacy of Isaria fumosorosea with Horticultural Oils for Mitigation of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae).

Science.gov (United States)

Kumar, Vivek; Avery, Pasco B; Ahmed, Juthi; Cave, Ronald D; McKenzie, Cindy L; Osborne, Lance S

2017-10-31

Horticultural oils are an important component of integrated management programs of several phytophagous arthropods and pathogens affecting fruit, ornamentals and vegetables in greenhouse and field production systems. Although effective against the target pest, their incompatibility with biological control agents can compromise efforts to develop eco-friendly management programs for important agricultural pests. In this study, we assessed the in vitro effect of selected refined petroleum oils used in citrus and other horticultural crops with a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea (PFR-97) under laboratory conditions. Further, we used leaf disk bioassays to evaluate the combined efficacy of petroleum oils and I. fumosorosea against the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), a major pest of citrus in the United States. All five petroleum oil treatments (Orchex, Sun Pure, Conoco Blend -1, Conoco Blend -2, and JMS) were compatible with I. fumosorosea blastospores, as none of them were found to affect I. fumosorosea colony-forming units and radial fungal growth measured at 3, 6, 9, and 12 days post-inoculation. All mixed treatments performed better than I. fumosorosea alone against D. citri , where the highest mean survival time of D. citri was 12.5 ± 0.7 days. No significant differences in D. citri survival time and I. fumosorosea growth (fungal development index) on dead cadavers, which is important for determining their horizontal transmission, were observed when mixed with Orchex, Sun Pure, Conoco Blend -2, and JMS. Results indicated that horticultural oils in combination with I. fumosorosea could offer citrus growers an alternative treatment for integrating into their current management programs while battling against D. citri in citrus production systems. Due to their eco-friendly, broad-spectrum effect, it could provide control against various citrus pests, while also encouraging the retention of effective

Final Report: Results of Environmental Site Investigation at Sylvan Grove, Kansas

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine M [Argonne National Lab. (ANL), Argonne, IL (United States)

2014-09-01

Sylvan Grove is located in western Lincoln County, approximately 60 mi west of Salina, Kansas (Figure 1.1). From 1954 to 1966, the Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility at the northeastern edge of Sylvan Grove. During this time, commercial grain fumigants containing carbon tetrachloride were in common use to preserve grain in storage. In 1998, the Kansas Department of Health and Environment (KDHE) found carbon tetrachloride above the maximum contaminant level (MCL) of 5 μg/L in groundwater from one private well used for livestock and lawn and garden watering. The 1998 KDHE sampling at Sylvan Grove was conducted under the USDA private well sampling program. To determine whether the former CCC/USDA facility at Sylvan Grove is a potential contaminant source and its possible relationship to the contamination in groundwater, the CCC/USDA proposed to conduct an environmental site investigation, in accordance with the Intergovernmental Agreement between the KDHE and the Farm Service Agency (FSA) of the USDA. Argonne National Laboratory, on behalf of the CCC/USDA, developed a work plan (Argonne 2012) for the site investigation and a supplemental work plan for indoor and ambient air sampling (Appendix A). The proposed work was approved by the KDHE (2012a, 2013). The investigations were performed by the Environmental Science Division of Argonne National Laboratory, on behalf of the CCC/USDA. The main activities for the site investigation were conducted in June 2012, and indoor and ambient air sampling was performed in February 2013. This report presents the findings of the investigations at Sylvan Grove.

Analyses of mitogenome sequences revealed that Asian citrus psyllid (Diaphorina citri) from California was related to those from Florida but different from those in Southern China

Science.gov (United States)

Asian citrus psyllid (ACP, Diaphorina citri Kuwayama; Hemiptera: Liviidae) transmits “Candidatus Liberibacter asiaticus” (CLas), an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB, yellow shoot disease, also called citrus greening disease). HLB is threatening citrus prod...

Citrus Functional Genomics and Molecular Modeling in Relation to Citrus sinensis (Sweet Orange) Infection with Xylella fastidiosa (Citrus Variegated Chlorosis).

Science.gov (United States)

Dwivedi, Upendra N; Tiwari, Sameeksha; Prasanna, Pragya; Awasthi, Manika; Singh, Swati; Pandey, Veda P

2016-08-01

Citrus are among the economically most important fruit tree crops in the world. Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa infection, is a serious disease limiting citrus production at a global scale. With availability of citrus genomic resources, it is now possible to compare citrus expressed sequence tag (EST) data sets and identify single-nucleotide polymorphisms (SNPs) within and among different citrus cultivars that can be exploited for citrus resistance to infections, citrus breeding, among others. We report here, for the first time, SNPs in the EST data sets of X. fastidiosa-infected Citrus sinensis (sweet orange) and their functional annotation that revealed the involvement of eight C. sinensis candidate genes in CVC pathogenesis. Among these genes were xyloglucan endotransglycosylase, myo-inositol-1-phosphate synthase, and peroxidase were found to be involved in plant cell wall metabolism. These have been further investigated by molecular modeling for their role in CVC infection and defense. Molecular docking analyses of the wild and the mutant (SNP containing) types of the selected three enzymes with their respective substrates revealed a significant decrease in the binding affinity of substrates for the mutant enzymes, thus suggesting a decrease in the catalytic efficiency of these enzymes during infection, thereby facilitating a favorable condition for infection by the pathogen. These findings offer novel agrigenomics insights in developing future molecular targets and strategies for citrus fruit cultivation in ways that are resistant to X. fastidiosa infection, and by extension, with greater harvesting efficiency and economic value.

Influence of the Sting Nematode, Belonolaimus longicaudalus, on Young Citrus Trees.

Science.gov (United States)

Kaplan, D T

1985-10-01

The sting nematode, Belonolaimus longicaudatus, was associated with poor growth of citrus in a central Florida nursery. Foliage of trees was sparse and chlorotic. Affected rootstocks included Changsha and Cleopatra mandarin orange; Flying Dragon, Rubidoux, and Jacobsen trifoliate orange; Macrophylla and Milam lemon; Palestine sweet lime; sour orange; and the hybrids - Carrizo, Morton, and Rusk citrange and Swingle citrumelo. Root symptoms included apical swelling, development of swollen terminals containing 3-5 apical meristems and hyperplastic tissue, coarse roots, and a reduction in the number of fibrous roots. Population densities as high as 392 sting nematodes per liter soil were detected, with 80% of the population occurring in the top 30 cm of soil; however, nematodes were detected to 107 cm deep. Although an ectoparasite, the nematode was closely associated with citrus root systems and was transported with bare root nursery stock. Disinfestation was accomplished by hot water treatment (49 C for 5 minutes).

Influence of Tree Size and Application Rate on Expression of Thiamethoxam in Citrus and Its Efficacy Against Diaphorina citri (Hemiptera: Liviidae).

Science.gov (United States)

Langdon, K W; Schumann, R; Stelinski, L L; Rogers, M E

2018-04-02

Neonicotinoids are a key group of insecticides used to manage Diaphorina citri Kuwayama (Hemiptera: Liviidae), in Florida citrus. Diaphorina citri is the vector of Candidatus Liberibacter asiaticus, the presumed causal agent of huanglongbing, a worldwide disease of citrus. A two-season field study was conducted to evaluate the effect of tree size and application rate on the expression of thiamethoxam in young citrus following application to the soil. D. citri adult and nymph abundance was also correlated with thiamethoxam titer in leaves. Tree size and application rate each significantly affected thiamethoxam titer in leaf tissue. The highest mean thiamethoxam titer observed (33.39 ppm) in small trees (mean canopy volume = 0.08 m3) occurred after application of the high rate (0.74 g Platinum 75SG per tree) tested. There was a negative correlation between both nymph and adult abundance with increasing thiamethoxam titer in leaves. A concentration of 64.63 ppm thiamethoxam was required to reach a 1% probability of encountering a flush shoot with at least one adult D. citri, while 19.05 ppm was required for the same probability of encountering nymphs. The LC90 for the field population was 7.62 ppm thiamethoxam when administered through ingestion. Exposure to dosages as low as 7.62 ppm would likely result in sublethal exposure of some proportion of the population, which could exacerbate resistance development. Based on our results, subsequent work should investigate the use of neonicotinoids by foliar rather than soil application to maintain the chemical class in future insecticide management programs in Florida citrus.

Espécies de cigarrinhas (Hemiptera, Cicadellidae, Cicadellinae em pomares de citros da região de Bebedouro, SP, com descrição de uma espécie nova de Acrogonia Stål

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Rosangela Cristina Marucci

2002-01-01

Full Text Available Sharpshooter leafhoppers (Hemiptera, Cicadellidae, Cicadellinae in citrus groves of the area of Bebedouro, SP, with description of a new species of Acrogonia Stål. Sixteen species of Cicadellidae, subfamily Cicadellinae, were collected and identified: 11 of the tribe Cicadellini and five of the tribe Proconiini. The ten most common species, together with a new species, are characterized based on external morphology and male genitalia: Acrogonia citrina Marucci & Cavichioli sp. nov.; Bucephalogonia xanthophis (Berg, 1879; Dilobopterus costalimai Young, 1977; Ferrariana trivittata (Signoret, 1854; Hortensia similis (Walker, 1851; Macugonalia cavifrons (Stål, 1862; M. leucomelas (Walker, 1851; Oncometopia facialis (Signoret, 1854; Plesiommata corniculata Young, 1977 and P. mollicella (Fowler, 1900. The leafhopper samples were collected in citrus groves and in adjacent habitats (woods, swamp, cultivable plain, spontaneous vegetation of the grove, coffee crop and sugarcane at the counties of Bebedouro and Monte Azul Paulista and in the district of Turvínia. The collecting methods were: insect net, yellow sticky cards, portable suction trap and Malaise trap. Identification keys were elaborated for the 16 species. There is a great diversity of Cicadellinae species in the citric groves. In the three areas sampled, it was collected a larger number of species of the tribe Cicadellini than of the tribe Proconiini. In the Bebedouro area, the vector species of Xylella fastidiosa, A. citrina sp. nov., B. xanthophis, D. costalimai and O. facialis, were collected in the citrus groves and in all adjacent habitats.

Citrus leprosis transmission by Brevipalpus yothersi mites through non citrus hosts

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Guillermo León M.

2017-05-01

Full Text Available Citrus leprosis virus (C i LV was detected in Colombia at the eastern plains in 2004; it is a threat the disease spreads to other regions of the country. The main vector is Brevipalpus yothersi Baker (formerly identified as Brevipalpus phoenicis. This research determined the viability of B. yothersi to transmit C i LV to citrus plants, after been hosted in non-citrus plants. To virus acquisition, mites spent three days on symptomatic orange (Citrus x sinensis leaves positives to C i LV-C2; then mites were placed on six non-citrus plants (Dieffenbachia sp., Hibiscus rosa-sinensis,Codiaeum variegatum, Swinglea glutinosa, Sida acutaand Stachytarpheta cayennensis. A randomized design with 6 treatments and 4 replicates was carried out. After scheduled time in non-citrus plants, mites were three days relocated on C. x sinensis healthy plants. Leaves of receptor plants, were evaluated to the occurrence or absence of symptoms and collected for RT-PCR tests. B. yothersi mites were able to transmit the C i LV virus over 85 % of Valencia orange plants (Citrus x sinensis L., after feeding from 2-20 days on non-citrus host plants. The first leprosis symptoms on C. x sinensis leaves was confirmed from 14 to 51 days after transmission. The present research work further established that C i LV-C2 is a persistently transmitted virus. The implement quarantine diagnostic measures to prevent spread of CiLV to disease-free zones is suggested.

Small RNA profiling reveals phosphorus deficiency as a contributing factor in symptom expression for citrus huanglongbing disease.

Science.gov (United States)

Zhao, Hongwei; Sun, Ruobai; Albrecht, Ute; Padmanabhan, Chellappan; Wang, Airong; Coffey, Michael D; Girke, Thomas; Wang, Zonghua; Close, Timothy J; Roose, Mikeal; Yokomi, Raymond K; Folimonova, Svetlana; Vidalakis, Georgios; Rouse, Robert; Bowman, Kim D; Jin, Hailing

2013-03-01

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.

Harvesting Method Affects Water Dynamics and Yield of Sweet Orange with Huanglongbing

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Said A. Hamido

2018-03-01

Full Text Available Changes in grove management practices may change crop water dynamics. The objective of this study was to estimate sap flow, stem water potential (Ψstem, and citrus yield as affected by harvesting methods in sweet orange (Citrus sinensis trees affected by Huanglongbing. The study was initiated in March 2015 for two years on five-year-old commercial sweet orange trees at a commercial grove located at Felda, Florida (26.61° N, 81.48° W on Felda fine sand soil (Loamy, siliceous, superactive, hyperthermic Arenic Endoaqualfs. All measurements were replicated before and after harvest in four experiments (A, B, C and D under hand and mechanical harvesting treatments. Sap flow measurements were taken on four trees per treatment with two sensors per tree. Sap flow measured by the heat balance method at hourly intervals during March and April of 2015 and 2016 significantly declined after harvesting by 25% and 35% after hand and mechanical harvesting, respectively. Ψstem measured after harvest was significantly higher than measurements before harvest. The average value of Ψstem measured increased by 10% and 6% after hand and mechanical harvesting, respectively. Mechanical harvesting exhibited lower fruit yields that averaged between 83%, 63%, 49% and 36% of hand-harvested trees under A, B, C and D experiments, respectively. It is concluded that the hand harvesting method is less stressful and less impactful on tree water uptake and fruit yield compared with mechanical harvesting.

Natural parasitism of Diaphorina citri Kuwayama (Hemiptera, Psyllidae nymphs by Tamarixia radiata Waterston (Hymenoptera, Eulophidae in São Paulo orange groves Parasitismo natural de ninfas de Diaphorina citri Kuwayama (Hemiptera, Psyllidae por Tamarixia radiata Waterston (Hymenoptera, Eulophidae em pomares de laranja em São Paulo

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Paulo Eduardo Branco Paiva

2012-12-01

Full Text Available The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922 in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72% of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March, with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.O psilídeo Diaphorina citri Kuwayama 1908 tornou-se a principal praga dos citros no estado de São Paulo após a introdução do huanglongbing ou grenning dos citros. Este estudo avaliou as proporções de ninfas de terceiro a quinto ínstares de D. citri parasitadas por Tamarixia radiata (Waterston, 1922 em pomares de laranja submetidos a pulverizações constantes de inseticidas em dez regiões produtoras, Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins e São João da Boa Vista. Foram coletadas 69 amostras de ramos jovens infestados com ninfas de D. citri obtidas entre 2005 e 2008 em pomares de 1 a 20 anos de idade, das cultivares Hamilin, Pera, Valencia e Natal. O parasitóide T. radiata encontra-se amplamente distribuído em pomares de São Paulo, tendo sido observado em 50 amostras (72%, com taxa média de

GC-MS analysis of headspace and liquid extracts for metabolomic differentiation of citrus Huanglongbing and zinc deficiency in leaves of 'Valencia' sweet orange from commercial groves.

Science.gov (United States)

Cevallos-Cevallos, Juan Manuel; García-Torres, Rosalía; Etxeberria, Edgardo; Reyes-De-Corcuera, José Ignacio

2011-01-01

Citrus Huanglongbing (HLB) is considered the most destructive citrus disease worldwide. Symptoms-based detection of HLB is difficult due to similarities with zinc deficiency. To find metabolic differences between leaves from HLB-infected, zinc-deficient, and healthy 'Valencia' orange trees by using GC-MS based metabolomics. Analysis based on GC-MS methods for untargeted metabolite analysis of citrus leaves was developed and optimized. Sample extracts from healthy, zinc deficient, or HLB-infected sweet orange leaves were submitted to headspace solid phase micro-extraction (SPME) and derivatization treatments prior to GC-MS analysis. Principal components analysis achieved correct classification of all the derivatized liquid extracts. Analysis of variance revealed 6 possible biomarkers for HLB, of which 5 were identified as proline, β-elemene, (-)trans- caryophyllene, and α-humulene. Significant (P < 0.05) differences in oxo-butanedioic acid, arabitol, and neo-inositol were exclusively detected in samples from plants with zinc deficiency. Levels of isocaryophyllen, α-selinene, β-selinene, and fructose were significantly (P < 0.05) different in healthy leaves only. Results suggest the potential of using identified HLB biomarkers for rapid differentiation of HLB from zinc deficiency. Copyright © 2010 John Wiley & Sons, Ltd.

78 FR 66380 - Final Environmental Impact Statement for the Restoration of the Mariposa Grove of Giant Sequoias...

Science.gov (United States)

2013-11-05

... sequoia habitat, wetlands, and soundscapes within the Mariposa Grove, this alternative would relocate... for restoration of wetlands, soundscapes, and giant sequoia habitat within the Mariposa Grove by...

The WRKY Transcription Factor Family in Citrus: Valuable and Useful Candidate Genes for Citrus Breeding.

Science.gov (United States)

Ayadi, M; Hanana, M; Kharrat, N; Merchaoui, H; Marzoug, R Ben; Lauvergeat, V; Rebaï, A; Mzid, R

2016-10-01

WRKY transcription factors belong to a large family of plant transcriptional regulators whose members have been reported to be involved in a wide range of biological roles including plant development, adaptation to environmental constraints and response to several diseases. However, little or poor information is available about WRKY's in Citrus. The recent release of completely assembled genomes sequences of Citrus sinensis and Citrus clementina and the availability of ESTs sequences from other citrus species allowed us to perform a genome survey for Citrus WRKY proteins. In the present study, we identified 100 WRKY members from C. sinensis (51), C. clementina (48) and Citrus unshiu (1), and analyzed their chromosomal distribution, gene structure, gene duplication, syntenic relation and phylogenetic analysis. A phylogenetic tree of 100 Citrus WRKY sequences with their orthologs from Arabidopsis has distinguished seven groups. The CsWRKY genes were distributed across all ten sweet orange chromosomes. A comprehensive approach and an integrative analysis of Citrus WRKY gene expression revealed variable profiles of expression within tissues and stress conditions indicating functional diversification. Thus, candidate Citrus WRKY genes have been proposed as potentially involved in fruit acidification, essential oil biosynthesis and abiotic/biotic stress tolerance. Our results provided essential prerequisites for further WRKY genes cloning and functional analysis with an aim of citrus crop improvement.

The Ladbroke Grove-Katnook carbon dioxide natural laboratory: a recent CO{sub 2} accumulation in a lithic sandstone reservoir

Energy Technology Data Exchange (ETDEWEB)

Watson, M.N. [Adelaide Univ., SA (Australia). Australian School of Petroleum; Zwingmann, N. [CSIRO Petroleum, Bentley, WA (Australia); Lemon, N.M. [Santos Ltd., Adelaide, SA (Australia)

2004-08-01

The Ladbroke Grove and Katnook Gas Fields, within the western Otway Basin, southeastern South Australia, provide a natural laboratory to study the effects of CO{sub 2} on siliciclastic reservoirs. CO{sub 2} degassing from nearby volcanics has migrated into the methane accumulation of the Ladbroke Grove Field within the Pretty Hill Formation. CO{sub 2} levels in the Ladbroke Grove Field range from 26 to 57 mol% while Katnook has less than 1 mol%. In Ladbroke Grove, the CO{sub 2} has altered or dissolved most of the reactive minerals, somewhat constrained by the Pleistocene to Recent age of the CO{sub 2} influx. The developed late-stage kaolinite, quartz and less soluble carbonate are products of the reactions involving CO{sub 2} and reactive minerals. The major formation water types were identified using the geochemical code EQ3NR. Ladbroke Grove waters above the gas-water contact (GWC) have bicarbonate levels an order of magnitude higher than the other waters analysed. Below the GWC, Ladbroke Grove and Katnook formation waters have similar ionic compositions, however, pH levels in Ladbroke Grove are low relative to Katnook. The Ladbroke Grove Field has efficiently stored CO{sub 2} in a gaseous and aqueous phase since the influx began in the Pleistocene. In addition, due to the high amount of reactive minerals within the reservoir, mineralisation of ferroan carbonates has also occurred as a more permanent form of mineral storage of some of the CO{sub 2}. (author)

78 FR 59649 - Approval of Subzone Status, Hardinger Transfer Co., Erie and Grove City, Pennsylvania

Science.gov (United States)

2013-09-27

..., Hardinger Transfer Co., Erie and Grove City, Pennsylvania On July 24, 2013, the Executive Secretary of the Foreign-Trade Zones (FTZ) Board docketed an application submitted by the Erie Western Pennsylvania Port..., on behalf of Hardinger Transfer Co., in Erie and Grove City, Pennsylvania. The application was...

A two-component lure for better detection of pest Euwallacea nr. fornicatus in Florida avocado groves

Science.gov (United States)

In recent years, several ambrosia beetles morphologically similar to the Asian tea shot-hole borer, Euwallacea fornicatus Eichhoff (Coleoptera: Curculionidae: Scolytinae), have become established in Israel and the USA (both California and Florida). Currently referred to as E. near fornicatus, membe...

An ethnobotanical study of medicinal plants used in sacred groves of Kumaon Himalaya, Uttarakhand, India.

Science.gov (United States)

Singh, Harsh; Husain, Tariq; Agnihotri, Priyanka; Pande, P C; Khatoon, Sayyada

2014-05-28

International organizations recognize the importance of sacred groves and place them into the context of sustainable development and also emphasize to conserve biodiversity through protection of sacred groves and sties. The significance of medicinal plants from Himalayan region is well known to the world. Therefore, present study was conducted in identified sacred groves of Kumaon Himalaya to investigate and document the utilization of medicinal plants by various local communities and tribal people. The study was conducted during 2008-2011 in four seasons of the year. Information was collected from 70 locals from different sacred groves by using free listing interviews with randomly selected informants and semi-structured questionnaires; plant specimens were collected, identified and deposited at the CSIR-NBRI herbarium (LWG), Lucknow, India. Seven sacred groves viz., Dhwaj, Haat Kali, Hokra, Malay Nath, Nakuleshwar, Narayan Swami Ashram and Patal Bhuvneshwar were identified from the Pithoragarh district of Kumaon Himalaya. 89 medicinal plants belonging to 52 families and 77 genera of which, 2 are lichens, 4 are pteridophytes, 3 are gymnosperms and remaining 80 plant species are angiosperms. 6 plant species are reported with new therapeutic uses for the first time in this paper. Highest informant׳s consensus factor value was found in liver disorder (0.55) and least by body pains (0.23). 55 ethnomedicinal plants are showing 100% fidelity level against various diseases. Sacred groves in Kumaon region of Indian Himalaya are rich sources and best repository of ethno-medicinally important plants with many rare, endangered and threatened species. It is an excellent example of unique traditional way of in situ conservation of different plant species. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Transitioning Natures: Robert Schuller’s Garden Grove Experiment

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Antonio Petrov

2016-09-01

Full Text Available Through the lens of Evangelist Reverend Robert H. Schuller’s Garden Grove drive-in walk-in church, this paper aims to exemplify how his architecture has transcended existing geographies that have long been anchored by the epistemology of what can be referred to as traditional “religious” architecture. This paper examines how Schuller instrumentalized broader imbrications of political contexts to change or manipulate the traditional religious subject. It also presents how Robert Schuller’s Garden Grove experiment reconceptualized “territory” as an evolving ideological dimension; not as a trajectory, or as transitory space, but as inhabitable third nature. My analysis challenges established readings of religious architecture as being interiorized manifestations. To do so, it poses the following questions: how does this meta-geographical dimension shed new light on questions of (traditional architectural aesthetics in Protestant architecture? What spaces and politics does it produce? Does the third nature have a history of its own?

Global genetic variation in the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae) and the endosymbiont Wolbachia: links between Iran and the USA detected.

Science.gov (United States)

Lashkari, Mohammadreza; Manzari, Shahab; Sahragard, Ahad; Malagnini, Valeria; Boykin, Laura M; Hosseini, Reza

2014-07-01

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is one of the most serious pests of citrus in the world, because it transmits the pathogen that causes citrus greening disease. To determine genetic variation among geographic populations of D. citri, microsatellite markers, mitochondrial gene cytochrome oxidase I (mtCOI) and the Wolbachia-Diaphorina, wDi, gene wsp sequence data were used to characterize Iranian and Pakistani populations. Also, a Bayesian phylogenetic technique was utilized to elucidate the relationships among the sequences data in this study and all mtCOI and wsp sequence data available in GenBank and the Wolbachia database. Microsatellite markers revealed significant genetic differentiation among Iranian populations, as well as between Iranian and Pakistani populations (FST  = 0.0428, p citri populations in Iran, India, Saudi Arabia, Brazil, Mexico, Florida and Texas (USA) are similar. Wolbachia, wDi, wsp sequences were similar among Iranian populations, but different between Iranian and Pakistani populations. The South West Asia (SWA) group is the most likely source of the introduced Iranian populations of D. citri. This assertion is also supported by the sequence similarity of the Wolbachia, wDi, strains from the Florida, USA and Iranian D. citri. These results should be considered when looking for biological controls in either country. © 2013 Society of Chemical Industry.

Agrobacterium-mediated transformation of Citrus sinensis and Citrus limonia epicotyl segments

OpenAIRE

Almeida,Weliton Antonio Bastos de; Mourão Filho,Francisco de Assis Alves; Mendes,Beatriz Madalena Januzzi; Pavan,Alexandra; Rodriguez,Adriana Pinheiro Martinelli

2003-01-01

Genetic transformation allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. The objective of this research was to establish a protocol for genetic transformation of Valencia and Natal sweet oranges (Citrus sinensis L. Osbeck) and Rangpur lime (Citrus limonia L. Osbeck). Epicotyl segments of germinated in vitro plantlets (three weeks in darkness and two weeks in a 16-h photoperiod) were used...

Nutritional deficiency in citrus with symptoms of citrus variegated chlorosis disease

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ME. Silva-Stenico

Full Text Available It is well known that citrus plants that have been infected by Xylella fastidiosa display nutritional deficiencies, probably caused by production of extracellular polymers by the bacteria that block normal nutrient flow through the xylem. The aim of this work was to study the mineral composition of specific foliar areas in different stages of infection in citrus. Thus, the concentrations of macro and micronutrients in leaves of citrus infected by X. fastidiosa were measured. Samples from four infected citrus orchards in the State of São Paulo, Brazil, were respectively collected from Santa Rita do Passa Quatro, Neves Paulista, Gavião Peixoto and Paraíso counties. The presence of X. fastidiosa in leaves was confirmed by polymerase chain reaction (PCR using specific PCR primers. To understand the variation in leaf-nutrient content in citrus plants, we used foliar nutrient values from control (non-symptomatic plants as a reference. Chemometric analysis showed that the deficiency of P and K in symptomatic trees for all orchards and high concentrations of Fe, Mn and Zn were observed in chlorotic areas, although other studies revealed deficiency of zinc in leaves. This is the first report showing that a correlation between chlorotic citrus leaf and higher concentrations of Fe, Mn and Zn are observed when infected and healthy plants were compared.

78 FR 16294 - Draft Environmental Impact Statement for Restoration of the Mariposa Grove of Giant Sequoias...

Science.gov (United States)

2013-03-14

... Environmental Impact Statement for Restoration of the Mariposa Grove of Giant Sequoias, Yosemite National Park, Madera, and Mariposa Counties, CA AGENCY: National Park Service, Interior. ACTION: Notice of availability... the Mariposa Grove of giant sequoias in Yosemite National Park. This Draft EIS presents three...

Citrus and Prunuscopia-like retrotransposons.

Science.gov (United States)

Asíns, M J; Monforte, A J; Mestre, P F; Carbonell, E A

1999-08-01

Many of the world's most important citrus cultivars ("Washington Navel", satsumas, clementines) have arisen through somatic mutation. This phenomenon occurs fairly often in the various species and varieties of the genus.The presence of copia-like retrotransposons has been investigated in fruit trees, especially citrus, by using a PCR assay designed to detect copia-like reverse transcriptase (RT) sequences. Amplification products from a genotype of each the following species Citrus sinensis, Citrus grandis, Citrus clementina, Prunus armeniaca and Prunus amygdalus, were cloned and some of them sequenced. Southern-blot hybridization using RT clones as probes showed that multiple copies are integrated throughout the citrus genome, while only 1-3 copies are detected in the P. armeniaca genome, which is in accordance with the Citrus and Prunus genome sizes. Sequence analysis of RT clones allowed a search for homologous sequences within three gene banks. The most similar ones correspond to RT domains of copia-like retrotransposons from unrelated plant species. Cluster analysis of these sequences has shown a great heterogeneity among RT domains cloned from the same genotype. This finding supports the hypothesis that horizontal transmission of retrotransposons has occurred in the past. The species presenting a RT sequence most similar to citrus RT clones is Gnetum montanum, a gymnosperm whose distribution area coincides with two of the main centers of origin of Citrus spp. A new C-methylated restriction DNA fragment containing a RT sequence is present in navel sweet oranges, but not in Valencia oranges from which the former originated suggesting, that retrotransposon activity might be, at least in part, involved in the genetic variability among sweet orange cultivars. Given that retrotransposons are quite abundant throughout the citrus genome, their activity should be investigated thoroughly before commercializing any transgenic citrus plant where the transgene(s) is part

Evaluation of the Tolerance of Some Citrus Rootstocks to Citrus Nematode in Greenhouse (Tylenchulus semipenetrans

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Y. Mohammad Alian

2018-02-01

Full Text Available Introduction: Citrus nematode is one of the most important damaging nematodes of citrus trees, spreading widely in most areas under citrus planting causing dieback, the gradual decline of trees and crop decrease in citrus orchards. Eighty citrus cultivars and species are sensitive to this nematode. From other nematode hosts, we can refer to olive, fig, medlar, persimmon, pear and grapevine. Surveys Full filled in Mazandaran province is indicative of the widespread of this nematode in citrus horticulture and the level of infection in some samples is so high, thus it is necessary to use different ways of controlling this parasite. Materials and Methods: This research was carried out for 2 successive years and the reaction of sin citrus rootstocks including Citromelo, Poncirus, Sour Orange, Bakraee, Rough lemon and Off-type to citrus nematode under controlled conditions in the greenhouse was evaluated. Three months years old plants of this rootstock Were planted in completely random design with 5 replications in pots containing the population of 40 larvae per cubic centimeter of soil and after six months, the level of infection of roots was investigated and then the most tolerable rootstock for nematode was introduced on the basis of the least population of young females and adult females injected in one gram of root volume. Results and Discussion: Experiment results on the basis of LSD test in two successive years indicated that there is a meaningful statistical difference between Citrumelo and poncirus Poncirus with the least population of nematode of adult female on the root and other treatments the results show that sour orange and off-type rootstocks are the most sensitive to citrus nematode, poncirus Poncirus and Citrumelo are the most tolerable to nematode Bakraee and Rough lemon are in the biotype group with average tolerance (relatively sensitive to citrus nematode. Purpose of this research is to assess the sensitivity level of six citrus

78 FR 66355 - Pleasant Grove City, UT; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

Science.gov (United States)

2013-11-05

... City, UT; Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and... Grove City, Utah (Pleasant Grove) filed a notice of intent to construct a qualifying conduit hydropower facility, pursuant to section 30 of the Federal Power Act, as amended by section 4 of the Hydropower...

THE BIOLOGICAL VALUES AND CONSERVATION STATUS OF SACRED GROVES IN THE BALASORE WILDLIFE DIVISION, ODISHA: A CASE STUDY

OpenAIRE

Raj Kishore MOHANTA; Bhupendra Singh ADHIKARI; Hemanta Kumar SAHU; Kedar Kumar SWAIN

2012-01-01

On a global scale, the existing Sacred Groves (SGs) are based on ancestral worship and focus on the conservation of forest patches. Sacred groves are distributed over a wide ecosystem and help in the conservation of rare and endemic species. Well preserved sites are store houses of biological, ecological, medicinal, ethno-cultural and religious values. We documented the state of 13 Sacred Groves in Balasore, Odisha during March 2011. For a detailed investigation, sample areas were set, for th...

77 FR 59709 - Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations

Science.gov (United States)

2012-10-01

... occur. The pathogen can also be transmitted by two insect vectors in the family Psyllidae: Diaphorina... California due to the presence of Asian citrus psyllid (ACP), a vector of the bacterial pathogen that causes... INFORMATION: Background Citrus greening, also known as Huanglongbing disease of citrus, is considered to be...

CPm gene diversity in field isolates of Citrus tristeza virus from Colombia.

Science.gov (United States)

Oliveros-Garay, Oscar Arturo; Martinez-Salazar, Natalhie; Torres-Ruiz, Yanneth; Acosta, Orlando

2009-01-01

The nucleotide sequence diversity of the CPm gene from 28 field isolates of Citrus tristeza virus (CTV) was assessed by SSCP and sequence analyses. These isolates showed two major shared haplotypes, which differed in distribution: A1 was the major haplotype in 23 isolates from different geographic regions, whereas R1 was found in isolates from a discrete region. Phylogenetic reconstruction clustered A1 within an independent group, while R1 was grouped with mild isolates T30 from Florida and T385 from Spain. Some isolates contained several minor haplotypes, which were very similar to, and associated with, the major haplotype.

Sacred Groves: Myths, Beliefs, and Biodiversity Conservation—A Case Study from Western Himalaya, India

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Sushma Singh

2017-01-01

Full Text Available Religious and traditional beliefs, cultural mores, and practices play a crucial role in the conservation of environment and biodiversity. The present paper describes a case study of two sacred groves in Western Himalaya. Sacred groves (SGs are patches of land that are communally protected with religious zeal. A preliminary survey was conducted in these SGs to study their role in biodiversity conservation. The data collected included the general information regarding the SGs and the associated deity, nearest human habitation, access to them, and their floral and faunal diversity. Ethnomedicinal property of plants was collected from the indigenous communities. Many taboos are associated with both the SGs, which help in managing resources well through ritual representation. Different festivals are organized, where the local communities reaffirm their commitment to the forest and the deity. Sacred groves, in general, are a valuable tool of biodiversity conservation. But people’s changing attitudes, erosion of traditional beliefs, and human impact have caused degradation of sacred groves over the years. Their conservation would not be possible without the active participation of the local people. By improving their living standards and by giving benefits of conservation to them, long-term conservation goals in these SGs can be achieved.

Effect of Nigerian citrus ( Citrus sinensis Osbeck) honey on ethanol ...

African Journals Online (AJOL)

The effect of Nigerian citrus (Citrus sinensis Osbeck) honey on ethanol metabolism was tested using 45 consenting individuals in apparent good health and between the ages of 25 and 35 years. The subjects were moderate social drinkers matched in terms of body weight and build. The results obtained showed that on ...

Evaluation of resistance to asiatic citrus canker among selections of pera sweet orange (Citrus sinensis)

Science.gov (United States)

Asiatic citrus canker (ACC, caused by the bacterium Xanthomonas citri subsp. citri) is a destructive disease of citrus in Brazil and in several other citrus-producing countries. ACC management is problematic, and bactericides such as copper can be reasonably efficacious but do not completely control...

Sweet orange trees grafted on selected rootstocks fertilized with nitrogen, phosphorus and potassium

OpenAIRE

Quaggio,José Antônio; Mattos Junior,Dirceu; Cantarella,Heitor; Stuchi,Eduardo Sanches; Sempionato,Otávio Ricardo

2004-01-01

The majority of citrus trees in Brazil are grafted on 'Rangpur lime' (Citrus limonia Osb.) rootstock. Despite its good horticultural performance, search for disease tolerant rootstock varieties to improve yield and longevity of citrus groves has increased. The objective of this work was to evaluate yield efficiency of sweet oranges on different rootstocks fertilized with N, P, and potassium. Tree growth was affected by rootstock varieties; trees on 'Swingle' citrumelo [Poncirus trifoliata (L....

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.

IDENTIFICATION AND QUANTIFICATION OF DIFFERENTIALLY EXPRESSED GENES ASSOCIATED WITH CITRUS BLIGHT (Citrus spp.

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José Renato de Abreu

2015-02-01

Full Text Available Brazil is the largest citrus producer in the world, being responsible for more than 20% of its production, which is, however still low due to phytosanitary issues such as citrus blight. Citrus blight is an anomaly whose causes still have not yet been determined, therefore there are no efficient control measures to minimize the production losses with the use of resistant varieties being considered the most appropriate method. However, little is known about the genes involved in the defense response of the plants to this anomaly. Considering that many physiological alterations associated with plant stress responses are controlled at a transcriptional level, in this study we sought the identification and characterization of the gene expression products differentially expressed in the response to the citrus blight. Through the suppressive subtractive hybridization technique, expressed cDNA libraries were built using mRNAs isolated from "Cravo" lemon tree roots (Citrus limonia L. Osbeck under "Pera" orange (Citrus sinensis L. Osbeck of healthy and sick plants. 129 clones were obtained by subtraction and their sequences were compared in databases. 34 of them linked to proteins associated to stress processes, while the others were similar to sequences of unknown functions or did not present similarity with sequences deposited in the databases. 3 genes were selected and their expressions were studied by RT - qPCR in real-time. Plants with citrus blight presented an increase of the expression level in two of those genes, suggesting that these can be directly involved with this anomaly.

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.

Microjets of citrus fruit

Science.gov (United States)

Smith, Nicholas; Dickerson, Andrew

2017-11-01

The rupture of oil glands in the citrus exocarp is a common experience to the discerning citrus consumer. When peeled, oil cavities housed with the citrus exocarp often rupture outwardly in response to externally applied bending stresses. Bending of the peel compresses the soft material surrounding the glands, the albedo, increasing fluid pressure. Ultimately, the fluid pressure exceeds the failure strength of the outermost membrane, the flavedo. The ensuing high-velocity discharge of oil and exhaustive emptying of oil glands creates a novel method for jetting small quantities of the aromatic and volatile oil. We compare the jetting behavior across five citrus hybrids through high-speed videography and material testing of exocarps. The jetting oil undergoes an initial acceleration surpassing 5,000 gravities, reaching velocities in excess of 10 m/s. Film of citrus jets and mimicking jets in the lab reveal their high level of instability is caused by irregular and non-circular orifice geometry. Through material characterization and bending simulations, we rationalize the combination of material properties necessary to generate the internal gland pressures required for explosive dispersal.

Effect of irrigation and fertilization on crop yield and fruit quality of the Tahiti lime Citrus latifolia Tanaka (Rutaceae

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Diana Dorado Guerra

2015-01-01

Full Text Available In a seven years old citrus grove of Tahiti lime Citrus latifolia Tanaka (Rutaceae located in El Espinal, Tolima, Colombia, which has a predominantly negative water balance throughout the year, we evaluated the effect of irrigation and fertilization on yield and fruit quality in 2009 and 2011. Trees were subjected to three levels of water based on the evapotranspiration reference (ETo: L1=100 %, L2=70 % and L3=50 %. We applied three nitrogen treatments: N1=nitrogen required by the nutritional balance, N2=twice the level of nitrogen used in N1, and N3=fertilizer application used by the common farmer. We evaluated the performance, fruit weight, polar and equatorial diameter of fruit, shell thickness, weight and percentage of juice, acidity, soluble solids and vitamin C. The experiment was conducted under a randomized complete block design in a split plot arrangement; the variance and means of the data were statistically analyzed with SAS. And optimal response is between irrigation and fruit quality interaction was obtained with irrigation L1 and fertilization N2. We obtained the highest values in the response variables when the highest amount of water was applied L1, regardless of fertilizer applications, indicating that a lower water supply not only affects the performance of the plant, but also the quality of the fruit, minimizing market opportunities.

Estimation of Fluoride Concentration of Various Citrus and Non-Citrus Fruits Commonly Consumed and Commercially Available in Mathura City

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Navin Anand Ingle

2013-01-01

Full Text Available Background: Since fluoride is available from various sources, the total ingestion of fluoride by a person should be estimated taking into consideration the fluoride consumed from all the sources including fruits. There are very few epidemiological studies carried out associated with fluoride estimation in fruit samplesand especially in the Indian scenario Objective: To estimate and compare the fluoride concentration of different commercially available citrus and non-citrus fruits in Mathura city. Materials & Method: Fifteen different types of fruits commercially available and consumed by people ofMathura City were collected. Out of the 15 fruit samples 5 were citrus fruits and 10 were non-citrus fruits. The fluoride estimation of fruit samples was done at Central Laboratory,Lucknow. Juices of all 15 fruit samples were prepared, from each sample 10 ml of juice was measured and fluoride testing of each sample was carried out by using Orion 4 star -ion electrode analyzer. The collected data was analyzed using the statistical software program SPSS, version 17. Results: The fluoride concentration in citrus fruits ranged from 0.04ppm (Orange to 0.08 ppm (Tomato while in non-citrus fruits it ranged from 0.04ppm (chikoo to 0.18 ppm (Guava. No significant difference was observed between the mean fluoride concentration of citrus and non citrus fruits. Conclusions: Both citrus and non citrus fruits have fluorides. Guava was found to have the maximumamount of fluoridecontent (0.18 ppm among both the citrus and non citrus fruits.

Genomic Variability of Citrus tristeza virus (CTV Isolates Introduced into Morocco

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Bouabid Lbida

2004-08-01

Full Text Available Genomic variability of the coat protein gene of Citrus tristeza virus isolates obtained from old Meyer lemon introductions in Morocco and more recent budwood introductions from Spain were studied. The coat protein gene of the virus was amplified directly from infected tissue by immunocapture RT-PCR and analysed by single stranded conformation polymorphism (SSCP and sequencing. Each isolate consisted of several related genomic variants, typical of a quasi-species. Although SSCP analysis has only limited typing ability it could be used in an initial screening to discriminate between isolates of different origin and to analyse the genomic structure of each isolate. Sequence analysis showed that the isolates of Spanish origin were closely related to mild isolates characterised in Florida and in Portugal. The Meyer lemon isolate on the other hand was related to severe strains of Meyer lemon characterised in Florida some years ago and to other severe strains from Brasil. A knowledge of the coat protein gene sequence is useful to trace the origin of the isolates.

Chemical and behavioral analysis of the cuticular hydrocarbons from Asian citrus psyllid, Diaphorina citri.

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Mann, Rajinder S; Rouseff, Russell L; Smoot, Jack; Rao, Nandikeswara; Meyer, Wendy L; Lapointe, Stephen L; Robbins, Paul S; Cha, Dong; Linn, Charles E; Webster, Francis X; Tiwari, Siddharth; Stelinski, Lukasz L

2013-06-01

Huanglongbing (HLB) is the most destructive disease of citrus worldwide. The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the vector of the phloem-inhabiting bacterium, Candidatus Liberibacter asiaticus, which is presumed to cause HLB in Florida citrus. Laboratory and field studies were conducted to examine the behavioral responses of male and female D. citri to their cuticular extracts. In olfactometer assays, more male D. citri were attracted to one, five, or 10 female cuticular extract equivalent units than blank controls. The results were confirmed in field studies in which clear or yellow traps baited with 10 female cuticular extract equivalent units attracted proportionately more males than clear traps baited with male cuticular extract or unbaited traps. Analyses of cuticular constituents of male and female D. citri revealed differences between the sexes in chemical composition of their cuticular extracts. Laboratory bioassays with synthetic chemicals identified from cuticular extracts indicated that dodecanoic acid attracted more males than clean air. Traps baited with dodecanoic acid did not increase total catch of D. citri as compared with blank traps at the dosages tested; however, the sex ratio of psyllid catch was male biased on traps baited with the highest lure loading dosage tested (10.0 mg). © 2012 The Authors Insect Science © 2012 Institute of Zoology, Chinese Academy of Sciences.

A Climatic Classification for Citrus Winter Survival in China.

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Shou, Bo Huang

1991-05-01

The citrus tree is susceptible to frost damage. Winter injury to citrus from freezing weather is the major meteorological problem in the northern pail of citrus growing regions in China. Based on meteorological data collected at 120 stations in southern China and on the extent of citrus freezing injury, five climatic regions for citrus winter survival in China were developed. They were: 1) no citrus tree injury. 2) light injury to mandarins (citrus reticulate) or moderate injury to oranges (citrus sinensis), 3) moderate injury to mandarins or heavy injury to oranges, 4) heavy injury to mandarins, and 5) impossible citrus tree growth. This citrus climatic classification was an attempt to provide guidelines for regulation of citrus production, to effectively utilize land and climatic resources, to chose suitable citrus varieties, and to develop methods to prevent injury by freezing.

THE BIOLOGICAL VALUES AND CONSERVATION STATUS OF SACRED GROVES IN THE BALASORE WILDLIFE DIVISION, ODISHA: A CASE STUDY

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Raj Kishore MOHANTA

2012-09-01

Full Text Available On a global scale, the existing Sacred Groves (SGs are based on ancestral worship and focus on the conservation of forest patches. Sacred groves are distributed over a wide ecosystem and help in the conservation of rare and endemic species. Well preserved sites are store houses of biological, ecological, medicinal, ethno-cultural and religious values. We documented the state of 13 Sacred Groves in Balasore, Odisha during March 2011. For a detailed investigation, sample areas were set, for the assessment of floral and faunal diversity, ethno-cultural values and management status. A total of 58 floral species and 13 faunal species were recorded. In Balasore, Sacred Groves are small in size and can act as starting points for any long term conservation plan of biodiversity. The communities have kept their faith and traditions linked to these mini nuclei of rich biodiversity in the landscape. Therefore, any conservation program can begin from local communities, by taking them into consideration as trustworthy awareness building factors.

Citrus leprosis virus N: A New Dichorhavirus Causing Citrus Leprosis Disease.

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Ramos-González, Pedro Luis; Chabi-Jesus, Camila; Guerra-Peraza, Orlene; Tassi, Aline Daniele; Kitajima, Elliot Watanabe; Harakava, Ricardo; Salaroli, Renato Barbosa; Freitas-Astúa, Juliana

2017-08-01

Citrus leprosis (CL) is a viral disease endemic to the Western Hemisphere that produces local necrotic and chlorotic lesions on leaves, branches, and fruit and causes serious yield reduction in citrus orchards. Samples of sweet orange (Citrus × sinensis) trees showing CL symptoms were collected during a survey in noncommercial citrus areas in the southeast region of Brazil in 2013 to 2016. Transmission electron microscopy analyses of foliar lesions confirmed the presence of rod-like viral particles commonly associated with CL in the nucleus and cytoplasm of infected cells. However, every attempt to identify these particles by reverse-transcription polymerase chain reaction tests failed, even though all described primers for the detection of known CL-causing cileviruses and dichorhaviruses were used. Next-generation sequencing of total RNA extracts from three symptomatic samples revealed the genome of distinct, although highly related (>92% nucleotide sequence identity), viruses whose genetic organization is similar to that of dichorhaviruses. The genome sequence of these viruses showed trees and those used for the transmission of one of the characterized isolates to Arabidopsis plants were anatomically recognized as Brevipalpus phoenicis sensu stricto. Molecular and biological features indicate that the identified viruses belong to a new species of CL-associated dichorhavirus, which we propose to call Citrus leprosis N dichorhavirus. Our results, while emphasizing the increasing diversity of viruses causing CL disease, lead to a reevaluation of the nomenclature of those viruses assigned to the genus Dichorhavirus. In this regard, a comprehensive discussion is presented.

Overexpression of a modified plant thionin enhances disease resistance to citrus canker and huanglongbing (HLB, citrus greening)

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Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States citrus industry. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized e...

Sampling history and 2009--2010 results for pesticides and inorganic constituents monitored by the Lake Wales Ridge Groundwater Network, central Florida

Science.gov (United States)

Choquette, Anne F.; Freiwald, R. Scott; Kraft, Carol L.

2012-01-01

The Lake Wales Ridge Monitoring (LWRM) Network was established to provide a long-term record of water quality of the surficial aquifer in one of the principal citrus-production areas of Florida. This region is underlain by sandy soils that contain minimal organic matter and are highly vulnerable to leaching of chemicals into the subsurface. This report documents the 1989 through May 2010 sampling history of the LWRM Network and summarizes monitoring results for 38 Network wells that were sampled during the period January 2009 through May 2010. During 1989 through May 2010, the Network’s citrus land-use wells were sampled intermittently to 1999, quarterly from April 1999 to October 2009, and thereafter quarterly to semiannually. The water-quality summaries in this report focus on the period January 2009 through May 2010, during which the Network’s citrus land-use wells were sampled six times and the non-citrus land-use wells were sampled two times. Within the citrus land-use wells sampled, a total of 13 pesticide compounds (8 parent pesticides and 5 degradates) were detected of the 37 pesticide compounds analyzed during this period. The most frequently detected compounds included demethyl norflurazon (83 percent of wells), norflurazon (79 percent), aldicarb sulfoxide (41 percent), aldicarb sulfone (38 percent), imidacloprid (38 percent), and diuron (28 percent). Agrichemical concentrations in samples from the citrus land-use wells during the 2009 through May 2010 period exceeded Federal drinking-water standards (maximum contaminant levels, MCLs) in 1.5 to 24 percent of samples for aldicarb and its degradates (sulfone and sulfoxide), and in 68 percent of the samples for nitrate. Florida statutes restrict the distance of aldicarb applications to drinking-water wells; however, these statutes do not apply to monitoring wells. Health-screening benchmark levels that identify unregulated chemicals of potential concern were exceeded for norflurazon and diuron in 29 and

Solar-energy-system performance evaluation: Northview Elementary School (Howard's Grove) Howard's Grove, Wisconsin, September 1978-April 1979

Energy Technology Data Exchange (ETDEWEB)

Shenfish, K.L.

1979-01-01

The Northview Elementary School in Howard's Grove, Wisconsin is provided space heating by a system consisting of an array of flat plate air collectors and a rock bed. Auxiliary heat is supplied by a fuel oil boiler. The system and its operation are briefly described, and its performance is analyzed using a system energy balance technique. The performance of major subsystems is also presented. (LEW)

Weeping dragon, a unique ornamenal citrus

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‘Weeping Dragon’ is a new ornamental citrus cultivar developed by intercrossing of two unusual and unique citrus types, Poncirus trifoliata cultivated variety (cv.) Flying Dragon, and Citrus sinensis cv. ‘Cipo’. This new hybrid cultivar combines strongly contorted and weeping growth traits in a smal...

78 FR 41259 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus

Science.gov (United States)

2013-07-10

... therefore opposed importation of fresh citrus fruit from Uruguay until its effectiveness could be validated...'' imports. The commenter stated that this argument is invalid due to the year-round marketing of citrus... metric tons, which is less than 3 percent of U.S. production. Uruguay's total fresh orange and lemon...

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

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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.

Citrus allergy from pollen to clinical symptoms.

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Rosa Anna Iorio

Full Text Available Allergy to citrus fruits is often associated with pollinosis and sensitization to other plants due to a phenomenon of cross-reactivity. The aims of the present study were to highlight the cross-reactivity among citrus and the major allergenic pollens/fruits, throughout clinical and molecular investigations, and to evaluate the sensitization frequency to citrus fruits in a population of children and adults with pollinosis. We found a relevant percentage of sensitisation (39% to citrus fruits in the patients recruited and in all of them the IgE-mediated mechanism has been confirmed by the positive response to the prick-to-prick test. RT-PCR experiments showed the expression of Cit s 1, Cit s 3 and a profilin isoform, already described in apple, also in Citrus clementine pollen. Data of multiple sequence alignments demonstrated that Citrus allergens shared high percentage identity values with other clinically relevant species (i.e. Triticum aestivum, Malus domestica, confirming the possible cross-allergenicity citrus/grasses and citrus/apple. Finally, a novelty of the present work has been the expression of two phospholipaseA2 isoforms (PLA2 α and β in Citrus as well as in Triticum pollens; being PLA2 able to generate pro-inflammatory factors, this enzyme could participate in the activation of the allergenic inflammatory cascade.

[Climatic suitability of citrus in subtropical China].

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Duan, Hai-Lai; Qian, Huai-Sui; Li, Ming-Xia; Du, Yao-Dong

2010-08-01

By applying the theories of ecological suitability and the methods of fuzzy mathematics, this paper established a climatic suitability model for citrus, calculated and evaluated the climatic suitability and its spatiotemporal differences for citrus production in subtropical China, and analyzed the climatic suitability of citrus at its different growth stages and the mean climatic suitability of citrus in different regions of subtropical China. The results showed that the citrus in subtropical China had a lower climatic suitability and a higher risk at its flower bud differentiation stage, budding stage, and fruit maturity stage, but a higher climatic suitability and a lower risk at other growth stages. Cold damage and summer drought were the key issues affecting the citrus production in subtropical China. The citrus temperature suitability represented a latitudinal zonal pattern, i. e., decreased with increasing latitude; its precipitation suitability was high in the line of "Sheyang-Napo", medium in the southeast of the line, low in the northwest of the line, and non in high mountainous area; while the sunlight suitability was in line with the actual duration of sunshine, namely, higher in high-latitude areas than in low-latitude areas, and higher in high-altitude areas than in plain areas. Limited by temperature factor, the climatic suitability was in accordance with temperature suitability, i. e., south parts had a higher suitability than north parts, basically representing latitudinal zonal pattern. From the analysis of the inter-annual changes of citrus climatic suitability, it could be seen that the citrus climatic suitability in subtropical China was decreasing, and had obvious regional differences, suggesting that climate change could bring about the changes in the regions suitable for citrus production and in the key stages of citrus growth.

SCREENING FITOKIMIA, AKTIVITAS ANTIOKSIDAN DAN ANTIMIKROBA PADA BUAH JERUK LEMON(Citrus limon DAN JERUK NIPIS (Citrus aurantiifolia

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Anindya Nirmala Permata

2018-03-01

Full Text Available The desire to live healthy by eating natural foods and drinks into the lifestyle of the community. Orange becomes one of the fruits that become functional food to maintain and maintain health. The purpose of this research is to know the difference of antioxidant and antimicrobial activity on Citrus limon and Citrus aurantiifolia. The research method is laboratory experimental research with descriptive analysis. This research was conducted in February-April 2017 at the Laboratory of Plant Biological Microbiology and Plant Chemistry Department of Biology State University of Malang. Phytochemical screening by color reaction method, total phenol with Folin Ciocalteu method, antioxidant activity with DPPH method and antimicrobial activity with disc method. Screening results show the presence of saponins and alkaloids but there are no flavonoids, terpenoids and tannins. Total phenol test showed total phenol content in Lemon (Citrus limon of 110,25 mg GAE / 100ml while in Lime (Citrus aurantiifolia 116,5 mg GAE / 100ml. The antioxidant activity of Lemon Citrus (Citrus limon 49.593 g / ml and Lime (Citrus aurantiifolia 49.589g / ml. Antimicrobial activity test obtained the highest zone of resistance at 100% concentration of each citrus fruit. The conclusion of this study is that there is a difference of antioxidant and antimicrobial activity in both oranges, where the lemon fruits (C.limon antioxidant activity is higher than and Lime (C. aurantiifolia, while the antimicrobial activity of lemon (C. aurantiifolia is higher Rather than lemon (C.limon.

Sweet orange trees grafted on selected rootstocks fertilized with nitrogen, phosphorus and potassium

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Quaggio José Antônio

2004-01-01

Full Text Available The majority of citrus trees in Brazil are grafted on 'Rangpur lime' (Citrus limonia Osb. rootstock. Despite its good horticultural performance, search for disease tolerant rootstock varieties to improve yield and longevity of citrus groves has increased. The objective of this work was to evaluate yield efficiency of sweet oranges on different rootstocks fertilized with N, P, and potassium. Tree growth was affected by rootstock varieties; trees on 'Swingle' citrumelo [Poncirus trifoliata (L. Raf. × C. paradisi Macf.] presented the smallest canopy (13.3 m³ in the fifth year after tree planting compared to those on 'Rangpur lime' and 'Cleopatra' mandarin [C. reshni (Hayata hort. ex Tanaka] grown on the same grove. Although it was observed an overall positive relationship between canopy volume and fruit yield (R² = 0.95**, yield efficiency (kg m-3 was affected by rootstocks, which demonstrated 'Rangpur lime' superiority in relation to Cleopatra. Growth of citrus trees younger than 5-yr-old might be improved by K fertilization rates greater than currently recommended in Brazil, in soils with low K and subjected to nutrient leaching losses.

Phagostimulants for the Asian citrus psyllid also elicit volatile release from citrus leaves

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Chemical cues that elicit orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of great interest because it is the primary vector of the causal pathogen of citrus greening disease. We identified an optimal blend ratio of formic and acetic acids that stimulate...

Chemical composition, antioxidant and antimicrobial activities of citrus jambhiri lush and citrus reticulata blanco essential oils

International Nuclear Information System (INIS)

Sadaf, S.; Shahid, M.; Iqbal, Z.

2009-01-01

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)

Degradation products of citrus volatile organic compounds (VOCs) acting as phagostimulants that increase probing behavior of Asian citrus psyllid

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Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri Kuwayama, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroanten...

The representativeness of Olea pollen from olive groves and the late Holocene landscape reconstruction in central Mediterranean

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Florenzano, Assunta; Mercuri, Anna Maria; Rinaldi, Rossella; Rattighieri, Eleonora; Fornaciari, Rita; Messora, Rita; Arru, Laura

2017-10-01

Modern pollen spectra are an invaluable reference tool for paleoenvironmental and cultural landscape reconstructions, but the importance of knowing the pollen rain released from orchards remains underexplored. In particular, the role of cultivated trees is in past and current agrarian landscapes has not been fully investigated. Here, we present a pollen analysis of 70 surface soil samples taken from 12 olive groves in Basilicata and Tuscany, two regions of Italy that exemplify this cultivation in the Mediterranean basin. This study was carried out to assess the representativeness of Olea pollen in modern cultivations. Although many variables can influence the amount of pollen observed in soils, it was clear that most of the pollen was deposited below the trees in the olive groves. A rapid decline in the olive pollen percentages (c. 85% on average) was found when comparing samples taken from IN vs. OUT of each grove. The mean percentages of Olea pollen obtained from the archaeological sites close to the studied orchards suggest that olive groves were established far from the Roman farmhouses of Tuscany. Further south, in the core of the Mediterranean basin, the cultivation of Olea trees was likely situated approximately 500–1000 m from the rural sites in Basilicata, and dated from the Hellenistic to the Medieval period.

Signaling pathways in a Citrus EST database

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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.

The changing landscape of sacred groves in Kerala (India): A critical view on the role of religion in nature conservation

NARCIS (Netherlands)

Notermans, C.D.; Nugteren, A.; Sunny, S.

2016-01-01

Sacred groves are an age-old and world-wide phenomenon, traditionally consisting of forest zones, protected by people based on their spiritual relationship with the deities or ancestral spirits believed to reside there. India alone counts nearly 50,000 sacred groves, with 2000 in Kerala where they

Communicating the role of science in managing giant sequoia groves

Science.gov (United States)

Douglas D. Pilrto; Robert R. Rogers; Mary Chislock Bethke

1997-01-01

Management of giant sequoia groves has been and continues to be a hotly debated issue. The debate has reached Congress, with all parties seeking resolution as to what constitutes an ecologically and publicly acceptable management approach. Determining the correct management approach and communicating that approach to the general public is the crux of the problem....

Immunogenesity of spesific protein molecular weight 16 KDa (PS16 leaf of siam citrus infected by citrus vein phloem degeneration (CVPD disease

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Made Sritamin

2012-02-01

Full Text Available Citrus Vein Phloem degeneration (CVPD is an important citrus disese, which damaged citrus plantation and causing decrease of citrus production. In Indonesia, the CVPD disease caused by Liberobacter asiaticum bactery and the disease spread out by vectir insect Diaphorina citri and using infected bud in wood grafting. In infected citrus plant, two specific protein molecules with molecular weigt 16 kDa and 66 kDa are found. These protein molecules are not found in healthy citrus plant. The immunogenicity of PS16 accumulated on leaf of citrus plant infected by CVPD is known yet. The research material were leaves of citrus plant infected CVPD, leaves of healthy citrus plant and reagent used these research are for isolation of the total protein leaf of citrus plant, SDS-PAGE electroforesis, electroelution of PS16, ELISA Methods, Dot-Blot Method, anti-PS16 as aprimery antibody and secondary antibody is anti-Rabbit IgG Conjugated AP. The result of the research showed that of PS16 accumulated on leaf of citrus plant infected CVPD has immunogenic character. It is indicated by increase of the titer anti-PS16 after first immunization ang 2nd booster by indirect ELISA method and can be used to induce antibody (anti-PS16 and so showed that positive reaction between PS16 with anti-PS16. It is indicated by purples dark blue on cellulose membrane by Dot Blot method.

The aconitate hydratase family from Citrus

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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

The potential for citrus cryotherapy

Science.gov (United States)

Citrus collections of pathogen-free plants are needed for breeding, research, and distribution to the user community. The Citrus Research Board funded research project “Development of cryotherapy as an improved method of eliminating graft transmissible pathogens in Citrus” sought to use cryotherapy,...

Spatio-temporary diagnosis of hydro-halomorphia in the Algerian southeast: The case of soils palm groves of the Ksar of Ouargla

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Siboukeur, A.; Bouhoun, M. Daddi

2018-05-01

The palm grove of Ksar is one of the oldest date palm groves in the region of Ouargla which is located in south-eastern Algeria. Although it is distinguished by an extraordinary genetic diversity, these groves are threatened by many socioeconomic and environmental constraints. Indeed, we witness year after year the degradation of this precious heritage. Our work aims to highlight the hydro-edaphic degradation of the date palm environment in Ksar of Ouargla. For this, we opted for a geographical approach using systematic random sampling methods. We conducted two campaigns: one in winter 2015 on 97 points and the second in winter 2016 on 89 points. Soil samples were taken at the 0-40 cm surface layer in parallel the water table was registered up to 2 m deep. This methodological approach has enabled us to achieve spatial and temporal evolution salinity cards of soil and water table, and estimate the level of degradation in Ksar palm grove. The soil salinization was the focus of the study in both years. In fact, 82.80% of the soils belong to the classes: salty, very salty and extremely salty, ranging from 0.18 to 15.91 dSm-1. The recorded values exceed the critical tolerance limit of the date palm. Fifty-tree points sixty-six percent (53.66%) of the phreatic waters are excessively salty which can reduce further yield of dates. This diagnosis shows a significant hydro-edaphic degradation in the palm grove. The management and rehabilitation of this old palm remains essential to ensure the sustainability of date palm groves heritage.

Genome wide selection in Citrus breeding.

Science.gov (United States)

Gois, I B; Borém, A; Cristofani-Yaly, M; de Resende, M D V; Azevedo, C F; Bastianel, M; Novelli, V M; Machado, M A

2016-10-17

Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seq TM (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

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.

Land use and biodiversity patterns of the herpetofauna: The role of olive groves

Science.gov (United States)

Carpio, Antonio J.; Oteros, Jose; Tortosa, Francisco S.; Guerrero-Casado, José

2016-01-01

The intensification of agriculture has significant environmental consequences. This intensification entails the simplification and homogenisation of the landscape, which leads to strong negative impacts at ecosystem level, including declines in animal biodiversity. The purpose of this study was to assess the effect of different land uses on reptilian and amphibian biodiversity patterns at a regional scale by analysing a large database on the presence of amphibians and reptiles in Andalusia (southern Spain). GIS techniques and the Ecological-Niche Factor Analysis (ENFA) were applied in order to assess whether the habitat was suitable for each reptilian and amphibian species, when the land use variables were excluded. The incongruence between the potential and the observed species richness was then correlated with the main types of land use in Andalusia. Our results showed that irrigated and unirrigated olive groves were associated with a biodiversity deficit of amphibians and reptiles respectively, whereas natural forests and pastures, along with more heterogeneous crops areas, were more suitable. A clustering analysis showed that generalist species were related to olive groves whereas rare and specialist species were related to land uses related to natural vegetation. In summary, our results indicate that large areas covered by olives groves harbour less amphibian and reptilian diversity, thus suggesting that agro-environmental schemes should be carried to promote the species richness in these crops.

The Representativeness of Olea Pollen from Olive Groves and the Late Holocene Landscape Reconstruction in Central Mediterranean

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Assunta Florenzano

2017-10-01

Full Text Available Modern pollen spectra are an invaluable reference tool for paleoenvironmental and cultural landscape reconstructions, but the importance of knowing the pollen rain released from orchards remains underexplored. In particular, the role of cultivated trees is in past and current agrarian landscapes has not been fully investigated. Here, we present a pollen analysis of 70 surface soil samples taken from 12 olive groves in Basilicata and Tuscany, two regions of Italy that exemplify this cultivation in the Mediterranean basin. This study was carried out to assess the representativeness of Olea pollen in modern cultivations. Although many variables can influence the amount of pollen observed in soils, it was clear that most of the pollen was deposited below the trees in the olive groves. A rapid decline in the olive pollen percentages (c. 85% on average was found when comparing samples taken from IN vs. OUT of each grove. The mean percentages of Olea pollen obtained from the archeological sites close to the studied orchards suggest that olive groves were established far from the Roman farmhouses of Tuscany. Further south, in the core of the Mediterranean basin, the cultivation of Olea trees was likely situated ~500–1,000 m from the rural sites in Basilicata, and dated from the Hellenistic to the Medieval period.

Evidence of behavior-based utilization by the Asian citrus psyllid of a combination of UV and green or yellow wavelengths.

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Thomson M Paris

Full Text Available The Asian citrus psyllid, Diaphorina citri, vectors huanglongbing (HLB, the most serious disease affecting citrus globally. D. citri and HLB have spread to the major citrus growing regions of North America causing billions of dollars of damage in Florida alone. The visual behavior of D. citri is not well characterized and more knowledge is needed to improve attractive traps for monitoring and control of the D. citri. Bioassays were conducted to evaluate attraction to light transmitted through different colored filters. The addition of ultra-violet light (< 400 nm enhanced attraction of D. citri to transparent visual targets made of green or yellow filters. However, attraction to blue targets was unaffected by UV light. This is the first study to demonstrate a phytophagous insect responding to a hue that is a combination of long and short wavelengths. Further testing is needed to determine how D. citri uses such discriminatory powers in the field. Our results further imply that D. citri utilize color vision, as the less intense yellow and green hues were chosen over white light. In summary, this research provides an increased understanding of D. citri visual behavior and can be used for the development of a more attractive D. citri trap than those currently available.

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

Science.gov (United States)

2013-02-06

...] australis, causal agent of sweet orange scab); and a pathogen (Xanthomonas citri subsp. citri, causal agent... oranges (Citrus sinensis (L.) Osbeck), lemons (C. limon (L.) Burm. f.), four species of mandarins (C... of the reading room). The PRA, titled ``Importation of Fresh Citrus Fruit, including Sweet Orange...

Hydrology of the coastal springs ground-water basin and adjacent parts of Pasco, Hernando, and Citrus Counties, Florida

Science.gov (United States)

Knochenmus, Lari A.; Yobbi, Dann K.

2001-01-01

The coastal springs in Pasco, Hernando, and Citrus Counties, Florida consist of three first-order magnitude springs and numerous smaller springs, which are points of substantial ground-water discharge from the Upper Floridan aquifer. Spring flow is proportional to the water-level altitude in the aquifer and is affected primarily by the magnitude and timing of rainfall. Ground-water levels in 206 Upper Floridan aquifer wells, and surface-water stage, flow, and specific conductance of water from springs at 10 gaging stations were measured to define the hydrologic variability (temporally and spatially) in the Coastal Springs Ground-Water Basin and adjacent parts of Pasco, Hernando, and Citrus Counties. Rainfall at 46 stations and ground-water withdrawals for three counties, were used to calculate water budgets, to evaluate long-term changes in hydrologic conditions, and to evaluate relations among the hydrologic components. Predictive equations to estimate daily spring flow were developed for eight gaging stations using regression techniques. Regression techniques included ordinary least squares and multiple linear regression techniques. The predictive equations indicate that ground-water levels in the Upper Floridan aquifer are directly related to spring flow. At tidally affected gaging stations, spring flow is inversely related to spring-pool altitude. The springs have similar seasonal flow patterns throughout the area. Water-budget analysis provided insight into the relative importance of the hydrologic components expected to influence spring flow. Four water budgets were constructed for small ground-water basins that form the Coastal Springs Ground-Water Basin. Rainfall averaged 55 inches per year and was the only source of inflow to the Basin. The pathways for outflow were evapotranspiration (34 inches per year), runoff by spring flow (8 inches per year), ground-water outflow from upward leakage (11 inches per year), and ground-water withdrawal (2 inches per year

Dispersal of normal and irradiated laboratory strains and wild strains of the olive fly Dacus oleae in an olive grove

International Nuclear Information System (INIS)

Fletcher, B.S.; Economopoulos, A.P.

1976-01-01

Studies on the dispersal rates of normal and γ-irradiated laboratory-reared as well as wild Dacus oleae (Gmelin) were carried out in an olive grove using protein-baited McPhail traps. No differences were found in the dispersal rates of normal and irradiated laboratory-cultured flies or between males and females. The mean distance travelled by the surviving flies up to 2 weeks after release was 180-190 m, and by that time only ca. 13% of the flies remained alive in the grove. No laboratory-reared flies were trapped outside the olive grove. The limited amount of data obtained with wild flies suggested that they may disperse over greater distances than laboratory-reared flies

Economic injury levels for Asian citrus psyllid control in process oranges from mature trees with high incidence of huanglongbing.

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Cesar Monzo

Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri Kuwayama, is the key pest of citrus wherever it occurs due to its role as vector of huanglongbing (HLB also known as citrus greening disease. Insecticidal vector control is considered to be the primary strategy for HLB management and is typically intense owing to the severity of this disease. While this approach slows spread and also decreases severity of HLB once the disease is established, economic viability of increasingly frequent sprays is uncertain. Lacking until now were studies evaluating the optimum frequency of insecticide applications to mature trees during the growing season under conditions of high HLB incidence. We related different degrees of insecticide control with ACP abundance and ultimately, with HLB-associated yield losses in two four-year replicated experiments conducted in commercial groves of mature orange trees under high HLB incidence. Decisions on insecticide applications directed at ACP were made by project managers and confined to designated plots according to experimental design. All operational costs as well as production benefits were taken into account for economic analysis. The relationship between management costs, ACP abundance and HLB-associated economic losses based on current prices for process oranges was used to determine the optimum frequency and timing for insecticide applications during the growing season. Trees under the most intensive insecticidal control harbored fewest ACP resulting in greatest yields. The relationship between vector densities and yield loss was significant but differed between the two test orchards, possibly due to varying initial HLB infection levels, ACP populations or cultivar response. Based on these relationships, treatment thresholds during the growing season were obtained as a function of application costs, juice market prices and ACP densities. A conservative threshold for mature trees with high incidence of HLB would help

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...

Soil management system in hazelnut groves (Corylus sp. versus the presence of ground beetles (Coleoptera: Carabidae

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Nietupski Mariusz

2015-01-01

Full Text Available Sustaining biodiversity as well as taking advantage of the natural environment’s resistance are the key elements which should be considered when designing integrated plans for the protection of hazelnut groves. An effort has been made in this study to analyse the impact of different soil cultivation methods in hazelnut groves, on the species composition and number of individuals in carabid assemblages (Coleoptera: Carabidae. Another aim was to determine which method of inter-row soil management had the least negative effect on assemblages of these beetles. Because of the type of habitat, the xerothermic species characteristic for southeastern Europe, i.e. Calathus ambiguus, Poecilus lepidus, Harpalus calceatus, and H. griseus, were the most numerous. The qualitative and quantitative analysis of the captured individuals implied that the optimal soil tillage system in young hazelnut groves is when soil is kept fallow with machines or chemicals, or when soil is covered with manure. The least favourable practice for the appearance of ground beetles of the Carabidae family is the use of polypropylene fabric, bark or sawdust, to cover soil

Early events of citrus greening (Huanglongbing) disease development at the ultrastructural level.

Science.gov (United States)

Folimonova, Svetlana Y; Achor, Diann S

2010-09-01

Citrus greening (Huanglongbing [HLB]) is one of the most destructive diseases of citrus worldwide. The causal agent of HLB in Florida is thought to be 'Candidatus Liberibacter asiaticus'. Understanding of the early events in HLB infection is critical for the development of effective measures to control the disease. In this work, we conducted cytopathological studies by following the development of the disease in citrus trees graft inoculated with 'Ca. L. asiaticus'-containing material under greenhouse conditions to examine the correlation between ultrastructural changes and symptom production, with the main objective of characterizing the early events of infection. Based on our observations, one of the first degenerative changes induced upon invasion of the pathogen appears to be swelling of middle lamella between cell walls surrounding sieve elements. This anatomical aberration was often observed in samples from newly growing flushes in inoculated sweet orange and grapefruit trees at the early "presymptomatic" stage of HLB infection. Development of symptoms and their progression correlated with an increasing degree of microscopic aberrations. Remarkably, the ability to observe the bacterium in the infected tissue also correlated with the degree of the disease progression. Large numbers of bacterial cells were found in phloem sieve tubes in tissue samples from presymptomatic young flushes. In contrast, we did not observe the bacteria in highly symptomatic leaf samples, suggesting a possibility that, at more advanced stages of the disease, a major proportion of 'Ca. L. asiaticus' is present in a nonviable state. We trust that observations reported here advance our understanding of how 'Ca. L. asiaticus' causes disease. Furthermore, they may be an important aid in answering a question: when and where within an infected tree the tissue serves as a better inoculum source for acquisition and transmission of the bacterium by its psyllid vector.

Enhanced Acquisition Rates of 'Candidatus Liberibacter asiaticus' by the Asian Citrus Psyllid (Hemiptera: Liviidae) in the Presence of Vegetative Flush Growth in Citrus.

Science.gov (United States)

Sétamou, Mamoudou; Alabi, Olufemi J; Kunta, Madhurababu; Jifon, John L; da Graça, John V

2016-10-01

The Asian citrus psyllid preferentially feeds and exclusively reproduces on young, newly emerged flush shoots of citrus. Asian citrus psyllid nymphs feed and complete their life stages on these flush shoots. Recent studies conducted under greenhouse conditions have shown that the transmission rates of 'Candidatus Liberibacter asiaticus' (CLas), the putative causal agent of huanglongbing disease of citrus, are enhanced when flush shoots are present. However, it is unclear if CLas acquisition by migrant adult Asian citrus psyllids is similarly enhanced. To address this knowledge gap, cohorts of Asian citrus psyllid adults were allowed 1-wk acquisition access period (AAP) on flushing and nonflushing shoots of qPCR-tested symptomatic (CLas+) and asymptomatic (CLas-) 10-yr-old sweet orange trees under field conditions. After the AAP, they were tested for CLas by qPCR. Progeny Asian citrus psyllid adults that emerged 4 wk post-AAP were similarly retrieved and tested. Eighty percent of flushing and 30% of nonflushing CLas+ trees produced infective Asian citrus psyllid adults, indicating that flush shoots have greater potential to be inoculum sources for CLas acquisition. Concomitantly, 21.1% and 6.0% infective adults were retrieved, respectively, from flushing and nonflushing CLas+ trees, indicating that Asian citrus psyllid adults acquire CLas more efficiently from flush shoots relative to mature shoots. In addition, 12.1% of infective Asian citrus psyllid adult progeny were obtained from 70% of flushing CLas+ trees. Significantly lower mean Ct values were also obtained from infective adults retrieved from flushing relative to nonflushing trees. The results underscore the role of flush shoots in CLas acquisition and the need to protect citrus trees from Asian citrus psyllid infestations during flush cycles. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email

Impact and ecosystem service of forest and sacred grove as saviour of water quantity and quality in Garhwal Himalaya, India.

Science.gov (United States)

Jana, Purna; Dasgupta, Sabyasachi; Todaria, Nagendra P

2017-08-29

The present study was conducted in environs of the sacred grove of Garhwal Himalaya, India, with a view to assess the impacts of sacred groves and forests on the quality and quantity of water and also to assess the effect of seasonality on perennial stream quality. Water samples were collected from three randomly selected stream spots of both the sacred grove dominated by deodar (Cedrus deodara) and the non-sacred patch dominated by oak (Quercus leucotrichophora). Water samples from both patches were within the World Health Organization (WHO) standard limits. Based on an already established water quality index, water quality of both patches was safe for domestic and irrigation purposes but needs treatment for drinking purposes. Results of the present study also showed a very prominent impact of forest type as well as management condition on water quality and quantity. The water discharge from an oak forest shows more consistency than the discharge from a deodar forest. Due to the presence of the sacred grove, the area has become the source of good quality water supply during lean season for the surrounding villages. Water quality and quantity differed along with the change in season. The sacred grove and the existing forest leave a great impression on local dwellers, as due to its presence, local dwellers never run out of water supply during the dry season. As a result, the villagers sincerely want to protect the area for the sake of their own well-being.

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

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

Chemical-Petrographic Types and Shock Metamorphism of 184 Grove Mountains Equilibrated Ordinary Chondrites

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Deqiu Dai

2018-06-01

Full Text Available We reported the petrography and mineral chemistry of 184 equilibrated ordinary chondrites collected from Grove Mountains, Antarctica. The chemical-petrographic types and shock metamorphism degrees of these chondrites were assigned. They were classified into 46 H groups (22 H4, 20 H5, and four H6, 133 L groups (eight L4, 75 L5, and 50 L6, and five LL groups (four LL4 and one LL5. Some of these chondrites could be paired; however, both H and L group meteorites were affected. Further studies such as terrestrial ages and thermal luminescence are required in order to confirm the pairings. The relative abundances of H, L, and LL are different in Grove Mountain meteorites, when compared to those in Transcontinental Ridge meteorites. Based on the shock effects, the shock metamorphism degrees of these chondrites were assigned. Compared to previous studies, the heavily shocked samples of S4 and S5 have a higher fraction (59 out of 184 in Grove Mountain ordinary chondrites. The L group (54 out of 59 is the dominant chemical group in the heavily shocked chondrites, except for five meteorites which belong to the H group. The shock metamorphism degrees of the H and L groups are distinct, which may indicate different surface properties in their parent bodies. In addition, the petrologic types and shock degrees are probably closely related, with the most heavily shocked chondrites observed in types 5 and 6.

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...

Scientific Opinion on a technical file submitted by the Japanese Authorities to support a derogation request from the EU import requirements for bonsai and topiary trees that are host plants of Anoplophora chinensis

DEFF Research Database (Denmark)

Baker, R.; Candresse, T.; Dormannsné Simon, E.

2010-01-01

Following a request from the EU Commission, the EFSA PLH Panel conducted a scientific opinion on risk analysis and supporting documents provided by APHIS/USDA in support of the request to remove the Union's plant health import requirement that citrus fruit imported into the EU be sourced from...... host is rare. But the withdrawal of the current EU requirement that citrus fruit imported into the EU be sourced from groves where no symptoms of citrus canker have been observed in the field of production and in its immediate vicinity since the beginning of the last cycle of vegetation, will increase...

Lighting intensity of the soilsurface and restocking of oak groves

Science.gov (United States)

Slepykh, Victor; Zubko, Anna; Povolotckaia, Nina

2016-04-01

Oak groves of Caucasian Mineral Vody region (CMVR) possess a high ecological and balneological potential which defines the significance of their preservation and reproduction [1]. The role assessment of lighting intensity on renewal of oak groves was carried out on four trial squares (ts) in natural sixty-seven years old forest stand with prevalence of English oak (Quercus robur L.) with unimodal sity (type of the habitat - C1). The illumination was measured at the grass level by the universal measuring instrument of meteoparameters ATT-9508 with an illumination sensor of ATA-1591. The assessment of reforestation was carried out according to the established standards [2]. In the winter of 2005 there was conducted a selecting cutting cabin of the forest stand according to a local method on ts2 with intensity 30%, on ts4 - 50% after which the illumination on the soil surface in relation to illumination of an open place in the summer of 2005 increased from 4.9% to 33.9% on ts2, and from 5.9% to 24.4% on ts4. But by 2014 the illumination decreased till 3.0% on ts2, till 5.4% on ts4 because of an intensive soil grassing down. The control was carried out by ts1 and ts3 on which from 2005 to 2014 the illumination of the soil surface decreased from 4 to 2% as a result of the development of all storeys. As a result due to an intensive soil grassing-down, the total quantity of young oak trees decreased from 2005 to 2014 from 25.6 thousand pcs/ha to 5.9 thousand pcs/ha on ts2; on from 17.3 thousand pcs/ha to 4.0 thousand pcs/ha on ts4. At the same time the total quantity of young oak trees on control squares increased respectively for 1.4% (from 18.8 thousand pcs/ha to 19.1 thousand pcs/ha) on ts1, for 38.7% (from 25.2 thousand pcs/ha to 41.1 thousand pcs/ha). The experiment showed that small young oak trees perishes in the first years of their life from a lack of light and competition from grasland vegetation without providing successful reforestation. Conclusion. So it is

How Attractive Is Upland Olive Groves Landscape? Application of the Analytic Hierarchy Process and GIS in Southern Spain

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Olexandr Nekhay

2016-11-01

Full Text Available The upland olive groves of Andalusia (Southern Spain are an example of fragile landscape from an ecological point of view. The wildfire and soil erosion risks that can result in the desertification of the area are the main components of fragility. This paper focuses on the visual quality assessment of this agricultural system as a mean to their economic and environmental sustainability. The case study is represented by the upland olive groves of the municipality of Montoro where rural tourism is an important economic activity. We carried out a personal interview survey on 480 citizens to determine their visual preferences regarding three representative types of olive plantation landscape to be transferred to landscape level through a Geographical Information Systems (GIS. The Analytic Hierarchy Process (AHP multicriteria decision-making technique was the method used to derive preferences from the survey. The results suggest that olive farming systems with grass vegetation cover between the trees are the preferred landscape type (0.42, followed very closely by the non-productive olive groves (0.41. The conventional olive farming system was the least preferred landscape (0.17. The visual quality map presents five categories, revealing that most of the olive groves in the study area belong to the very low visual quality category (93% of the total area.

Multilocus microsatellite analysis of 'Candidatus Liberibacter asiaticus' associated with citrus Huanglongbing worldwide.

Science.gov (United States)

Islam, Md-Sajedul; Glynn, Jonathan M; Bai, Yang; Duan, Yong-Ping; Coletta-Filho, Helvecio D; Kuruba, Gopal; Civerolo, Edwin L; Lin, Hong

2012-03-20

Huanglongbing (HLB) is one of the most destructive citrus diseases in the world. The disease is associated with the presence of a fastidious, phloem-limited α- proteobacterium, 'Candidatus Liberibacter asiaticus', 'Ca. Liberibacter africanus' or 'Ca. Liberibacter americanus'. HLB-associated Liberibacters have spread to North America and South America in recent years. While the causal agents of HLB have been putatively identified, information regarding the worldwide population structure and epidemiological relationships for 'Ca. L. asiaticus' is limited. The availability of the 'Ca. L. asiaticus' genome sequence has facilitated development of molecular markers from this bacterium. The objectives of this study were to develop microsatellite markers and conduct genetic analyses of 'Ca. L. asiaticus' from a worldwide collection. Two hundred eighty seven isolates from USA (Florida), Brazil, China, India, Cambodia, Vietnam, Taiwan, Thailand, and Japan were analyzed. A panel of seven polymorphic microsatellite markers was developed for 'Ca. L. asiaticus'. Microsatellite analyses across the samples showed that the genetic diversity of 'Ca. L. asiaticus' is higher in Asia than Americas. UPGMA and STRUCTURE analyses identified three major genetic groups worldwide. Isolates from India were genetically distinct. East-southeast Asian and Brazilian isolates were generally included in the same group; a few members of this group were found in Florida, but the majority of the isolates from Florida were clustered separately. eBURST analysis predicted three founder haplotypes, which may have given rise to three groups worldwide. Our results identified three major genetic groups of 'Ca. L. asiaticus' worldwide. Isolates from Brazil showed similar genetic makeup with east-southeast Asian dominant group, suggesting the possibility of a common origin. However, most of the isolates recovered from Florida were clustered in a separate group. While the sources of the dominant 'Ca. L

Citrus water use in South Africa

CSIR Research Space (South Africa)

Vahrmeijer, JT

2012-09-01

Full Text Available scheduling is needed to justify the quantity of water needed for the production of citrus. Models, which are formidable tools to predict water use and crop performance, are therefore vital to provide accurate estimates of citrus water use across different...

Amplification of DNA of Xanthomonas axonopodis pv. citri from historic citrus canker herbarium specimens.

Science.gov (United States)

Li, Wenbin; Brlansky, Ronald H; Hartung, John S

2006-05-01

Herbaria are important resources for the study of the origins and dispersal of plant pathogens, particularly bacterial plant pathogens that incite local lesions in which large numbers of pathogen genomes are concentrated. Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus bacterial canker disease, is a notable example of such a pathogen. The appearance of novel strains of the pathogen in Florida and elsewhere make it increasingly important to understand the relationships among strains of this pathogen. USDA-ARS at Beltsville, Maryland maintains approximately 700 herbarium specimens with citrus canker disease lesions up to 90 years old, originally collected from all over the world, and so is an important resource for phytogeographic studies of this bacterium. Unfortunately, DNA in herbarium specimens is degraded and may contain high levels of inhibitors of PCR. In this study, we compared a total of 23 DNA isolation techniques in combination with 31 novel primer pairs in order to develop an efficient protocol for the analysis of Xac DNA in herbarium specimens. We identified the most reliable extraction method, identified in terms of successful amplification by our panel of 31 primer pairs. We also identified the most robust primer pairs, identified as successful in the largest number of extracts prepared by different methods. We amplified Xac genomic sequences up to 542 bp long from herbarium samples up to 89 years old. Primers varied in effectiveness, with some primer pairs amplifying Xac DNA from a 1/10,000 dilution of extract from a single lesion from a citrus canker herbarium specimen. Our methodology will be useful to identify pathogens and perform molecular analyses of bacterial and possibly fungal genomes from herbarium specimens.

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.

Effect of genotype and environment on citrus juice carotenoid content.

Science.gov (United States)

Dhuique-Mayer, Claudie; Fanciullino, Anne-Laure; Dubois, Cecile; Ollitrault, Patrick

2009-10-14

A selection of orange and mandarin varieties belonging to the same Citrus accession and cultivated in Mediterranean (Corsica), subtropical (New Caledonia), and tropical areas (principally Tahiti) were studied to assess the effect of genotype and environmental conditions on citrus juice carotenoid content. Juices from three sweet orange cultivars, that is, Pera, Sanguinelli, and Valencia ( Citrus sinensis (L.) Osbeck), and two mandarin species ( Citrus deliciosa Ten and Citrus clementina Hort. ex Tan), were analyzed by HPLC using a C(30) column. Annual carotenoid content variations in Corsican fruits were evaluated. They were found to be very limited compared to variations due to varietal influences. The statistical analysis (PCA, dissimilarity tree) results based on the different carotenoid compounds showed that citrus juice from Corsica had a higher carotenoid content than citrus juices from tropical origins. The tropical citrus juices were clearly differentiated from citrus juices from Corsica, and close correlations were obtained between beta-cryptoxanthin and phytoene (r = 0.931) and beta-carotene and phytoene (r = 0.918). More broadly, Mediterranean conditions amplified interspecific differentiation, especially by increasing the beta-cryptoxanthin and cis-violaxanthin content in oranges and beta-carotene and phytoene-phytofluene content in mandarins. Thus, at a quantitative level, environmental conditions also had a major role in determining the levels of carotenoids of nutritional interest, such as the main provitamin A carotenoids in citrus juice (beta-cryptoxanthin and beta-carotene).

Homologues of CsLOB1 in citrus function as disease susceptibility genes in citrus canker.

Science.gov (United States)

Zhang, Junli; Huguet-Tapia, Jose Carlos; Hu, Yang; Jones, Jeffrey; Wang, Nian; Liu, Sanzhen; White, Frank F

2017-08-01

The lateral organ boundary domain (LBD) genes encode a group of plant-specific proteins that function as transcription factors in the regulation of plant growth and development. Citrus sinensis lateral organ boundary 1 (CsLOB1) is a member of the LBD family and functions as a disease susceptibility gene in citrus bacterial canker (CBC). Thirty-four LBD members have been identified from the Citrus sinensis genome. We assessed the potential for additional members of LBD genes in citrus to function as surrogates for CsLOB1 in CBC, and compared host gene expression on induction of different LBD genes. Using custom-designed transcription activator-like (TAL) effectors, two members of the same clade as CsLOB1, named CsLOB2 and CsLOB3, were found to be capable of functioning similarly to CsLOB1 in CBC. RNA sequencing and quantitative reverse transcription-polymerase chain reaction analyses revealed a set of cell wall metabolic genes that are associated with CsLOB1, CsLOB2 and CsLOB3 expression and may represent downstream genes involved in CBC. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Evaluation of Chemical Composition and Biological Activities of Citrus pseudolimon and Citrus grandis Peel Essential Oils

International Nuclear Information System (INIS)

Sajid, A.; Hanif, M.A.; Shahid, M.

2016-01-01

Essential oils and their volatile constituents are used extensively to prevent and treat human diseases. In the past decades, worldwide demand for citrus essential oils has greatly increased. Citrus essential oils containing 85-99 percent volatile and 1-15 percent non-volatile components. Essential oils from Citrus pseudolimon and Citrus grandis peels were extracted through steam distillation and characterized by GC-MS. C. pseudolimon has thirty six and C. grandis has thirty three total components; limonene 47.07 percent and 71.48 percent was the major component in both oils respectively. Antioxidant activity was checked by 2, 2-diphenyl-1-picrylhydrazyl radical assay and β-carotene/linoleic acid bleaching test. Both oils have modest activity. The antimicrobial potential was assessed against different bacterial and fungus strains. C. pseudolimon oil possessed strong activity against all tested strains while C. grandis has moderate activity. The antitumor activity was evaluated by potato disc assay, C. pseudolimon showed 81.25 inhibition. Hence the essential oils could have a great potential in pharmaceutical industry. (author)

The Distribution of Coumarins and Furanocoumarins in Citrus Species Closely Matches Citrus Phylogeny and Reflects the Organization of Biosynthetic Pathways.

Directory of Open Access Journals (Sweden)

Audray Dugrand-Judek

Full Text Available Citrus plants are able to produce defense compounds such as coumarins and furanocoumarins to cope with herbivorous insects and pathogens. In humans, these chemical compounds are strong photosensitizers and can interact with medications, leading to the "grapefruit juice effect". Removing coumarins and furanocoumarins from food and cosmetics imply additional costs and might alter product quality. Thus, the selection of Citrus cultivars displaying low coumarin and furanocoumarin contents constitutes a valuable alternative. In this study, we performed ultra-performance liquid chromatography coupled with mass spectrometry analyses to determine the contents of these compounds within the peel and the pulp of 61 Citrus species representative of the genetic diversity all Citrus. Generally, Citrus peel contains larger diversity and higher concentrations of coumarin/furanocoumarin than the pulp of the same fruits. According to the chemotypes found in the peel, Citrus species can be separated into 4 groups that correspond to the 4 ancestral taxa (pummelos, mandarins, citrons and papedas and extended with their respective secondary species descendants. Three of the 4 ancestral taxa (pummelos, citrons and papedas synthesize high amounts of these compounds, whereas mandarins appear practically devoid of them. Additionally, all ancestral taxa and their hybrids are logically organized according to the coumarin and furanocoumarin pathways described in the literature. This organization allows hypotheses to be drawn regarding the biosynthetic origin of compounds for which the biogenesis remains unresolved. Determining coumarin and furanocoumarin contents is also helpful for hypothesizing the origin of Citrus species for which the phylogeny is presently not firmly established. Finally, this work also notes favorable hybridization schemes that will lead to low coumarin and furanocoumarin contents, and we propose to select mandarins and Ichang papeda as Citrus

Drought Tip: Irrigating Citrus with Limited Water

OpenAIRE

Faber, Ben

2015-01-01

As an evergreen in California's Mediterranean climate, with wet winters and dry summers, citrus requires some water all year long. Depending on the cultivar and rootstock, citrus can sustain certain levels of drought stress.

Expression and functional analysis of citrus carotene hydroxylases: unravelling the xanthophyll biosynthesis in citrus fruits.

Science.gov (United States)

Ma, Gang; Zhang, Lancui; Yungyuen, Witchulada; Tsukamoto, Issei; Iijima, Natsumi; Oikawa, Michiru; Yamawaki, Kazuki; Yahata, Masaki; Kato, Masaya

2016-06-29

Xanthophylls are oxygenated carotenoids and fulfill critical roles in plant growth and development. In plants, two different types of carotene hydroxylases, non-heme di-iron and heme-containing cytochrome P450, were reported to be involved in the biosynthesis of xanthophyll. Citrus fruits accumulate a high amount of xanthophylls, especially β,β-xanthophylls. To date, however, the roles of carotene hydroxylases in regulating xanthophyll content and composition have not been elucidated. In the present study, the roles of four carotene hydroxylase genes (CitHYb, CitCYP97A, CitCYP97B, and CitCYP97C) in the biosynthesis of xanthophyll in citrus fruits were investigated. Phylogenetic analysis showed that the four citrus carotene hydroxylases presented in four distinct clusters which have been identified in higher plants. CitHYb was a non-heme di-iron carotene hydroxylase, while CitCYP97A, CitCYP97B, and CitCYP97C were heme-containing cytochrome P450-type carotene hydroxylases. Gene expression results showed that the expression of CitHYb increased in the flavedo and juice sacs during the ripening process, which was well consistent with the accumulation of β,β-xanthophyll in citrus fruits. The expression of CitCYP97A and CitCYP97C increased with a peak in November, which might lead to an increase of lutein in the juice sacs during the ripening process. The expression level of CitCYP97B was much lower than that of CitHYb, CitCYP97A, and CitCYP97C in the juice sacs during the ripening process. Functional analysis showed that the CitHYb was able to catalyze the hydroxylation of the β-rings of β-carotene and α-carotene in Escherichia coli BL21 (DE3) cells. Meanwhile, when CitHYb was co-expressed with CitCYP97C, α-carotene was hydroxylated on the β-ring and ε-ring sequentially to produce lutein. CitHYb was a key gene for β,β-xanthophyll biosynthesis in citrus fruits. CitCYP97C functioned as an ε-ring hydroxylase to produce lutein using zeinoxanthin as a substrate

Evaluating citrus germplasm for huanglongbing (HLB) resistance: USDA-ARS Inoculation Program

Science.gov (United States)

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it vectors bacteria responsible for a serious disease of citrus known as huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program for screening citrus germplasm for resistance to the di...

Mechanical Damage Detection of Indonesia Local Citrus Based on Fluorescence Imaging

Science.gov (United States)

Siregar, T. H.; Ahmad, U.; Sutrisno; Maddu, A.

2018-05-01

Citrus experienced physical damage in peel will produce essential oils that contain polymethoxylated flavone. Polymethoxylated flavone is fluorescence substance; thus can be detected by fluorescence imaging. This study aims to study the fluorescence spectra characteristic and to determine the damage region in citrus peel based on fluorescence image. Pulung citrus from Batu district, East Java, as a famous citrus production area in Indonesia, was used in the experiment. It was observed that the image processing could detect the mechanical damage region. Fluorescence imaging can be used to classify the citrus into two categories, sound and defect citruses.

Huanglongbing increases Diplodia Stem End Rot in Citrus sinensis

Science.gov (United States)

Huanglongbing (HLB), one of the most devastating diseases of citrus is caused by the a-Proteobacteria Candidatus Liberibacter. Diplodia natalensis Pole-Evans is a fungal pathogen which has been known to cause a postharvest stem-end rot of citrus, the pathogen infects citrus fruit under the calyx, an...

Citrus tissue culture employing vegetative explants.

Science.gov (United States)

Chaturvedi, H C; Singh, S K; Sharma, A K; Agnihotri, S

2001-11-01

Citrus being a number one fruit of the world due to its high nutritional value, huge production of fruits and fruit products, the citrus industry may be considered a major fruit industry. Though citrus orchard area in India is comparable to USA, the produce is far less, while its export is nil. Biotechnology has played an outstanding role in boosting the citrus industry, e.g., in Spain, which is now the biggest exporter of citrus fruit with the application of micrografting. Amongst the fruit trees, perhaps the maximum tissue culture research has been done in citrus during the past four decades, however, the results of practical value are meagre. The shortfalls in citrus tissue culture research and some advancements made in this direction along with bright prospects are highlighted, restricting the review to vegetative explants only. Whilst utilization of nucellar embryogenesis is limited to rootstocks, the other aspects, like, regeneration and proliferation of shoot meristems measuring 200 microm in length--a global breakthrough--of two commercially important scion species, Citrus aurantifolia and C. sinensis and an important rootstock, C. limonia, improvement of micrografting technique, cloning of the same two scion species as well as some Indian rootstock species, employing nodal stem segments of mature trees, of immense practical value have been elaborated. A rare phenomenon of shift in the morphogenetic pattern of differentiation from shoot bud differentiation to embryoid formation occurred during the long-term culture of stem callus of C. grandis. Stem callus-regenerated plants of C. aurantifolia, C. sinensis and C. grandis showed variation in their ploidy levels and a somaclonal variant of C. sinensis, which produced seedless fruits was isolated. Tailoring of rooting in microshoots to a tap root-like system by changing the inorganic salt composition of the rooting medium, resulting in 100% transplant success, and germplasm preservation through normal growth

Evaluation of the effects, on canopy arthropods, of two agricultural management systems to control pests in olive groves from north-east of Portugal.

Science.gov (United States)

Santos, Sónia A P; Pereira, José A; Torres, Laura M; Nogueira, António J A

2007-02-01

This study aims to investigate the effect of management regime on canopy arthropod community of the olive tree (Olea europaea L.). Field studies were performed in two successive years, 2002 and 2003, in two olive groves, one under organic farming and the other under integrated protection. The integrated protection grove was sprayed once a year in June, with dimethoate, to control the anthophagous generation of the olive moth, Prays oleae (Bern.). From April to November of each year, the canopy arthropods were sampled weekly. PRC method was used to analyse the effect of management regime at the community level and results showed that taxa responded differently to insecticide application suggesting that the organic grove was a more suitable habitat for the arthropods than the integrated protection grove. Abundance of arthropods peaked in May and June for both years but, after spraying with dimethoate, decreased significantly in integrated protection grove, recovering very slowly thereafter. Psocoptera, Miridae, Formicidae and Coccinellidae were the most sensitive taxa to insecticide application. Their decreasing in abundance was more evident in the second year of the trial. On the other hand chrysopids showed some tolerance to insecticide applications. These results suggest that the timing of spray is of utmost importance in reducing the side effects of spraying on beneficial arthropods. Moreover, differences in population susceptibility as well as in life cycle patterns must be considered.

Study of the thermal degradation of citrus seeds

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Montoya, V. [Centro de Quimica, Instituto de Ciencias, Universidad Autonoma de Puebla, Apdo. Postal J-55, Puebla 72570, Pue (Mexico); Instituto Nacional del Carbon, CSIC, Apartado 73, E-33080 Oviedo (Spain); Montes-Moran, M.A. [Instituto Nacional del Carbon, CSIC, Apartado 73, E-33080 Oviedo (Spain); Elizalde-Gonzalez, M.P. [Centro de Quimica, Instituto de Ciencias, Universidad Autonoma de Puebla, Apdo. Postal J-55, Puebla 72570, Pue (Mexico)

2009-09-15

The citrus seeds are one of the principal residues in the juice industry and their utilization can decrease significantly the problems of their final disposal. In this work the thermal degradation of three Mexican citrus seeds: orange (Citrus sinensis), lemon (Citrus Limon) and grapefruit (Citrus paradisi) was studied in nitrogen atmosphere. The two components (embryo and husk) of the seeds were characterized separately. The results showed that the thermal effects are very similar between the three embryos and the three husks. The embryos show higher degradability, superior content of nitrogen and higher heating value than the husks. The thermal degradation of the components of the three seeds is completed at 600 C and it is considered to be a global process derived from the decomposition of their principal components (cellulose, hemicellulose and lignin). The results suggest that mixing the three entire seeds will not lead to a severe deviation from their individual thermal behavior and that the industry could apply them for carbonization purposes. (author)

Quantitation of flavonoid constituents in citrus fruits.

Science.gov (United States)

Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M

1999-09-01

Twenty-four flavonoids have been determined in 66 Citrus species and near-citrus relatives, grown in the same field and year, by means of reversed phase high-performance liquid chromatography analysis. Statistical methods have been applied to find relations among the species. The F ratios of 21 flavonoids obtained by applying ANOVA analysis are significant, indicating that a classification of the species using these variables is reasonable to pursue. Principal component analysis revealed that the distributions of Citrus species belonging to different classes were largely in accordance with Tanaka's classification system.

HPLC-MS analysis of secondary metabolites in leaves from orange trees infected with Huanglongbing: A 9-month time series study

Science.gov (United States)

Huanglongbing (HLB) disease, presumably caused by Canditatus Liberibacter asiaticus (CLas), is threatening one million acres of commercial citrus groves that have an annual production value of approximately $3 billion across the U.S. The objectives of this study were to identify the earliest signifi...

Diaphorina citri (Hemiptera: Liviidae) responses to microcontroller-buzzer communication signals of potential use in vibration traps

Science.gov (United States)

Monitoring of Diaphorina citri Kuwayama populations is an important component of efforts to reduce damage caused by huanglongbing, a devastating disease it vectors in citrus groves. Currently, D. citri is monitored primarily by unbaited sticky traps or visual inspection of trees. A potentially more ...

Citrus tristeza virus: An increasing trend in the virus occurrence and ...

African Journals Online (AJOL)

ABC

2015-07-29

Jul 29, 2015 ... Citrus tristeza clostervirus (CTV) is one of the most damaging fruit viruses playing havoc in citrus ... diseases of citrus trees reported in Pakistan are tristeza, .... bark. Vein clearing and stem pitting were also observed on sweet orange trees sour ..... disposal of source of inoculum by removing old citrus trees ...

Physicochemical Characteristics of Citrus Seed Oils from Kerman, Iran

Directory of Open Access Journals (Sweden)

Mohammad Reazai

2014-01-01

Full Text Available Recently, there has been a great deal of attention on usage, byproducts, and wastes of the food industry. There have been many studies on the properties of citrus seeds and extracted oil from citrus grown in Kerman, Iran. The rate of oil content of citrus seeds varies between 33.4% and 41.9%. Linoleic acid (33.2% to 36.3% is the key fatty acid found in citrus seeds oil and oleic (24.8% to 29.3% and palmitic acids (23.5% to 29.4% are the next main fatty acids, respectively. There are also other acids found at trivial rates such as stearic, palmitoleic, and linolenic. With variation between 0.54 meg/kg and 0.77 mgq/kg in peroxide values of citrus seed oils, acidity value of the oil varies between 0.44% and 0.72%. The results of the study showed that citrus seeds under study (orange and sour lemon grown in Kerman province and the extracted oil have the potential of being used as the source of edible oil.

Understanding the dynamics of citrus water use

CSIR Research Space (South Africa)

Taylor, NJ

2012-12-01

Full Text Available The quantification of water use of citrus orchards is important in order to prevent stress developing in the orchard and to avoid wasting precious water resources. Measurement of citrus orchard water use is not possible under all environ-mental...

(HLB) infected citrus

African Journals Online (AJOL)

ONOS

2010-09-06

Sep 6, 2010 ... 1Departments of Crop Science, Faculty of Agriculture, University Putra Malaysia, 43400 Serdang, Selangor Darul ... Huanglongbing (HLB) disease, also known as citrus ..... Huanglongbing: A destructive, newly-emerging,.

76 FR 77386 - Amendment to and Establishment of Restricted Areas; Warren Grove, NJ

Science.gov (United States)

2011-12-13

... responsibility. The FAA is taking this action to provide the airspace needed for realistic military training so that aircrews can acquire and maintain proficiency in high altitude weapons employment and other modern... proposed rulemaking (NPRM) to expand the Warren Grove Range in order to raise the maximum altitude of the...

Asian citrus psyllid RNAi pathway - RNAi evidence

Science.gov (United States)

In silico analyses of the draft genome of Diaphorina citri, the Asian citrus psyllid, for genes within the Ribonucleic acid interference(RNAi), pathway was successful. The psyllid is the vector of the plant-infecting bacterium, Candidatus Liberibacter asiaticus (CLas), which is linked to citrus gree...

Somatic Embryogenesis: Still a Relevant Technique in Citrus Improvement.

Science.gov (United States)

Omar, Ahmad A; Dutt, Manjul; Gmitter, Frederick G; Grosser, Jude W

2016-01-01

The genus Citrus contains numerous fresh and processed fruit cultivars that are economically important worldwide. New cultivars are needed to battle industry threatening diseases and to create new marketing opportunities. Citrus improvement by conventional methods alone has many limitations that can be overcome by applications of emerging biotechnologies, generally requiring cell to plant regeneration. Many citrus genotypes are amenable to somatic embryogenesis, which became a key regeneration pathway in many experimental approaches to cultivar improvement. This chapter provides a brief history of plant somatic embryogenesis with focus on citrus, followed by a discussion of proven applications in biotechnology-facilitated citrus improvement techniques, such as somatic hybridization, somatic cybridization, genetic transformation, and the exploitation of somaclonal variation. Finally, two important new protocols that feature plant regeneration via somatic embryogenesis are provided: protoplast transformation and Agrobacterium-mediated transformation of embryogenic cell suspension cultures.

Lichenized fungi of a chestnut grove in Livari (Rumija, Montenegro)

Science.gov (United States)

Mayrhofer, Helmut; Drescher, Anton; Stešević, Danijela; Bilovitz, Peter O.

2016-01-01

Sixty taxa (59 species and 1 variety) of lichenized fungi are reported from a chestnut grove in Livari. The majority of them (55 species and 1 variety) occurred on Castanea sativa. The recently described Xylographa soralifera is new to the Balkan Peninsula. The lichenicolous fungus Monodictys epilepraria growing on Lepraria rigidula is new to Montenegro. The lichen mycota is compared with similar localities in Italy and Switzerland. The species composition in Livari is most similar to the Montieri site in Tuscany. PMID:26869743

Citrus paradisi: an effective bio-adsorbent for arsenic (v) remediation

International Nuclear Information System (INIS)

Khaskheli, M.I.; Memon, S.Q.; Parveen, S.

2014-01-01

In the present study As(V) was removed by citrus paradise (grape fruit) peel. Kinetics of the adsorption reaction was analyzed by the Pseudo second order and Morris-weber equations. Freundlich and Langmuir isotherm models were utilized for understanding of the relationship between the arsenic ions and citrus paradise peel adsorbent. The maximum measured uptake capacity of citrus paradise was 37.76 mg.g/sup -1/ at pH 4. FT-IR characterization of unloaded and As (V) loaded citrus paradisi peel adsorbent showed the participation of carbonyl (CO) and hydroxyl (OH) groups in adsorption process. The proposed citrus paradis peel adsorbent with optimized parameters was used for the removal of arsenic from arsenic contaminated real water samples. (author)

Groei van ongelijkjarige mengingen van grove den en berk op arme zandgronden; resultaten van metingen in 22 opstanden op de Veluwe en de Sallandse Heuvelrug

NARCIS (Netherlands)

Wijdeven, S.M.J.; Oosterbaan, A.; Berg, v.d. C.; Jole, van M.

2000-01-01

Het voorkomen en de groei van berk in ongelijkjarige mengingen van grove den en berk is bepaald op basis van opstandgemiddelden. Er is geen duidelijk verband tussen het voorkomen en de groei van berk en de schermdichtheid van grove den. Actuele groeigegevens zijn noodzakelijk voor een nadere

Metalized polyethylene mulch to repel Asian citrus psyllid, slow spread of huanglongbing and improve growth of new citrus plantings.

Science.gov (United States)

Croxton, Scott D; Stansly, Philip A

2014-02-01

Greening or huanglongbing (HLB) is a debilitating disease of citrus caused by Candidatus Liberibactor asiaticus and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. HLB now occurs worldwide in all major citrus growing regions except the Mediterranean and Australia. Management relies principally on insecticidal control of the ACP vector, but is insufficient, even for young trees which are most susceptible to the disease. We tested the ability of metalized polyethylene mulch to repel adult ACP as well as effects on incidence of HLB and early tree growth. Metalized mulch significantly reduced ACP populations and HLB incidence compared to whiteface mulch or bare ground. In addition, metalized mulch, together with the associated drip irrigation and fertigation system, increased soil moisture, reduced weed pressure, and increased tree growth rate. Metalized mulch slows spread of ACP and therefore HLB pressure on young citrus trees. Metalized mulch can thereby augment current control measures for young trees based primarily on systemic insecticides. Additional costs could be compensated for by increased tree growth rate which would shorten time to crop profitability. These advantages make a compelling case for large-scale trials using metalized mulch in young citrus plantings threatened by HLB. © 2013 Society of Chemical Industry.

Citrus peel extract incorporated ice cubes to protect the quality of common pandora: Fish storage in ice with citrus.

Science.gov (United States)

Yerlikaya, Pinar; Ucak, Ilknur; Gumus, Bahar; Gokoglu, Nalan

2015-12-01

The objective of this study was to investigate the effects of ice with albedo and flavedo fragments of Citrus (Grapefruit (Citrus paradisi) and Bitter orange (Citrus aurantium L.)) extracts on the quality of common pandora (Pagellus erythrinus). Concentrated citrus extracts were diluted with distilled water (1/100 w/v) before making of ice. The ice cubes were spread on each layer of fishes and stored at 0 °C for 15 days. The pH value showed a regular increase in all samples. TVB-N levels of bitter orange treatment groups were recorded lower than the other groups reaching to 25.11 ± 0.02 mg/100 g at the end of the storage. The TMA-N values of bitter orange treatment groups were lower than that of control and grapefruit treatment groups. In terms of TBARS value, alteration was observed in the control samples and this value significantly (p extracts treatment groups at the end of storage since their antioxidant capacity. The oxidation was suppressed in citrus extracts treatment groups, especially in bitter orange flavedo treatment. The results showed the bitter orange albedo and bitter orange flavedo extracts in combination with ice storage have more effectiveness in controlling the biochemical indices in common pandora.

Detection of Citrus psorosis virus in the northwestern citrus production area of Argentina by using an improved TAS-ELISA.

Science.gov (United States)

Zanek, Maria Cecilia; Peña, Eduardo; Reyes, Carina Andrea; Figueroa, Julia; Stein, Beatriz; Grau, Oscar; Garcia, Maria Laura

2006-11-01

Citrus Psorosis in Argentina is a serious disease. Citrus is produced in two regions located in the northeast (NE) and northwest (NW) area of the country. These two areas have different climates and soil types, and therefore different citrus species and varieties are cultivated. In the NE region, Psorosis is epidemic, and in the NW region, the disease was described on several occasions since 1938, but it is not observed commonly in the orchards. Recently, trees with symptoms of Psorosis were observed in the Tucumán and Salta Provinces located in the NW region. Epidemiological studies in Argentina and Texas suggested that the disease is spread naturally by an unknown vector. The causal agent of the disease is the Citrus psorosis virus (CPsV), which can be detected by TAS-ELISA, RT-PCR and indicator plants. A new more rapid TAS-ELISA-HRP (horseradish peroxidase) is described which is more reliable, faster and more sensitive than the currently used for this virus, the TAS-ELISA-AP (alkaline phosphatase). Psorosis was detected by this improved method in few trees in the orchards of the Tucumán Province, in the NW citrus region, although natural spread does not seem to occur.

Comparative analysis of juice volatiles in selected mandarins, mandarin relatives and other citrus genotypes.

Science.gov (United States)

Yu, Yuan; Bai, Jinhe; Chen, Chunxian; Plotto, Anne; Baldwin, Elizabeth A; Gmitter, Frederick G

2018-02-01

Citrus fruit flavor is an important attribute prioritized in variety improvement. The present study compared juice volatiles compositions from 13 selected citrus genotypes, including six mandarins (Citrus reticulata), three sour oranges (Citrus aurantium), one blood orange (Citrus sinensis), one lime (Citrus limonia), one Clementine (Citrus clementina) and one satsuma (Citrus unshiu). Large differences were observed with respect to volatile compositions among the citrus genotypes. 'Goutou' sour orange contained the greatest number of volatile compounds and the largest volatile production level. 'Ponkan' mandarin had the smallest number of volatiles and 'Owari' satsuma yielded the lowest volatile production level. 'Goutou' sour orange and 'Moro' blood orange were clearly distinguished from other citrus genotypes based on the analysis of volatile compositions, even though they were assigned into one single group with two other sour oranges by the molecular marker profiles. The clustering analysis based on the aroma volatile compositions was able to differentiate mandarin varieties and natural sub-groups, and was also supported by the molecular marker study. The gas chromatography-mass spectrometry analysis of citrus juice aroma volatiles can be used as a tool to distinguish citrus genotypes and assist in the assessment of future citrus breeding programs. The aroma volatile profiles of the different citrus genotypes and inter-relationships detected among volatile compounds and among citrus genotypes will provide fundamental information on the development of marker-assisted selection in citrus breeding. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Exploratory survey on the maintenance of Osun-Osogbo sacred grove, Nigeria

Directory of Open Access Journals (Sweden)

GE Oseghale

2014-01-01

Full Text Available This paper examined the maintenance state of Osun- Osogbo grove in Osogbo – which is an organically evolved cultural edifice and landscape associated with the Yoruba traditional religion and culture. This was with a view to unfolding the level of deterioration, identifying the causes of decay, and providing appropriate maintenance solutions. In order to carry out this assessment, selected cultural properties like the first palace, the second palace, scared spaces, individual shrines, Osun worship points in the grove, Oja- Ontoto shrine, the sculptures, the suspension bridge, were examined through physical surveys. The analysis is also dependent on data procured through the administration of questionnaire. Findings revealed that these cultural properties were generally ill-maintained and in a serious state of disrepair. It is also confirmed that the main factors affecting maintenance of these cultural properties were inadequate funds for maintenance, high cost of repairs and poor construction techniques. There is no specialized organization to inspect the monuments and advise for efficient maintenance regularly. It is mainly through maintenance of heritage buildings that cultural significance of these monuments can be sustained for the need of upcoming generation. This would be difficult to achieve if the best practice approach to the maintenance and management of heritage properties is not fully adopted.

Modelling the number of olive groves in Spanish municipalities

Energy Technology Data Exchange (ETDEWEB)

Huete, M.D.; Marmolejo, J.A.

2016-11-01

The univariate generalized Waring distribution (UGWD) is presented as a new model to describe the goodness of fit, applicable in the context of agriculture. In this paper, it was used to model the number of olive groves recorded in Spain in the 8,091 municipalities recorded in the 2009 Agricultural Census, according to which the production of oil olives accounted for 94% of total output, while that of table olives represented 6% (with an average of 44.84 and 4.06 holdings per Spanish municipality, respectively). UGWD is suitable for fitting this type of discrete data, with strong left-sided asymmetry. This novel use of UGWD can provide the foundation for future research in agriculture, with the advantage over other discrete distributions that enables the analyst to split the variance. After defining the distribution, we analysed various methods for fitting the parameters associated with it, namely estimation by maximum likelihood, estimation by the method of moments and a variant of the latter, estimation by the method of frequencies and moments. For oil olives, the chi-square goodness of fit test gives p-values of 0.9992, 0.9967 and 0.9977, respectively. However, a poor fit was obtained for the table olive distribution. Finally, the variance was split, following Irwin, into three components related to random factors, external factors and internal differences. For the distribution of the number of olive grove holdings, this splitting showed that random and external factors only account about 0.22% and 0.05%. Therefore, internal differences within municipalities play an important role in determining total variability. (Author)

Effect of intercropping of maize in citrus orchards on citrus leaf miner infestation and population of its natural enemies

International Nuclear Information System (INIS)

Ahmed, S.; Khan, M.A.; Qasam, M.

2012-01-01

An experiment was conducted to determine the effect of intercropping of maize fodder in months of monsoon (July to October), in Faisalabad, Pakistan, on infestation of citrus leaf miner (CLM) (Phyllocnistis citrella Stanton) and its predators. Lemon, Kinnow, Grapefruit and Musambi intercropped with and without maize were selected for recording data on these insects. Percent leaf miner infestation and number of predators were recorded from randomly selected branches of citrus trees. Results showed that intercropped plots of each variety had low infestation of citrus miner and high population of coccinellids and Chrysoperla carnea and Musambi was 8.40+-0.144 and 12.72+-0.171 in intercropped and 9.12+-0.169 and 14.52+-0.200 in wihtout intercropped plots, respectively. Interaction of population of Chrysoperla carnea and coccinellids was non-significant for months, varieties and intercropping but was significant within months, varieties and intercropping. The possibility of using maize fodder as intercrop in autumn in citrus is discussed. (author)

Nematode Community Composition under Various Irrigation Schemes in a Citrus Soil Ecosystem.

Science.gov (United States)

Porazinska, D L; McSorley, R; Duncan, L W; Graham, J H; Wheaton, T A; Parsons, L R

1998-06-01

Interest in the sustainability of farming practices has increased in response to environmental problems associated with conventional agricultural management often adopted for the production of herbaceous crops, ornamentals, and fruit crops. Availability of measures of the status of the soil ecosystem is of immediate importance, particularly for environmental assessment and monitoring programs. This study investigated the effects of various irrigation regimes (an example of an agricultural management practice) on the structure of the nematode fauna in a citrus orchard in the sandy ridge area of Central Florida. Ecological measures such as community structure indices, diversity indices, and maturity indices were assessed and related to irrigation intensity. Maturity index was an effective measure in distinguishing differences between irrigation regimes, whereas other indices of community structure were not. Of various nematode genera and trophic groups, only omnivores and the omnivore genera. Aporcelaimellus and Eudorylaimus responded to irrigation treatments.

Comparing organic and conventional olive groves relative to energy use and greenhouse gas emissions associated with the cultivation of two varieties

International Nuclear Information System (INIS)

Taxidis, Efstratios T.; Menexes, George C.; Mamolos, Andreas P.; Tsatsarelis, Constantinos A.; Anagnostopoulos, Christos D.; Kalburtji, Kyriaki L.

2015-01-01

Highlights: • Multivariate statistical methods were applied to evaluate 88 olive groves. • Three main groups (high, medium, low energy inputs) were revealed. • The grouping was based on management practices and geographical location. • Best farming practices regulate the balance between environment and agriculture. - Abstract: Organic farming is applied in olive groves in Lesvos Island the last 20 years. “Kolovi” and “Adramitiani”, two dominant varieties are cultivated. Since there is limited research for energy inputs in olive groves, 62 conventional and 26 organic farms were selected during 2011–2013 in order to (a) determine the differences in energy flow among farming systems and varieties, (b) group olive groves based on energy flow indicators, (c) compare the CO 2 -equivalent emissions among farming systems and varieties. A combination of univariate and multivariate statistical methods was applied. Hierarchical Cluster Analysis (HCA) revealed three farm groups, all consisted of conventional and/or organic olive groves and included both varieties. Group 1 had the lowest energy inputs, while Group 3 the highest. Fuels and transportation, as energy inputs, had the highest contribution in farms’ grouping. A large number of external variables was studied, most of which (fruit production, olive oil production, pomace production, shoot production, olive oil energy production, pomace energy production, shoot energy production, total energy inputs, total energy outputs, intensity, energy efficiency, and energy productivity) had statistically significant differences among the three Groups. Management practices along with geographical location could be a reasonable explanation for the differences between the groups of studied olive groves. Group 3 had the highest non-renewable energy inputs (14,683.5 MJ ha −1 ) and consumption (2.4 MJ kg −1 ) and gas emissions (1.27 Mg ha −1 CO 2 , 0.17 kg ha −1 CH 4 , and 10.31 g ha −1 N 2 O). Group 2 had

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...

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...

Citrus paradisi: An Effective bio-adsorbent for Arsenic (V Remediation

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Mazhar I. Khaskheli

2014-06-01

Full Text Available In the present study As (V was removed by citrus paradisi (grape fruit peel. Kinetics of the adsorption reaction was analyzed by the Pseudo second order and Morris-weber equations. Freundlich and Langmuir isotherm models were utilized for understanding of the relationship between the arsenic ions and citrus paradisi peel adsorbent. The maximum measured uptake capacity of citrus paradisi was 37.76 mg.g-1 at pH 4. FT-IR characterization of unloaded and As (V loaded citrus paradisi peel adsorbent showed the participation of carbonyl (CO and hydroxyl (OH groups in adsorption process. The proposed citrus paradisi peel adsorbent with optimized parameters was used for the removal of arsenic from arsenic contaminated real water samples.

Development of loop-mediated isothermal amplification and SYBR green real-time PCR methods for the detection of Citrus yellow mosaic badnavirus in citrus species.

Science.gov (United States)

Anthony Johnson, A M; Dasgupta, I; Sai Gopal, D V R

2014-07-01

Citrus yellow mosaic badnavirus (CMBV) is an important pathogen in southern India spread by infected citrus propagules. One of the measures to arrest the spread of CMBV is to develop methods to screen and certify citrus propagules as CMBV-free. The methods loop-mediated isothermal amplification (LAMP) and SYBR green real-time PCR (SGRTPCR) have been developed for the efficient detection of CMBV in citrus propagules. This paper compares the sensitivities of LAMP and SGRTPCR with polymerase chain reaction (PCR) for the detection of CMBV. Whereas PCR and LAMP were able to detect CMBV from a minimum of 10 ng of total DNA of infected leaf samples, SGRTPCR could detect the same from 1 ng of total DNA. Using SGRTPCR, the viral titres were estimated to be the highest in rough lemon and lowest in Nagpur Mandarin of the five naturally infected citrus species tested. The results will help in designing suitable strategies for the sensitive detection of CMBV from citrus propagules. Copyright © 2014 Elsevier B.V. All rights reserved.

Conventional and Indigenous Biodiversity Conservation Approach: A Comparative Study of Jachie Sacred Grove and Nkrabea Forest Reserve

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Samuel Boadi

2017-01-01

Full Text Available Conventional managed forests and sacred groves are seldom assessed to determine their effectiveness in biodiversity conservation strategies. This study investigated tree and insect diversity in Jachie sacred grove (JSG and Nkrabea forest reserve (NFR in Ashanti region, Ghana. The study area constituted eight plots of 50 × 50 m along two 300 m long transects. Insects were sampled in eight pitfall traps, diagonally between the transects. Out of 150 individuals, 13 species in NFR and 15 species from JSG were registered. Celtis mildbraedii was the most dominant species in NFR = 43.18% and JSG = 23.58%. Mean DBH showed a significant relationship with basal area in NFR and JSG. Tree diversity and richness were higher in JSG (H′ = 1.43–2.3 ± 0.10; D = 1.8–3.69 ± 0.30 compared to NFR (H′ = 0.86–1.56 ± 0.09; D = 1.1–2.3 ± 0.57. However, insect diversity was higher in NFR (H′ = 1.34 ± 0.10 than in JSG (H′ = 0.5 ± 0.005. Camponotus furvus and Pachycondyla tarsata were most abundant in JSG and NFR, respectively. These findings will help conservationists work closely with traditional authorities in protecting sacred groves as key biodiversity hotspots.

Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

Science.gov (United States)

Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

2013-04-01

Soil Erosion is a natural process that shapes the Earth. Due to the impact of agriculture, soil erosion rates increase, landforms show gullies and rills, and soils are depleted. In the Mediterranean, wheat, olive and vineyards were the main agriculture products, but new plantations are being found in sloping terrain due to the drip-irrigation. This new strategy results in the removal of the traditional terraces in order to make suitable for mechanization the agriculture plantation. Citrus is a clear example of the impact of the new chemical agriculture with a high investment in herbicides, pesticides, mechanisation, land levelling and drip computer controlled irrigation systems. The new plantation of citrus orchards is found in the Mediterranean, but also in California, Florida, China and Brazil. Chile, Argentina, and South Africa are other producers that are moving to an industrial production of citrus. This paper shows how the citrus plantations are found as one of the most aggressive plantation due to the increase in soil erosion, and how we can apply successful control strategies. The research into the high erosion rates of citrus orchard built on the slopes are mainly found in China (Wu et al., 1997; Xu et al., 2010; Wang et al., 2011; Wu et al., 2011; Liu et al., 2011; Lü et al., 2011; Xu et al., 2012) and in the Mediterranean (Cerdà and Jurgensen, 2008; 2009; Cerdà et al., 2009a; 2009b; Cerdà et al., 2011; 2012) Most of the research done devoted to the measurements of the soil losses but also some research is done related to the soil properties (Lu et al., 1997; Lü et al., 2012; Xu et al., 2012) and the impact of cover crops to reduce the soil losses (Lavigne et al., 2012; Le Bellec et al., 2012) and the use of residues such as dried citrus peel in order to reduce the soil losses. There are 116 million tonnes of citrus produced yearly, and this affects a large surface of the best land. The citrus orchards are moving from flood irrigated to drip

Citrus plastid-related gene profiling based on expressed sequence tag analyses

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Tercilio Calsa Jr.

2007-01-01

Full Text Available Plastid-related sequences, derived from putative nuclear or plastome genes, were searched in a large collection of expressed sequence tags (ESTs and genomic sequences from the Citrus Biotechnology initiative in Brazil. The identified putative Citrus chloroplast gene sequences were compared to those from Arabidopsis, Eucalyptus and Pinus. Differential expression profiling for plastid-directed nuclear-encoded proteins and photosynthesis-related gene expression variation between Citrus sinensis and Citrus reticulata, when inoculated or not with Xylella fastidiosa, were also analyzed. Presumed Citrus plastome regions were more similar to Eucalyptus. Some putative genes appeared to be preferentially expressed in vegetative tissues (leaves and bark or in reproductive organs (flowers and fruits. Genes preferentially expressed in fruit and flower may be associated with hypothetical physiological functions. Expression pattern clustering analysis suggested that photosynthesis- and carbon fixation-related genes appeared to be up- or down-regulated in a resistant or susceptible Citrus species after Xylella inoculation in comparison to non-infected controls, generating novel information which may be helpful to develop novel genetic manipulation strategies to control Citrus variegated chlorosis (CVC.

Plant wealth of a sacred grove: Mallur Gutta, Telangana state, India

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Suthari S

2016-10-01

Full Text Available Sateesh Suthari,1 Ramesh Kandagalta,2 Ajmeera Ragan,2 Vatsavaya S Raju,2 1Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 2Plant Systematics Laboratory, Department of Botany, Kakatiya University, Warangal, India Abstract: The Mallur Gutta (Hill of Warangal district in Telangana state, India, reputed as a habitat for medicinal plants, was inventoried from 2009 to 2015 for its plant wealth through the traditional knowledge of the local people. The Hindu temples of Lord Sri Laxminarasimha Swamy and Lord Hanuman, and the ethnic worship of mahua trees indicated it was a sacred grove which was selected as a Medicinal Plants Conservation Area. The exploration of Mallur Gutta resulted in the enumeration and documentation of plant wealth representing 470 species of 318 genera pertaining to 95 families of vascular plants. The importance of the grove as the residence for many rare or medicinal species in the state of Telangana is documented. The plant diversity is analyzed in terms of growth and life forms which indicate the prevailing microclimate, ecological opportunities and the species richness. The ecological services rendered by the Mallur Gutta forest ecosystem are documented to study how the great majority of the species are used by the ethnic and nonethnic people, and also the pilgrims who visit the shrine for its serenity. The study also identified two major threats to the conservation of hill ecosystem and the archeological site: 1 biotic pressure (the ever-increasing pilgrims, grazing by cattle, goat and sheep, the development activities taken up for the pilgrims, nondegradable litter thrown, collection of medicinal plants and widening of the pathway to the Chintamani perennial stream – the trampling and alien plant invasions of the marsh sustaining the stream; and 2 the potential for fire spreading from burning the litter. The study suggests the need to initiate remedial measures toward ecosystem

Citrus Tristeza Virus: An Increasing Trend in the Virus Occurrence ...

African Journals Online (AJOL)

Citrus tristeza clostervirus (CTV) is one of the most damaging fruit viruses playing havoc in citrus orchards around the world. Here, we report, an ELISA-based indexing of citrus trees over a period of eight years (2002 to 2010) in Northwest Pakistan, revealing that the incidence of CTV is increasing mainly with the distribution ...

Annotation of the Asian citrus psyllid genome reveals a reduced innate immune system

Science.gov (United States)

Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuway...

Detection of Citrus Trees from Uav Dsms

Science.gov (United States)

Ok, A. O.; Ozdarici-Ok, A.

2017-05-01

This paper presents an automated approach to detect citrus trees from digitals surface models (DSMs) as a single source. The DSMs in this study are generated from Unmanned Aerial Vehicles (UAVs), and the proposed approach first considers the symmetric nature of the citrus trees, and it computes the orientation-based radial symmetry in an efficient way. The approach also takes into account the local maxima (LM) information to verify the output of the radial symmetry. Our contributions in this study are twofold: (i) Such an integrated approach (symmetry + LM) has not been tested to detect (citrus) trees (in orchards), and (ii) the validity of such an integrated approach has not been experienced for an input, e.g. a single DSM. Experiments are performed on five test patches. The results reveal that our approach is capable of counting most of the citrus trees without manual intervention. Comparison to the state-of-the-art reveals that the proposed approach provides notable detection performance by providing the best balance between precision and recall measures.

76 FR 11399 - Proposed Amendment to and Establishment of Restricted Areas, Warren Grove; NJ

Science.gov (United States)

2011-03-02

... that the FAA take this action due to the increased need for aircrew training in high-altitude weapons... increased aircrew training in high altitude weapons delivery tactics. This training requires higher... Grove Range, NJ, in order to raise the maximum altitude of the range from the current 14,000 feet mean...

Modelling the number of olive groves in Spanish municipalities

Directory of Open Access Journals (Sweden)

María-Dolores Huete

2016-03-01

Full Text Available The univariate generalized Waring distribution (UGWD is presented as a new model to describe the goodness of fit, applicable in the context of agriculture. In this paper, it was used to model the number of olive groves recorded in Spain in the 8,091 municipalities recorded in the 2009 Agricultural Census, according to which the production of oil olives accounted for 94% of total output, while that of table olives represented 6% (with an average of 44.84 and 4.06 holdings per Spanish municipality, respectively. UGWD is suitable for fitting this type of discrete data, with strong left-sided asymmetry. This novel use of UGWD can provide the foundation for future research in agriculture, with the advantage over other discrete distributions that enables the analyst to split the variance. After defining the distribution, we analysed various methods for fitting the parameters associated with it, namely estimation by maximum likelihood, estimation by the method of moments and a variant of the latter, estimation by the method of frequencies and moments. For oil olives, the chi-square goodness of fit test gives p-values of 0.9992, 0.9967 and 0.9977, respectively. However, a poor fit was obtained for the table olive distribution. Finally, the variance was split, following Irwin, into three components related to random factors, external factors and internal differences. For the distribution of the number of olive grove holdings, this splitting showed that random and external factors only account about 0.22% and 0.05%. Therefore, internal differences within municipalities play an important role in determining total variability.

The effect of pre spring spray to reduce of citrus important pests.

Science.gov (United States)

Hashemi, B; Damavandian, M R; Shoushtaril, R Vafaei; Tafaghodynia, B

2008-10-01

The importance of pre spring spray against citrus aphids, Pulvinaria aurantii Cockerell and Panonychus citri McGregor that are the most important pest of citrus during spring was tested. In this research, 150 trees ten years old sweet orange (Thomson navel on Citrus aurantium (root stocks)) in a citrus orchard approximately three hectares sampled. The experiment was laid out in a totally randomized (one-way) design replicated five times. According to the results, the pre spring spray do not effect on population density of citrus aphids and P. aurantii during March, April, May and June. However, the P. citri population decreased. Therefore, it seems the pre spring spray in citrus orchards is not necessary, but if P. citri is observed, the pre spring spray should be recommended.

The Types of Essentials Oil Components Isolated From the Leaves of Citrus Aurantifolia and Citrus Nobilis

OpenAIRE

Wulandari, Mutiara Juni; Mohammad Anwar Jamaludin,, Lailatul Riska, Agustin Laela Prunama; Mumun Nurmilawati, Indra Fauzi

2015-01-01

Essential oil or known as the eteris oil (etheric oil) was result from secondary metabolism of a plant. In general essential oil contains of citronellal, Citronelal, Citronelol, Limonen, β-Pinene dan sabinene. The components essential oil derived from citrus plants commonly used by perfume industry, on other hand it is used as essentials oil orange flavour addition in some drinks and food, and also as an antioxidant and anti cancer. One of the essential oil is produced by Citrus aurantifolia ...

The quest for a non-vector psyllid: Natural variation in acquisition and transmission of the huanglongbing pathogen ‘Candidatus Liberibacter asiaticus’ by Asian citrus psyllid isofemale lines

Science.gov (United States)

Ammar, El-Desouky; Hall, David G.; Hosseinzadeh, Saeed

2018-01-01

Genetic variability in insect vectors is valuable to study vector competence determinants and to select non-vector populations that may help reduce the spread of vector-borne pathogens. We collected and tested vector competency of 15 isofemale lines of Asian citrus psyllid, Diaphorina citri, vector of ‘Candidatus Liberibacter asiaticus’ (CLas). CLas is associated with huanglongbing (citrus greening), the most serious citrus disease worldwide. D. citri adults were collected from orange jasmine (Murraya paniculata) hedges in Florida, and individual pairs (females and males) were caged on healthy Murraya plants for egg laying. The progeny from each pair that tested CLas-negative by qPCR were maintained on Murraya plants and considered an isofemale line. Six acquisition tests on D. citri adults that were reared as nymphs on CLas-infected citrus, from various generations of each line, were conducted to assess their acquisition rates (percentage of qPCR-positive adults). Three lines with mean acquisition rates of 28 to 32%, were classified as ‘good’ acquirers and three other lines were classified as ‘poor’ acquirers, with only 5 to 8% acquisition rates. All lines were further tested for their ability to inoculate CLas by confining CLas-exposed psyllids for one week onto healthy citrus leaves (6–10 adults/leaf/week), and testing the leaves for CLas by qPCR. Mean inoculation rates were 19 to 28% for the three good acquirer lines and 0 to 3% for the three poor acquirer lines. Statistical analyses indicated positive correlations between CLas acquisition and inoculation rates, as well as between CLas titer in the psyllids and CLas acquisition or inoculation rates. Phenotypic and molecular characterization of one of the good and one of the poor acquirer lines revealed differences between them in color morphs and hemocyanin expression, but not the composition of bacterial endosymbionts. Understanding the genetic architecture of CLas transmission will enable the

Citrus fruit quality assessment; producer and consumer perspectives

Science.gov (United States)

Consumption of citrus fruit and juices is popular with consumers worldwide and makes an important contribution to a healthy diet. Nevertheless, consumer preferences for citrus have undergone significant changes over the last twenty years and it is important to understand what consumers are looking ...

Citrus Seed Oils Efficacy against Larvae of Aedes aegypti

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Hazrat Bilal

2017-10-01

Full Text Available Background: Dengue fever is a serious public health issue in Pakistan for many years. Globally plants have been reported to contain compounds with insecticidal properties. These properties have been demonstrated more recently on the larval stages of mosquitoes. Therefore, Citrus cultivar seeds were evaluated for larvicidal potential against the primary dengue vector Aedes aegypti.Methods: Extraction of oil was done by a steam distillation method and oils were evaluated according to WHO guidelines for larvicides 2005 for evaluation of insecticidal properties of citrus seed extracts against mosquito larvae.Result: Among the Citrus cultivar seed oil, rough lemon (Citrus jambhiri had the lowest LC50 value (200.79ppm, while musambi (C. sinensis var musambi had the highest LC50 value (457.30ppm after 24 h of exposure.Conclusion: Citrus cultivars have some larvicidal potential but C. jambhiri had the greatest potential against A. ae­gypti larvae. Further small-scale field trials using the extracts of C. jambhiri will be conducted to determine opera­tional feasibility.

Monitoring Citrus Soil Moisture and Nutrients Using an IoT Based System

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Xueyan Zhang

2017-02-01

Full Text Available Chongqing mountain citrus orchard is one of the main origins of Chinese citrus. Its planting terrain is complex and soil parent material is diverse. Currently, the citrus fertilization, irrigation and other management processes still have great blindness. They usually use the same pattern and the same formula rather than considering the orchard terrain features, soil differences, species characteristics and the state of tree growth. With the help of the ZigBee technology, artificial intelligence and decision support technology, this paper has developed the research on the application technology of agricultural Internet of Things for real-time monitoring of citrus soil moisture and nutrients as well as the research on the integration of fertilization and irrigation decision support system. Some achievements were obtained including single-point multi-layer citrus soil temperature and humidity detection wireless sensor nodes and citrus precision fertilization and irrigation management decision support system. They were applied in citrus base in the Three Gorges Reservoir Area. The results showed that the system could help the grower to scientifically fertilize or irrigate, improve the precision operation level of citrus production, reduce the labor cost and reduce the pollution caused by chemical fertilizer.

The role of rabbit density and the diversity of weeds in the development of cover crops in olive groves

Energy Technology Data Exchange (ETDEWEB)

Guerrero-Casado, J.; Carpio, A.J.; Prada, L.M.; Tortosa, F.S.

2015-07-01

Cover crops are an effective means to reduce soil erosion and to provide food and shelter for wildlife. However, in areas of intensive farming, which are characterised by the scarcity of weed communities, wild herbivores may focus their grazing on cover crops, which could make their implementation difficult. In this work, we test whether rabbit grazing can prevent the growth of herbaceous cover crops in olive groves in Southern Spain in addition to assessing the role of rabbit abundance and diversity of weeds in the development of cover crops. This question has been addressed by sowing Bromus rubens between the rows of five olive groves in Cordoba province (Spain). We then monitored the surface covered by B. rubens, along with both diversity of weed communities and rabbit abundance. Two rabbit exclusion areas were also placed in each olive grove in order to assess the impact of rabbits on the development of cover crops. Our results showed that the surface occupied by B. rubens was considerably higher in the rabbit exclusion areas (mean 56.8 ± 5.65 %) than in those areas in which they could feed (mean 35.6 ± 4.32 %). The coverage occupied by cover crops was higher in areas with lower rabbit density, although this relationship was modulated by the weed diversity index, since in areas with the same rabbit abundance the coverage was higher in those with a richer weed community. These findings suggest that high rabbit abundances can prevent the development of herbaceous cover crops in olive groves, particularly in areas in which alternative food resources (measured as weed diversity) are scarce. (Author)

The role of rabbit density and the diversity of weeds in the development of cover crops in olive groves

Directory of Open Access Journals (Sweden)

José Guerrero-Casado

2015-09-01

Full Text Available Cover crops are an effective means to reduce soil erosion and to provide food and shelter for wildlife. However, in areas of intensive farming, which are characterised by the scarcity of weed communities, wild herbivores may focus their grazing on cover crops, which could make their implementation difficult. In this work, we test whether rabbit grazing can prevent the growth of herbaceous cover crops in olive groves in Southern Spain in addition to assessing the role of rabbit abundance and diversity of weeds in the development of cover crops. This question has been addressed by sowing Bromus rubens between the rows of five olive groves in Cordoba province (Spain. We then monitored the surface covered by B. rubens, along with both diversity of weed communities and rabbit abundance. Two rabbit exclusion areas were also placed in each olive grove in order to assess the impact of rabbits on the development of cover crops. Our results showed that the surface occupied by B. rubens was considerably higher in the rabbit exclusion areas (mean 56.8 ± 5.65 % than in those areas in which they could feed (mean 35.6 ± 4.32 %. The coverage occupied by cover crops was higher in areas with lower rabbit density, although this relationship was modulated by the weed diversity index, since in areas with the same rabbit abundance the coverage was higher in those with a richer weed community. These findings suggest that high rabbit abundances can prevent the development of herbaceous cover crops in olive groves, particularly in areas in which alternative food resources (measured as weed diversity are scarce.

Worrying about ‘Vertical Landscapes’: Terraced Olive Groves and Ecosystem Services in Marginal Land in Central Italy

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Elena Brunori

2018-04-01

Full Text Available Terraced Mediterranean areas are distinctive man-made landscapes with historical and cultural relevance. Terraced land abandonment driven by physical and economic constraints had important ecological consequences. This study focuses on a marginal agricultural district in southern Latium, central Italy, where terracing dated back to the Roman period and olive groves are the main agricultural use. A diachronic assessment of land-use transformations was carried out to identify landscape dynamics and drivers of change around terraced land. Terraced landscape systems (TLS, derived from spatial aggregation of neighboring terraced patches, have been analyzed for landscape transformations considering slope as the main stratification variable. Structural and functional characteristics of TLS were analyzed using a landscape ecology approach. Soil bio-chemical indicators were finally assessed to study the impact of terraced olive agro-ecosystems on soil-related ecosystems services. The empirical findings outlined that TLS in central Italy are sensitive to urbanization and land abandonment. Cultivated terraces prevailed up to gentle-medium slope land, uncultivated and wooded areas dominated terraces on steep slopes. In this context, poly-cultural olive groves proved to be a cropping system particularly resilient to global change, irrespective of land slope. Terraced systems and extensive poly-cultural olive groves play a role in preserving ecosystem integrity, landscape quality, soil functionality and, therefore, environmental sustainability.

Development of sparse-seeded mutant kinnow (Citrus reticulata ...

African Journals Online (AJOL)

... crops like citrus, induced mutation for seedlessness in Kinnow with gamma irradiation of dormant bud which was attempted at the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad. Dormant bud irradiation-cum-grafting technique was employed, using the Citrus jambhiri rootstock for propagation of the scion.

Consumer preferences for fresh citrus: Impacts of demographic and behavioral characteristics

Science.gov (United States)

From 2000 to 2006, per capita consumption of fresh citrus fruit increased by 11.0%, but the relative shares of types of citrus consumed changed. Per capita consumption of the historically dominant citrus fruit, fresh oranges, experienced a continuous decline from 12.4 pounds to 7.4 pounds from 1990 ...

A phagostimulant blend for the Asian citrus psyllid

Science.gov (United States)

Chemical cues that condition orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of great interest because it is the primary vector of the causal pathogen of citrus greening disease. Previous work in our lab identified a blend of formic and acetic acids as s...

Pesticides and nitrate in groundwater underlying citrus croplands, Lake Wales Ridge, central Florida, 1999-2005.

Science.gov (United States)

Choquette, Anne F.

2014-01-01

This report summarizes pesticide and nitrate (as nitrogen) results from quarterly sampling of 31 surficial-aquifer wells in the Lake Wales Ridge Monitoring Network during April 1999 through January 2005. The wells, located adjacent to citrus orchards and used for monitoring only, were generally screened (sampled) within 5 to 40 feet of the water table. Of the 44 citrus pesticides and pesticide degradates analyzed, 17 were detected in groundwater samples. Parent pesticides and degradates detected in quarterly groundwater samples, ordered by frequency of detection, included norflurazon, demethyl norflurazon, simazine, diuron, bromacil, aldicarb sulfone, aldicarb sulfoxide, deisopropylatrazine (DIA), imidacloprid, metalaxyl, thiazopyr monoacid, oxamyl, and aldicarb. Reconnaissance sampling of five Network wells yielded detection of four additional pesticide degradates (hydroxysimazine, didealkylatrazine, deisopropylhydroxyatrazine, and hydroxyatrazine). The highest median concentration values per well, based on samples collected during the 1999–2005 period (n=14 to 24 samples per well), included 3.05 µg/L (micrograms per liter) (simazine), 3.90 µg/L (diuron), 6.30 µg/L (aldicarb sulfone), 6.85 µg/L (aldicarb sulfoxide), 22.0 µg/L (demethyl norflurazon), 25.0 µg/ (norflurazon), 89 µg/ (bromacil), and 25.5 mg/L (milligrams per liter) (nitrate). Nitrate concentrations exceeded the 10 mg/L (as nitrogen) drinking water standard in one or more groundwater samples from 28 of the wells, and the median nitrate concentration among these wells was 14 mg/L. Sampled groundwater pesticide concentrations exceeded Florida’s health-guidance benchmarks for aldicarb sulfoxide and aldicarb sulfone (4 wells), the sum of aldicarb and its degradates (6 wells), simazine (2 wells), the sum of simazine and DIA (3 wells), diuron (2 wells), bromacil (1 well), and the sum of norflurazon and demethyl norflurazon (1 well). The magnitude of fluctuations in groundwater pesticide

The role of social learning for social-ecological systems in Korean village groves restoration

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Eunju Lee

2015-03-01

Full Text Available Recently, social learning has been recognized as a means to foster adaptation to changing conditions, and more broadly, social-ecological systems resilience. However, the discussion of social learning and social-ecological resilience in different cultural contexts is limited. In this study we introduce the Korean Village Groves Restoration Project (VGRP through the lens of social learning, and discuss implications of the VGRP for resilience in villages impacted by industrialization and decline of traditional forest resources. We conducted open-ended interviews with VGRP leaders, government and NGO officials, and residents in four villages in South Korea, and found that villages responded to ecosystem change in ways that could be explained by the characteristics of social learning including interaction, integration, systems orientation, and reflection. However, the processes of learning varied among the four villages, and were associated with different levels of learning and different learning outcomes related to changes in village grove management and governance. The cultural and historical context can be used to help understand social learning processes and their outcomes in the Korean cases.

Survey of current crop management practices in a mixed-ricefield landscape, Mekong Delta, Vietnam - potential of habitat manipulation for improved control of citrus leafminer and citrus red mite

NARCIS (Netherlands)

Mele, van P.; Lenteren, van J.C.

2002-01-01

In the Mekong Delta, Vietnam, the citrus leafminer Phyllocnistis citrella (CLM) and the citrus red mite Panonychus citri are major pests in both sweet orange (Citrus sinensis) and Tieu mandarin (C. reticulata). Survey data indicate that these pest problems might be aggravated after farmers have

7 CFR 319.56-41 - Citrus from Peru.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Peru. 319.56-41 Section 319.56-41... from Peru. Grapefruit (Citrus paradisi), limes (C. aurantiifolia), mandarins or tangerines (C... States from Peru under the following conditions: (a) The fruit must be accompanied by a permit issued in...

Citrus Production, Constraints and Management Practices in Ethiopia

African Journals Online (AJOL)

Citrus is economically important fruit crop in Ethiopia. However, its production is seriously constrained by various diseases including Pseudocercospora leaf and fruit spot. Surveys were conducted between June 2012 and May 2013 in the main citrus production areas of the country to assess the spread of the disease, and to ...

Exploring the psychological factors involved in the Ladbroke Grove rail accident

OpenAIRE

Stanton, Neville A.; Walker, Guy H.

2011-01-01

Ten years after the event and the question as to exactly why a driver passed a signal at danger to cause the Ladbroke Grove rail disaster is still an open one. This paper uses the literature on human error and cognition, combined with critical path analysis, to provide further insight. Five aspects of train operation are drawn out of the known facts surrounding the incident: custom and practice in the use of the Driver's Reminder Appliance, operation and use of the Automatic Warning System, t...

Towards the identification of flower-specific genes in Citrus spp

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Marcelo Carnier Dornelas

2007-01-01

Full Text Available Citrus sinensis is a perennial woody species, for which genetic approaches to the study of reproductive development are not readily amenable. Here, the usefulness of the CitEST Expressed Sequence Tag (EST database is demonstrated as a reliable new resource for identifying novel genes exclusively related to Citrus reproductive biology. We performed the analysis of an EST dataset of the CitEST Project containing 4,330 flower-derived cDNA sequences. Relying on bioinformatics tools, sequences exclusively present in this flower-derived sequence collection were selected and used for the identification of Citrus putative flower-specific genes. Our analysis revealed several Citrus sequences showing significant similarity to conserved genes known to have flower-specific expression and possessing functions related to flower metabolism and/or reproductive development in diverse plant species. Comparison of the Citrus flower-specific sequences with all available plant peptide sequences unraveled 247 unique transcripts not identified elsewhere within the plant kingdom. Additionally, 49 transcripts, for which no biological function could be attributed by means of sequence comparisons, were found to be conserved among plant species. These results allow further gene expression analysis and possibly novel approaches to the understanding of reproductive development in Citrus.

Citrus Tristeza Virus on the Island of Crete

DEFF Research Database (Denmark)

Shegani, M.; Tsikou, D.; Velimirovic, A.

2012-01-01

Over a period of two years, more than 5,000 citrus trees were tested for the presence of Citrus tristeza virus (CTV) on the island of Crete, resulting in thirty eight positives. Comparisons of the relative transcript levels of CTV p23, coat protein (CP), polymerase (POL) and an intergenic (POL/p3...

Factors affecting transmission rates of 'Candidatus Liberibacter asiaticus' by Asian citrus psyllid

Science.gov (United States)

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it transmits a bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) responsible for a serious disease of citrus known as Asiatic huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program...

Citrus stand ages regulate the fraction alteration of soil organic carbon under a citrus/Stropharua rugodo-annulata intercropping system in the Three Gorges Reservoir area, China.

Science.gov (United States)

Zhang, Yang; Ni, Jiupai; Yang, John; Zhang, Tong; Xie, Deti

2017-08-01

Soil carbon fractionation is a valuable indicator in assessing stabilization of soil organic matter and soil quality. However, limited studies have addressed how different vegetation stand ages under intercropping agroforestry systems, could affect organic carbon (OC) accumulation in bulk soil and its physical fractions. A field study thus investigated the impact of citrus plantation age (15-, 25-, and 45-year citrus) on the bulk soil organic carbon (SOC) and SOC fractions and yields of Stropharia rugoso-annulata (SRA) in the Three Gorges Reservoir area, Chongqing, China. Results indicated that the intercropping practice of SRA with citrus significantly increased the SOC by 57.4-61.6% in topsoil (0-10 cm) and by 24.8-39.9% in subsoil (10-30 cm). With a significantly higher enhancement under the 25-year citrus stand than the other two stands, all these citrus stands of three ages also resulted in a significant increase of free particulate OC (fPOC, 60.1-62.4% in topsoil and 34.8-46.7% in subsoil), intra-micro aggregate particulate OC (iPOC, 167.6-206.0% in topsoil and 2.77-61.09% in subsoil), and mineral-associated OC (MOC, 43.6-46.5% in topsoil and 26.0-51.5% in subsoil). However, there were no significant differences in yields of SRA under three citrus stands. Our results demonstrated that citrus stand ages did play an important role in soil carbon sequestration and fractionation under a citrus/SRA intercropping system, which could therefore provide a sustainable agroforestry system to enhance concurrently the SOC accumulation while mitigating farmland CO 2 emission.

Green Synthesis and Biological Activities of Gold Nanoparticles Functionalized with Citrus reticulata, Citrus aurantium, Citrus sinensis and Citrus grandis

International Nuclear Information System (INIS)

Islam, N. U.; Shahid, M.; Ahsan, F.; Khan, I.; Shah, M. R.; Khan, M. A.

2015-01-01

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)

Geologic map of the Western Grove quadrangle, northwestern Arkansas

Science.gov (United States)

Hudson, Mark R.; Turner, Kenzie J.; Repetski, John E.

2006-01-01

This map summarizes the geology of the Western Grove 7.5-minute quadrangle in northern Arkansas that is located on the southern flank of the Ozark dome, a late Paleozoic regional uplift. The exposed bedrock of this map area comprises approximately 1,000 ft of Ordovician and Mississippian carbonate and clastic sedimentary rocks that have been mildly folded and broken by faults. A segment of the Buffalo River loops through the southern part of the quadrangle, and the river and adjacent lands form part of Buffalo National River, a park administered by the U.S. National Park Service. This geologic map provides information to better understand the natural resources of the Buffalo River watershed, particularly its karst hydrogeologic framework.

Overexpression of a citrus NDR1 ortholog increases disease resistance in Arabidopsis

Science.gov (United States)

Emerging devastating diseases, such as Huanglongbing (HLB) and citrus canker, have caused tremendous losses to the citrus industry worldwide. Genetic engineering is a powerful approach that could allow us to increase citrus resistance against these diseases. The key to the success of this approach r...

Descriptions of new varieties recently distributed from the Citrus Clonal Protection Program

Science.gov (United States)

The Citrus Clonal Protection Program (CCPP) is operated through the Department of Plant Pathology and Microbiology at University of California (UC) Riverside and is funded in large part by The California Citrus Research Board (CRB). The CCPP processes citrus propagative material in two phases. First...

A Comparison of the Volatile Components of Cold Pressed Hamlin and Valencia (Citrus sinensis (L. Osbeck Orange Oils Affected by Huanglongbing

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Brittany M. Xu

2017-01-01

Full Text Available Volatiles from huanglongbing (HLB symptomatic and asymptomatic cold pressed orange oils from Florida Hamlin and Valencia fruit were assessed. Qualitative gas-liquid chromatography studies showed the presence of several compounds (β-longifolene, perillene, and 4-decenal which are not commonly identified in Citrus sinensis (L. Osbeck oils. Oils derived from huanglongbing symptomatic fruit had lower concentrations of linalool, decanal, citronellol, neral, geranial, carvone, dodecanal, and 2-decenal and higher concentrations of citronellal compared to asymptomatic fruit. A comparison to historic literature of orange oil investigations before HLB was of issue in Florida orange crops showed lower levels of linalool, decanal, neral, and geranial in Hamlin peel oil samples, as well as higher levels of dodecanal. Valencia peel oil samples showed lower concentrations of linalool and increased concentration of citronellol and dodecanal. As a result of huanglongbing (HLB phenomena, the concentrations of several important volatiles found in Hamlin and Valencia peel oil profiles have changed compared to historic values. Differences in volatile concentrations of symptomatic and asymptomatic HLB affected peel oil compounds in orange fruit are identified.

Runoff and sediment yield of tilled and spontaneous grass-covered olive groves grown on sloping land

NARCIS (Netherlands)

Palese, A.M.; Ringersma, Jacquelijn; Baartman, J.E.M.; Peters, P.; Xiloyannis, C.

2015-01-01

Soil erosion in olive groves is a widespread phenomenon in the Mediterranean Basin. Many studies have investigated the effects of tillage and herbaceous ground cover (spontaneous or seeded) in their effectiveness to reduce soil erosion in a wide range of Mediterranean sites under different

Identification of zygotic and nucellar seedlings in citrus interspecific ...

African Journals Online (AJOL)

ajl yemi

2011-12-19

Dec 19, 2011 ... Department of Plant Breeding and Improvement, Iran Citrus Research Institute, Mottahari Street, Ramsar, .... (C. aurantium) rootstock plants for further agronomic evaluation .... literatures may be attributed to pollination efficiency and ... zygotic seedlings in Swingle citromelo Citrus paradisi × Poncirus tifoliata.

Penicillium digitatum metabolites on synthetic media and citrus fruits

DEFF Research Database (Denmark)

Ariza, M.R.; Larsen, Thomas Ostenfeld; Petersen, Bent O.

2002-01-01

Penicillium digitatum has been cultured on citrus fruits and yeast extract sucrose agar media (YES).Cultivation of fungal cultures on solid medium allowed the isolation of two novel tryptoquivaline-like metabolites, tryptoquialanine A (1) and tryptoquialanine B (2), also biosynthesized on citrus...

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.

Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

Science.gov (United States)

Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

2011-02-01

The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

Botanical insecticides in controlling Kelly's citrus thrips (Thysanoptera: Thripidae) on organic grapefruits.

Science.gov (United States)

Vassiliou, V A

2011-12-01

Kelly's citrus thrips, Pezothrips kellyanus (Bagnall) (Thysanoptera: Thripidae) was first recorded in Cyprus in 1996 and became an economic citrus pest. In Cyprus, Kelly's citrus thrips larvae cause feeding damage mainly on immature lemon and grapefruit fruits. Use of botanical insecticides is considered an alternative tool compared with synthetic chemicals, in offering solutions for healthy and sustainable citrus production. During 2008-2010, the efficacy of the botanical insecticides azadirachtin (Neemex 0.3%W/W and Oikos 10 EC), garlic extract (Alsa), and pyrethrins (Vioryl 5%SC) was evaluated in field trials against Kelly's citrus thrips larval stage I and II aiming at controlling the pest's population and damage to organic grapefruit fruits. In each of the trial years treatments with pyrethrins and azadirachtin (Neemex 0.3%W/W) were the most effective against Kelly's citrus thrips compared with the untreated control (for 2008: P extract showed the lowest effect from all the botanicals used compared with the untreated control.

Inhibitory effect of Epstein-Barr virus activation by Citrus fruits, a cancer chemopreventor.

Science.gov (United States)

Iwase, Y; Takemura, Y; Ju-ichi, M; Kawaii, S; Yano, M; Okuda, Y; Mukainaka, T; Tsuruta, A; Okuda, M; Takayasu, J; Tokuda, H; Nishino, H

1999-05-24

To search useful compounds in Citrus fruit for cancer chemoprevention, we carried out a primary screening of extracts of fruit peels and seeds from 78 species of the genus Citrus and those from two Fortunella and one Poncirus species, which were closely related to the genus Citrus. These Citrus extracts inhibited the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) as a useful screening method for anti-tumor promoters. Our results indicated that Citrus containing substances may be inhibit susceptibility factors involved in the events leading to the development of cancer.

ENZYMATIC KINETIC STUDY HYDROLASE FROM CITRUS

Directory of Open Access Journals (Sweden)

Israel Hernández

2015-09-01

Full Text Available In this paper the degrading activity of enzymes derived from orange peels (Citrus x sinensis, grapefruit (Citrus paradise and pineapple (Ananas comosus on the organic matter in wastewater is evaluated. This activity is measured indirectly by quantifying the biochemical oxygen demand (COD before and after degradation process based on a period of time using the HACH DR / 2010, and then the kinetic study was performed by the differential method and integral with the experimental data, obtaining a reaction order of 1 to pectinase (orange, and order 2 for bromelain (pineapple.

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.

Developing cryotherapy to eliminate graft-transmissible pathogens in citrus

Science.gov (United States)

This article summarizes research being conducted as part of a project funded by the California Citrus Research Board to develop cryotherapy (freezing buds in liquid nitrogen, and then recovering them) as a viable method for elimination of graft transmissible pathogens from Citrus. There are current...

Weed Biomass and Weed Species Diversity of Juvenile Citrus Trees Intercrop with some Arable Crops

Directory of Open Access Journals (Sweden)

Patience Mojibade OLORUNMAIYE

2012-02-01

Full Text Available A preliminary study was carried out to evaluate the performances of eight crops in the intercrop of citrus with arable crops at the National Horticultural Research Institute (NIHORT Ibadan, Nigeria. Eight arable crops: maize, cucumber, sweet potato, Corchorus olitorius, large green, grain amaranth, Mucuna pruriens var. utilis, and groundnut were intercropped with young citrus trees in the early planting season of 2010 with sole citrus as control. The experiment was laid out in a completely randomized block design with three replicates. Data were collected on weed flora, weed density and weed dry weight. Results showed that the relative frequencies of weeds in all the plots were less than 4% at both 6 and 9WAP. Gomphrena celosoides, Oldenlandia corymbosa and Tridax procumbens were most preponderant in appearing in all the plots. Tridax procumbens had a consistent relative frequency (2.34% in all the plots except in citrus/maize plot (0.78% at 9 WAP. Significantly lower broadleaf weed densities were obtained in citrus/sweet potato, citrus/large green, control plot and citrus/cucumber (28.67, 45.00, 50.00 and 76.33 m-2 respectively than in citrus/groundnut plot (143.00 m-2. Similarly, significantly lower grass weed densities were produced in citrus/Mucuna and citrus/sweet potato (0.33 m-2 each plots than the control plot (11.33 m-2. Whereas citrus/corchorus plot produced significantly lower broadleaf weed dry weight (37.59 g m-2 than citrus/Mucuna plot (126.47 g m-2 at 3WAP, citrus/large green plot (16.15 g m-2 and citrus/groundnut plot (123.25 g m-2 followed the same trend at 6 WAP. Sedges dry weights were less than 7 g m-2 in all the plots compared with control plot.

Chlorophyll Fluorescence Imaging Uncovers Photosynthetic Fingerprint of Citrus Huanglongbing

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Haiyan Cen

2017-08-01

Full Text Available Huanglongbing (HLB is one of the most destructive diseases of citrus, which has posed a serious threat to the global citrus production. This research was aimed to explore the use of chlorophyll fluorescence imaging combined with feature selection to characterize and detect the HLB disease. Chlorophyll fluorescence images of citrus leaf samples were measured by an in-house chlorophyll fluorescence imaging system. The commonly used chlorophyll fluorescence parameters provided the first screening of HLB disease. To further explore the photosynthetic fingerprint of HLB infected leaves, three feature selection methods combined with the supervised classifiers were employed to identify the unique fluorescence signature of HLB and perform the three-class classification (i.e., healthy, HLB infected, and nutrient deficient leaves. Unlike the commonly used fluorescence parameters, this novel data-driven approach by using the combination of the mean fluorescence parameters and image features gave the best classification performance with the accuracy of 97%, and presented a better interpretation for the spatial heterogeneity of photochemical and non-photochemical components in HLB infected citrus leaves. These results imply the potential of the proposed approach for the citrus HLB disease diagnosis, and also provide a valuable insight for the photosynthetic response to the HLB disease.

76 FR 75558 - Environmental Impact Statement for Restoration of the Mariposa Grove of Giant Sequoias, Yosemite...

Science.gov (United States)

2011-12-02

... tree. Fire plays an important role in giant sequoia ecology, creating canopy openings and releasing soil nutrients needed for seedling establishment. Fire scars on the trees indicate that fires occurred... and sites within the Grove include the parking areas, gift shop, ticket booth, tram staging area...

Zgorzel pędow borówki wysokiej wywołana przez grzyb Godronia cassandrae f. vaccinii (Peck. Groves [The canker of highbush blueberry caused by Godronia cassandrae f. vaccinii (Peck. Groves

Directory of Open Access Journals (Sweden)

Z. Borecki

2015-06-01

Full Text Available Fusicoccum canker of highbush blueberry was first detected in 1973 in Poland. The diseases appeared on the shoots of variety Jersey in the collection of the Department of Pomology, Agricultural University, Warsaw-Ursyn6w. The disease was caused by the fungus Godronia cassandrae f. vaccinii {Peck. Groves. The conidial stage is known as Topospora myrtilli (Felfch. Boermema syn. Fusicoccum putrefaciens Shear.

The Allocation of Advertising and Research Dollars in the Florida Orange Juice Industry

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Mark G. Brown

2010-01-01

Full Text Available This study considers the allocation of Florida citrus-grower money between advertising and research programs to maximize grower revenue net of program costs. The allocation depends on the impact of advertising on demand and the impacts of research on the cost of production and supply. A number of studies have estimated the impact of advertising on OJ demand, but little is known about the impact of research. Research on citrus greening, a disease that has no known cure, is examined in the present study. There are no past studies to reliably gauge the impact of this research. The approach taken here is to ask if a given amount of research dollars is needed to reduce average production costs by certain amount, then what should be spent on advertising based on past estimates of the elasticity of demand with respect to advertising. The optimal ratio of advertising to research dollars increases with the advertising elasticity and declines with the amount of research money needed to reduce average costs. The results of this study provide a range for this ratio based on different advertising elasticities and amounts of research dollars needed to reduce production costs. The approach provides an indication of the importance of advertising given expectations on the research needed to successfully fight this disease.

Alternative oxidase (AOX) constitutes a small family of proteins in Citrus clementina and Citrus sinensis L. Osb.

Science.gov (United States)

Araújo Castro, Jacqueline; Gomes Ferreira, Monique Drielle; Santana Silva, Raner José; Andrade, Bruno Silva; Micheli, Fabienne

2017-01-01

The alternative oxidase (AOX) protein is present in plants, fungi, protozoa and some invertebrates. It is involved in the mitochondrial respiratory chain, providing an alternative route for the transport of electrons, leading to the reduction of oxygen to form water. The present study aimed to characterize the family of AOX genes in mandarin (Citrus clementina) and sweet orange (Citrus sinensis) at nucleotide and protein levels, including promoter analysis, phylogenetic analysis and C. sinensis gene expression. This study also aimed to do the homology modeling of one AOX isoform (CcAOXd). Moreover, the molecular docking of the CcAOXd protein with the ubiquinone (UQ) was performed. Four AOX genes were identified in each citrus species. These genes have an open reading frame (ORF) ranging from 852 bp to 1150 bp and a number of exons ranging from 4 to 9. The 1500 bp-upstream region of each AOX gene contained regulatory cis-elements related to internal and external response factors. CsAOX genes showed a differential expression in citrus tissues. All AOX proteins were predicted to be located in mitochondria. They contained the conserved motifs LET, NERMHL, LEEEA and RADE-H as well as several putative post-translational modification sites. The CcAOXd protein was modeled by homology to the AOX of Trypanosona brucei (45% of identity). The 3-D structure of CcAOXd showed the presence of two hydrophobic helices that could be involved in the anchoring of the protein in the inner mitochondrial membrane. The active site of the protein is located in a hydrophobic environment deep inside the AOX structure and contains a diiron center. The molecular docking of CcAOXd with UQ showed that the binding site is a recessed pocket formed by the helices and submerged in the membrane. These data are important for future functional studies of citrus AOX genes and/or proteins, as well as for biotechnological approaches leading to AOX inhibition using UQ homologs.

β-Cryptoxanthin and Zeaxanthin Pigments Accumulation to Induce Orange Color on Citrus Fruits

Science.gov (United States)

Hidayati Sumiasih, Inanpi; Poerwanto, Roedhy; Efendi, Darda; Agusta, Andria; Yuliani, Sri

2018-01-01

Degreening, a transformation process of green color on citrus peel to be orange color on tropical low-land citrus fruits often fails. Orange color of the citrus peel comes from the mixture carotenoid pigments, such as zeaxanthine and mainly β-cryptoxanthin and β-citraurin. The accumulation of β-citraurin occurs when the fruits are exposed to low temperature, and otherwise, it will fail to occur. Precooling treatment on lowland tropical citrus fruits is expected to stimulate the accumulation of β-citraurin. The results showed the most favorable color obtained from precooling and 24-hour ethylene exposure duration. This treatment could decrease total chlorophyll and β-carotene content as well as proven to increase 3 times the accumulation of β-cryptoxanthin in accelerating the appearance of bright orange color on citrus peel. Degreening gave no significant effect to internal quality of Citrus reticulata.

"Forest Grove School District v. T.A." Supreme Court Case: Implications for School Psychology Practice

Science.gov (United States)

Dixon, Shauna G.; Eusebio, Eleazar C.; Turton, William J.; Wright, Peter W. D.; Hale, James B.

2011-01-01

The 2009 "Forest Grove School District v. T.A." United States Supreme Court case could have significant implications for school psychology practice. The Court ruled that the parents of a student with a disability were entitled to private school tuition reimbursement even though T.A. had not been identified with a disability or previously…

Productive and vegetative behavior of olive cultivars in super high-density olive grove

Directory of Open Access Journals (Sweden)

Primo Proietti

2015-02-01

Full Text Available In recent years, there has been an increase in interest in super high-density (SHD olive (Olea europaea L. groves because they offer early entry into production, increased productivity and the possibility of using modified mechanical vine harvesters. This study was carried out in a young SHD olive grove to examine vegetative, histo-anatomical and productive characteristics and oil quality of the Spanish Arbequina and Italian Maurino and Leccino cultivars, characterized by low, low-to-medium and high vigor, respectively. Arbequina had low vigor and limited development in height and width, as well as a high leaf/wood ratio. Maurino had a canopy volume similar to that of Arbequina and, despite a great tendency to grow in height, had low vigor, a rather compact vegetative habitus, but good lighting in the canopy and high production efficiency. In Maurino, a greater palisade parenchyma height and a larger exposed lateral surface area of the palisade parenchyma cells were observed. In the fourth year after planting, fruit production of Arbequina was about 30 % less than Leccino and Maurino. The oil content on a dry weight basis was slightly higher in Arbequina and Maurino than in Leccino. Oil quality was good for all cultivars.

Iglesia en Garden Grove, California

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Neutra, Richard J.

1964-04-01

Full Text Available The Community Church, in Garden Grove has a ground area of 1067 m2 and provides 672 seats for the congregation. Its total planned capacity is 1000 people. The total project involves halls for cultural and social activities, church office, kitchen, as well as secondary annexes; also a Sunday school, with a nursery and schoolrooms for children of various ages. Outdoors, there is an ample parking space, where the motorcars—the Americans' second home—can be orientated facing the altar. Thus their occupants can follow the Mass visually, when the large sliding doors are opened, at the beginning of the service; then, at the end of the service these doors are slowly and solemnly closed. Furthermore, these automobile owners can also follow the service by listening to it through individual loudspeakers, which are supplied to each vehicle. Once more Mr. Neutra has designed thinking of man as a human being, and finding room for the women the children and the men who go to church not only inside the church, but also within the more intimate atmosphere of their own cars. He feels that religion must be something living, evolving with the times. The modern congregation is not that of the primitive Christians, living in their sombre catacombs, nor is it similar to the picturesque and intense believers of the Middle Ages. He has therefore created a happy solution, very apt to the anxious and hopeful people of today.La iglesia de la Comunidad de Garden Grove ocupa una superficie de 1.067,45 m2, y dispone de 672 asientos y capacidad total para 1.000 feligreses. El complejo parroquial consta, además, de una serie de dependencias anexas: salas para actividades culturales, sociales, oficinas de la parroquia, cocina..., etc., y una escuela dominical; esta última, con guardería infantil y aulas para grupos de diferentes edades. En el exterior ha sido dispuesta una zona de aparcamiento, en la que los coches familiares—segunda casa de los norteamericanos�

First record of Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) in citrus in Brazil.

Science.gov (United States)

Lemos, W P; da Silva, R A; Araújo, S C A; Oliveira, E L A; da Silva, W R

2011-01-01

Anastrepha serpentina (Wiedemann) is recorded for the first time in citrus (Rutaceae) in Brazil. Specimens were obtained from sweet orange (Citrus sinensis) sampled in the municipalities of Belém and Capitão Poço, and from mandarin orange (Citrus reticulata) from Tomé-Açu, state of Pará, Brazil.

First record of Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) in citrus in Brazil

OpenAIRE

Lemos, WP; Silva, RA da; Araújo, SCA; Oliveira, ELA; Silva, WR da

2011-01-01

Anastrepha serpentina (Wiedemann) is recorded for the first time in citrus (Rutaceae) in Brazil. Specimens were obtained from sweet orange (Citrus sinensis) sampled in the municipalities of Belém and Capitão Poço, and from mandarin orange (Citrus reticulata) from Tomé-Açu, state of Pará, Brazil.

CHEMICAL COMPOSITION AND TOXICITY OF CITRUS ESSENTIAL OILS ON Dysmicoccus brevipes (HEMIPTERA: PSEUDOCOCCIDAE)

OpenAIRE

MARTINS, GISELE DOS SANTOS OLIVEIRA; ZAGO, HUGO BOLSONI; COSTA, ADILSON VIDAL; ARAUJO JUNIOR, LUIS MOREIRA DE; CARVALHO, JOSÉ ROMÁRIO DE

2017-01-01

ABSTRACT The insect Dysmicoccus brevipes (Hemiptera: Pseudococcidae) has been reported as an important pest for several crops, especially coffee. The citrus essential oils can be obtained as by-products of the citrus-processing industry and have been tested as an alternative to control different insect groups. Therefore, the objective of this work was to determine the chemical composition and evaluate the toxicity of commercial sweet orange (Citrus sinensis), bitter orange (Citrus aurantium) ...

(JASR) VOL. 10, No. 2, 2010 69 CITRUS FARMERS PRODUCTION

African Journals Online (AJOL)

oma

Emerging trends and advances in the citrus industry globally necessitates updating ... citrus is ranked first among other fruit crops by farmers (NIHORT, 2000). .... the arduous task of producing horticultural crops which are pest, diseases and ...

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

Although Citrus is the most globally significant tree fruit, its domestication history is poorly understood. Cultivated citrus types are believed to comprise selections from and/or hybrids of several wild progenitor species, but the identities of these progenitors, and their contribution to modern cultivars, remain controversial. Here we report the genomes of a collection of mandarins, pummelos, and oranges, including a high quality reference sequence from a haploid Clementine mandarin. By comparative genome analysis we show that these cultivated types can be derived from two progenitor species. Cultivated pummelos represent selections from a single progenitor species C. maxima. Unexpectedly, however, we find that cultivated mandarins are introgressions of C. maxima into a distinct second population that we identify with the ancestral wild mandarin species C. reticulata. Sweet and sour oranges are found to be interspecific hybrids. Sweet orange, the most widely cultivated citrus, arose as the offspring of previously admixed individuals. In contrast, sour (or Seville) orange is an F1 hybrid of pure C. maxima and C. reticulata parents, implying that wild mandarins were part of the early breeding germplasm. Surprisingly, we also find that a wild Chinese mandarin from Mangshan, China shows substantial sequence divergence from C. reticulata and appears to represent a distinct taxon. Understanding the relationships and phylogeny of cultivated citrus through genome analysis will clarify taxonomic relationships and enable previously inconceivable opportunities for sequence-directed genetic improvement. Citrus are widely consumed worldwide as juice or fresh fruit, providing important sources of vitamin C and other health-promoting compounds. Global production in 2012 exceeded 86 million metric tons, with an estimated value of US$9 billion (http://www.fas.usda.gov/psdonline/circulars/citrus.pdf). The very narrow genetic diversity of cultivated citrus makes it highly

Host range and genetic relatedness of Colletotrichum acutatum isolates from fruit crops and leatherleaf fern in Florida.

Science.gov (United States)

MacKenzie, S J; Peres, N A; Barquero, M P; Arauz, L F; Timmer, L W

2009-05-01

Isolates of Colletotrichum acutatum were collected from anthracnose-affected strawberry, leatherleaf fern, and Key lime; ripe-rot-affected blueberry; and postbloom fruit drop (PFD)-affected sweet orange in Florida. Additional isolates from ripe-rot-affected blueberry were collected from Georgia and North Carolina and from anthracnose-affected leatherleaf fern in Costa Rica. Pathogenicity tests on blueberry and strawberry fruit; foliage of Key lime, leatherleaf fern, and strawberry; and citrus flowers showed that isolates were highly pathogenic to their host of origin. Isolates were not pathogenic on foliage of heterologous hosts; however, several nonhomologous isolates were mildly or moderately pathogenic to citrus flowers and blueberry isolates were pathogenic to strawberry fruit. Based on sequence data from the internal transcribed spacer (ITS)1-5.8S rRNA-ITS2 region of the rDNA repeat, the glutaraldehyde-3-phosphate dehydrogenase intron 2 (G3PD), and the glutamine synthase intron 2 (GS), isolates from the same host were identical or very similar to each other and distinct from those isolated from other hosts. Isolates from leatherleaf fern in Florida were the only exception. Among these isolates, there were two distinct G3PD and GS sequences that occurred in three of four possible combinations. Only one of these combinations occurred in Costa Rica. Although maximum parsimony trees constructed from genomic regions individually displayed little or no homoplasy, there was a lack of concordance among genealogies that was consistent with a history of recombination. This lack of concordance was particularly evident within a clade containing PFD, Key lime, and leatherleaf fern isolates. Overall, the data indicated that it is unlikely that a pathogenic strain from one of the hosts examined would move to another of these hosts and produce an epidemic.

Repellency of Selected Psidium guajava cultivars to the Asian citrus psyllid, Diaphorina citri

Science.gov (United States)

Asiatic huanglongbing (HLB)(also known as citrus greening disease) is the most devastating disease of citrus worldwide. It is caused by a bacterium ‘Candidatus Liberibacter asiaticus’ and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. Considerable research has been conducted toward...

Morphometric comparisons of Diaphorina citri (Hemiptera: Liviidae) populations from Iran, USA and Pakistan.

Science.gov (United States)

Lashkari, Mohammadreza; Hentz, Matthew G; Boykin, Laura M

2015-01-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), vector of citrus greening disease pathogen, Huanglongbing (HLB), is considered the most serious pest of citrus in the world. Prior molecular based studies have hypothesized a link between the D. citri in Iran and the USA (Florida). The purpose of this study was to collect morphometric data from D. citri populations from Iran (mtCOI haplotype-1), Florida (mtCOI haplotype-1), and Pakistan (mtCOI haplotype-6), to determine whether different mtCOI haplotypes have a relationship to a specific morphometric variation. 240 samples from 6 ACP populations (Iran-Jiroft, Chabahar; Florida-Ft. Pierce, Palm Beach Gardens, Port St. Lucie; and Pakistan-Punjab) were collected for comparison. Measurements of 20 morphological characters were selected, measured and analysed using ANOVA and MANOVA. The results indicate differences among the 6 ACP populations (Wilks' lambda = 0.0376, F = 7.29, P citri species in this study, (1) Iran, (2) USA (Florida) and (3) Pakistan population. Morphometric comparisons provided further resolution to the mtCOI haplotypes and distinguished the Florida and Iranian populations.

76 FR 54801 - Reynolds Food Packaging LLC, a Subsidiary of Reynolds Group Holding Limited, Grove City, PA...

Science.gov (United States)

2011-09-02

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-75,183] Reynolds Food Packaging LLC, a Subsidiary of Reynolds Group Holding Limited, Grove City, PA; Notice of Revised Determination... (TAA) applicable to workers and former workers of Reynolds Food Packaging LLC, a subsidiary of Reynolds...

Systemic translocation and metabolism of 14C-metalaxyl in citrus

International Nuclear Information System (INIS)

Musumeci, M.R.; Ruegg, E.F.

1984-01-01

Systemic uptake and translocation of 14 C-metalaxyl to citrus seedlings from soils (Humic Gley and Yellow Red Latosol) with different physical - chemical properties are studied. Seedlings of Citrus limonia are treated with 14 C-metalaxyl. (M.A.C.) [pt

Authenticity analysis of citrus essential oils by HPLC-UV-MS on oxygenated heterocyclic components

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Hao Fan

2015-03-01

Full Text Available Citrus essential oils are widely applied in food industry as the backbone of citrus flavors. Unfortunately, due to relatively simple chemical composition and tremendous price differences among citrus species, adulteration has been plaguing the industry since its inception. Skilled blenders are capable of making blends that are almost indistinguishable from authentic oils through conventional gas chromatography analysis. A reversed-phase high performance liquid chromatography (HPLC method was developed for compositional study of nonvolatile constituents in essential oils from major citrus species. The nonvolatile oxygenated heterocyclic components identified in citrus oils were proved to be more effective as markers in adulteration detection than the volatile components. Authors are hoping such an analysis procedure can be served as a routine quality control test for authenticity evaluation in citrus essential oils.

In vitro Propagation of Citrus limonia Osbeck Through Nucellar Embryo Culture

OpenAIRE

Alka Jajoo

2010-01-01

Citrus limonia Osbeck is a promising rootsctock for commercial citrus species with sturdy anddisease and drought resistant characters. A n efficient and highly reproducible plant regeneration protocol hasbeen developed from nucellar embryo of Citrus limonia. Murashige and Skoogs medium was used for plantregeneration from nucellar embryos. It was noted that 6-benzylaminopurine at a concentration of 2.22 mMinduced highest number of multiple shoots as 18.26 shoots per explant. O n transfer of in...

Pterostichus neilgaimani sp. nov., a new species of ground beetles (Coleoptera: Carabidae) from relict sacred grove in Eastern Georgia.

Science.gov (United States)

Chaladze, Giorgi; Kalatozishvili, Levan; Janiashvili, Zurab; Bakuradze, Giorgi

2017-10-03

A new species of ground beetles (Coleoptea: Carabidae) belonging to the subgenus Aphaonus Reitter, 1887 (genus Pterostichus Bonelli, 1810) is described, based on two specimens collected from the sacred grove of Khevsha (Eastern Georgia).

Improved annotation of the insect vector of citrus greening disease: Biocuration by a diverse genomics community

Science.gov (United States)

The Asian citrus psyllid (Diaphorina citri Kuwayama) is the insect vector of the bacterium Candidatus Liberibacter asiaticus (CLas), the pathogen associated with citrus Huanglongbing (HLB, citrus greening). HLB threatens citrus production worldwide. Suppression or reduction of the insect vector usin...

Insecticidal activity of some citrus oils against culex quinquefasciatus

International Nuclear Information System (INIS)

Saeed, H. M. A.

2009-01-01

The present study deals with the larvicidal potency of peel oils of grapefruit (Citrus paradise), sweet orange (Citrus sinensis) and lime (Citrus aurantifolia) on 4''th instar larvae of the mosquito, Culex quinquefasciatus. Orange oil was the most effective followed by grapefruit oil and then lime oil. The toxicity of the oils applied to the 4''th instar larval stage was extended to pupal and adult stages. All oils produced deleterious effects on fecundity of survivors of sublethal doses. By the aid of chemical analysis of oils, the active compound was found to be limonene, a monoterpene compound. The percentages limonene were 97.15%, 92.46% and 32.29% for orange, grapefruit and lime respectively.(Author)

Exogenous application of methyl jasmonate and salicylic acid on citrus foliage: Effecs on foliar volatiles and aggregation behavior of Asian citrus psyllid (Diaphorina citri)

Science.gov (United States)

Methyl jasmonate (MeJA) and salicylic acid (SA) are well-known activators of chemical defenses in plants. The SA pathway is involved in citrus response to infection by Candidatus Liberibacter asiaticus (CLas); less is known about the role of jasmonates in citrus defense response. We examined the eff...

Simulation of olive grove gross primary production by the combination of ground and multi-sensor satellite data

Science.gov (United States)

Brilli, L.; Chiesi, M.; Maselli, F.; Moriondo, M.; Gioli, B.; Toscano, P.; Zaldei, A.; Bindi, M.

2013-08-01

We developed and tested a methodology to estimate olive (Olea europaea L.) gross primary production (GPP) combining ground and multi-sensor satellite data. An eddy-covariance station placed in an olive grove in central Italy provided carbon and water fluxes over two years (2010-2011), which were used as reference to evaluate the performance of a GPP estimation methodology based on a Monteith type model (modified C-Fix) and driven by meteorological and satellite (NDVI) data. A major issue was related to the consideration of the two main olive grove components, i.e. olive trees and inter-tree ground vegetation: this issue was addressed by the separate simulation of carbon fluxes within the two ecosystem layers, followed by their recombination. In this way the eddy covariance GPP measurements were successfully reproduced, with the exception of two periods that followed tillage operations. For these periods measured GPP could be approximated by considering synthetic NDVI values which simulated the expected response of inter-tree ground vegetation to tillages.

Behavioral assay on Asian citrus psyllid attraction to orange jasmine

Science.gov (United States)

The Asian citrus psyllid (ACP) is an important pest because it transmits a bacterium putatively responsible for huanglongbing, a devastating citrus disease. Research on ACP chemical ecology is of interest with respect to identifying attractants and repellents for managing the psyllid. We report on a...

Assessment of citrus marketing in Benue and Kano states of Nigeria ...

African Journals Online (AJOL)

Assessment of citrus marketing in Benue and Kano states of Nigeria. ... tends towards pure competition. Keywords: Benue, citrus, gini coefficient, Kano, marketing, pure competition, traders. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT

Diversity of endophytic bacterial populations and their interaction with Xylella fastidiosa in citrus plants

NARCIS (Netherlands)

Araujo, W.L.; Marcon, J.; jr. Maccheroni, W.; Elsas, van J.D.; Vuurde, van J.W.L.; Azevedo, de J.L.

2002-01-01

Citrus variegated chlorosis (CVC) is caused by Xylella fastidiosa, a phytopathogenic bacterium that can infect all Citrus sinensis cultivars. The endophytic bacterial communities of healthy, resistant, and CVC-affected citrus plants were studied by using cultivation as well as

Studies on the development of functional powder from citrus peel.

Science.gov (United States)

Kang, H J; Chawla, S P; Jo, C; Kwon, J H; Byun, M W

2006-03-01

The suitability of citrus peels, generated as a by-product of the juice industry, as a source of antioxidants was investigated. Citrus peel powder was prepared by lyophilizing 70% ethanol extract from citrus peels. Extraction was carried out at room temperature (20 degrees C) for 72 h. The extract was subjected to gamma-irradiation treatment (20 kGy). The aqueous solutions of citrus peel powder were examined for color characteristics and antioxidant potential in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, beta-carotene bleaching and nitrite scavenging activities. There were significant changes in Hunter color values due to irradiation. The a*- and b*-values decreased due to radiation treatment. DPPH radical scavenging, beta-carotene bleaching and nitrite scavenging activities were not affected by irradiation treatment. Nitrite scavenging activity was the highest in the extract at pH 1.2 followed by pH 4.2 and 6.0. These functional properties of the aqueous solution were found to be stable in heat treatment. It could significantly improve oxidative stability of lipids in fish meat system. Based on these results there may be opportunities to use citrus peel powder as a functional component in the food processing industry with gamma irradiation treatment improving its color characteristics without adversely influencing the functional properties.

Resistance evaluation of Pera (Citrus sinensis) genotypes to citrus canker in greenhouse conditions

Science.gov (United States)

Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri results in serious yield losses and phytoregulation penalties. The use of resistant genotypes is recognized as an important tool to facilitate control of the pathogen. Studies have show that artificial inoculation results in typic...

Determination of limonin and nomilin contents in different citrus cultivars using high performance liquid chromatography

International Nuclear Information System (INIS)

Bilal, H.; Hassan, S.; Sahar, S.; Akram, W.; Sahar, S.

2013-01-01

High perlorrnance liquid chromatography (HPLC) analysis was done to quantify the amount of limonoids (nomilin and nomilin) in seven selected citrus cultivars. According to the HPLC analysis red blood orange (Citrus sinensis var red blood orange) had maximum amount of limonin (479.77 ug/rnl.), while rough lemon (Citrus jambhiri) had no limonin content. in case of nomonin, rough lemon (Citrus jambhir) had maximum amount of nomilin (54.23 micro g/ML)) while succari (citrus sinensis var succari) had very low amount of nomilin (0.37 micro g/Ml). (author)

First records of parasitoids attacking the Asian citrus psyllid in Ecuador

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Diego E. Portalanza

Full Text Available ABSTRACT First records of parasitoids attacking the Asian citrus psyllid in Ecuador. The objective of the current study was to investigate the presence of natural enemies of Diaphorina citri (Hemiptera: Liviidae (the Asian citrus psyllid in Ecuador. Incidence of parasitoid Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae was assessed between November 2015 and March 2016, in Letamendi, Febres-Cordero and Tarqui, urban districts of Guayaquil. Highest incidence of parasitism occurred in those regions and seasons of the year with the highest temperatures commensurate with increase of citrus plant shoots. Similar to their host, these parasitoids appear to have established in Ecuador by accident, and were not the result of purposeful introduction. This fortuitous introduction is a potentially helpful tool in controlling the Asian citrus psyllid, and potentially Huanglongbing.

The Composition, Antioxidant and Antibacterial Activities of Cold-Pressed and Distilled Essential Oils of Citrus paradisi and Citrus grandis (L. Osbeck

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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.

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.

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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

Phylogenetic Relationships of Citrus and Its Relatives Based on matK Gene Sequences

Science.gov (United States)

Penjor, Tshering; Uehara, Miki; Ide, Manami; Matsumoto, Natsumi; Matsumoto, Ryoji

2013-01-01

The genus Citrus includes mandarin, orange, lemon, grapefruit and lime, which have high economic and nutritional value. The family Rutaceae can be divided into 7 subfamilies, including Aurantioideae. The genus Citrus belongs to the subfamily Aurantioideae. In this study, we sequenced the chloroplast matK genes of 135 accessions from 22 genera of Aurantioideae and analyzed them phylogenetically. Our study includes many accessions that have not been examined in other studies. The subfamily Aurantioideae has been classified into 2 tribes, Clauseneae and Citreae, and our current molecular analysis clearly discriminate Citreae from Clauseneae by using only 1 chloroplast DNA sequence. Our study confirms previous observations on the molecular phylogeny of Aurantioideae in many aspects. However, we have provided novel information on these genetic relationships. For example, inconsistent with the previous observation, and consistent with our preliminary study using the chloroplast rbcL genes, our analysis showed that Feroniella oblata is not nested in Citrus species and is closely related with Feronia limonia. Furthermore, we have shown that Murraya paniculata is similar to Merrillia caloxylon and is dissimilar to Murraya koenigii. We found that “true citrus fruit trees” could be divided into 2 subclusters. One subcluster included Citrus, Fortunella, and Poncirus, while the other cluster included Microcitrus and Eremocitrus. Compared to previous studies, our current study is the most extensive phylogenetic study of Citrus species since it includes 93 accessions. The results indicate that Citrus species can be classified into 3 clusters: a citron cluster, a pummelo cluster, and a mandarin cluster. Although most mandarin accessions belonged to the mandarin cluster, we found some exceptions. We also obtained the information on the genetic background of various species of acid citrus grown in Japan. Because the genus Citrus contains many important accessions, we have

Phylogenetic relationships of citrus and its relatives based on matK gene sequences.

Directory of Open Access Journals (Sweden)

Tshering Penjor

Full Text Available The genus Citrus includes mandarin, orange, lemon, grapefruit and lime, which have high economic and nutritional value. The family Rutaceae can be divided into 7 subfamilies, including Aurantioideae. The genus Citrus belongs to the subfamily Aurantioideae. In this study, we sequenced the chloroplast matK genes of 135 accessions from 22 genera of Aurantioideae and analyzed them phylogenetically. Our study includes many accessions that have not been examined in other studies. The subfamily Aurantioideae has been classified into 2 tribes, Clauseneae and Citreae, and our current molecular analysis clearly discriminate Citreae from Clauseneae by using only 1 chloroplast DNA sequence. Our study confirms previous observations on the molecular phylogeny of Aurantioideae in many aspects. However, we have provided novel information on these genetic relationships. For example, inconsistent with the previous observation, and consistent with our preliminary study using the chloroplast rbcL genes, our analysis showed that Feroniella oblata is not nested in Citrus species and is closely related with Feronia limonia. Furthermore, we have shown that Murraya paniculata is similar to Merrillia caloxylon and is dissimilar to Murraya koenigii. We found that "true citrus fruit trees" could be divided into 2 subclusters. One subcluster included Citrus, Fortunella, and Poncirus, while the other cluster included Microcitrus and Eremocitrus. Compared to previous studies, our current study is the most extensive phylogenetic study of Citrus species since it includes 93 accessions. The results indicate that Citrus species can be classified into 3 clusters: a citron cluster, a pummelo cluster, and a mandarin cluster. Although most mandarin accessions belonged to the mandarin cluster, we found some exceptions. We also obtained the information on the genetic background of various species of acid citrus grown in Japan. Because the genus Citrus contains many important accessions

Phylogenetic relationships of citrus and its relatives based on matK gene sequences.

Science.gov (United States)

Penjor, Tshering; Yamamoto, Masashi; Uehara, Miki; Ide, Manami; Matsumoto, Natsumi; Matsumoto, Ryoji; Nagano, Yukio

2013-01-01

The genus Citrus includes mandarin, orange, lemon, grapefruit and lime, which have high economic and nutritional value. The family Rutaceae can be divided into 7 subfamilies, including Aurantioideae. The genus Citrus belongs to the subfamily Aurantioideae. In this study, we sequenced the chloroplast matK genes of 135 accessions from 22 genera of Aurantioideae and analyzed them phylogenetically. Our study includes many accessions that have not been examined in other studies. The subfamily Aurantioideae has been classified into 2 tribes, Clauseneae and Citreae, and our current molecular analysis clearly discriminate Citreae from Clauseneae by using only 1 chloroplast DNA sequence. Our study confirms previous observations on the molecular phylogeny of Aurantioideae in many aspects. However, we have provided novel information on these genetic relationships. For example, inconsistent with the previous observation, and consistent with our preliminary study using the chloroplast rbcL genes, our analysis showed that Feroniella oblata is not nested in Citrus species and is closely related with Feronia limonia. Furthermore, we have shown that Murraya paniculata is similar to Merrillia caloxylon and is dissimilar to Murraya koenigii. We found that "true citrus fruit trees" could be divided into 2 subclusters. One subcluster included Citrus, Fortunella, and Poncirus, while the other cluster included Microcitrus and Eremocitrus. Compared to previous studies, our current study is the most extensive phylogenetic study of Citrus species since it includes 93 accessions. The results indicate that Citrus species can be classified into 3 clusters: a citron cluster, a pummelo cluster, and a mandarin cluster. Although most mandarin accessions belonged to the mandarin cluster, we found some exceptions. We also obtained the information on the genetic background of various species of acid citrus grown in Japan. Because the genus Citrus contains many important accessions, we have

Evaluation of the Spatiotemporal Dynamics of Oxytetracycline and Its Control Effect Against Citrus Huanglongbing via Trunk Injection.

Science.gov (United States)

Hu, Jiahuai; Wang, Nian

2016-12-01

Citrus huanglongbing (HLB) or greening is a devastating bacterial disease that has destroyed millions of trees and is associated with phloem-residing 'Candidatus Liberibacter asiaticus' (Las) in Florida. In this study, we evaluated the spatiotemporal dynamics of oxytetracycline in planta and its control effect against HLB via trunk injection. Las-infected 'Hamlin' sweet orange trees on 'Swingle' citrumelo rootstock at the early stage of decline were treated with oxytetracycline hydrochloride (OTC) using trunk injection with varying number of injection ports. Spatiotemporal distribution of OTC and dynamics of Las populations were monitored by high-performance liquid chromatography method and qPCR assay, respectively. Uniform distribution of OTC throughout tree canopies and root system was achieved 2 days postinjection. High levels of OTC (>850 µg/kg) were maintained in leaf and root for at least 1 month and moderate OTC (>500 µg/kg) persisted for more than 9 months. Reduction of Las populations in root system and leaves of OTC-treated trees were over 95% and 99% (i.e., 1.76 and 2.19 log reduction) between 2 and 28 days postinjection. Conditions of trees receiving OTC treatment were improved, fruit yield was increased, and juice acidity was lowered than water-injected control even though their differences were not statistically significant during the test period. Our study demonstrated that trunk injection of OTC could be used as an effective measure for integrated management of citrus HLB.

Effect of limonene on anaerobic digestion of citrus waste and pretreatments for its improvement

OpenAIRE

RUIZ FUERTES, BEGOÑA

2016-01-01

[EN] Anaerobic digestion is a sustainable and technically sound way to valorise citrus waste if the inhibitory effect of the citrus essential oil (CEO) is controlled. Several strategies have been proposed to overcome these difficulties: keeping the organic loading rate (OLR) in low values to avoid excess dosage of inhibitor, supplementing the citrus waste with nutrient and buffering solutions or pre-treating the citrus waste in order to reduce the CEO concentration, either by recovery or by d...

Digestion kinetics of carbohydrate fractions of citrus by-products

DEFF Research Database (Denmark)

Lashkari, Saman; Taghizadeh, Akbar

2015-01-01

The present experiment was carried out to determine the digestion kinetics of carbohydrate fractions of citrus by-products. Grapefruit pulp (GP), lemon pulp (LE), lime pulp (LI) and orange pulp (OP) were the test feed. Digestion kinetic of whole citrus by-products and neutral detergent fiber (NDF......) fraction and acid detergent fiber (ADF) fractions of citrus by-products were measured using the in vitro gas production technique. Fermentation kinetics of the neutral detergent soluble carbohydrates (NDSC) fraction and hemicelluloses were calculated using a curve subtraction. The fermentation rate...... of whole was the highest for the LE (p by-products lag time was longer for hemicellulose than other carbohydrate fractions. There was no significant difference among potential gas production (A) volumes of whole test feeds (p

Taxonomy and phylogeny of the genus citrus based on the nuclear ribosomal dna its region sequence

International Nuclear Information System (INIS)

Sun, Y.L.

2015-01-01

The genus Citrus (Aurantioideae, Rutaceae) is the sole source of the citrus fruits of commerce showing high economic values. In this study, the taxonomy and phylogeny of Citrus species is evaluated using sequence analysis of the ITS region of nrDNA. This study is based on 26 plants materials belonging to 22 Citrus species having wild, domesticated, and cultivated species. Through DNA alignment of the ITS sequence, ITS1 and ITS2 regions showed relatively high variations of sequence length and nucleotide among these Citrus species. According to previous six-tribe discrimination theory by Swingle and Reece, the grouping in our ITS phylogenetic tree reconstructed by ITS sequences was not related to tribe discrimination but species discrimination. However, the molecular analysis could provide more information on citrus taxonomy. Combined with ITS sequences of other subgenera in then true citrus fruit tree group, the ITS phylogenetic tree indicated subgenera Citrus was monophyletic and nearer to Fortunella, Poncirus, and Clymenia compared to Microcitrus and Eremocitrus. Abundant sequence variations of the ITS region shown in this study would help species identification and tribe differentiation of the genus Citrus. (author)

AN EXPLORATION OF FACTORS AFFECTING DEVELOPMENT OF CITRUS INDUSTRY IN TANZANIA: EMPIRICAL EVIDENCE FROM MUHEZA DISTRICT, TANGA REGION

Directory of Open Access Journals (Sweden)

Robert Makorere

2014-04-01

Full Text Available The paper stresses on understanding factors affecting development of citrus industry in Tanzania particularly in Muheza District, in Tanga region. Citrus fruit is one of the most important crops in Muheza District of Tanga region in Tanzania particularly in improving rural farmers’ income. The study employed institutional framework methodology. The study disclosed that the government of Tanzania has been implementing various agricultural development programmes in improving citrus fruit production as well as to enhance farmers’ income. However, yet the results reveal that the citrus farming practices in the surveyed area are not well developed. And these are because citruses are still grown under rain fed regime without any form of irrigation, citrus seedlings are produced by individual farmers locally in their backyard nurseries. There is no professional company responsible for seedling production. Also, citrus farmers’ skills in citrus husbandry practices are limited. Lastly, all citrus varieties used contain many seeds in the citrus fruits whereas the market demands seedless citrus fruits. It is therefore, recommended that the policy maker should focus on development of citrus industry in Tanzania using proper institutional framework support, which could increase growth and development of citrus production through the provision of subsides for inputs to reduce cost of production and enlightenment campaigns to improve farmer’s knowledge and technical skills on how to reach lucrative markets.

GABA Pathway Rate-Limit Citrate Degradation in Postharvest Citrus Fruit Evidence from HB Pumelo (Citrus grandis) × Fairchild (Citrus reticulata) Hybrid Population.

Science.gov (United States)

Sheng, Ling; Shen, Dandan; Yang, Wei; Zhang, Mingfei; Zeng, Yunliu; Xu, Juan; Deng, Xiuxin; Cheng, Yunjiang

2017-03-01

Organic acids are a major index of fresh fruit marketing properties. However, the genetic effects on the organic acid level in postharvest citrus fruit still remain unknown. Here, we used the fruits of about 40 lines in a hybrid population (high-acid "HB Pumelo" × low-acid "Fairchild") to analyze the organic acid metabolism of postharvest citrus fruit. A transgressive content of titratable acid (TA) was observed, which was attributed to citrate accumulation. High- and low-acid fruits (No. 130, 168 and No. 080, 181, respectively) were chosen for further study. Gene expression analysis on citrate metabolism showed that the high accumulation of citrate could be attributed to the low activity of γ-aminobutyric acid (GABA) shunt, and was partially due to the block of tricarboxylic acid (TCA) cycle by low mitochondrial aconitase (m-ACO) expression. TA level was significantly negatively correlated with weight loss in fruits during postharvest storage, implying a close relationship between organic acid and water metabolism.

Correlation of electronic monitoring and stylet pathways elucidate the role of sclerenchymatous ring as a barrier to phloem feeding on citrus leaves by Asian citrus psyllid

Science.gov (United States)

Asian citrus psyllid (ACP, Diaphorina. citri) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacterium that causes the economically devastating citrus greening disease. Recent studies have shown a fibrous ring of thick-wal...

Utilization of founder lines for improved Citrus biotechnology via RMCE

Science.gov (United States)

On October 1st 2011 the CRB chose to fund a unique research project, the development of citrus cultivars specifically for genetic engineering (GE). The objective of this research was to develop GE citrus ‘Founder Lines’ containing DNA sequences that will allow the precise insertion of genes for de...

(JASR) VOL. 10, No. 2, 2010 69 CITRUS FARMERS PRODUCTION

African Journals Online (AJOL)

oma

models of citrus, production of bottled citrus juice, jams and marmalades. Although a lot of work has been done in development of improved technologies for ..... Acta. Horticulturae 123:23-27. Owoeye, T (2010) Nigeria: Training farmers will boost agricultural production. www.freshplaza.com/news_detail. Umeh, V.C, Garcia ...

7 CFR 905.153 - Procedure for determining handlers' permitted quantities of red seedless grapefruit when a...

Science.gov (United States)

2010-01-01

... MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE... committee their Florida citrus fruit dealer's license number, their Florida Department of Agriculture and...

Oppenheimer&Groves : The duality that led to Trinity /.

Energy Technology Data Exchange (ETDEWEB)

Connaughton, T. G. (Theresa G.); Smith, S. E. (Sharon E.)

2001-01-01

The alliance of J. Robert Oppenheimer, scientist, and Leslie R. Groves, military leader, is often interpreted as the classic example of the clash between the academic mind and the military style. Evidence suggests, instead, that it was a collaboration that led to the dawn of the nuclear age. Instead of a clash, it was collaboration and an implosion of the diverse talents needed for the success of this project. Discussion of these flawed and fascinating individuals still ignites controversy today. This presentation will explore the backgrounds and personalities of these two men and their work together to accomplish their mission. Was the aftermath inevitable, given a relationship based on respect, but perhaps not trust? The genesis of the modern military-industrial complex rested on the genius of these two men, though they personify two distinct American sub-cultures. What lessons can be drawn from their wartime and post-war relationship? What analogies can be drawn for current American values?

Resistance of citrus genotypes to Phyllocnitis citrella Stainton (Lepidoptera: Gracillariidae).

Science.gov (United States)

Santos, M S; Vendramim, J D; Lourenção, A L; Pitta, R M; Martins, E S

2011-01-01

The development and reproduction of the citrus leafminer (CLM), Phyllocnistis citrella Stainton, were evaluated in six citrus genotypes in order to identify genotypes with resistance traits that could be applied in a program for the development of citrus varieties resistant to the citrus leafminer. Tests were conducted under controlled laboratory conditions (25 ± 1ºC, 70 ± 10% RH, and 14h photophase). Seedlings of each genotype tested were infested with eggs obtained from a stock colony of CLM maintained on 'Cravo' lemon (Citrus limonia L. Osbeck), and the duration and survival of the eggs, larval and pupal stages, pupal size and weight, fecundity and longevity of adults, and sex ratio were evaluated. No influence was observed on the duration and survival of eggs, larvae and pupae of P. citrella. However, pupae obtained in the hybrid C x R(4) were significantly smaller and lighter than pupae from the remaining treatments. Adult females from the hybrids C x R(4) and C x R(315) were the least fecund. However, the lowest value for the corrected reproductive potential (CRP) was recorded in the hybrid C x R(315), suggesting that this genotype is the least favorable for the development and reproduction of CLM. On the other hand, the highest CRP value obtained in the 'Rugoso' lemon confirms the susceptibility of this genotype, indicating it as the most suitable for CLM.

7 CFR 301.75-17 - Funds for the replacement of certified citrus nursery stock.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Funds for the replacement of certified citrus nursery... nursery stock. Subject to the availability of appropriated funds, a commercial citrus nursery may be eligible to receive funds to replace certified citrus nursery stock in accordance with the provisions of...

Detection of mechanical and disease stresses in citrus plants by fluorescence spectroscopy

Science.gov (United States)

Belasque, J., Jr.; Gasparoto, M. C. G.; Marcassa, L. G.

2008-04-01

We have investigated the detection of mechanical and disease stresses in citrus plants (Citrus limonia [L.] Osbeck) using laser-induced fluorescence spectroscopy. Due to its economic importance we have chosen to investigate the citrus canker disease, which is caused by the Xanthomonas axonopodis pv. citri bacteria. Mechanical stress was also studied because it plays an important role in the plant's infection by such bacteria. A laser-induced fluorescence spectroscopy system, composed of a spectrometer and a 532 nm10 mW excitation laser was used to perform fluorescence spectroscopy. The ratio of two chlorophyll fluorescence bands allows us to detect and discriminate between mechanical and disease stresses. This ability to discriminate may have an important application in the field to detect citrus canker infected trees.

LRR-RLK family from two Citrus species: genome-wide identification and evolutionary aspects.

Science.gov (United States)

Magalhães, Diogo M; Scholte, Larissa L S; Silva, Nicholas V; Oliveira, Guilherme C; Zipfel, Cyril; Takita, Marco A; De Souza, Alessandra A

2016-08-12

Leucine-rich repeat receptor-like kinases (LRR-RLKs) represent the largest subfamily of plant RLKs. The functions of most LRR-RLKs have remained undiscovered, and a few that have been experimentally characterized have been shown to have important roles in growth and development as well as in defense responses. Although RLK subfamilies have been previously studied in many plants, no comprehensive study has been performed on this gene family in Citrus species, which have high economic importance and are frequent targets for emerging pathogens. In this study, we performed in silico analysis to identify and classify LRR-RLK homologues in the predicted proteomes of Citrus clementina (clementine) and Citrus sinensis (sweet orange). In addition, we used large-scale phylogenetic approaches to elucidate the evolutionary relationships of the LRR-RLKs and further narrowed the analysis to the LRR-XII group, which contains several previously described cell surface immune receptors. We built integrative protein signature databases for Citrus clementina and Citrus sinensis using all predicted protein sequences obtained from whole genomes. A total of 300 and 297 proteins were identified as LRR-RLKs in C. clementina and C. sinensis, respectively. Maximum-likelihood phylogenetic trees were estimated using Arabidopsis LRR-RLK as a template and they allowed us to classify Citrus LRR-RLKs into 16 groups. The LRR-XII group showed a remarkable expansion, containing approximately 150 paralogs encoded in each Citrus genome. Phylogenetic analysis also demonstrated the existence of two distinct LRR-XII clades, each one constituted mainly by RD and non-RD kinases. We identified 68 orthologous pairs from the C. clementina and C. sinensis LRR-XII genes. In addition, among the paralogs, we identified a subset of 78 and 62 clustered genes probably derived from tandem duplication events in the genomes of C. clementina and C. sinensis, respectively. This work provided the first comprehensive

DNA Barcode Reference Library for the African Citrus Triozid, Trioza erytreae (Hemiptera: Triozidae): Vector of African Citrus Greening.

Science.gov (United States)

Khamis, F M; Rwomushana, I; Ombura, L O; Cook, G; Mohamed, S A; Tanga, C M; Nderitu, P W; Borgemeister, C; Sétamou, M; Grout, T G; Ekesi, S

2017-12-05

Citrus (Citrus spp.) production continues to decline in East Africa, particularly in Kenya and Tanzania, the two major producers in the region. This decline is attributed to pests and diseases including infestation by the African citrus triozid, Trioza erytreae (Del Guercio) (Hemiptera: Triozidae). Besides direct feeding damage by adults and immature stages, T. erytreae is the main vector of 'Candidatus Liberibacter africanus', the causative agent of Greening disease in Africa, closely related to Huanglongbing. This study aimed to generate a novel barcode reference library for T. erytreae in order to use DNA barcoding as a rapid tool for accurate identification of the pest to aid phytosanitary measures. Triozid samples were collected from citrus orchards in Kenya, Tanzania, and South Africa and from alternative host plants. Sequences generated from populations in the study showed very low variability within acceptable ranges of species. All samples analyzed were linked to T. erytreae of GenBank accession number KU517195. Phylogeny of samples in this study and other Trioza reference species was inferred using the Maximum Likelihood method. The phylogenetic tree was paraphyletic with two distinct branches. The first branch had two clusters: 1) cluster of all populations analyzed with GenBank accession of T. erytreae and 2) cluster of all the other GenBank accession of Trioza species analyzed except T. incrustata Percy, 2016 (KT588307.1), T. eugeniae Froggatt (KY294637.1), and T. grallata Percy, 2016 (KT588308.1) that occupied the second branch as outgroups forming sister clade relationships. These results were further substantiated with genetic distance values and principal component analyses. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.

The diversity of the Andalusian olive grove: from territory to landscape (The case study of the province of Jaén

Directory of Open Access Journals (Sweden)

José Domingo Sánchez Martínez

2018-02-01

Full Text Available Olive grove is the most common crop and the economic basis of much of the rural municipalities of Andalusia, often reaching the condition of monoculture. To contribute to the maintenance and development of these territories, the conservation and enhancement of the landscape and culture of the olive grove is currently seen as an asset for sustainable development and regional competitiveness. The objective of our work is to show the vast internal diversity it contains, and how this is reflected in landscape terms. So, we’ve created a spatial database in which agricultural, chronological and spatial variables are integrated. As a final result four broad categories of olive landscapes are presented: marginal, in protected areas, traditional and productivists.

PAYMENT FOR ECOSYSTEM SERVICE FOR CARBON CREDITS FROM ITALIAN OLIVE GROVES. SOME ISSUES REGARDING THE MODE OF PAYMENT

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Silvia Coderoni

2014-10-01

Full Text Available In Italy, olive farming is one of the most interesting examples of carbon sink in agricultural soils. The olive agro-ecosystems can in fact ensure effective action in CO2 fixation encouraging the process of carbon storage on the organic matter of the soil. Starting from the assumption that a different and more “carbon oriented” management of Italian olive groves system could represent a promising way to increase the carbon stored in agricultural land, this paper explores the possibility to implement a Payment for Ecosystem Services (PES scheme to increase the provision of carbon sink by olive groves. The analysis focuses on the definition of the sealable ecosystem service, according to the actual policy framework and on the mode of payment that could be established. Results, suggest that an output-based payment, though more environmentally efficient, could not be enough to incentivise farmers to join the PES, as the payment per hectare might be lower using this approach.

In vitro pollen germination of five citrus species

International Nuclear Information System (INIS)

Khan, S.A.; Perveen, A.

2014-01-01

The aim of present study is In vitro germination of the pollen grains of five Citrus species belonging to the family Rutaceae viz., Citrus aurantium L. var., aurantium Hook.f., C. limon (L.) Brum. f., C. paradisii Macfad, C. reticulata Blanco and C. sinensis (L.) Osbeck. using hanging drop technique. The germination was checked up to 48 weeks, for the pollen stored at different temperatures like 4 degree C, -20 degree C, -30 degree C and -60 degree C. The study indicates that low temperature and low relative humidity is better than high temperature and humidity with respect to pollen germination capacity and viability. Freeze dryer (-60 degree C) seems to be the best method to maintain pollen viability of stored pollen grains for a long period of time. Among five species Citrus aurantium, C. limon and C. sinensis showed high percentage of germination as compared to C. reticulata and C. paradisii. (author)

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. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A new modified resource budget model for nonlinear dynamics in citrus production

International Nuclear Information System (INIS)

Ye, Xujun; Sakai, Kenshi

2016-01-01

Highlights: • A theoretical modeling and simulation study of the nonlinear dynamics in citrus is conducted. • New leaf growth is incorporated into the model as a major factor responsible for the yield oscillations. • A Ricker-type equation for the relationship between costs for flowering and fruiting is proposed. • A generic form of the resource budget model for the nonlinear dynamics in citrus is obtained. • The new model is tested with experimental data for two citrus trees. - Abstract : Alternate bearing or masting is a general yield variability phenomenon in perennial tree crops. This paper first presents a theoretical modeling and simulation study of the mechanism for this dynamics in citrus, and then provides a test of the proposed models using data from a previous 16-year experiment in a citrus orchard. Our previous studies suggest that the mutual effects between vegetative and reproductive growths caused by resource allocation and budgeting in plant body might be considered as a major factor responsible for the yield oscillations in citrus. Based on the resource budget model proposed by Isagi et al. (J Theor Biol. 1997;187:231-9), we first introduce the new leaf growth as a major energy consumption component into the model. Further, we introduce a nonlinear Ricker-type equation to replace the linear relationship between costs for flowering and fruiting used in Isagi's model. Model simulations demonstrate that the proposed new models can successfully simulate the reproductive behaviors of citrus trees with different fruiting dynamics. These results may enrich the mechanical dynamics in tree crop reproductive models and help us to better understand the dynamics of vegetative-reproductive growth interactions in a real environment.

Spatial and temporal analyses of citrus sudden death as a tool to generate hypotheses concerning its etiology.

Science.gov (United States)

Bassanezi, Renato B; Bergamin Filho, Armando; Amorim, Lilian; Gimenes-Fernandes, Nelson; Gottwald, Tim R; Bové, Joseph M

2003-04-01

ABSTRACT Citrus sudden death (CSD), a new disease of unknown etiology that affects sweet orange grafted on Rangpur lime, was visually monitored for 14 months in 41 groves in Brazil. Ordinary runs analysis of CSD-symptomatic trees indicated a departure from randomness of symptomatic trees status among immediately adjacent trees mainly within rows. The binomial index of dispersion (D) and the intraclass correlation (k) for various quadrat sizes suggested aggregation of CSD-symptomatic trees for almost all plots within the quadrat sizes tested. Estimated parameters of the binary form of Taylor's power law provided an overall measure of aggregation of CSD-symptomatic trees for all quadrat sizes tested. Aggregation in each plot was dependent on disease incidence. Spatial autocorrelation analysis of proximity patterns suggested that aggregation often existed among quadrats of various sizes up to three lag distances; however, significant lag positions discontinuous from main proximity patterns were rare, indicating a lack of spatial association among discrete foci. Some asymmetry was also detected for some spatial autocorrelation proximity patterns, indicating that within-row versus across-row distributions are not necessarily equivalent. These results were interpreted to mean that the cause of the disease was most likely biotic and its dissemination was common within a local area of influence that extended to approximately six trees in all directions, including adjacent trees. Where asymmetry was indicated, this area of influence was somewhat elliptical. Longer-distance patterns were not detected within the confines of the plot sizes tested. Annual rates of CSD progress based on the Gompertz model ranged from 0.37 to 2.02. Numerous similarities were found between the spatial patterns of CSD and Citrus tristeza virus (CTV) described in the literature, both in the presence of the aphid vector, Toxoptera citricida. CSD differs from CTV in that symptoms occur in sweet orange

Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro

OpenAIRE

Ivanovi?, ?arko; Perovi?, Tatjana; Popovi?, Tatjana; Blagojevi?, Jovana; Trkulja, Nenad; Hrn?i?, Snje?ana

2017-01-01

Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin (Citrus reticulata) in Montenegro, using multilocus sequence analysis of gyrB, rpoD, and gap1 gene sequences. Gene sequences from...

Carcass characteristics and meat quality of heavy swine fed different citrus pulp levels

Directory of Open Access Journals (Sweden)

P.H. Watanabe

2010-08-01

Full Text Available An assay with 36 swine initially weighting 83.7±5.1kg body weight (BW was carried out to evaluate the effects of the use of different dietary citrus pulp levels, 0, 10%, 20%, and 30%, upon digestive organs weights, carcass characteristics, and meat quality of animals subjected to qualitative feed restriction program, and slaughtered at 130kg BW. Linear response (P0.05. Higher levels of citrus pulp neither decreased backfat thickness nor increased amount of lean meat, indicative that qualitative feed restriction was not efficient. Positive linear effect (P<0.05 on pH measured 24 hours after slaughter and negative linear effect (P<0.05 on color characteristics as function of citrus pulp dietary levels were verified. Citrus pulp addition in qualitative feed restriction program may not be effective. As no deleterious effects upon meat qualities were observed, citrus pulp can be used as an alternative feedstuff for finishing swine.

Larvicidal Activity of Citrus Limonoids against Aedes albopictus Larvae

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Hazrat Bilal

2012-12-01

Full Text Available Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecticidestherefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to suppressmosquito larval population.Methods: WHO recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used.Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis wasthe best in terms of LC50 (297 ppm, % mortality (97% and LT50 (18.49 hours then freutrall early (Citrus reticulatewith LC50 (377.4 ppm, % mortality (88% and LT50 (31 hours, While nomilin gave lowest LC50 (121.04 ppm than limonin (382.22 ppm after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 μg/ml and 21.19 μg/ml than freutrall early (5.29 μg/ml and 3.89 μg/ml respectively.Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required.

Weed control and persistence of two oxyfluorfen formulations in olive groves under non tillage conditions.

Science.gov (United States)

Martínez, M J; Farsaoui, K; de Prado, R

2004-01-01

To obtain profitable yields in olive groves, residual preemergence herbicides are applied in October or November before the winter rains, and before the winter annual weeds germinate. Simazine, one of the herbicides most used for weed control in olive groves, has recently been banned. Oxyfluorfen is presented as a good alternative to simazine in olive fields. Experiments were carried out in 2002 and 2003 to evaluate the behaviour of two oxyfluorfen formulations, 2XL and G4F, at 480 g a.i. ha(-1) for three different soil management systems with three replications (1. bare soil; 2. bare soil and grassed buffer strips, chemically controlled and 3. bare soil and grassed buffer strips with controlled mowing; under non tillage conditions in all three cases). The most important species that survived 2XL and G4F treatments was Sagina apetala ARD. Oxyfluorfen residues were evaluated throughout 158 days after the applications. Three soil samples from each plot were collected, mixed and air dried. The herbicide extractions were made with methanol and the residues were analyzed by HPLC. We found no differences between the two formulations, but results showed that recoveries of oxyfluorfen were higher in plots with chemically controlled buffer grassed strips than in the other soil management types.

Overexpression of a modified plant thionin enhances disease resistance to citrus canker and Huanglongbing (HLB)

Science.gov (United States)

Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States 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 ec...

Comparative Analysis of Flower Volatiles from Nine Citrus at Three Blooming Stages

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Muhammad Azam

2013-11-01

Full Text Available Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.

Avaliação nutricional de citrinos em agricultura biológica Nutritional evaluation of citrus orchard under organic farming

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I. Domingos

2009-01-01

Full Text Available Neste trabalho apresentam-se alguns resultados preliminares referentes à caracterização e avaliação do estado nutricional de um pomar de laranjeiras (Citrus sinensis (L. Osb. cv. ‘Valencia Late’ instalado em agricultura biológica num solo com elevado teor de calcário activo do Centro de Experimentação Agrária de Tavira da Direcção Regional de Agricultura do Algarve. Com o objectivo de caracterizar o solo do pomar em estudo foram realizadas colheitas de solo a duas profundidades (0-25 e 25-50 cm e efectuadas diversas determinações, nomeadamente: textura, matéria orgânica, fósforo e potássio assimiláveis, e calcário total e activo. Durante 2 anos (2002 e 2003 foram efectuadas colheitas de flores na plena floração e colheitas de folhas de Abril a Outubro e foi determinada a sua composição mineral (macro e micronutrientes. Nas mesmas datas de amostragem fizeram-se estimativas do teor de clorofila total das folhas através da utilização do aparelho de SPAD-502. Os resultados são discutidos com base nas variações sazonais dos nutrientes nas folhas e flores e comparados com os valores referenciados para a agricultura convencional. Foi ainda testada a aplicabilidade de um modelo de diagnóstico nutricional, baseado na análise floral, e estabelecido para citrinos em agricultura convencional.This study presents some preliminary results concerning the characterization and evaluation of the nutritional status of a or-ganic-grown orange grove (Citrus sinensis (L. Osb. cv. ‘Valencia Late’ established on a calcareous soil in the south of Portugal (Tavira -Direcção Regional de Agricultura do Algarve. Composite soil samples were collected at two depths (0-25 and 25-50cm and various parameters were determined namely: texture, organic matter, extractable phosphorus and potassium, and total and active lime. During two years (2002 and 2003 the mineral composition of flowers (full bloom and leaves between April and October was

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

Energy Technology Data Exchange (ETDEWEB)

Cary,; Bruce, R [Santa Fe, NM; Stubben, Christopher J [Los Alamos, NM

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.

In silico analysis of phytohormone metabolism and communication pathways in citrus transcriptome

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Vera Quecini

2007-01-01

Full Text Available Plant hormones play a crucial role in integrating endogenous and exogenous signals and in determining developmental responses to form the plant body throughout its life cycle. In citrus species, several economically important processes are controlled by phytohormones, including seed germination, secondary growth, fruit abscission and ripening. Integrative genomics is a powerful tool for linking newly researched organisms, such as tropical woody species, to functional studies already carried out on established model organisms. Based on gene orthology analyses and expression patterns, we searched the Citrus Genome Sequencing Consortium (CitEST database for Expressed Sequence Tags (EST consensus sequences sharing similarity to known components of hormone metabolism and signaling pathways in model species. More than 600 homologs of functionally characterized hormone metabolism and signal transduction members from model species were identified in citrus, allowing us to propose a framework for phytohormone signaling mechanisms in citrus. A number of components from hormone-related metabolic pathways were absent in citrus, suggesting the presence of distinct metabolic pathways. Our results demonstrated the power of comparative genomics between model systems and economically important crop species to elucidate several aspects of plant physiology and metabolism.

Oxygenated heterocyclic compounds to differentiate Citrus spp. essential oils through metabolomic strategies.

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Masson, Jerome; Liberto, Erica; Beolor, Jean-Claude; Brevard, Hugues; Bicchi, Carlo; Rubiolo, Patrizia

2016-09-01

This study aimed to characterise and discriminate 44 authenticated commercial samples of citrus essential oils (EO) from seven species (bergamot, lemon, bigarade, orange, mandarin, grapefruit, lime) by analysing the non-volatile oxygenated heterocyclic compounds (OHC) by UHPLC/TOF-HRMS, multivariate data analysis (PCA, PLS-DA) and metabolomic strategies; the OHC fraction includes coumarins, furocoumarins, and polymethoxylated flavonoids. Two different approaches were adopted: (i) targeted profiling based on quantifying 18 furocoumarins and coumarins, some of which are regulated by law, and (ii) targeted fingerprinting based on 140 OHCs reported in citrus essential oils, from which 38 discriminant markers were defined. This approach correctly discriminated the Citrus species; its "sensitivity" to relatively low adulteration rate (10%) was highly satisfactory. The proposed method is complementary to that of analysing the citrus EO volatile part by GC techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hybrid Origins of Citrus Varieties Inferred from DNA Marker Analysis of Nuclear and Organelle Genomes

Science.gov (United States)

Kitajima, Akira; Nonaka, Keisuke; Yoshioka, Terutaka; Ohta, Satoshi; Goto, Shingo; Toyoda, Atsushi; Fujiyama, Asao; Mochizuki, Takako; Nagasaki, Hideki; Kaminuma, Eli; Nakamura, Yasukazu

2016-01-01

Most indigenous citrus varieties are assumed to be natural hybrids, but their parentage has so far been determined in only a few cases because of their wide genetic diversity and the low transferability of DNA markers. Here we infer the parentage of indigenous citrus varieties using simple sequence repeat and indel markers developed from various citrus genome sequence resources. Parentage tests with 122 known hybrids using the selected DNA markers certify their transferability among those hybrids. Identity tests confirm that most variant strains are selected mutants, but we find four types of kunenbo (Citrus nobilis) and three types of tachibana (Citrus tachibana) for which we suggest different origins. Structure analysis with DNA markers that are in Hardy–Weinberg equilibrium deduce three basic taxa coinciding with the current understanding of citrus ancestors. Genotyping analysis of 101 indigenous citrus varieties with 123 selected DNA markers infers the parentages of 22 indigenous citrus varieties including Satsuma, Temple, and iyo, and single parents of 45 indigenous citrus varieties, including kunenbo, C. ichangensis, and Ichang lemon by allele-sharing and parentage tests. Genotyping analysis of chloroplast and mitochondrial genomes using 11 DNA markers classifies their cytoplasmic genotypes into 18 categories and deduces the combination of seed and pollen parents. Likelihood ratio analysis verifies the inferred parentages with significant scores. The reconstructed genealogy identifies 12 types of varieties consisting of Kishu, kunenbo, yuzu, koji, sour orange, dancy, kobeni mikan, sweet orange, tachibana, Cleopatra, willowleaf mandarin, and pummelo, which have played pivotal roles in the occurrence of these indigenous varieties. The inferred parentage of the indigenous varieties confirms their hybrid origins, as found by recent studies. PMID:27902727

Genome-wide comparative analysis reveals similar types of NBS genes in hybrid Citrus sinensis genome and original Citrus clementine genome and provides new insights into non-TIR NBS genes.

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Yunsheng Wang

Full Text Available In this study, we identified and compared nucleotide-binding site (NBS domain-containing genes from three Citrus genomes (C. clementina, C. sinensis from USA and C. sinensis from China. Phylogenetic analysis of all Citrus NBS genes across these three genomes revealed that there are three approximately evenly numbered groups: one group contains the Toll-Interleukin receptor (TIR domain and two different Non-TIR groups in which most of proteins contain the Coiled Coil (CC domain. Motif analysis confirmed that the two groups of CC-containing NBS genes are from different evolutionary origins. We partitioned NBS genes into clades using NBS domain sequence distances and found most clades include NBS genes from all three Citrus genomes. This suggests that three Citrus genomes have similar numbers and types of NBS genes. We also mapped the re-sequenced reads of three pomelo and three mandarin genomes onto the C. sinensis genome. We found that most NBS genes of the hybrid C. sinensis genome have corresponding homologous genes in both pomelo and mandarin genomes. The homologous NBS genes in pomelo and mandarin suggest that the parental species of C. sinensis may contain similar types of NBS genes. This explains why the hybrid C. sinensis and original C. clementina have similar types of NBS genes in this study. Furthermore, we found that sequence variation amongst Citrus NBS genes were shaped by multiple independent and shared accelerated mutation accumulation events among different groups of NBS genes and in different Citrus genomes. Our comparative analyses yield valuable insight into the structure, organization and evolution of NBS genes in Citrus genomes. Furthermore, our comprehensive analysis showed that the non-TIR NBS genes can be divided into two groups that come from different evolutionary origins. This provides new insights into non-TIR genes, which have not received much attention.

Nutrient digestibility and evaluation of protein and carbohydrate fractionation of citrus by-products

DEFF Research Database (Denmark)

Lashkari, Saman; Taghizadeh, Akbar

2013-01-01

The protein and carbohydrate fractionation and nutrient digestibility of citrus by‐products were determined. Ruminal, intestinal and total tract CP disappearance values were measured by a modified three‐step (MTSP) method and in vitro CP disappearance method (IVCP). Test feeds were orange pulp (OP...... to the results, it could be concluded that citrus by‐products have high nutritive value and also, the in vitro techniques can be easily used to determine of the nutritive value of citrus by‐products....

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

Evaluation of antioxidant potential of citrus peel extracts

International Nuclear Information System (INIS)

Chatha, S.A.S.; Hussain, A.I.; Asi, M.R.

2011-01-01

The antioxidant potential of different solvent extracts of three different locally grown citrus varieties; grape fruit, lemon and mussambi, was assessed using some antioxidant assays like estimation of total phenolic contents (TPC), total flavonoids contents (TFC), percentage inhibition of linoleic acid oxidation and DPPH free radical scavenging capacity. The yield of extracts was found in the range of 17.92-30.8%. TPC, TFC, percent inhibition of linoleic acid oxidation and DPPH radical scavenging capacity of different citrus peel extracts were found in range of 2.72 - 3.77 g/100g as Gallic Acid Equivalent (GAE), 2.20-2.98 g/100g as Catechine Equivalent (CE), 68.20 - 91.78% and 19.53 - 41.88 mg/mL, respectively. Statistical analysis showed significant (p < 0.05) variations in the yield and antioxidant potentials of the extracts with respect to different species and solvent systems. From the results it is reasonable to say that methanolic extracts of citrus peels have exhibited varying degree of antioxidant potentials. (author)

Genome editing of the disease susceptibility gene CsLOB1 in citrus confers resistance to citrus canker.

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Jia, Hongge; Zhang, Yunzeng; Orbović, Vladimir; Xu, Jin; White, Frank F; Jones, Jeffrey B; Wang, Nian

2017-07-01

Citrus is a highly valued tree crop worldwide, while, at the same time, citrus production faces many biotic challenges, including bacterial canker and Huanglongbing (HLB). Breeding for disease-resistant varieties is the most efficient and sustainable approach to control plant diseases. Traditional breeding of citrus varieties is challenging due to multiple limitations, including polyploidy, polyembryony, extended juvenility and long crossing cycles. Targeted genome editing technology has the potential to shorten varietal development for some traits, including disease resistance. Here, we used CRISPR/Cas9/sgRNA technology to modify the canker susceptibility gene CsLOB1 in Duncan grapefruit. Six independent lines, D LOB 2, D LOB 3, D LOB 9, D LOB 10, D LOB 11 and D LOB 12, were generated. Targeted next-generation sequencing of the six lines showed the mutation rate was 31.58%, 23.80%, 89.36%, 88.79%, 46.91% and 51.12% for D LOB 2, D LOB 3, D LOB 9, D LOB 10, D LOB 11 and D LOB 12, respectively, of the cells in each line. D LOB 2 and D LOB 3 showed canker symptoms similar to wild-type grapefruit, when inoculated with the pathogen Xanthomonas citri subsp. citri (Xcc). No canker symptoms were observed on D LOB 9, D LOB 10, D LOB 11 and D LOB 12 at 4 days postinoculation (DPI) with Xcc. Pustules caused by Xcc were observed on D LOB 9, D LOB 10, D LOB 11 and D LOB 12 in later stages, which were much reduced compared to that on wild-type grapefruit. The pustules on D LOB 9 and D LOB 10 did not develop into typical canker symptoms. No side effects and off-target mutations were detected in the mutated plants. This study indicates that genome editing using CRISPR technology will provide a promising pathway to generate disease-resistant citrus varieties. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Citrus genebank collections: International collaboration opportunities between the U.S. and Russia

Science.gov (United States)

Citrus germplasm is conserved in genebanks at sites around the world to provide genetic resources for breeding and research programs. The value of genebank collections is particularly evident as diseases and climate change threaten citrus production areas. We provide historical, inventory, and maint...

A stable RNA virus-based vector for citrus trees

International Nuclear Information System (INIS)

Folimonov, Alexey S.; Folimonova, Svetlana Y.; Bar-Joseph, Moshe; Dawson, William O.

2007-01-01

Virus-based vectors are important tools in plant molecular biology and plant genomics. A number of vectors based on viruses that infect herbaceous plants are in use for expression or silencing of genes in plants as well as screening unknown sequences for function. Yet there is a need for useful virus-based vectors for woody plants, which demand much greater stability because of the longer time required for systemic infection and analysis. We examined several strategies to develop a Citrus tristeza virus (CTV)-based vector for transient expression of foreign genes in citrus trees using a green fluorescent protein (GFP) as a reporter. These strategies included substitution of the p13 open reading frame (ORF) by the ORF of GFP, construction of a self-processing fusion of GFP in-frame with the major coat protein (CP), or expression of the GFP ORF as an extra gene from a subgenomic (sg) mRNA controlled either by a duplicated CTV CP sgRNA controller element (CE) or an introduced heterologous CE of Beet yellows virus. Engineered vector constructs were examined for replication, encapsidation, GFP expression during multiple passages in protoplasts, and for their ability to infect, move, express GFP, and be maintained in citrus plants. The most successful vectors based on the 'add-a-gene' strategy have been unusually stable, continuing to produce GFP fluorescence after more than 4 years in citrus trees

Socio-economic determinants of the awareness and adoption of citrus production practices in Pakistan

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Saleem Ashraf

2015-09-01

Full Text Available Citrus is the leading fruit of Pakistan and famous worldwide especially kinnow cultivar because of its pleasant taste and remarkable quality. The yield of citrus per hectare in Pakistan is almost half of potential due to non-adoption of recommended horticultural practices by citrus growers. Adopting a decision regarding the improvement of practices is usually influenced by various factors including farmers' socio-economic attributes. In order to determine the relationship between socio-economic aspects and the awareness and adoption of recommended citrus production practices the present study was carried out in Sargodha district from central Punjab, Pakistan. The Study was based upon cross sectional survey research design due to availability of sampling frame, probability (random sampling was applied for sample selection. Through random sampling, 120 citrus growers were selected as sample. Structured questionnaire administered through interview was used as a research instrument. Analysis of the data collected from the targeted citrus growers revealed a highly significant influence of education on awareness and adoption. Moreover, significant association was found between citrus cultivation area and awareness and adoption of improved practices. Age also showed significant association with awareness and adoption. Moreover, dominancy of middle aged farmers and illiteracyin the study area strongly point the need of provision of formal and non-formal education and training program for farmers. Young generation needs to be focused and reorientation of youth clubs may help in better way to gain the utmost outcome.

Cedar Grove: An Interdisciplinary Investigation of a Late Caddo Farmstead in the Red River Valley.

Science.gov (United States)

1983-10-31

render all rimless Natchitoches Engraved body sherds (Figure 1 l-48h). These could be from an unrecorded variety unsortable to type. This is a good...Aloerta, Alford and Arlis. At Cedar Grove the only types mnat renders these 17 Dewey rims unsertaoie to type. Two that use these patterns are Foster...i’auconte) ) 0-H) extent of .ts distribution before contact. It was used in California (Ross 1940; Heizer and Treganza 1944). It aiso occurred in

Quantitative study of flavonoids in leaves of citrus plants.

Science.gov (United States)

Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M; Koizumi, M; Ito, C; Furukawa, H

2000-09-01

Leaf flavonoids were quantitatively determined in 68 representative or economically important Citrus species, cultivars, and near-Citrus relatives. Contents of 23 flavonoids including 6 polymethoxylated flavones were analyzed by means of reversed phase HPLC analysis. Principal component analysis revealed that the 7 associations according to Tanaka's classification were observed, but some do overlap each other. Group VII species could be divided into two different subgroups, namely, the first-10-species class and the last-19-species class according to Tanaka's classification numbers.

Induction of apoptosis by Citrus paradisi essential oil in human leukemic (HL-60) cells.

Science.gov (United States)

Hata, Tomona; Sakaguchi, Ikuyo; Mori, Masahiro; Ikeda, Norikazu; Kato, Yoshiko; Minamino, Miki; Watabe, Kazuhito

2003-01-01

Limonene is a primary component of citrus essential oils (EOs) and has been reported to induce apoptosis on tumor cells. Little is known about induction of apoptosis by citrus EOs. In this study, we examined induction of apoptosis by Citrus aurantium var. dulcis (sweet orange) EO, Citrus paradisi (grapefruit) EO and Citrus limon (lemon) EO. These EOs induced apoptosis in HL-60 cells and the apoptosis activities were related to the limonene content of the EOs. Moreover, sweet orange EO and grapefruit EO may contain components besides limonene that have apoptotic activity. To identify the components with apoptotic activity, grapefruit EO was fractionated using silica gel columns, and the components were analyzed by GC-MS. The n-hexane fraction contained limonene, and the dichloromethane fraction (DF) contained aldehyde compounds and nootkatone. Decanal, octanal and citral in the DF showed strong apoptotic activity, suggesting that the aldehyde compounds induced apoptosis strongly in HL-60 cells.

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...

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

Quantification of Xylella fastidiosa from Citrus Trees by Real-Time Polymerase Chain Reaction Assay.

Science.gov (United States)

Oliveira, Antonio C; Vallim, Marcelo A; Semighini, Camile P; Araújo, Welington L; Goldman, Gustavo H; Machado, Marcos A

2002-10-01

ABSTRACT Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC), a destructive disease of sweet orange cultivars in Brazil. Polymerase chain reaction (PCR)-based assays constitute the principal diagnostic method for detection of these bacteria. In this work, we established a real-time quantitative PCR (QPCR) assay to quantify X. fastidiosa in naturally and artificially infected citrus. The X. fastidiosa cell number detected in the leaves increased according to the age of the leaf, and bacteria were not detected in the upper midrib section in young leaves, indicating temporal and spatial distribution patterns of bacteria, respectively. In addition, the X. fastidiosa cell number quantified in leaves of 'Pera' orange and 'Murcott' tangor reflected the susceptible and resistant status of these citrus cultivars. None of the 12 endophytic citrus bacteria or the four strains of X. fastidiosa nonpathogenic to citrus that were tested showed an increase in the fluorescence signal during QPCR. In contrast, all 10 CVC-causing strains exhibited an increase in fluorescence signal, thus indicating the specificity of this QPCR assay. Our QPCR provides a powerful tool for studies of different aspects of the Xylella-citrus interactions, and can be incorporated into breeding programs in order to select CVC-resistant plants more quickly.

Space-time variability of citrus leprosis as strategic planning for crop management.

Science.gov (United States)

Andrade, Daniel J; Lorençon, José R; Siqueira, Diego S; Novelli, Valdenice M; Bassanezi, Renato B

2018-01-31

Citrus leprosis is the most important viral disease of citrus. Knowledge of its spatiotemporal structure is fundamental to a representative sampling plan focused on the disease control approach. Such a well-crafted sampling design helps to reduce pesticide use in agriculture to control pests and diseases. Despite the use of acaricides to control citrus leprosis vector (Brevipalpus spp.) populations, the disease has spread rapidly through experimental areas. Citrus leprosis has an aggregate spatial distribution, with high dependence among symptomatic plants. Temporal variation in disease incidence increased among symptomatic plants by 4% per month. Use of acaricides alone to control the vector of leprosis is insufficient to avoid its incidence in healthy plants. Preliminary investigation into the time and space variation in the incidence of the disease is fundamental to select a sampling plan and determine effective strategies for disease management. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Citrus sinensis annotation project (CAP): a comprehensive database for sweet orange genome.

Science.gov (United States)

Wang, Jia; Chen, Dijun; Lei, Yang; Chang, Ji-Wei; Hao, Bao-Hai; Xing, Feng; Li, Sen; Xu, Qiang; Deng, Xiu-Xin; Chen, Ling-Ling

2014-01-01

Citrus is one of the most important and widely grown fruit crop with global production ranking firstly among all the fruit crops in the world. Sweet orange accounts for more than half of the Citrus production both in fresh fruit and processed juice. We have sequenced the draft genome of a double-haploid sweet orange (C. sinensis cv. Valencia), and constructed the Citrus sinensis annotation project (CAP) to store and visualize the sequenced genomic and transcriptome data. CAP provides GBrowse-based organization of sweet orange genomic data, which integrates ab initio gene prediction, EST, RNA-seq and RNA-paired end tag (RNA-PET) evidence-based gene annotation. Furthermore, we provide a user-friendly web interface to show the predicted protein-protein interactions (PPIs) and metabolic pathways in sweet orange. CAP provides comprehensive information beneficial to the researchers of sweet orange and other woody plants, which is freely available at http://citrus.hzau.edu.cn/.

Distribution and quantification of Candidatus Liberibacter americanus, agent of huanglongbing disease of citrus in São Paulo State, Brasil, in leaves of an affected sweet orange tree as determined by PCR.

Science.gov (United States)

Teixeira, Diva C; Saillard, Colette; Couture, Carole; Martins, Elaine C; Wulff, Nelson A; Eveillard-Jagoueix, Sandrine; Yamamoto, Pedro T; Ayres, Antonio J; Bové, Joseph M

2008-06-01

Huanglongbing (HLB), an insect-transmitted disease of citrus, known for many years in Asia and Africa, has appeared in the state of São Paulo State (SSP), Brazil, in 2004, and the state of Florida, USA, in 2005. HLB endangers the very existence of citrus, as trees infected with the bacterial pathogen, irrevocably decline. In the absence of curative procedures, control of HLB is difficult and only based on prevention. Even though not available in culture, the HLB bacterium could be shown to be Gram-negative and to represent a new candidate genus, Candidatus Liberibacter, in the alpha subdivision of the Proteobacteria. Three Candidatus (Ca.) L. species occur: Ca. L. africanus in Africa, Ca. L. asiaticus in Asia, SSP, and Florida, and Ca. L. americanus in SSP. The liberibacters occur exclusively in the phloem sieve tubes. On affected trees, HLB symptoms are often seen on certain branches only, suggesting an uneven distribution of the Liberibacter. Occurrence of Ca. L. americanus, the major HLB agent in SSP, has been examined in 822 leaf samples from an affected sweet orange tree by two conventional PCR techniques and a newly developed real time (RTi) PCR, also used for quantification of the Liberibacter in the leaves. Even though RTi-PCR was able to detect as few as 10 liberibacters per gram of leaf tissue (l/g), no liberibacters could be detected in any of the many leaf samples from a symptomless branch, while in blotchy mottle leaves from symptomatic branches of the same tree, the Liberibacter titer reached values as high as 10(7)l/g. These results demonstrate the uneven distribution of the Liberibacter in HLB-affected trees.

Male Gametophytic Screening of Citrus Genotypes for Salt Stress Tolerance

Directory of Open Access Journals (Sweden)

A. Barandan

2016-07-01

Full Text Available Citrus species are classified as a sensitive group of trees to salt stress, but the levels of their sensitivity or tolerance to salt are different among cultivars. In order to evaluate the effects of salinity stress on pollen germination of some citrus cultivars, an experiment was performed in factorial, based on completely randomized design in three replications with Cleopatra mandarin (Citrus reshni and Poncirus trifoliata as tolerant and sensitive controls along with 13 genotypes. Pollen grains of these genotypes were cultured in media containing different levels of sodium chloride (0, 0.87, 1.6, 2.4, 3.1 dS/m along with 15% sucrose, 0.7% agar and 100 mg/L boric acid. In order to understand the biochemical responses of pollen grains to salt stress, they were cultured in liquid media with three levels of salinity (i.e. 0, 0.87 and 1.6 dS/m and then the amounts of total protein and enzyme activities of superoxide dismutase (SOD and ascorbate peroxidase (APX were evaluated. Significant differences of pollen germination (P ≤ 0.01 were observed in different salinity levels, but there were no significant differences in pollen tube growth. Pollen germination in Cleopatra was greater in comparison to Poncirus trifoliate, indicating that Cleopatra is a tolerant cultivar. The amounts of total protein and enzyme activities of SOD and APX were influenced by genotypes, salinity levels and their interactions (P ≤ 0.01. Considering the fastness and accuracy of this type of experiment, the evaluation of citrus pollen responses may, potentially, be hired as an initial screening criteria for detecting salt-sensitive varieties from the tolerant citrus ones.

Identification and Molecular Characterization of Nuclear Citrus leprosis virus, a Member of the Proposed Dichorhavirus Genus Infecting Multiple Citrus Species in Mexico.

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Roy, Avijit; Stone, Andrew L; Shao, Jonathan; Otero-Colina, Gabriel; Wei, Gang; Choudhary, Nandlal; Achor, Diann; Levy, Laurene; Nakhla, Mark K; Hartung, John S; Schneider, William L; Brlansky, Ronald H

2015-04-01

Citrus leprosis is one of the most destructive diseases of Citrus spp. and is associated with two unrelated virus groups that produce particles primarily in either the cytoplasm or nucleus of infected plant cells. Symptoms of leprosis, including chlorotic spots surrounded by yellow haloes on leaves and necrotic spots on twigs and fruit, were observed on leprosis-affected mandarin and navel sweet orange trees in the state of Querétaro, Mexico. Serological and molecular assays showed that the cytoplasmic types of Citrus leprosis virus (CiLV-C) often associated with leprosis symptomatic tissues were absent. However, using transmission electron microscopy, bullet-shaped rhabdovirus-like virions were observed in the nuclei and cytoplasm of the citrus leprosis-infected leaf tissues. An analysis of small RNA populations from symptomatic tissue was carried out to determine the genome sequence of the rhabdovirus-like particles observed in the citrus leprosis samples. The complete genome sequence showed that the nuclear type of CiLV (CiLV-N) present in the samples consisted of two negative-sense RNAs: 6,268-nucleotide (nt)-long RNA1 and 5,847-nt-long RNA2, excluding the poly(A) tails. CiLV-N had a genome organization identical to that of Orchid fleck virus (OFV), with the exception of shorter 5' untranslated regions in RNA1 (53 versus 205 nt) and RNA2 (34 versus 182 nt). Phylogenetic trees constructed with the amino acid sequences of the nucleocapsid (N) and glycoproteins (G) and the RNA polymerase (L protein) showed that CiLV-N clusters with OFV. Furthermore, phylogenetic analyses of N protein established CiLV-N as a member of the proposed genus Dichorhavirus. Reverse-transcription polymerase chain reaction primers for the detection of CiLV-N were designed based on the sequence of the N gene and the assay was optimized and tested to detect the presence of CiLV-N in both diseased and symptom-free plants.

Energy requirement and economic analysis of citrus production in Turkey

Energy Technology Data Exchange (ETDEWEB)

Ozkan, Burhan E-mail: bozkan@akdeniz.edu.tr; Akcaoz, Handan; Karadeniz, Feyza

2004-07-01

The aim of this research was to examine the energy requirements of the inputs and output in citrus production in the Antalya province of Turkey. Data for the production of citrus fruits (orange, lemon and mandarin) were collected from 105 citrus farms by using a face to face questionnaire method. The research results revealed that lemon production was the most energy intensive among the three fruits investigated. The energy input of chemical fertilizer (49.68%), mainly nitrogen, has the biggest share in the total energy inputs followed by Diesel (30.79%). The lemon production consumed a total of 62 977.87 MJ/ha followed by orange and mandarin with 60 949.69 and 48 838.17 MJ/ha, respectively. The energy ratios for orange, mandarin and lemon were estimated to be 1.25, 1.17 and 1.06, respectively. On average, the non-renewable form of energy input was 95.90% of the total energy input used in citrus production compared to only 3.74% for the renewable form. The benefit-cost ratio was the highest in orange production (2.37) followed by lemon. The results indicate that orange production in the research area is most remunerative to growers compared to lemon and mandarin.

Within-orchard edge effects of the azimuth of the sun on Diaphorina citri adults in mature orchards

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Huanglongbing (HLB) has been considered the most devastating disease of citrus. The bacterium and vector associated with HLB in Florida are ‘Candidatus Liberibacter asiaticus’ and Diaphorina citri (Asian citrus psyllid), respectively. D. citri is positively phototropic, and higher populations have b...

Genome-wide comparative analysis reveals similar types of NBS genes in hybrid Citrus sinensis genome and original Citrus clementine genome and provides new insights into non-TIR NBS genes

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In this study, we identified and compared nucleotide-binding site (NBS) domain-containing genes from three Citrus genomes (C. clementina, C. sinensis from USA and C. sinensis from China). Phylogenetic analysis of all Citrus NBS genes across these three genomes revealed that there are three approxima...

Quantifying runoff water quality characteristics from nurseries and avocado groves subjected to altered irrigation and fertilizer regimes

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Samant, S. A.; Beighley, R. E.

2007-12-01

In agriculture, improper, excessive or poorly timed irrigation and fertilizer applications can result in increased pollutants in runoff and degraded water quality. Specifically, the cultivation of salt sensitive plants and nurseries require significant irrigation and fertilizer that leads to high nutrient leaching. In southern California, a large producer of Avocados and nursery plant, waterways are often subjected to elevated nutrient concentrations, which stress the aquatic ecosystem. In this research, the specific objectives are to determine optimal irrigation and fertilizer application rates for minimizing nutrient and sediment export from avocado groves and nurseries. Altered irrigation and fertilizer application experiments will be implemented and monitored at the San Diego State University's Santa Margarita Ecological Reserve, which contains a 12 ha avocado grove and newly constructed 0.4 ha nursery. The study will last for twelve months, with runoff from natural rainfall or irrigation sampled and analyzed for nutrient concentrations on a monthly basis. The growth rate, leaf nutrient content and plant yield will also be monitored monthly. The nursery site is divided into eight plots (13.5-m x 13.5-m), with each plot containing 1200 plants consisting of four commonly used landscaping varieties in southern California. The avocado grove of the Hass variety is divided into four 1-ha plots. The experimental plots represent combinations of irrigation and fertilization practices with different methods and rates. In all cases, irrigation is fully automated based on soil moisture. To assess the effectiveness of the altered irrigation and fertilizer strategies, runoff water quality and plant yield will be compared to controlled treatments. This research is intended to provide a better understanding of how irrigation and fertilizer management can be used for the long-term reduction of nutrients in the Santa Margarita Watershed, which in turn will lead to improved

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%.

Ant exclusion in citrus over an 8-year period reveals a pervasive yet changing effect of ants on a Mediterranean spider assemblage.

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Mestre, L; Piñol, J; Barrientos, J A; Espadaler, X

2013-09-01

Ants and spiders are ubiquitous generalist predators that exert top-down control on herbivore populations. Research shows that intraguild interactions between ants and spiders can negatively affect spider populations, but there is a lack of long-term research documenting the strength of such interactions and the potentially different effects of ants on the diverse array of species in a spider assemblage. Similarly, the suitability of family-level surrogates for finding patterns revealed by species-level data (taxonomic sufficiency) has almost never been tested in spider assemblages. We present a long-term study in which we tested the impact of ants on the spider assemblage of a Mediterranean citrus grove by performing sequential 1-year experimental exclusions on tree canopies for 8 years. We found that ants had a widespread influence on the spider assemblage, although the effect was only evident in the last 5 years of the study. During those years, ants negatively affected many spiders, and effects were especially strong for sedentary spiders. Analyses at the family level also detected assemblage differences between treatments, but they concealed the different responses to ant exclusion shown by some related spider species. Our findings show that the effects of experimental manipulations in ecology can vary greatly over time and highlight the need for long-term studies to document species interactions.

Efficacy of an autodisseminator of an entomopathogenic fungus, Isaria fumosorosea, to suppress Asian citrus psyllid, Diaphorina citri, under greenhouse conditions

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The Asian citrus psyllid (ACP), transmits the causative agents of citrus greening disease or huanglongbing (HLB), the most devastating disease of citrus trees in the world today. ACP dwelling in noncommercial citrus (neighborhoods, commercial landscapes, etc.) can stymie area-wide management program...

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis fruits in Vietnam.

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Ivana Puglisi

Full Text Available Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis, a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana rootstocks grafted with 'King' mandarin (Citrus nobilis and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi, sweet orange (Citrus x sinensis and bergamot (Citrus x bergamia as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata. This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam.

Science.gov (United States)

Puglisi, Ivana; De Patrizio, Alessandro; Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano; Cacciola, Santa Olga

2017-01-01

Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with 'King' mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

Citrus plant nutritional profile in relation to huanglongbing prevalence in Pakistan

International Nuclear Information System (INIS)

Razi, M.F.U.D.; Khan, I.A.; Jaskani, M.J.

2011-01-01

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)

Comparative evaluation of 12 immature citrus fruit extracts for the inhibition of cytochrome P450 isoform activities.

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Fujita, Tadashi; Kawase, Atsushi; Niwa, Toshiro; Tomohiro, Norimichi; Masuda, Megumi; Matsuda, Hideaki; Iwaki, Masahiro

2008-05-01

In a previous study we found that 50% ethanol extracts of immature fruits of Citrus unshiu (satsuma mandarin) have anti-allergic effects against the Type I, II and IV allergic reactions. However, many adverse interactions between citrus fruit, especially grapefruit juice, and drugs have been reported due to the inhibition of cytochrome P450 (CYP) activities. The purpose of this study was to examine the competitive inhibitory effects of extracts from immature citrus fruit on CYP activity. Extracts were prepared from 12 citrus species or cultivars, and were tested against three kinds of major CYPs, CYP2C9, CYP2D6 and CYP3A4, in human liver microsomes. We also estimated the amounts of flavonoids (narirutin, hesperidin, naringin and neohesperidin) and furanocoumarins (bergapten, 6',7'-dihydroxybergamottin and bergamottin) in each extract using HPLC. Citrus paradisi (grapefruit) showed the greatest inhibition of CYP activities, while Citrus unshiu which has an antiallergic effect, showed relatively weak inhibitory effects. Extracts having relatively strong inhibitory effects for CYP3A4 tended to contain higher amounts of naringin, bergamottin and 6',7'-dihydroxybergamottin. These results, providing comparative information on the inhibitory effects of citrus extracts on CYP isoforms, suggest that citrus extracts containing high levels of narirutin and hesperidin and lower levels of furanocoumarins such as C. unshiu are favorable as antiallergic functional ingredients.

High Resolution Forecasts in the Florida Straits: Predicting the Modulations of the Florida Current and Connectivity Around South Florida and Cuba

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Kourafalou, V.; Kang, H.; Perlin, N.; Le Henaff, M.; Lamkin, J. T.

2016-02-01

Connectivity around the South Florida coastal regions and between South Florida and Cuba are largely influenced by a) local coastal processes and b) circulation in the Florida Straits, which is controlled by the larger scale Florida Current variability. Prediction of the physical connectivity is a necessary component for several activities that require ocean forecasts, such as oil spills, fisheries research, search and rescue. This requires a predictive system that can accommodate the intense coastal to offshore interactions and the linkages to the complex regional circulation. The Florida Straits, South Florida and Florida Keys Hybrid Coordinate Ocean Model is such a regional ocean predictive system, covering a large area over the Florida Straits and the adjacent land areas, representing both coastal and oceanic processes. The real-time ocean forecast system is high resolution ( 900m), embedded in larger scale predictive models. It includes detailed coastal bathymetry, high resolution/high frequency atmospheric forcing and provides 7-day forecasts, updated daily (see: http://coastalmodeling.rsmas.miami.edu/). The unprecedented high resolution and coastal details of this system provide value added on global forecasts through downscaling and allow a variety of applications. Examples will be presented, focusing on the period of a 2015 fisheries cruise around the coastal areas of Cuba, where model predictions helped guide the measurements on biophysical connectivity, under intense variability of the mesoscale eddy field and subsequent Florida Current meandering.

First Record of Diaphorina citri (Hemiptera: Psyllidae) in Ecuador Infesting Urban Citrus and Orange Jasmine Trees

Science.gov (United States)

Cornejo, J.F.; Chica, E.J.

2014-01-01

Abstract Adults and nymphs of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), were collected in the Guayaquil, Samborondón, and Durán cantons in coastal Ecuador. Psyllids were found in high numbers in citrus ( Citrus spp., Sapindales: Rutaceae) and orange jasmine ( Murraya exotica [L.] Jack, Sapindales: Rutaceae) trees within the Guayaquil-Samborondon-Duran conurbation; however, none was found during scoutings in the main citrus producing areas in coastal Ecuador. To the best of our knowledge, this is the first report of D. citri in Ecuador and the Pacific coastal plain of South America. PMID:25527601

Involvement of an ethylene response factor in chlorophyll degradation during citrus fruit degreening

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Chlorophyll degradation naturally occurs during plant senescence. However, in fruit such as citrus, it is a positive characteristic, as degreening is an important colour development contributing to fruit quality. In the present work, Citrus sinensis Osbeck, cv. Newhall fruit was used as a model for ...

Relationships between mycorrhizas and antioxidant enzymes in citrus (citrus tangerina) seedlings inoculated with glomus mosseae

International Nuclear Information System (INIS)

Liu, C.Y.; Wu, Q.S.

2014-01-01

A potted experiment was conducted to evaluate the effects of an arbuscular mycorrhizal fungus (AMF), Glomus mosseae, on growth performance and superoxide dismutase (SOD) and catalase (CAT) activities of citrus (Citrus tangerina) seedlings. After five months of AMF inoculation, mycorrhizal colonization and vesicles, but not arbuscules and entry points, increased with the increase of inoculated mycorrhizal dosages among 5-40 g (32 spores/g dosage). Mycorrhizal inoculation with 10-40 g dosages significantly increased plant growth traits, including plant height, stem diameter, and shoot, root and total fresh weights. Higher leaf chlorophyll content was found in all the mycorrhizal plants, compared with the non-mycorrhizal plants. Inoculation with G. mosseae markedly decreased SOD and CAT activities of leaf and root, except an increase of either root CAT with the 20 g mycorrhizal treatment or root SOD with the 20 and 40 g mycorrhizal treatments. In addition, mycorrhizal colonization and vesicles significantly positively correlated with root SOD and without root CAT. We also discussed the relationships between mycorrhizal effects on antioxidant enzymes and growth environment of host plants. (author)

Founder lines for improved citrus biotechnology

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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...

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.

Behavioral assays for evaluating host preferences of Euwallacea nr. fornicatus (Coleoptera: Curculionidae: Scolytinae).

Science.gov (United States)

In 2010, the exotic ambrosia beetle, Euwallacea nr. fornicatus Eichhoff (Coleoptera: Curculionidae: Scolytinae) was first discovered in Florida avocado groves. Introduction of its symbiotic Fusarium spp. fungi into galleries in the xylem tissue results in Fusarium-dieback disease. Unlike most ambros...

Etiology of three recent diseases of citrus in São Paulo State: sudden death, variegated chlorosis and huanglongbing.

Science.gov (United States)

Bové, Joseph Marie; Ayres, Antonio Juliano

2007-01-01

, citrus variegated chlorosis (CVC), was observed in 1987 in the Triangulo Mineiro of Minas Gerais State and the northern and north-eastern parts of SSP. By 2000, the disease affected already 34% of the 200 million sweet orange trees in SSP. By 2005, the percentage had increased to 43%, and CVC was present in all citrus growing regions of Brazil. Electron microscopy showed that xylem-limited bacteria were present in all symptomatic sweet orange leaves and fruit tissues tested, but not in similar materials from healthy, symptomless trees. Bacteria were consistently cultured from twigs of CVC-affected sweet orange trees but not from twigs of healthy trees. Serological analyses showed the CVC bacterium to be a strain of Xylella fastidiosa. The disease could be reproduced and Koch's postulates fulfilled, by mechanically inoculating a pure culture of X. fastidiosa isolate 8.1.b into sweet orange seedlings. The genome of a CVC strain of X. fastidiosa was sequenced in SSP in the frame of a project supported by FAPESP and Fundecitrus. X. fastidiosa is the first plant pathogenic bacterium, the genome of which has been sequenced. Until recently, America was free of huanglongbing (HLB), but in March 2004 and August 2005, symptoms of the disease were recognized, respectively in the State of São Paulo (SSP) and in Florida, USA. HLB was known in China since 1870 and in South Africa since 1928. Because of its destructiveness and its rapid spread by efficient psyllid insect-vectors, HLB is probably the most serious citrus disease. HLB is caused by a phloem sieve tube-restricted Gram negative bacterium, not yet available in culture. In the 1990s, the bacterium was characterized by molecular techniques as a member of the alpha proteobacteria designated Candidatus Liberibacter africanus for the disease in Africa, and Candidatus Liberibacter asiaticus for HLB in Asia. In SSP, Ca. L. asiaticus is also present, but most of the trees are infected with a new species, Candidatus Liberibacter

Improving eye safety in citrus harvest crews through the acceptance of personal protective equipment, community-based participatory research, social marketing, and community health workers.

Science.gov (United States)

Tovar-Aguilar, J Antonio; Monaghan, Paul F; Bryant, Carol A; Esposito, Andrew; Wade, Mark; Ruiz, Omar; McDermott, Robert J

2014-01-01

For the last 10 years, the Partnership for Citrus Workers Health (PCWH) has been an evidence-based intervention program that promotes the adoption of protective eye safety equipment among Spanish-speaking farmworkers of Florida. At the root of this program is the systematic use of community-based preventive marketing (CBPM) and the training of community health workers (CHWs) among citrus harvester using popular education. CBPM is a model that combines the organizational system of community-based participatory research (CBPR) and the strategies of social marketing. This particular program relied on formative research data using a mixed-methods approach and a multilevel stakeholder analysis that allowed for rapid dissemination, effective increase of personal protective equipment (PPE) usage, and a subsequent impact on adoptive workers and companies. Focus groups, face-to-face interviews, surveys, participant observation, Greco-Latin square, and quasi-experimental tests were implemented. A 20-hour popular education training produced CHWs that translated results of the formative research to potential adopters and also provided first aid skills for eye injuries. Reduction of injuries is not limited to the use of safety glasses, but also to the adoption of timely intervention and regular eye hygiene. Limitations include adoption in only large companies, rapid decline of eye safety glasses without consistent intervention, technological limitations of glasses, and thorough cost-benefit analysis.

Response of sweet orange (Citrus sinensis) to 'Candidatus Liberibacter asiaticus' infection: microscopy and microarray analyses.

Science.gov (United States)

Kim, Jeong-Soon; Sagaram, Uma Shankar; Burns, Jacqueline K; Li, Jian-Liang; Wang, Nian

2009-01-01

Citrus greening or huanglongbing (HLB) is a devastating disease of citrus. HLB is associated with the phloem-limited fastidious prokaryotic alpha-proteobacterium 'Candidatus Liberibacter spp.' In this report, we used sweet orange (Citrus sinensis) leaf tissue infected with 'Ca. Liberibacter asiaticus' and compared this with healthy controls. Investigation of the host response was examined with citrus microarray hybridization based on 33,879 expressed sequence tag sequences from several citrus species and hybrids. The microarray analysis indicated that HLB infection significantly affected expression of 624 genes whose encoded proteins were categorized according to function. The categories included genes associated with sugar metabolism, plant defense, phytohormone, and cell wall metabolism, as well as 14 other gene categories. The anatomical analyses indicated that HLB bacterium infection caused phloem disruption, sucrose accumulation, and plugged sieve pores. The up-regulation of three key starch biosynthetic genes including ADP-glucose pyrophosphorylase, starch synthase, granule-bound starch synthase and starch debranching enzyme likely contributed to accumulation of starch in HLB-affected leaves. The HLB-associated phloem blockage resulted from the plugged sieve pores rather than the HLB bacterial aggregates since 'Ca. Liberibacter asiaticus' does not form aggregate in citrus. The up-regulation of pp2 gene is related to callose deposition to plug the sieve pores in HLB-affected plants.

Potentiometric Surface of the Upper Floridan Aquifer, West-Central Florida, May 2006

Science.gov (United States)

Ortiz, A.G.

2007-01-01

-level data are collected in May and September each year to show the approximate annual low and high water-level conditions, respectively. Most of the water-level data for this map were collected by the U.S. Geological Survey during the period May 15-19, 2006. Supplemental water-level data were collected by other agencies and companies. A corresponding potentiometric-surface map was prepared for areas east and north of the Southwest Florida Water Management District boundary by the U.S. Geological Survey office in Altamonte Springs, Florida (Kinnaman, 2006). Most water-level measurements were made during a 5-day period; therefore, measurements do not represent a 'snapshot' of conditions at a specific time, nor do they necessarily coincide with the seasonal low water-level condition. Water-Level Changes Water levels in about 95 percent of the wells measured in May 2006 were lower than the May 2005 water levels (Ortiz and Blanchard, 2006). May 2006 water levels in 403 wells ranged from about 26 feet below to about 6 feet above May 2005 water levels (fig. 1). Significant water level declines occurred in eastern Manatee County, southwestern Polk County, southeastern Hillsborough County, and in all of Hardee County. The largest water level declines occurred in southwestern Hardee County. The largest water level rises occurred in south-central Pasco County, northeastern Levy County, northwestern Marion County, and along the gulf coast from Pasco County to Citrus County (fig. 1). Water levels in about 96 percent of the wells measured in May 2006 were lower than the September 2005 water levels (Ortiz, 2006). May 2006 water levels in 397 wells ranged from about 31 feet below to 3 feet above the September 2005 water levels. The largest water level decline was in west-central Hardee County and the largest rise in water levels was in south-central Pasco County.

Effects of soil-applied imidacloprid on Asian citrus psyllid (Hemiptera: Psyllidae) feeding behavior

Science.gov (United States)

The Asian citrus psyllid, Diaphorina citri Kuwayama is one of the most important pests of citrus due to its status as a vector of Candidatus Liberibacter asiaticus, the bacterium associated with huanglongbing (HLB) disease. The use of insecticides for vector control is the primary method of managing...

The Cottage Grove fault system (Illinois Basin): Late Paleozoic transpression along a Precambrian crustal boundary

Science.gov (United States)

Duchek, A.B.; McBride, J.H.; Nelson, W.J.; Leetaru, H.E.

2004-01-01

The Cottage Grove fault system in southern Illinois has long been interpreted as an intracratonic dextral strike-slip fault system. We investigated its structural geometry and kinematics in detail using (1) outcrop data, (2) extensive exposures in underground coal mines, (3) abundant borehole data, and (4) a network of industry seismic reflection profiles, including data reprocessed by us. Structural contour mapping delineates distinct monoclines, broad anticlines, and synclines that express Paleozoic-age deformation associated with strike slip along the fault system. As shown on seismic reflection profiles, prominent near-vertical faults that cut the entire Paleozoic section and basement-cover contact branch upward into outward-splaying, high-angle reverse faults. The master fault, sinuous along strike, is characterized along its length by an elongate anticline, ???3 km wide, that parallels the southern side of the master fault. These features signify that the overall kinematic regime was transpressional. Due to the absence of suitable piercing points, the amount of slip cannot be measured, but is constrained at less than 300 m near the ground surface. The Cottage Grove fault system apparently follows a Precambrian terrane boundary, as suggested by magnetic intensity data, the distribution of ultramafic igneous intrusions, and patterns of earthquake activity. The fault system was primarily active during the Alleghanian orogeny of Late Pennsylvanian and Early Permian time, when ultramatic igneous magma intruded along en echelon tensional fractures. ?? 2004 Geological Society of America.

Evaluation and public acceptance of irradiated strawberries and citrus fruits

International Nuclear Information System (INIS)

Del Mastro, Nelida L.; Kikuchi, Olivia K.; Villavicencio, Anna L.C.H.; Sabato, Susy F.; Rela, Paulo R.; Taipina, Magda S.; Mattiolo-Marchse, Sandra R.

1999-01-01

Irradiation is a physical process that can be applied to food in order to eliminate microorganisms, insects and other plagues as well as delay ripening or spoilage, thus lengthening its shelf life. In Brazil, the technique is only starting to be applied and is restricted to a few tons of dry or dehydrated food ingredients per year. Strawberry (Fragaria sp.) and citrus are usually attacked by various plagues. Both strawberry and citrus are included in the Brazilian legislation for irradiated foods. This work describes the first sensory trials of 2 varieties of strawberries and 3 varieties of citrus irradiated at IPEN. Irradiation was performed in a panoramic Co-60 source with doses ranging between 1.7 and 4 kGy. Untrained groups of panelists judged the quality of irradiated and non-irradiated control fruits. From the analysis of the results, it was concluded that there no significant differences in the characteristical properties of the fruits when they were irradiated with the doses recommended by the legislation. (author)

Selection processes in a citrus hybrid population using RAPD markers

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Oliveira Roberto Pedroso de

2003-01-01

Full Text Available The objective of this work was to evaluate the processes of selection in a citrus hybrid population using segregation analysis of RAPD markers. The segregation of 123 RAPD markers between 'Cravo' mandarin (Citrus reticulata Blanco and 'Pêra' sweet orange (C. sinensis (L. Osbeck was analysed in a F1 progeny of 94 hybrids. Genetic composition, diversity, heterozygosity, differences in chromosomal structure and the presence of deleterious recessive genes are discussed based on the segregation ratios obtained. A high percentage of markers had a skeweness of the 1:1 expected segregation ratio in the F1 population. Many markers showed a 3:1 segregation ratio in both varieties and 1:3 in 'Pêra' sweet orange, probably due to directional selection processes. The distribution analysis of the frequencies of the segregant markers in a hybrid population is a simple method which allows a better understanding of the genetics of citrus group.

Differential expression of genes of Xylella fastidiosa in xylem fluid of citrus and grapevine.

Science.gov (United States)

Shi, Xiangyang; Bi, Jianlong; Morse, Joseph G; Toscano, Nick C; Cooksey, Donald A

2010-03-01

Xylella fastidiosa causes a serious Pierce's disease (PD) in grapevine. Xylella fastidiosa cells from a PD strain were grown in a pure xylem fluid of a susceptible grapevine cultivar vs. xylem fluid from citrus, which is not a host for this strain of X. fastidiosa. When grown in grapevine xylem fluid, cells of the PD strain formed clumps and biofilm formed to a greater extent than in citrus xylem fluid, although the PD strain did grow in xylem fluid of three citrus varieties. The differential expression of selected genes of a PD X. fastidiosa strain cultured in the two xylem fluids was analyzed using a DNA macroarray. Compared with citrus xylem fluid, grapevine xylem fluid stimulated the expression of X. fastidiosa genes involved in virulence regulation, such as gacA, algU, xrvA, and hsq, and also genes involved in the biogenesis of pili and twitching motility, such as fimT, pilI, pilU, and pilY1. Increased gene expression likely contributes to PD expression in grapevine, whereas citrus xylem fluid did not support or possibly suppressed the expression of these virulence genes.

Expression of Arabidopsis Hexokinase in Citrus Guard Cells Controls Stomatal Aperture and Reduces Transpiration.

Science.gov (United States)

Lugassi, Nitsan; Kelly, Gilor; Fidel, Lena; Yaniv, Yossi; Attia, Ziv; Levi, Asher; Alchanatis, Victor; Moshelion, Menachem; Raveh, Eran; Carmi, Nir; Granot, David

2015-01-01

Hexokinase (HXK) is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (AtHXK1) under KST1, a guard cell-specific promoter. The expression of KST1 in the guard cells of citrus plants has been verified using GFP as a reporter gene. The expression of AtHXK1 in the guard cells of citrus reduced stomatal conductance and transpiration with no negative effect on the rate of photosynthesis, leading to increased water-use efficiency. The effects of light intensity and humidity on stomatal behavior were examined in rooted leaves of the citrus plants. The optimal intensity of photosynthetically active radiation and lower humidity enhanced stomatal closure of AtHXK1-expressing leaves, supporting the role of sugar in the regulation of citrus stomata. These results suggest that HXK coordinates photosynthesis and transpiration and stimulates stomatal closure not only in annual species, but also in perennial species.

Comparative transcriptome analysis unveils the tolerance mechanisms of Citrus hystrix in response to 'Candidatus Liberibacter asiaticus' infection.

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Yan Hu

Full Text Available Citrus Huanglongbing (HLB, a highly devastating citrus disease, is associated with 'Candidatus Liberibacter asiacitus' (CLas, a member of phloem-inhabiting α-proteobacteria. HLB can affect all cultivated citrus and no cure is currently available. Previous studies showed that Kaffir lime (Citrus hystrix, primarily grown in South Asia and Southeast Asia, was tolerant to HLB but the molecular mechanism remains unknown. In this study, gene expression profiling experiments were performed on HLB-tolerant C. hystrix and HLB-susceptible C. sinensis three months after inoculation with CLas using RNA-seq data. Differentially expressed genes (DEGs in the two citrus cultivars were mainly involved in diverse cellular functions including carbohydrate metabolism, photosynthesis, cell wall metabolism, secondary metabolism, hormone metabolism and oxidation/reduction processes. Notably, starch synthesis and photosynthesis process were not disturbed in CLas-infected C. hystrix. Most of the DEGs involved in cell wall metabolism and secondary metabolism were up-regulated in C. hystrix. In addition, the activation of peroxidases, Cu/Zn-SOD and POD4, may also enhance the tolerance of C. hystrix to CLas. This study provides an insight into the host response of HLB-tolerant citrus cultivar to CLas. C. hystrix is potentially useful for HLB-tolerant/resistant citrus breeding in the future.

The Evolutionary History and Spatiotemporal Dynamics of the NC Lineage of Citrus Tristeza Virus

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María José Benítez-Galeano

2017-10-01

Full Text Available Citrus tristeza virus (CTV is a major pathogen affecting citrus trees worldwide. However, few studies have focused on CTV’s evolutionary history and geographic behavior. CTV is locally dispersed by an aphid vector and long distance dispersion due to transportation of contaminated material. With the aim to delve deeper into the CTV-NC (New Clade genotype evolution, we estimated an evolution rate of 1.19 × 10−3 subs/site/year and the most common recent ancestor in 1977. Furthermore, the place of origin of the genotype was in the United States, and a great expansion of the population was observed in Uruguay. This expansion phase could be a consequence of the increment in the number of naïve citrus trees in Uruguayan orchards encompassing citrus industry growth in the past years.

Test Excavations at the Cedar Grove Site (3LA97): A Late Caddo Farmstead on the Red River.

Science.gov (United States)

1982-09-01

trees around Maya Lake, just eastward of the Cedar Grove site (Figure 3). There appears to be some lcorrelation in this region between floodplain prairies...Press, New York. Davis, E. Mott 1970 Archaeological and historical assessment of the Red River Basin in Texas. In Archeological and historical... Archaeological Conference, Atlanta. 113 4 -- - - - - .. .. .- .. - . . . Webb, Clarence B. 1945 A second historic Caddo site at Natchitoches, Louisiana

CITRUS AS A COMPONENT OF THE MEDITERRANEAN DIET

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Amilcar Duarte

2016-12-01

Full Text Available Citrus are native to southeastern Asia, but are present in the Mediterranean basin for centuries. This group of species has reached great importance in some of the Mediterranean countries and, in the case of orange, mandarin and lemon trees, they found here soil and climatic conditions which allows them to achieve a high level of fruit quality, even better than in the regions where they came from. Citrus fruits are present in the diet of the peoples living on the Mediterranean basin, at least since the time of the Roman Empire. In the 20th century they became the main crop in various agricultural areas of the Mediterranean, playing an important role in the landscape, in the diet of the overall population, and also in international trade. They are present in the gardens of palaces and monasteries, but also in the courtyards and orchards of the poorest families. Their fruits are not only a refreshing dessert, but also a condiment, or even a major component of many dishes. Citrus fruits have well-documented nutritional and health benefits. They can actually help prevent and cure some diseases and, above all, they are essential in a balanced and tasty diet.

Functional Characterization of a Flavonoid Glycosyltransferase in Sweet Orange (Citrus sinensis).

Science.gov (United States)

Liu, Xiaogang; Lin, Cailing; Ma, Xiaodi; Tan, Yan; Wang, Jiuzhao; Zeng, Ming

2018-01-01

Fruits of sweet orange ( Citrus sinensis ), a popular commercial Citrus species, contain high concentrations of flavonoids beneficial to human health. These fruits predominantly accumulate O -glycosylated flavonoids, in which the disaccharides [neohesperidose (rhamnosyl-α-1,2-glucose) or rutinose (rhamnosyl-α-1,6-glucose)] are linked to the flavonoid aglycones through the 3- or 7-hydroxyl sites. The biotransformation of the flavonoid aglycones into O -rutinosides or O -neohesperidosides in the Citrus plants usually consists of two glycosylation reactions involving a series of uridine diphosphate-sugar dependent glycosyltransferases (UGTs). Although several genes encoding flavonoid UGTs have been functionally characterized in the Citrus plants, full elucidation of the flavonoid glycosylation process remains elusive. Based on the available genomic and transcriptome data, we isolated a UGT with a high expression level in the sweet orange fruits that possibly encodes a flavonoid glucosyltransferase and/or rhamnosyltransferase. Biochemical analyses revealed that a broad range of flavonoid substrates could be glucosylated at their 3- and/or 7-hydrogen sites by the recombinant enzyme, including hesperetin, naringenin, diosmetin, quercetin, and kaempferol. Furthermore, overexpression of the gene could significantly increase the accumulations of quercetin 7- O -rhamnoside, quercetin 7- O -glucoside, and kaempferol 7- O -glucoside, implying that the enzyme has flavonoid 7- O -glucosyltransferase and 7- O -rhamnosyltransferase activities in vivo .

Low glyphosate rates do not affect Citrus limonia (L.) Osbeck seedlings.

Science.gov (United States)

Gravena, Renan; Victoria Filho, Ricardo; Alves, Pedro Luis Ca; Mazzafera, Paulo; Gravena, Adriana R

2009-04-01

Glyphosate is used to control weeds in citrus orchards, and accidental spraying or wind drift onto the seedlings may cause growth arrest owing to metabolism disturbance. Two experiments were carried out to investigate the effect of non-lethal rates (0, 180, 360 and 720 g AI ha(-1)) of glyphosate on four-month-old 'Cravo' lime, Citrus limonia (L.) Osbeck, seedlings. Photosynthesis and the concentrations of shikimic acid, total free amino acids and phenolic acids were evaluated. Only transitory effects were observed in the contents of shikimate and total free amino acids. No visual effects were observed. The present study showed that glyphosate at non-lethal rates, which is very usual when accidental spraying or wind drift occurs in citrus orchard, did not cause severe metabolic damage in 'Cravo' lime seedlings. Copyright (c) 2009 Society of Chemical Industry.

Florida sinkhole index

OpenAIRE

Spencer, Steven; Lane, Ed.

1995-01-01

The following data were compiled from the Florida Sinkhole Research Institute data base. That database, which contains approximately 1900 sinkholes, is available from the Florida Geological Survey upon request. The data are arranged alphabetically by county. The first two digits of the identification number represents the county. These numbers correspond to the Florida Department of Transportation county numbering system. Following the county number are three numbers which represe...

Deciphering the bacterial microbiome in huanglongbing-affected citrus treated with thermotherapy and sulfonamide antibiotics

Science.gov (United States)

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 bacteria...

Inhibitory effects of crude extracts from several plants on postharvest pathogens of citrus

Science.gov (United States)

Gong, Mingfu; Guan, Qinlan; Xu, Shanshan

2018-04-01

China is one of the most important origin of citrus. Enormous economic losses was caused by fungal diseases in citrus harvest storage every year. The effective antimicrobial substances of garlic, ginger, celery and pepper were extracted by ethanol extraction and water extraction respectively. The inhibitory effects of the crude extract on Penicillium sp. caused fungal diseases in citrus harvest storage were also determined. The results showed that the extracts of garlic, ginger and celery had inhibitory effect on P. sp., but the extracts of pepper had no inhibitory effect on P. sp.. The garlic ethanol extracts had the best inhibitory effect on P. citrinum.

Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro.

Science.gov (United States)

Ivanović, Žarko; Perović, Tatjana; Popović, Tatjana; Blagojević, Jovana; Trkulja, Nenad; Hrnčić, Snježana

2017-02-01

Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin ( Citrus reticulata ) in Montenegro, using multilocus sequence analysis of gyrB , rpoD , and gap1 gene sequences. Gene sequences from a collection of 54 reference pathotype strains of P. syringae from the Plant Associated and Environmental Microbes Database (PAMDB) was used to establish a genetic relationship with our isolates obtained from mandarin. Phylogenetic analyses of gyrB , rpoD , and gap1 gene sequences showed that P. syringae pv. syringae causes citrus blast in mandarin in Montenegro, and belongs to genomospecies 1. Genetic homogeneity of isolates suggested that the Montenegrian population might be clonal which indicates a possible common source of infection. These findings may assist in further epidemiological studies of this pathogen and for determining mandarin breeding strategies for P. syringae control.

Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro

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Žarko Ivanović

2017-02-01

Full Text Available Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin (Citrus reticulata in Montenegro, using multilocus sequence analysis of gyrB, rpoD, and gap1 gene sequences. Gene sequences from a collection of 54 reference pathotype strains of P. syringae from the Plant Associated and Environmental Microbes Database (PAMDB was used to establish a genetic relationship with our isolates obtained from mandarin. Phylogenetic analyses of gyrB, rpoD, and gap1 gene sequences showed that P. syringae pv. syringae causes citrus blast in mandarin in Montenegro, and belongs to genomospecies 1. Genetic homogeneity of isolates suggested that the Montenegrian population might be clonal which indicates a possible common source of infection. These findings may assist in further epidemiological studies of this pathogen and for determining mandarin breeding strategies for P. syringae control.

Modeling the incidence of citrus canker in leaves of the sweet orange variety ‘Pera’

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Danielle da Silva Pompeu

2017-01-01

Full Text Available Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri, is one of the most important diseases of citrus. The use of resistant genotypes plays an important role in the management and control of the disease and is the most environmentally sustainable approach to disease control. Citrus canker incidence was recorded in an experiment on nine genotypes of the sweet orange variety ‘Pera’ grafted on four rootstocks. The experiment was started in 2010 and the incidence of citrus canker on the leaves was recorded on a quarterly basis. The incidence data from the experiment were analyzed using a zero-inflated Beta regression model (RBIZ, which is the appropriate method to describe data with large numbers of zeros. Based on the residual analysis, the data fit the model well. The discrete component of the explanatory variable, rootstock, was not significant as a factor affecting the onset of disease, in contrast with the continuous component, genotype, which was significant in explaining the incidence of citrus canker.

Investigation of the effects of irradiation for quarantine treatment purposes on food quality and hygiene in citrus fruits

International Nuclear Information System (INIS)

2010-01-01

Mediterranean fruit fly (Ceratitis capitata) is a major problem in citrus production sector in Turkey. In order to overcome this problem, required irradiation doses were investigated for the quarantine treatment for 'Yafa' orange (Citrus sinensis (L) Osb.), 'Star ruby' grapefruit (Citrus paradisi Macf.); 'Satsuma' tangerine (Citrus reticulata Blanco) in this project. Chemical, physical and microbiological properties of unirradiated and irradiated (0.5, 1.0 and 1.5 kGy) fruits were determined in terms of weight loss, water soluble dry matter, pH, titratable acidity, alcohol insoluble pectin, apparent color of fruits, reducing sugar, total carotenoid, flavonoid, vitamin C contents, sensory properties of fruits, total aerob mesophilic bacteria and total yeast and mould counts of fruits. Results showed that, 0.1 kGy gamma irradiation dose is sufficient for effective quarantine treatment against the Mediterranean fruit fly in citrus fruits, low dose irradiation (≤1.0 kGy) applications had no detrimental effects on citrus fruits' quality except tangerines, microbial load of fruits were seriously affected by irradiation at 1.0 kGy. In addition, under this work we noticed that, irradiated citrus fruits could be detected by using DNA comet analysis method.

Citrus pulp pellets as an additive for orange bagasse silage

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R. K. Grizotto

2017-03-01

Full Text Available This study evaluated the fermentation profile of orange bagasse ensiled with three levels of dry matter (DM using citrus pulp pellets as a moisture-absorbing additive. Thirty experimental silos (3 treatments, 5 storage times, 2 replicates were prepared using 25-liter plastic buckets containing orange bagasse and three levels of pelleted citrus pulp (0, 6% and 20% as additive. A completely randomized design with repeated measures over time was used. The periods of anaerobic storage were 3, 7, 14, 28 and 56 days. Natural orange bagasse contained 13.9% DM, which increased to 19.1% and 25.5% with the inclusion of 6% and 20% citrus pulp pellets, respectively. The apparent density was inversely correlated with DM content and a higher level of compaction (982 kg/m3 was observed in the mass ensiled with the lowest DM level (13.9%. Additionally, lower compaction (910 kg/m3 was found in the mass ensiled with the additive. The chemical composition of the mass ensiled with or without citrus pulp pellets did not differ significantly in terms of protein, ether extract, neutral detergent fiber, lignin or in vitro DM digestibility (P≥0.05, as expected. Thus, it was possible to analyze only the effect of the inclusion of citrus pulp pellets on the increase in DM content. The inclusion of 20% of the additive reduced (P<0.01 losses due to effluent (98% less and gas production (81% less compared to the control treatment at the end of the anaerobic storage period. In this treatment, a higher (P≤0.05 log number of lactic acid bacteria (4.61 log CFU/g was also observed compared to the other treatments, indicating that the increase in DM favored the growth of these bacteria. In addition, the low yeast count (about 1 log CFU/g sample and the pH below 4.0, which were probably due to the production of lactic and acetic acids, show that the orange bagasse is rich in fermentable soluble carbohydrates and is indicated for ensiling. In conclusion, orange bagasse can be

Endophytic and pathogenic Phyllosticta species, with reference to those associated with Citrus Black Spot

NARCIS (Netherlands)

Glienke, C.; Pereira, O.L.; Stringari, D.; Fabris, J.; Kava-Cordeiro, V.; Galli-Terasawa, L.; Cunnington, J.; Shivas, R.G.; Groenewald, J.Z.; Crous, P.W.

2011-01-01

We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and

100% citrus juice: Nutritional contribution, dietary benefits, and association with anthropometric measures.

Science.gov (United States)

Rampersaud, Gail C; Valim, M Filomena

2017-01-02

Citrus juices such as 100% orange (OJ) and grapefruit juice (GJ) are commonly consumed throughout the world. This review examines the contributions of OJ and GJ to nutrient intake, diet quality, and fruit intake, and supports citrus juices as nutrient-dense beverages. This review also explores the research examining associations between OJ and GJ intake and anthropometric measures. Citrus juices are excellent sources of vitamin C and contribute other key nutrients such as potassium, folate, magnesium, and vitamin A. OJ intake has been associated with better diet quality in children and adults. OJ intake has not been associated with adverse effects on weight or other body measures in observational studies in children and adults. In adults, some observational studies report more favorable body mass index or body measure parameters in OJ consumers compared to nonconsumers. Intervention studies in adults report no negative impacts of OJ or GJ consumption on anthropometric measures, although these measures were typically not the primary outcomes examined in the studies. Moderate consumption of citrus juices may provide meaningful nutritional and dietary benefits and do not appear to negatively impact body weight, body composition, or other anthropometric measures in children and adults.

Evidence for host plant preference by Iphiseiodes quadripilis (Acari: Phytoseiidae) on Citrus.

Science.gov (United States)

Villanueva, Raul T; Childers, Carl C

2006-01-01

In this study, we present field and laboratory evidence on the preference of Iphiseiodes quadripilis (Banks) for grapefruit (Citrus paradisi Macfadyen) leaves compared with sweet orange (Citrus sinensis (L.) Osbeck) leaves. This preference was confirmed in four orchards whether leaf samples were taken from either border trees of contiguous grapefruit or sweet orange or interior row trees with both citrus species in adjacent rows. Iphiseiodes quadripilis was most abundant in grapefruit trees in spite of the greater abundance of the Texas citrus mite, Eutetranychus banksi (McGregor) (Acari: Tetranychidae) in sweet orange trees. Similar preference responses were observed in laboratory tests using a Y-tube olfactometer whether I. quadripilis were collected from sweet orange or grapefruit. Iphiseiodes quadripilis collected from grapefruit trees showed significant preference for grapefruit over sweet orange leaves in contact choice tests using an arena of alternating leaf strips (12 mm long x 2 mm wide) of sweet orange and grapefruit. However, I. quadripilis collected from sweet orange trees did not show preference for either grapefruit or sweet orange leaves. Based on these results, grapefruit leaves foster some unknown factor or factors that retain I. quadripilis in greater numbers compared with sweet orange leaves.

Breeding, genetic and genomic of citrus for disease resistance

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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

Citrus Flavonoid Supplementation Improves Exercise Performance in Trained Athletes

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Elvera Overdevest, Jeroen A. Wouters, Kevin H.M. Wolfs, Job J.M. van Leeuwen, Sam Possemiers

2018-03-01

Full Text Available Previous studies have shown that polyphenol supplementation may be an effective strategy to improve exercise performance, due to their antioxidant character and ability to stimulate NO production. These properties may contribute to exercise performance, yet no conclusive research has been performed in exploring the direct effects of citrus flavonoids on human exercise performance. Therefore, the purpose of this study was to assess whether supplementation of a customized citrus flavonoid (CF extract for 4 weeks improves cycling time-trial performance in trained male athletes. In a double-blind, randomized, parallel study, 39 healthy, trained males were given a daily dose of either 500 mg of a customized citrus flavonoid extract (CF or a placebo for 4 weeks. Exercise performance was tested by means of a time-trial test on a cycle ergometer, during which participants had to generate as much power as possible for duration of 10 minutes. Absolute power output significantly increased with 14.9 ± 3.9 W after 4 weeks of CF supplementation, corresponding with a 5.0% increase, compared to 3.8 ± 3.2 W (1.3% increase in placebo (p < 0.05. In addition, oxygen consumption/power ratio significantly decreased in the CF group compared to placebo (p = 0.001, and a trend was found in the change in peak power output in CF (18.2 ± 23.2 W versus placebo (-28.4 ± 17.6 W; p = 0.116. The current study is the first convincing report that citrus flavonoid supplementation can improve exercise performance, as shown by a significant increase in power output during the exercise test.

Elemental composition changes in citrus affected by the CVC disease

International Nuclear Information System (INIS)

Nadai Fernandes de, A.A.; Tagliaferro, F.S.; Turra, C.; Franca de, E.J.; Bacchi, M.A.

2008-01-01

The citrus variegated chlorosis (CVC) disease results in serious economical losses for the Brazilian citriculture. The influence of CVC disease on the elemental composition of citrus plants was investigated. Leaves of sweet orange varieties Hamlin, Pera Rio and Valencia were collected from healthy and CVC-affected trees for chemical characterization by instrumental neutron activation analysis (INAA). Significant differences between healthy and CVC-affected leaves were identified for Ca, Ce, Co, Eu, Fe, K, La, Na, Nd, Rb, Sc and Sm. Rare earth elements presented consistently higher mass fractions in the healthy leaves. (author)

Effect of Irrigation on Within-Grove Distribution of Red Palm Weevil Rhynchophorous ferrugineus

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Y. Aldryhim

2003-01-01

Full Text Available The red palm weevil (RPW Rhynchophorous ferrugineus (Oliv. is the most important pest attacking date palm trees. The objective of this study was to determine the effect of drip and flood irrigation on the within-grove distribution of RPW. The current study was started with the first appearance of the infestation to almost disappearance of the infestation. Results showed that more infested trees were detected in plots with flood irrigation. The number of infested trees in these plots represented 89% of the total infested trees. This study suggested that irrigation management and soil moisture are key factors in the dispersion of the RPW infestation and could be used as one of the integrated pest management tools.

Effect of Citrus paradisi extract and juice on arterial pressure both in vitro and in vivo.

Science.gov (United States)

Díaz-Juárez, J A; Tenorio-López, F A; Zarco-Olvera, G; Valle-Mondragón, L Del; Torres-Narváez, J C; Pastelín-Hernández, G

2009-07-01

Citrus paradisi (grapefruit) consumption is considered as beneficial and it is popularly used for the treatment of a vast array of diseases, including hypertension. In the present study, the coronary vasodilator and hypotensive effects of Citrus paradisi peel extract were assessed in the Langendorff isolated and perfused heart model and in the heart and lung dog preparation. In both models, Citrus paradisi peel extract decreased coronary vascular resistance and mean arterial pressure when compared with control values (60 +/- 15 x 10(7) dyn s cm(-5) vs 100 +/- 10 x 10(7) dyn s cm(-5) and 90 mmHg vs 130 +/- 15 mmHg, respectively). These decreases in coronary vascular resistance and mean arterial pressure were blocked when isolated and perfused hearts and mongrel dogs were pre-treated with L-NAME. In humans, Citrus paradisi juice decreased diastolic arterial pressure and systolic arterial pressure both in normotensive and hypertensive subjects. Citrus paradisi juice produced a greater decrease in mean arterial pressure when compared with Citrus sinensis juice, cow milk and a vitamin C-supplemented beverage. However, more detailed studies are required to isolate, purify and evaluate the chemical compounds responsible for this pharmacological effect and to clarify its possible role for treating hypertension. Copyright 2009 John Wiley & Sons, Ltd.

Soil organic matter on citrus plantation in Eastern Spain

Science.gov (United States)

Cerdà, Artemi; Pereira, Paulo; Novara, Agata; Prosdocimi, Massimo

2015-04-01

Citrus plantations in Eastern Spain are the main crop and Valencia region is the largest world exporter. The traditional plantation are located on flood irrigated areas and the new plantation are located on slopes were drip irrigation is the source of the wetting. It has been demonstrate that the citrus plantations contribute to high erosion rates on slopes (Cerdà et al., 2009b) as it is usual on agriculture land (Cerdà et al., 2009a), but when organic farming is present the soil erosion is much lower (Cerdà and Jurgensen, 2008; Cerdà et al., 2009; Cerdà and Jurgensen, 2011). This is a worldwide phenomenon (Wu et al., 2007; Wu et al., 2011; Xu et al., 2010; Xu et al., 2012a; Xu et al., 2012b), which are a key factor of the high erosion rates in rural areas (García Orenes et al., 2009: García Orenes et al., 20010; García Orenes et al., 2012; Haregewyn et al., 2013; Zhao et al., 2013). The key factor of the contrasted response of soils to the rain in citrus is the organic matter cover. This is why the Soil Erosion and Degradation Research Team developed a survey to determine the soil erosion rates on citrus orchards under different managements. A hundred of samples were collected in a citrus plantation on slope under conventional management (Chemical management), one on organic farming, one on traditional flood irrigated organic farming and one on traditional chemical flooding farm. The organic farming soils were treated with 10000 Kg ha-1 of manure yearly. The results show that the mean soil organic matter content was 1.24 %, 3.54%, 5,43% and 2.1% respectively, which show a clear impact of organic farming in the recovery of the soil organic matter. meanwhile the on the slopes and the flood-irrigated soils are Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7- ENV-2013- supported this research. References Cerdà, A., Flanagan, D.C., le Bissonnais

Expression of Arabidopsis hexokinase in citrus guard cells controls stomatal aperture and reduces transpiration

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Nitsan eLugassi

2015-12-01

Full Text Available Hexokinase (HXK is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (AtHXK1 under KST1, a guard cell-specific promoter. The expression of KST1 in the guard cells of citrus plants has been verified using GFP as a reporter gene. The expression of AtHXK1 in the guard cells of citrus reduced stomatal conductance and transpiration with no negative effect on the rate of photosynthesis, leading to increased water-use efficiency. The effects of light intensity and humidity on stomatal behavior were examined in rooted leaves of the citrus plants. The optimal intensity of photosynthetically active radiation and lower humidity enhanced stomatal closure of AtHXK1-expressing leaves, supporting the role of sugar in the regulation of citrus stomata. These results suggest that HXK coordinates photosynthesis and transpiration and stimulates stomatal closure not only in annual species, but also in perennial species.

Sustainable Use of Pesticide Applications in Citrus: A Support Tool for Volume Rate Adjustment

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Cruz Garcerá

2017-06-01

Full Text Available Rational application of pesticides by properly adjusting the amount of product to the actual needs and specific conditions for application is a key factor for sustainable plant protection. However, current plant protection product (PPP labels registered for citrus in EU are usually expressed as concentration (%; rate/hl and/or as the maximum dose of product per unit of ground surface, without taking into account those conditions. In this work, the fundamentals of a support tool, called CitrusVol, developed to recommend mix volume rates in PPP applications in citrus orchards using airblast sprayers, are presented. This tool takes into consideration crop characteristics (geometry, leaf area density, pests, and product and application efficiency, and it is based on scientific data obtained previously regarding the minimum deposit required to achieve maximum efficacy, efficiency of airblast sprayers in citrus orchards, and characterization of the crop. The use of this tool in several commercial orchards allowed a reduction of the volume rate and the PPPs used in comparison with the commonly used by farmers of between 11% and 74%, with an average of 31%, without affecting the efficacy. CitrusVol is freely available on a website and in an app for smartphones.

Species composition and abundance of Brevipalpus spp. on different citrus species in Mexican orchards.

Science.gov (United States)

Salinas-Vargas, D; Santillán-Galicia, M T; Valdez-Carrasco, J; Mora-Aguilera, G; Atanacio-Serrano, Y; Romero-Pescador, P

2013-08-01

We studied the abundance of Brevipalpus spp. in citrus orchards in the Mexican states of Yucatan, Quintana Roo and Campeche. Mites were collected from 100 trees containing a mixture of citrus species where sweet orange was always the main species. Eight collections were made at each location from February 2010 to February 2011. Mites from the genus Brevipalpus were separated from other mites surveyed and their abundance and relationships with the different citrus species were quantified throughout the collection period. A subsample of 25% of the total Brevipalpus mites collected were identified to species level and the interaction of mite species and citrus species were described. Brevipalpus spp. were present on all collection dates and their relative abundance was similar on all citrus species studies. The smallest number of mites collected was during the rainy season. Brevipalpus phoenicis (Geijskes) and Brevipalpus californicus (Banks) were the only two species present and they were found in all locations except Campeche, where only B. phoenicis was present. Yucatan and Campeche are at greater risk of leprosis virus transmission than Quintana Roo because the main vector, B. phoenicis, was more abundant than B. californicus. The implications of our results for the design of more accurate sampling and control methods for Brevipalpus spp. are discussed.

Effects on Asian Citrus Psyllid (Diaphorina citri Kuwayama) feeding behavior of fenpropathrin and chlorpyrifos within 24 hours of application

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Huanglongbing (HLB), also known as citrus greening disease, is one of the most destructive diseases affecting citrus production. The phloem-limited bacterium associated with HLB is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). One component of HLB managem...

Mapping the sensitivity of citrus crops to freeze stress using a geographical information system in Ramsar, Iran

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Hasan Zabihi

2016-12-01

Full Text Available Citrus, a cold-sensitive plant, often suffers from low temperature, which seriously affects citrus productivity. Environmental constraint factors have mixed impacts on horticulture that differ among the areas, periods and crops. This study presents a statistical analysis to investigate the freeze stress (FS conditions and morphometry, especially altitude and minimum temperature on citriculture at a regional scale. Based on the temperature isolines map and topography, this paper highlights the impact of altitude and minimum temperature on the citrus crop production using geographic information system (GIS techniques, statistical analysis and climatic data in Ramsar, Iran over a period of 30 years from 1980 to 2010. This study shows that the suitability varies in relation to the critical temperature and concludes that both minimum temperature and altitude have significant negative impact on citrus crop production. Climate change, in particular, occurring cold fronts in recent years during the citrus harvest time have been complicating this issue and increased the importance of freezes stress (FS. The results highlight that citrus crop orchards were more strongly affected by the minimum temperature, and along with the elevation ranges theses are major challenging factors.

Antimycotic Activity and Genotoxic Evaluation of Citrus sinensis and Citrus latifolia Essential Oils.

Science.gov (United States)

Ruiz-Pérez, Nancy J; González-Ávila, Marisela; Sánchez-Navarrete, Jaime; Toscano-Garibay, Julia D; Moreno-Eutimio, Mario A; Sandoval-Hernández, Teresa; Arriaga-Alba, Myriam

2016-05-03

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%) and α-myrcene (2.79%); and in C. latifolia, d-limonene (51.64%), β-thujene (14.85%), β-pinene (12.79%) and γ-terpinene (12.8%). Antifungal properties were studied by agar diffusion method, where C. sinensis presented low activity and C. latifolia essential oil was effective to inhibit growing of C. lusitaniae and C. guilliermondii with IC50 of 6.90 and 2.92 μg respectively. The minimum inhibitory concentrations (MIC) for C. sinensis were in a range of 0.42-3.71 μg and for C. latifolia of 0.22-1.30 μg. Genotoxic evaluation was done by Ames test where none of the oils induced point mutations. Flow cytometry was used to measure toxicity in human oral epithelial cells, C. sinensis was not cytotoxic and C. latifolia was toxic at 21.8 μg. These properties might bestow different odontological applications to each essential oil.

A novel carotenoid cleavage activity involved in the biosynthesis of Citrus fruit-specific apocarotenoid pigments

KAUST Repository

Rodrigo, María J.

2013-09-04

Citrus is the first tree crop in terms of fruit production. The colour of Citrus fruit is one of the main quality attributes, caused by the accumulation of carotenoids and their derivative C30 apocarotenoids, mainly ?-citraurin (3-hydroxy-?-apo-8?-carotenal), which provide an attractive orange-reddish tint to the peel of oranges and mandarins. Though carotenoid biosynthesis and its regulation have been extensively studied in Citrus fruits, little is known about the formation of C30 apocarotenoids. The aim of this study was to the identify carotenoid cleavage enzyme(s) [CCD(s)] involved in the peel-specific C30 apocarotenoids. In silico data mining revealed a new family of five CCD4-type genes in Citrus. One gene of this family, CCD4b1, was expressed in reproductive and vegetative tissues of different Citrus species in a pattern correlating with the accumulation of C30 apocarotenoids. Moreover, developmental processes and treatments which alter Citrus fruit peel pigmentation led to changes of ?-citraurin content and CCD4b1 transcript levels. These results point to the involvement of CCD4b1 in ?-citraurin formation and indicate that the accumulation of this compound is determined by the availability of the presumed precursors zeaxanthin and ?-cryptoxanthin. Functional analysis of CCD4b1 by in vitro assays unequivocally demonstrated the asymmetric cleavage activity at the 7?,8? double bond in zeaxanthin and ?-cryptoxanthin, confrming its role in C30 apocarotenoid biosynthesis. Thus, a novel plant carotenoid cleavage activity targeting the 7?,8? double bond of cyclic C40 carotenoids has been identified. These results suggest that the presented enzyme is responsible for the biosynthesis of C30 apocarotenoids in Citrus which are key pigments in fruit coloration. The Author 2013.

A novel carotenoid cleavage activity involved in the biosynthesis of Citrus fruit-specific apocarotenoid pigments

KAUST Repository

Rodrigo, Marí a J.; Alqué zar, Berta; Aló s, Enriqueta; Medina, Ví ctor; Carmona, Lourdes; Bruno, Mark; Al-Babili, Salim; Zacarí as, Lorenzo

2013-01-01

Citrus is the first tree crop in terms of fruit production. The colour of Citrus fruit is one of the main quality attributes, caused by the accumulation of carotenoids and their derivative C30 apocarotenoids, mainly ?-citraurin (3-hydroxy-?-apo-8?-carotenal), which provide an attractive orange-reddish tint to the peel of oranges and mandarins. Though carotenoid biosynthesis and its regulation have been extensively studied in Citrus fruits, little is known about the formation of C30 apocarotenoids. The aim of this study was to the identify carotenoid cleavage enzyme(s) [CCD(s)] involved in the peel-specific C30 apocarotenoids. In silico data mining revealed a new family of five CCD4-type genes in Citrus. One gene of this family, CCD4b1, was expressed in reproductive and vegetative tissues of different Citrus species in a pattern correlating with the accumulation of C30 apocarotenoids. Moreover, developmental processes and treatments which alter Citrus fruit peel pigmentation led to changes of ?-citraurin content and CCD4b1 transcript levels. These results point to the involvement of CCD4b1 in ?-citraurin formation and indicate that the accumulation of this compound is determined by the availability of the presumed precursors zeaxanthin and ?-cryptoxanthin. Functional analysis of CCD4b1 by in vitro assays unequivocally demonstrated the asymmetric cleavage activity at the 7?,8? double bond in zeaxanthin and ?-cryptoxanthin, confrming its role in C30 apocarotenoid biosynthesis. Thus, a novel plant carotenoid cleavage activity targeting the 7?,8? double bond of cyclic C40 carotenoids has been identified. These results suggest that the presented enzyme is responsible for the biosynthesis of C30 apocarotenoids in Citrus which are key pigments in fruit coloration. The Author 2013.

Leaching of indaziflam applied at two rates under different rainfall situations in Florida Candler soil.

Science.gov (United States)

Jhala, Amit J; Ramirez, Analiza H M; Singh, Megh

2012-03-01

Indaziflam {N-[(1R, 2S)-2,3-dihydro-2,6-dimethyl-1H-inden-1-yl]-6-[(1RS)-1fluoroethyl]-1,3,5-triazine-2,4-diamine} is a new pre-emergence herbicide recently registered for a broad spectrum weed control in Florida citrus. Experiments were conducted to evaluate leaching of indaziflam applied at 73 and 145 g ai ha(-1) in Florida Candler soil under simulated rainfall of 5, 10, and 15 cm ha(-1). Indaziflam leached the least (12.6 ± 0.6 cm) when applied at 73 g ai ha(-1) under 5 cm ha(-1) rainfall. Indaziflam leached furthest (30.2 ± 0.9 cm) when applied at 145 g ai ha(-1) under 15 cm ha(-1) rainfall. The visual control ratings of a bio-indicator species ryegrass (Lolium multiflorum L.) was 97% at 15 cm ha(-1) rainfall when indaziflam applied at 145 g ai ha(-1) in the 26 to 30 cm horizon indicating the maximum movement and activity of indaziflam. A dose response experiment was conducted to determine the sensitivity of ryegrass to various doses of indaziflam that confirmed that application of indaziflam at 29.20 g ai ha(-1) was sufficient to prevent germination of ryegrass. There was no mortality of ryegrass plants beyond the 30 cm and the biomass of ryegrass was comparable with untreated control indicating that indaziflam did not leach beyond this distance even under 15 cm ha(-1) rainfall.

Agrobacterium-mediated transformation of Citrus sinensis and Citrus limonia epicotyl segments Transformação genética em Citrus sinensis e Citrus limonia mediada por Agrobacterium tumefaciens a partir de segmentos de epicótilo

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Weliton Antonio Bastos de Almeida

2003-02-01

Full Text Available Genetic transformation allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. The objective of this research was to establish a protocol for genetic transformation of Valencia and Natal sweet oranges (Citrus sinensis L. Osbeck and Rangpur lime (Citrus limonia L. Osbeck. Epicotyl segments of germinated in vitro plantlets (three weeks in darkness and two weeks in a 16-h photoperiod were used as explants. These were co-cultivated with Agrobacterium tumefaciens strain EHA-105 and different experiments were done to evaluate the transformation efficiency: explants were co-cultivated with Agrobacterium for one, three or five days; explants were incubated with Agrobacterium suspension for 5, 10, 20 or 40 minutes; co-cultivation medium was supplemented with acetosyringone at 0, 100 or 200 µmol L-1; Explants ends had a longitudinal terminal incision (2-3 mm; co-cultivation temperatures of 19, 23 or 27°C were imposed. The experimental design was completely randomized in all experiments with five replications, each consisted of a Petri dish (100 x 15 mm with 30 explants and resulted in a total of 150 explants per treatment. Longitudinal terminal incision in the explant ends did not improve shoot regeneration. However, transgenic plants of all three cultivars were confirmed from explants that had been subjected to inoculation time of 20 minutes, co-culture of three days at 23-27°C, in the absence of acetosyringone.A transformação genética permite produzir cultivares com características específicas e pode, dessa forma ser associada a programas de melhoramento de citros. O objetivo deste trabalho foi estabelecer protocolos de transformação genética para as laranjas doce 'Valência' e 'Natal' (Citrus sinensis L. Osbeck, bem como para o limão 'Cravo'(Citrus limonia L. Osbeck. Segmentos de epicótilo de plântulas germinadas in vitro (três semanas no

Gamma irradiation as a quarantine treatment against eggs of Citrus black fly (Aleurocanthus woglumi Ashby)

International Nuclear Information System (INIS)

Villavicencio, Anna Lucia C.H.; Araujo, Michel M.; Fanaro, Gustavo B.; Costa, Helbert H.S.F.; Silva, Priscila P.V.; Arthur, Valter

2009-01-01

The citrus black fruit fly (Aleurocanthus woglumi Ashby) is an important pest of citrus originated in Southeast Asia and its first record in the new world was in Jamaica in 1913. In Brazil, it was detected in 2001 in the state of Para and more recently it was detected in Sao Paulo in 2008. This pest that attacks over 300 species of plants, but its main host are citrus. It is an A2 quarantine pest, because it is not spread throughout the country. The objective of this study was to test doses of 0 (control), 25, 50, 75, 100, 125, 150, 175 and 200 Gy of gamma irradiation for disinfection of eggs of the citrus black fruit fly in leaves of citrus plants. Treatment consisted of 5 replicates with 60 eggs each. Evaluations were performed in the following periods: 1, 3, 5, 7 and 10 days after irradiation. Under the conditions assayed, it could be concluded that a dose of 200 Gy caused 100% mortality of Aleurocanthus woglumi Ashby eggs and could be recommended as a successful quarantine processing against infested plants. (author)

Effects of oxamyl on the citrus nematode, Tylenchulus semipenetrans, and on infection of sweet orange.

Science.gov (United States)

Baines, R C; Small, R H

1976-04-01

Foliar sprays of 4 microg/ml oxamyl on sweet orange trees in a greenhouse slightly depressed the number of Tylenchulus semipenetrans larvae obtained from roots and soil, but similar treatments were not effective in two orchards. Soil drench treatments decreased the number of citrus nematode larvae obtained from roots or soil of citrus plants grown itt a greenhouse and in orchards. Exposure to 5-10 microg/ml of oxamyl in water was lethal to only a few second-stage larvae treated 10 days, and many second-stage larvae in 2.0 microg/ml oxamyl recovered motility when transferred to fresh water. Aqueous solutions of 50 and 100 microg/ml of oxamyl were toxic to citrus nematode larvae. Additional observations indicate that oxamyl interfered with hatch of citrus nematode larvae and was nematistatic and/or protected sweet orange roots from infection. Oxamyl degraded at different rates in two soils. The number of citrus nematode larvae that infected and developed on sweet orange roots was increased by an undetermined product of the degradation of oxamyl in soil, water, and possibly within plants. This product apparently was translocated in roots.

From which soil metal fractions Fe, Mn, Zn and Cu are taken up by olive trees (Olea europaea L., cv. 'Chondrolia Chalkidikis') in organic groves?

Science.gov (United States)

Chatzistathis, T; Papaioannou, A; Gasparatos, D; Molassiotis, A

2017-12-01

Organic farming has been proposed as an alternative agricultural system to help solve environmental problems, like the sustainable management of soil micronutrients, without inputs of chemical fertilizers. The purposes of this study were: i) to assess Fe, Mn, Zn and Cu bioavailability through the determination of sequentially extracted chemical forms (fractions) and their correlation with foliar micronutrient concentrations in mature organic olive (cv. 'Chondrolia Chalkidikis') groves; ii) to determine the soil depth and the available forms (fractions) by which the 4 metals are taken up by olive trees. DTPA extractable (from the soil layers 0-20, 20-40 and 40-60 cm) and foliar micronutrient concentrations were determined in two organic olive groves. Using the Tessier fractionation, five fractions, for all the metals, were found: exchangeable, bound to carbonates (acid-soluble), bound to Fe-Mn oxides (reducible), organic (oxidizable), as well as residual form. Our results indicated that Fe was taken up by the olive trees as organic complex, mainly from the soil layer 40-60 cm. Manganese was taken up from the exchangeable fraction (0-20 cm); Zinc was taken up as organic complex from the layers 0-20 and 40-60 cm, as well as in the exchangeable form from the upper 20 cm. Copper was taken up from the soil layers 0-20 and 40-60 cm as soluble organic complex, and as exchangeable ion from the upper 20 cm. Our data reveal the crucial role of organic matter to sustain metal (Fe, Zn and Cu) uptake -as soluble complexes-by olive trees, in mature organic groves grown on calcareous soils; it is also expected that these data will constitute a thorough insight and useful tool towards a successful nutrient and organic C management for organic olive groves, since no serious nutritional deficiencies were found. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inheritance and heritability of resistance to citrus leprosis.

Science.gov (United States)

Bastianel, Marinês; de Oliveira, Antonio Carlos; Cristofani, Mariângela; Filho, Oliveiro Guerreiro; Freitas-Astúa, Juliana; Rodrigues, Vandeclei; Astúa-Monge, Gustavo; Machado, Marcos Antônio

2006-10-01

ABSTRACT The genetic inheritance of resistance to leprosis, the most important viral disease of citrus in Brazil, was characterized through the phenotypic assessment of 143 hybrids resulting from crosses between tangor 'Murcott' (Citrus sinensis x C. reticulata) and sweet orange 'Pêra' (C. sinensis), considered to be resistant and susceptible to the disease, respectively. All plants were grafted onto Rangpur lime (C. limonia) and inoculated with Citrus leprosis virus, cytoplasmic type through the infestation with viruliferous mites, Brevipalpus phoenicis. The experiments were arranged in a completely randomized block design with 10 replicates. Incidence and severity of the disease in leaves and stems as well as plant growth parameters (plant height and stem diameter) were recorded for 3 years after the infestation with the viruliferous mites. The average values of all variables were analyzed using principal component analysis, discriminant factorial analysis, estimation of the clonal repeatability coefficients, and frequency of the distributions of the average values for each measured variable. The principal component analysis resulted in the identification of at least two groups with resistance and susceptibility to leprosis, respectively. About 99% of all hybrids were correctly classified according to the discriminant factorial analysis. The broad-sense heritability coefficients for characteristics associated with incidence and severity of leprosis ranged from 0.88 to 0.96. The data suggest that the inheritance of resistance to leprosis may be controlled by only a few genes.

Influence of sustainable irrigation regimes and agricultural practices on the soil CO2 fluxes from olive groves in SE Spain

Science.gov (United States)

Marañón-Jiménez, Sara; Serrano-Ortíz, Penelope; Vicente-Vicente, Jose Luis; Chamizo, Sonia; Kowalski, Andrew S.

2017-04-01

Olive (Olea europaea) is the dominant agriculture plantation in Spain and its main product, olive oil, is vital to the economy of Mediterranean countries. Given the extensive surface dedicated to olive plantations, olive groves can potentially sequester large amounts of carbon and contribute to mitigate climate change. Their potential for carbon sequestration will, however, largely depend on the management and irrigation practices in the olive grove. Although soil respiration is the main path of C release from the terrestrial ecosystems to the atmosphere and a suitable indicator of soil health and fertility, the interaction of agricultural management practices with irrigation regimes on soil CO2 fluxes have not been assessed yet. Here we investigate the influence of the presence of herbaceous cover, use of artificial fertilizers and their interaction with the irrigation regime on the CO2 emission from the soil to the atmosphere. For this, the three agricultural management treatments were established in replicated plots in an olive grove in the SE of Spain: presence of herbaceous cover ("H"), exclusion of herbaceous cover by using herbicides ("NH"), and exclusion of herbaceous cover along with addition of artificial fertilizers (0.55 kg m-2 year-1 of N, P, K solid fertilizer in the proportion 20:10:10, "NHF"). Within each management treatment, three irrigation regimes were also implemented in a randomized design: no-irrigation ("NO") or rain fed, full irrigation (224 l week-1 per olive tree, "MAX"), and a 50% restriction (112 l week-1 per olive tree, "MED"). Soil respiration was measured every 2-3 weeks at 1, 3, and 5 meters from each olive tree together with soil temperature and soil moisture in order to account for the spatial and seasonal variability over the year. Soil respiration was higher when herbaceous cover was present compared to the herbaceous exclusion, whereas the addition of fertilizer did not exert any significant effect. Although the different

Influence of landscape context on the abundance and diversity of bees in Mediterranean olive groves.

Science.gov (United States)

Tscheulin, T; Neokosmidis, L; Petanidou, T; Settele, J

2011-10-01

The diversity and abundance of wild bees ensures the delivery of pollination services and the maintenance of ecosystem diversity. As previous studies carried out in Central Europe and the US have shown, bee diversity and abundance is influenced by the structure and the composition of the surrounding landscape. Comparable studies have so far not been carried out in the Mediterranean region. The present study examines the influence of Mediterranean landscape context on the diversity and abundance of wild bees. To do this, we sampled bees in 13 sites in olive groves on Lesvos Island, Greece. Bees were assigned to five categories consisting of three body size groups (small, medium and large bees), the single most abundant bee species (Lasioglossum marginatum) and all species combined. The influence of the landscape context on bee abundance and species richness was assessed at five radii (250, 500, 750, 1000 and 1250 m) from the centre of each site. We found that the abundance within bee groups was influenced differently by different landscape parameters and land covers, whereas species richness was unaffected. Generally, smaller bees' abundance was impacted by landscape parameters at smaller scales and larger bees at larger scales. The land cover that influenced bee abundance positively was olive grove, while phrygana, conifer forest, broad-leaved forest, cultivated land, rock, urban areas and sea had mostly negative or no impact. We stress the need for a holistic approach, including all land covers, when assessing the effects of landscape context on bee diversity and abundance in the Mediterranean.

Incidence and epidemiology of Citrus tristeza virus in the Valencian community of Spain.

Science.gov (United States)

Cambra, M; Gorris, M T; Marroquín, C; Román, M P; Olmos, A; Martínez, M C; de Mendoza, A H; López, A; Navarro, L

2000-11-01

The first outbreak of citrus tristeza disease in Spain caused by Citrus tristeza virus (CTV) was recorded in 1957 in the Valencian Community (VC). In total c. 40 million trees, mainly of sweet orange and mandarin grafted on sour orange rootstocks, declined due to CTV. Large-scale surveys in different municipalities of the VC indicated that the disease spread very fast. Incidence increased from 11% in 1989 to 53% in 1998. Toxoptera aurantii and Aphis spiraecola (inefficient aphid vectors of CTV) predominated before 1985-87. Since then the relatively efficient vector Aphis gossypii has become dominant and induced an epidemic that has been modelled. The large number of A.gossypii that visited each clementine tree (estimated to exceed 97000 per year) explained the difference between the temporal pattern of spread of CTV in clementine which followed the Gompertz model and that in sweet orange (logistic model). The susceptibility of the different citrus species to CTV infection by aphids seems to depend on the number of young, succulent shoots produced. The epidemiological data allowed specific recommendations to be made to growers in order to facilitate a change to a modern citrus industry based on the use of selected varieties grafted on tristeza-tolerant rootstocks produced within a certification scheme. This has been done already in almost 90% of the VC citrus-growing area. The tristeza problem has been solved unless more aggressive isolates are introduced and become prevalent.

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...

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

International Nuclear Information System (INIS)

Zhang, Wenlin; Zhang, Lian Ying; Zhao, Xi Juan; Zhou, Zhiqin

2016-01-01

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater. - Graphical abstract: Citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward methylene blue removal. - Highlights: • Citrus pectin derived porous carbons (CPPCs) were synthesized a facile zinc chloride activation approach. • CPPCs had abundant macro/meso/micropores for trapping MB molecules. • CPPCs exhibited ultrahigh adsorption capacity, rapid adsorption rate and good reusability toward removal of MB.

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wenlin [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Zhang, Lian Ying [Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing 400715 (China); Zhao, Xi Juan [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing 400715 (China); Zhou, Zhiqin, E-mail: zhouzhiqin@swu.edu.cn [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing 400715 (China)

2016-11-15

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater. - Graphical abstract: Citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward methylene blue removal. - Highlights: • Citrus pectin derived porous carbons (CPPCs) were synthesized a facile zinc chloride activation approach. • CPPCs had abundant macro/meso/micropores for trapping MB molecules. • CPPCs exhibited ultrahigh adsorption capacity, rapid adsorption rate and good reusability toward removal of MB.

Spectrophotometric quantification of antioxidant phytochemicals in juices from four different varieties of citrus limon, indigenous to Pakistan

International Nuclear Information System (INIS)

Khosa, M.K.; Hussain, A.I.; Riaz, H.; Aslam, K.; Chatha, S.A.S.; Zia, K.M.

2011-01-01

This research work was carried out to quantify the total phenolics, flavonoids and carotenoides, vitamin C contents, reported as antioxidants, in juices of four varieties of Pakistani Citrus limon. Juice was extracted from fresh lemon samples using classical method and subjected to study the various quality parameters. The total phenolic contents from juices of Citrus limon, determined following the Folin-Ciocalteu assay were found in the range of 690.62-998.29 mg/L, showing the significant inter-varietals variations. The total flavonoids and vitamin C contents from juices of Citrus limon were found in the range of 211.36-220.34 and 18.87-25.1 mg/L, respectively. Whereas, the total carotenoides contents of Citrus limon juices were found in a low concentrations i.e. 0.05-0.08 mg/L. The statistical analysis showed significant (p 0.05) variation in total flavonoids contents among different varieties of Citrus limon. (author)

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.

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...

Odorants for surveillance and control of the Asian Citrus Psyllid (Diaphorina citri.

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Iliano V Coutinho-Abreu

Full Text Available 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.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%.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.

Temporal occurrence and niche preferences of Phytophthora species causing brown rot of citrus in the Central Valley of California

Science.gov (United States)

Brown rot of citrus fruits is caused by several species of Phytophthora and is currently of serious concern for the California citrus industry. Two species, P. syringae and P. hibernalis, are quarantine pathogens in China, a major export market for California citrus. To maintain trade and estimate t...

Exploiting BAC-end sequences for the mining, characterization and utility of new short sequences repeat (SSR) markers in Citrus.

Science.gov (United States)

Biswas, Manosh Kumar; Chai, Lijun; Mayer, Christoph; Xu, Qiang; Guo, Wenwu; Deng, Xiuxin

2012-05-01

The aim of this study was to develop a large set of microsatellite markers based on publicly available BAC-end sequences (BESs), and to evaluate their transferability, discriminating capacity of genotypes and mapping ability in Citrus. A set of 1,281 simple sequence repeat (SSR) markers were developed from the 46,339 Citrus clementina BAC-end sequences (BES), of them 20.67% contained SSR longer than 20 bp, corresponding to roughly one perfect SSR per 2.04 kb. The most abundant motifs were di-nucleotide (16.82%) repeats. Among all repeat motifs (TA/AT)n is the most abundant (8.38%), followed by (AG/CT)n (4.51%). Most of the BES-SSR are located in the non-coding region, but 1.3% of BES-SSRs were found to be associated with transposable element (TE). A total of 400 novel SSR primer pairs were synthesized and their transferability and polymorphism tested on a set of 16 Citrus and Citrus relative's species. Among these 333 (83.25%) were successfully amplified and 260 (65.00%) showed cross-species transferability with Poncirus trifoliata and Fortunella sp. These cross-species transferable markers could be useful for cultivar identification, for genomic study of Citrus, Poncirus and Fortunella sp. Utility of the developed SSR marker was demonstrated by identifying a set of 118 markers each for construction of linkage map of Citrus reticulata and Poncirus trifoliata. Genetic diversity and phylogenetic relationship among 40 Citrus and its related species were conducted with the aid of 25 randomly selected SSR primer pairs and results revealed that citrus genomic SSRs are superior to genic SSR for genetic diversity and germplasm characterization of Citrus spp.

Occurrence and Distribution of Citrus tristeza virus (CTV in the Jordan Valley

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G. Anfoka

2005-04-01

Full Text Available In a survey conducted in 2002 and 2003, Citrus tristeza virus (CTV was detected in the Jordan Valley. The direct tissue blot immunoassay (DTBIA indicated that 12.7 and 15.2% of samples tested in the central and northern Jordan Valley respectively were infected with CTV. Similar results showed that all citrus species grown in the Jordan Valley were susceptible to CTV. DAS-ELISA analysis of samples from a citrus orchard in the Dir Alla area with severe CTV symptoms indicated that 49% of samples were infected with CTV. Using a CTV specific primer pair (CTV1/CTV10, the coat protein gene of the virus was successfully amplified from leaf extracts obtained from CTVinfected trees by IC-RT-PCR. After cloning and sequencing the coat protein gene, the sequence of the amplified product was deposited in the GenBank.

Evaluation of systemic neonicotinoid insecticides for the management of the Asian citrus psyllid Diaphorina citri on containerized citrus.

Science.gov (United States)

Byrne, Frank J; Daugherty, Matthew P; Grafton-Cardwell, Elizabeth E; Bethke, James A; Morse, Joseph G

2017-03-01

Studies were conducted to evaluate uptake and retention of three systemic neonicotinoid insecticides, dinotefuran, imidacloprid and thiamethoxam, in potted citrus nursery plants treated at standard label rates. Infestation of these plants placed at a field site with moderate levels of Asian citrus psyllid (ACP) was monitored for 14 weeks following treatments, and insecticide residues in leaf tissue were quantified using enzyme-linked immunosorbent assay (ELISA). Bioassays were conducted using leaves harvested on various dates post-treatment to compare the efficacies of residues against adult ACP. Residues of the three neonicotinoids were detected in leaf tissues within 1 week after treatment. Peak concentrations established at 1 week for imidacloprid and dinotefuran and at 2 weeks for thiamethoxam. Imidacloprid and thiamethoxam outperformed the control and dinotefuran treatments at protecting trees from infestations by ACP eggs and nymphs. For a given insecticide concentration in leaf tissue, thiamethoxam induced the highest mortality of the three insecticides, and dinotefuran was the least toxic. If the time needed to achieve effective thresholds of a systemic neonicotinoid is known, treatments at production facilities could be scheduled that would minimize unnecessary post-treatment holding periods and ensure maximum retention of effective concentrations after the plants have shipped to retail outlets. The rapid uptake of the insecticides and retention at effective concentrations in containerized citrus suggest that the current 30 day post-treatment shipping restriction from production facilities to retail outlets outside of quarantine could be shortened to 14 days. Thiamethoxam should be added to the list of approved nursery treatments. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Use of the heat dissipation method for sap flow measurement in citrus nursery trees1

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Eduardo Augusto Girardi

2010-12-01

Full Text Available Sap flow could be used as physiological parameter to assist irrigation of screen house citrus nursery trees by continuous water consumption estimation. Herein we report a first set of results indicating the potential use of the heat dissipation method for sap flow measurement in containerized citrus nursery trees. 'Valencia' sweet orange [Citrus sinensis (L. Osbeck] budded on 'Rangpur' lime (Citrus limonia Osbeck was evaluated for 30 days during summer. Heat dissipation probes and thermocouple sensors were constructed with low-cost and easily available materials in order to improve accessibility of the method. Sap flow showed high correlation to air temperature inside the screen house. However, errors due to natural thermal gradient and plant tissue injuries affected measurement precision. Transpiration estimated by sap flow measurement was four times higher than gravimetric measurement. Improved micro-probes, adequate method calibration, and non-toxic insulating materials should be further investigated.

[Citrus boron nutrient level and its impact factors in the Three Gorges Reservoir region of Chongqing, China].

Science.gov (United States)

Zhou, Wei; Peng, Liang-Zhi; Chun, Chang-Pin; Jiang, Cai-Lun; Ling, Li-Li; Wang, Nan-Qi; Xing, Fei; Huang, Yi

2014-04-01

To investigate the level of boron nutrient in citrus and its impact factors, a total of 954 citrus leaf samples and 302 soil samples were collected from representative orchards in the 12 main citrus production counties in the Three Gorges Reservoir region of Chongqing to determine the boron content in citrus leaves, as well as the relationships between leaf boron content with soil available boron content, soil pH value, cultivar, rootstock and the age of tree. Results indicated that the leaf samples from 41.6% orchards (tree did affect the leaf boron content. The leaves from the orchards with soil pH of 4.5-6.4 demonstrated significantly higher boron contents than with the soil pH of 6.5-8.5. The leaf boron contents in the different cultivars was ranged as Satsuma mandarin > pomelo > valencia orange > sweet orange > tangor > navel orange. The citrus on trifoliate orange and sour pomelo rootstocks had significantly higher leaf boron contents than on Carrizo citrange and red tangerine rootstocks. Compared with the adult citrus trees (above 8 year-old), 6.6% more of leaf samples of younger trees (3 to 8 year-old) contained boron contents in the optimum range (35-100 mg x kg(-1)).

Morphometric comparisons of Diaphorina citri (Hemiptera: Liviidae populations from Iran, USA and Pakistan

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Mohammadreza Lashkari

2015-05-01

Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri Kuwayama (Hemiptera: Liviidae, vector of citrus greening disease pathogen, Huanglongbing (HLB, is considered the most serious pest of citrus in the world. Prior molecular based studies have hypothesized a link between the D. citri in Iran and the USA (Florida. The purpose of this study was to collect morphometric data from D. citri populations from Iran (mtCOI haplotype-1, Florida (mtCOI haplotype-1, and Pakistan (mtCOI haplotype-6, to determine whether different mtCOI haplotypes have a relationship to a specific morphometric variation. 240 samples from 6 ACP populations (Iran—Jiroft, Chabahar; Florida—Ft. Pierce, Palm Beach Gardens, Port St. Lucie; and Pakistan—Punjab were collected for comparison. Measurements of 20 morphological characters were selected, measured and analysed using ANOVA and MANOVA. The results indicate differences among the 6 ACP populations (Wilks’ lambda = 0.0376, F = 7.29, P < 0.0001. The body length (BL, circumanal ring length (CL, antenna length (AL, forewing length (WL and Rs vein length of forewing (RL were the most important characters separating the populations. The cluster analysis showed that the Iran and Florida populations are distinct from each other but separate from the Pakistan population. Thus, three subgroups can be morphologically discriminated within D. citri species in this study, (1 Iran, (2 USA (Florida and (3 Pakistan population. Morphometric comparisons provided further resolution to the mtCOI haplotypes and distinguished the Florida and Iranian populations.

Synergy and Other Interactions between Polymethoxyflavones from Citrus Byproducts

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Benito F. García

2015-11-01

Full Text Available 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 compounds and complex mixtures. The bioactivities and interactions were evaluated in wheat coleoptile bioassays and the antioxidant activity was evaluated by the al DPPH (2,2-diphenyl-1-picrylhdrazyl radical radical scavenging assay. The extracts, fractions and most of the isolated compounds (mainly polymethoxyflavones showed high activity in the wheat coleoptile bioassay. However, the antioxidant activity was not consistently high, except in the acetone extract fractions. Moreover, a study of the interactions with binary mixtures of polymethoxyflavones showed the occurrence of synergistic effects. The complex mixtures of fractions composed mainly of polymethoxyflavones caused a synergistic effect when it was added to a bioactive compound such as anethole. The results reported here highlight a new application for the wheat coleoptile bioassay as a quick tool to detect potential synergistic effects in compounds or mixtures.

Zinc treatment increases the titre of ‘Candidatus Liberibacter asiaticus’ in Huanglongbing-affected citrus plants while affecting the bacterial microbiomes

Science.gov (United States)

Huanglongbing (HLB)-affected citrus often display zinc deficiency symptoms. In this study, supplemental zinc was applied to citrus to determine its effect on Candidatus Liberibacter asiaticus (Las) titer, HLB symptoms, and leaf microbiome. HLB-affected citrus were treated with various amounts of zi...

78 FR 43881 - Florida Petroleum Reprocessors Site, Davie, Broward County, Florida; Notice of Settlement

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2013-07-22

... ENVIRONMENTAL PROTECTION AGENCY [FRL9836-2; CERCLA-04-2013-3758] Florida Petroleum Reprocessors... entered into a settlement with Jap. Tech, Inc. concerning the Florida Petroleum Reprocessors Site located.... Painter. Submit your comments by Site name Florida Petroleum Reprocesssors Site by one of the following...

efficacy of rehabilitation methods on citrus canker disease

African Journals Online (AJOL)

ACSS

Unfortunately it is increasingly devastated by canker disease. Several measures ... Le citronnier (Citrus sinensis) est une culture importante en Ouganda, où il est produit pour la consommation ... South- East Asian countries, from where it has.

Effects of Molasses on the Fermentation Quality of Wheat Straw and Poultry Litter Ensiled with Citrus Pulp

International Nuclear Information System (INIS)

Migwi, P.K; Gallanga, J.R; Barneveld, R.J

1999-01-01

Studies were conducted to find out whether inclusion of molasses had any effect on the fermentation quality and potential nutritive value of silage when wheat straw and poultry litter were ensiled with citrus pulp. A 4 x 2 factorial experiment in a randomized complete block design with four treatments (T) containing wheat straw, poultry litter and citrus pulp respectively on DM basis with 0 and 5% molasses, were prepared as follows-: T1 (75:25:0); T2 (60:25:15); T3 (45:25:30) and T4 (30:25:45). For each treatment in triplicate between 5-10 kg of thoroughly mixed material were ensiled for for a period of 60 days in 20-l hard plastic container laboratory silos, lined with a double layer of polythene bags. Inclusion of 5% molasses when ensiling wheat straw and poultry litter with 0, 15, 30 and 45% citrus pulp had no significant effect on pH, neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and in vitro OM digestibility. However, molasses resulted in a significant decrease in volatile fatty acids including N-butyric acid. There was a complete elimination of coliforms in all treatments, except in the silage that had neither molasses nor citrus pulp. There was a significant difference in titratable acidity levels between silage with 0 and 5% molasses, but this was only in silage with 30% citrus pulp. As the proportion of citrus pulp in silage increased from 0 to 45%, there was significant increase in silage acidity and also an increase in pH. However, there was no significant difference in pH between silage with 30 and 45% citrus pulp. There was a significant (P < 0.001) increase in in vitro OM digestibility from 0.33 to about 0.56 for silage with 0 and 45% citrus pulp respectively. It is concluded that when wheat straw and poultry litter are ensiled with citrus pulp, use of molasses offers no significant benefit inspite of the cost associated with its use. However, when no citrus pulp is included in the pre-mix, addition of some

Spatial Genetic Structure of Coffee-Associated Xylella fastidiosa Populations Indicates that Cross Infection Does Not Occur with Sympatric Citrus Orchards.

Science.gov (United States)

Francisco, Carolina S; Ceresini, Paulo C; Almeida, Rodrigo P P; Coletta-Filho, Helvécio D

2017-04-01

Xylella fastidiosa, an economically important plant-pathogenic bacterium, infects both coffee and citrus trees in Brazil. Although X. fastidiosa in citrus is well studied, knowledge about the population structure of this bacterium infecting coffee remains unknown. Here, we studied the population structure of X. fastidiosa infecting coffee trees in São Paulo State, Brazil, in four regions where citrus is also widely cultivated. Genotyping of over 500 isolates from coffee plants using 14 genomic microsatellite markers indicated that populations were largely geographically isolated, as previously found with populations of X. fastidiosa infecting citrus. These results were supported by a clustering analysis, which indicated three major genetic groups among the four sampled regions. Overall, approximately 38% of isolates showed significant membership coefficients not related to their original geographical populations (i.e., migrants), characterizing a significant degree of genotype flow among populations. To determine whether admixture occurred between isolates infecting citrus and coffee plants, one site with citrus and coffee orchards adjacent to each other was selected; over 100 isolates were typed from each host plant. No signal of natural admixture between citrus- and coffee-infecting isolates was found; artificial cross-infection assays with representative isolates also yielded no successful cross infection. A comparison determined that X. fastidiosa populations from coffee have higher genetic diversity and allelic richness compared with citrus. The results showed that coffee and citrus X. fastidiosa populations are effectively isolated from each other and, although coffee populations are spatially structured, migration has an important role in shaping diversity.

Effective antibiotics against 'Candidatus Liberibacter asiaticus' in HLB-affected citrus plants identified via the graft-based evaluation.

Science.gov (United States)

Zhang, Muqing; Guo, Ying; Powell, Charles A; Doud, Melissa S; Yang, Chuanyu; Duan, Yongping

2014-01-01

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.

Florida Energy Assurance Plan

Science.gov (United States)

Turner, Niescja E.; Murtagh, William; Guthrie, Kevin; Nykyri, Katariina; Radasky, William A.; Senkowicz, Eric

2012-08-01

This spring, Florida held the nation's first statewide emergency preparedness training and exercises geared specifically to the aftermath of severe geomagnetic events. Funded by the State of Florida Division of Emergency Management (FDEM) via a Department of Energy grant and held in collaboration with Watch House International, Inquesta Corporation, and the Florida Institute of Technology, the 17-19 April 2012 workshop had 99 on-site attendees in an oceanfront hotel in Melbourne, Florida, as well as 16 over live Web streaming. The workshop was the capstone to a three-month season of 21 regional space weather training sessions and workshops serving 386 attendees in total.

Deciphering the Bacterial Microbiome in Huanglongbing-Affected Citrus Treated with Thermotherapy and Sulfonamide Antibiotics.

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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.

Efficacy and safety of Citrus sudachi peel in obese adults: A randomized, double-blind, pilot study

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Masashi Akaike

2014-07-01

Full Text Available Objective: This study was undertaken to explore the efficacy and safety of Citrus sudachi peel for metabolic risk factors in obese male and female adults. Background: Citrus sudachi Hort. ex Shirai (Rutaceae, called “sudachi”, is a small, round, green citrus fruit that is mainly cultivated in Tokushima Prefecture in Japan. Our group reported that Citrus sudachi peel powder improved glucose tolerance and dyslipidemia in Zucher-fatty rats and reduced hyperglycemia and hypertriglyceridemia in GK diabetic rats. Materials and Methods: We conducted a randomized, double-blind, placebo-controlled trial in 40 participants with abdominal obesity and metabolic risk factors including hypertension, impaired glucose tolerance and elevated triglyceride levels. Participants were randomized to receive either tablets that contained 1.3 g dried Citrus sudachi peel powder or placebo tablets for 12 weeks. The sudachi peel group included 14 males and 5 females with a mean age of 54.5 years, and the placebo group included 18 males and 2 females with a mean age of 51.9 years. Results: Physical status including body weight, waist circumference and blood pressure and laboratory markers including metabolic parameters were not different at any observation point between the two groups. However, among participants with serum triglyceride levels of more than 120 mg/dl, body weight, waist circumference and serum triglyceride levels were significantly decreased at several observation points after the start of treatment in the sudachi peel group but not in the placebo group. No serious adverse events were observed in the sudachi peel group. Conclusions: Citrus sudachi peel has the potential effect to safely improve abdominal obesity and lower serum levels of TG in obese individuals with hypertriglyceridemia. A large-scale randomized, double-blind clinical study targeting subjects with both abdominal obesity and high TG levels is needed to confirm the metabolic effects of

Hypocholesterolemic properties of grapefruit (Citrus paradisii and shaddock (Citrus maxima juices and inhibition of angiotensin-1-converting enzyme activity

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Ganiyu Oboh

2014-12-01

Full Text Available Grapefruit (Citrus paradisii and shaddock (Citrus maxima juices are used in folk medicine for the management of hypertension and other cardiovascular diseases, but the mechanism of action by which they exert their therapeutic action is unclear. The aim of this study was to investigate the effect of grapefruit and shaddock juices on angiotensin-1-converting enzyme (ACE activity in vitro and the hypocholesterolemic properties of the juices in rats fed a high-cholesterol diet. Grapefruit juice had higher total phenol and flavonoid contents than shaddock juice, while both juices inhibited ACE activity in a dose-dependent manner. Furthermore, administration of the juices to rats fed a high-cholesterol diet caused a significant reduction in plasma total cholesterol, triglyceride, and low-density lipoprotein–cholesterol levels and an increase in high-density lipoprotein–cholesterol levels. The inhibition of ACE activity in vitro and in vivo hypocholesterolemic effect of the juices could explain the use of the juices in the management of cardiovascular diseases.

Quantification of Transfer of Salmonella from Citrus Fruits to Peel, Edible Portion, and Gloved Hands during Hand Peeling.

Science.gov (United States)

Jung, Jiin; Friedrich, Loretta M; Danyluk, Michelle D; Schaffner, Donald W

2017-06-01

Although studies have quantified bacterial transfer between hands and various materials, cross-contamination between the surface of fresh citrus fruit and the edible portions during hand peeling has not been reported. This study quantifies transfer of Salmonella to the edible portion of citrus fruit from a contaminated peel during hand peeling. Citrus fruits used for this study were Citrus sinensis (sweet orange) cultivars 'Valencia' and 'Navel', Citrus unshiu (Satsuma mandarins), Citrus reticulata × Citrus paradisi ('Minneola' tangelo or 'Honeybell'), and C. paradisi (grapefruit) cultivar 'Marsh'. An avirulent Salmonella Typhimurium LT2 (ATCC 700720) resistant to rifampin was used for all experiments. The inoculum containing approximately 9 log CFU/mL (50 μL) was spot inoculated onto the equator, stem, or styler of each fruit and allowed to dry for 24 h. Six volunteers put on single-use latex gloves and peeled inoculated fruit. Peel, edible fruit portion, and gloves were collected and enumerated separately. Three replicates of the study were performed in which each volunteer peeled two inoculated fruit of each variety (n = 36 fruit per variety). Cross-contamination from contaminated surface of citrus fruits to edible portion or gloved hands during peeling was affected by inoculation sites. Average Salmonella transfer to the edible portion ranged from 0.16% (Valencia inoculated at the equator) to 5.41% (navel inoculated at the stem). Average Salmonella transfer to gloved hands ranged from 0.41% (grapefruit inoculated at the stem) to 8.97% (navel inoculated at the stem). Most Salmonella remained on the peel of citrus fruits. The average level of Salmonella remaining on the peel ranged from 5.37% (Minneola inoculated at the equator) to 66.3% (Satsuma inoculated at the styler). When grapefruit was inoculated, the Salmonella that remained on the peel showed a bimodal pattern in which some individuals left almost all Salmonella on the peel, while others left

Florida Hydrogen Initiative

Energy Technology Data Exchange (ETDEWEB)

Block, David L

2013-06-30

The Florida Hydrogen Initiative (FHI) was a research, development and demonstration hydrogen and fuel cell program. The FHI program objectives were to develop Florida?s hydrogen and fuel cell infrastructure and to assist DOE in its hydrogen and fuel cell activities The FHI program funded 12 RD&D projects as follows: Hydrogen Refueling Infrastructure and Rental Car Strategies -- L. Lines, Rollins College This project analyzes strategies for Florida's early stage adaptation of hydrogen-powered public transportation. In particular, the report investigates urban and statewide network of refueling stations and the feasibility of establishing a hydrogen rental-car fleet based in Orlando. Methanol Fuel Cell Vehicle Charging Station at Florida Atlantic University ? M. Fuchs, EnerFuel, Inc. The project objectives were to design, and demonstrate a 10 kWnet proton exchange membrane fuel cell stationary power plant operating on methanol, to achieve an electrical energy efficiency of 32% and to demonstrate transient response time of less than 3 milliseconds. Assessment of Public Understanding of the Hydrogen Economy Through Science Center Exhibits, J. Newman, Orlando Science Center The project objective was to design and build an interactive Science Center exhibit called: ?H2Now: the Great Hydrogen Xchange?. On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications ? A. Raissi, Florida Solar Energy Center This project developed an on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. Chemochromic Hydrogen Leak Detectors for Safety Monitoring ? N. Mohajeri and N. Muradov, Florida Solar Energy Center This project developed and demonstrated a cost-effective and highly selective chemochromic (visual) hydrogen leak detector for safety

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

Science.gov (United States)

Cruz-Jaramillo, José Luis; Ruiz-Medrano, Roberto; Rojas-Morales, Lourdes; López-Buenfil, José Abel; Morales-Galván, Oscar; Chavarín-Palacio, Claudio; Ramírez-Pool, José Abrahán; Xoconostle-Cázares, Beatriz

2014-01-01

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. PMID:25004279

Current status of the Citrus leprosis virus (CiLV -C and its vector Brevipalpus phoenicis (Geijskes

Directory of Open Access Journals (Sweden)

Guillermo León M

2012-08-01

Full Text Available The Citrus leprosis virus CiLV-C is a quarantine disease of economic importance. Over the past 15 years, this disease has spread to several countries of Central and South America. Colombia has about 45,000 hectares of citrus planted with an annual production of 750,000 tonnes. The CiLV-C has only been detected in the departments of Meta, Casanare and recently Tolima. Meta has 4,300 hectares representing 10% of the national cultivated area, and Casanare, where CiLV-C appeared in 2004, has no more than 500 ha planted with citrus. The presence of the Citrus leprosis virus in Colombia could affect the international market for citrus, other crops and ornamental plants with the United States and other countries without the disease. The false spider mite Brevipalpus phoenicis (Geijskes (Acari: Tenuipalpidae is the main vector of the CiLV-C. Disease management is based on control programs of the vector and diminishing host plants. Chemical mite control is expensive, wasteful and generates resistance to different acaricides. This paper provides basic information on CiLV-C and its vector, advances in diagnosis and methods to control the disease and prevention of its spread

Isolation and identification of citrus psorosis virus Egyptian isolate (CPsV-EG).

Science.gov (United States)

Ghazal, S A; El-Dougdoug, Kh A; Mousa, A A; Fahmy, H; Sofy, A R

2008-01-01

Citrus psorosis ophiovirus (CPsV), is considered to be of the most serious and deter mental virus pathogen's citrus species trees in Egypt. CPsV-EG was isolated from infected citrus grapefruit (C. paradisi Macf.) at Agric. Res. Centre (ARC). The grapefruit which used for CPsV-EG isolate was found to be free from CTV, CEVd and Spiroplasma citri where as gave -ve results with DTBIA, tissue print hybridization and Diene's stain respectively. CPsV-EG was detected on the basis of biological indexing by graft inoculation which gave oak leaf pattern (OLP) on Dweet tangor and serological assay by DAS-ELISA using Mab specific CPsV. CPsV-EG was reacted with variable responses on 16 host plants belonging to 6 families. Only 8 host plants are susceptible and showed visible external symptoms which appeared as local, systemic and local followed by systemic infections. CPsV-EG isolate was transmitted from infected citrus to citrus by syringe and grafting and herbaceous plants by forefinger inoculation and syringe. The woody indicators and rootstocks were differed in response to CPsV-EG isolate which appeared as no-response, response, sensitivity and hypersensitivity. The serological characters represented as the antigenic determinants of CPsV-EG isolate related to monoclonal antibodies specific CPsV strain where as appeared precipitation reaction by DAS-ELISA and DTBIA. The partial fragment of RNA3 (coat protein gene) of CPsV-EG (-1140bp and -571bp) was amplified by reverse transcription-polymerase chain reaction (RT-PCR) from grapefruit tissues using two sets primers specific CPsV (CPV3 and CPV4) and (PS66 and PS65) respectively. The virus under study was identified as CPsV-EG isolate according to biological, serological and molecular characters.

Ultrasound-assisted extraction of Ca, K and Mg from in vitro citrus culture

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Arruda Sandra C. C.

2003-01-01

Full Text Available An ultrasound extraction procedure for Ca, K and Mg from in vitro plant cultures is proposed, comparing cultures of different embryogenic levels of Citrus sinensis and Citrus limonia, employing ultrasound energy. Parameters related to metals extraction, such as plant material sampling, acid concentration and sonication time were investigated. For accuracy check, the proposed ultrasound extraction procedure was compared with a microwave-assisted digestion procedure and no differences in the results were verified at 95% of the confidence level. With this simple and accurate extraction procedure, it was possible to determine differences in Ca, K and Mg concentrations during Citrus embryo formation/development and between cultures (embryogenic and non-embryogenic. Finally, the ultrasound extraction method demonstrated to be an excellent alternative for handless sampling and operational costs.

An evaluation of sequence tagged microsatellite site markers for genetic analysis within Citrus and related species.

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Kijas, J M; Fowler, J C; Thomas, M R

1995-04-01

Microsatellites, also called sequence tagged microsatellite sites (STMSs), have become important markers for genome analysis but are currently little studied in plants. To assess the value of STMSs for analysis within the Citrus plant species, two example STMSs were isolated from an intergeneric cross between rangpur lime (Citrus x limonia Osbeck) and trifoliate orange (Poncirus trifoliata (L.) Raf.). Unique flanking primers were constructed for polymerase chain reaction amplification both within the test cross and across a broad range of citrus and related species. Both loci showed length variation between test cross parents with alleles segregating in a Mendelian fashion to progeny. Amplification across species showed the STMS flanking primers to be conserved in every genome tested. The traits of polymorphism, inheritance, and conservation across species mean that STMS markers are ideal for genome mapping within Citrus, which contains high levels of genetic variability.

Effect of irradiation as quarantine treatment on citrus fruit quality

International Nuclear Information System (INIS)

Betancurt, Pablo; Montalban, Antonio; Arcia, Patricia; Borthagaray, Maria D.; Curutchet, Ana; Pica, Leticia; Soria, Alejandra; Abreu, Anibal V.; Ares, M. Ines

2009-01-01

Gamma radiations have been used to improve sanitation treatments without significant effects on fresh fruit quality. The objective of this work was to evaluate the fruit quality characteristics of citrus variety Valencia (Valencia Late), main variety produced and exported in Uruguay. All samples were stored at 3-5 deg C, 80% RH, for 20 and 40 days. Irradiation doses used were 0,35 kGy min. and 0,80 kGy max. (doses that also eliminate the fruit fly). Irradiation experiments were conducted using irradiation equipment from Atomic Center (CAE), year 1968, Co60 source, 800.000 Ci. The effects of irradiation on sensory qualities and physical characteristics were studied. The attributes evaluated were visual appearance (1- 4 hedonic scale, expert), overall acceptance (1-9 hedonic scale, consumers), texture (TAB Stevens, speed: 2m/s, distance: 2mm), yield of juice and colour (Hunter values). In general, no significant changes in these parameters were observed after irradiation. Quality was not significantly affected by doses usually applied to decrease the viability of pathogen that cause citrus Scab. This is an important contribution for the protocols that would allow citrus fruit exportation. (author)

Costs and benefits of insecticide and foliar nutrient applications to huanglongbing-infected citrus trees.

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Tansey, James A; Vanaclocha, Pilar; Monzo, Cesar; Jones, Moneen; Stansly, Philip A

2017-05-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), vectors Candidatus Liberibacter asiaticus, which causes huanglongbing (HLB). In Florida, HLB incidence is approaching 100% statewide. Yields have decreased and production costs have increased since 2005. Despite this, some growers are maintaining a level of production and attribute this in part to aggressive psyllid control and foliar nutrition sprays. However, the value of these practices is debated. A replicated field study was initiated in 2008 in a commercial block of 'Valencia' sweet orange trees to evaluate individual and combined effects of foliar nutrition and ACP control. Results from 2012-2016 are presented. Insecticides consistently reduced ACP populations. However, neither insecticide nor nutrition applications significantly influenced HLB incidence or PCR copy number in mature trees. In reset trees, infection continued to build and reached 100% in all treatments. Greatest yields (kg fruit ha -1 ) and production (kg solids ha -1 ) were obtained from trees receiving both insecticides and foliar nutrition. All treatments resulted in production and financial gains relative to controls. However, material and application costs associated with the nutrition component offset these gains, resulting in lesser benefits than insecticides applied alone. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Biochemical response of skin-coated citrus fruits irradiated for preservation

International Nuclear Information System (INIS)

Ahmed, E.S.

1977-01-01

Orange fruits (citrus Sinensis) Kind Egyptian Balady variety, were irradiated for 100, 200 and 400 Krad γ-ray doses in combination with sodium orthophenylphenate, 0.0025% incorporated in wax coatings as preirradiation treatment. The data revealed the utility of combined treatment to control postharvest decay in citrus fruits. 100 Krad extend shelflife of skin-coated fruits by 15 weeks without significant losses in Vitamin C, reducing sugars, or free amino acids and without storage disorders. Unirradiated non skin-coated and unirradiated skin-coated had a shelf-life of 7, and 10 weeks, respectively, under the same experimental storage conditions (14-20 C and R.H. 65-75%)

'Florida Beauty' strawberry

Science.gov (United States)

‘Florida Beauty’ strawberry (Fragaria x ananassa) originated from a 2012 cross made by the Queensland breeding program between Queensland Australia selection 2010-119 (female parent) and ‘Florida Radiance’ (male parent). Selection 2010-119 was chosen as a parent for its excellent fruit shape and fl...

Abiotic water quality control on mangrove distribution in estuarine ...

African Journals Online (AJOL)

Due to climate change impacts and the resulting sea-level rise, saline waters have been ... (17.80 to 27.10 dS/m), while pH and DO levels were lower in the 2 km channel than in ...... grove forest in Florida, Puerto Rico, Mexico, and Costa Rica.

A filter paper-based liquid culture system for citrus shoot organogenesis - a mixture-amount experiment

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The objective of this study was to determine the effects of a static liquid culture system on shoot regeneration from citrus epicotyl explants. Two citrus types were used, Carrizo citrange and Ridge Pineapple sweet orange. A liquid culture system comprised of a Petri dish, cellulose filter paper dis...

Development of K-bioassay for the efficient potassium fertilization of citrus tree

Energy Technology Data Exchange (ETDEWEB)

U, Jang Kual [Cheju National University, Cheju (Korea, Republic of); Han, Hae Ryong [Cheju National University, Cheju (Korea, Republic of); Moon, Duk Young; Kim, Chang Myung; Lim, Han Cheol; Moon, Do Kyung [Cheju Citrus Research Institute, Cheju (Korea, Republic of); Song, Sung Jun [Cheju National Univerisity, Cheju (Korea, Republic of)

1994-12-31

a Similar to the {sup 42} K uptake, {sup 86} Rb uptake by the roots of Hordeum distichum grown in the hydroponic culture was negatively correlated with the concentration of K supplied previously, showing that {sup 86} Rb can be used for the K-bioassay. {sup 86} Rb having longer half life(18.86 day) than {sup 42} K(12.36 hr) allowed the use of larger number of root samples. {sup 86} Rb uptake of 3 years old Citrus unshiu Marc. grown in water culture decreased drastically with the increase of K concentration of the culture solution, thus demonstrating that the nutrition status of K for citrus trees can be diagnosed by K-bioassay using {sup 86} Rb tracer. {sup 86} Rb uptake by the excised roots of Hordeum distichum correlated with the exchangeable K in soil. The amount of exchangeable K in soil for the optimal plant growth can be determined by its relationship. {sup 42} K- and {sup 86} Rb-uptake by the Hordeum distichum roots were markedly inhibited by 5 x 10{sup -3} M KCN in the bioassay solution, indicating that uptake is metabolically controlled. There was no significant relationship between K content in citrus leaves and K concentration in the water-culture medium. It is concluded that K-bioassay is a potentially useful tool for determining of K requirement in citrus trees. (author)

[Parasitism in Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in Citrus orchards in Montenegro, RS, Brazil].

Science.gov (United States)

Jahnke, Simone M; Redaelli, Luiza R; Diefenbach, Lúcia M G

2006-01-01

Phyllocnistis citrella Stainton, the citrus-leafminer, is an important pest of citrus worldwide. Knowledge of natural parasitism levels is fundamental to the establishment of tactics of management and control of this species. This work aimed to evaluate the parasitism in two citrus orchards, one of 'Montenegrina' (Citrus deliciosa Ten.) and the other of 'Murcott' (C. sinensis (L.) Osbeck x C. reticulata Blanco), located in Montenegro, RS. In fortnightly samplings, from July/2001 to June/2003, all leaves containing P. citrella pupae from randomly selected plants were collected and maintained individually until emergence of the parasitoids or the citrus-leafminer. Parasitism was calculated considering the number of emerged parasitoids relative to the total number of emerged individuals. Correlation and linear regression tests were done to evaluate the relationship and the influence of biotic and abiotic factors upon the parasitism index. In both orchards the greatest parasitism percentage was registered on autumn in both years. The total percentage was 36.2% in 'Murcott' and 26.4% in 'Montenegrina' in the first year, and 30.2% and 37.6%, respectively, in the second year. In 'Murcott', this index did not differed between the years (chi2 = 2.06; df = 1; P > 0.05), in 'Montenegrina' the parasitism was significantly higher in the second year (chi2 = 7.36; df = 1; P < 0.05). The correlation and linear regression tests indicated a strong influence, in the parasitism index, of the host populational density registered in the previous 45 and 135 days.

The effect of pomelo citrus (Citrus maxima var. Nambangan), vitamin C and lycopene towards the number reduction of mice (Mus musculus) apoptotic hepatocyte caused of ochratoxin A

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Badriyah, Hastuti, Utami Sri

2017-06-01

Foods can contaminated by some mycotoxin produced by molds. Ochratoxin A is a sort of mycotoxin that cause structural damage on hepatocytes. Pomelo citrus (Citrus maxima var. Nambangan) contain vitamin C and lycopene that have antioxidant character. This research is done to: 1)examine the effect of pomelo citrus juice, vitamin C, and lycopene treatment towards the number reduction of mice apoptotic hepatocytes caused by ochratoxin A exposure, 2)examine the effect of vitamin C mixed with lycopene treatment towards the number reduction of mice apoptotic hepatocytes caused by ochratoxin A exposure. The experimental group used male mice strain BALB-C in the age of three month and bodyweight 20-30 grams devided in 4 experiment group and control group. The experiment group I were administered pomelo citrus juice 0,5 ml/30 grams BW/day orally during 2 weeks and then administered with ochratoxin in the dose of 1 mg/kg BW during 1 week. The experiment group II were administered with vitamin C in the dose of 5,85 µg/30g BW with the same methods. The experiment group III were administered with lycopene in the dose of 0,1025 µg/30 g BW with the same methods. The experiment group IV were administered with vitamin C mixed with lycopene with the same methods. The control group were administered with ochratoxin A in the dose of 1 mg/kg BW per oral during 1 week. The apoptotic hepatocyte number were count by microscopic observation of hepatocyte slides from experiment group as well as control group with cytochemical staining. The research result shows that: 1) the pomelo citrus juice, vitamin C as well as lycopene administration could reduce the mice apoptotic hepatocyte number caused by ochratoxin A exposure, compared with the mice apoptotic hepatocyte number caused by ochratoxin A exposure only; 2) the vitamin C mixed with lycopene could reduce the mice apoptotic hepatocyte number caused by ochratoxin A exposure compared with the mice apoptotic hepatocyte number caused by

Sugar and acid content of Citrus prediction modeling using FT-IR fingerprinting in combination with multivariate statistical analysis.

Science.gov (United States)

Song, Seung Yeob; Lee, Young Koung; Kim, In-Jung

2016-01-01

A high-throughput screening system for Citrus lines were established with higher sugar and acid contents using Fourier transform infrared (FT-IR) spectroscopy in combination with multivariate analysis. FT-IR spectra confirmed typical spectral differences between the frequency regions of 950-1100 cm(-1), 1300-1500 cm(-1), and 1500-1700 cm(-1). Principal component analysis (PCA) and subsequent partial least square-discriminant analysis (PLS-DA) were able to discriminate five Citrus lines into three separate clusters corresponding to their taxonomic relationships. The quantitative predictive modeling of sugar and acid contents from Citrus fruits was established using partial least square regression algorithms from FT-IR spectra. The regression coefficients (R(2)) between predicted values and estimated sugar and acid content values were 0.99. These results demonstrate that by using FT-IR spectra and applying quantitative prediction modeling to Citrus sugar and acid contents, excellent Citrus lines can be early detected with greater accuracy. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Genetic transformation in citrus: Thinking outside the box

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Conventional breeding methods to incorporate resistance in citrus are very slow, due to extended juvenility from seedling trees and multiple generations needed to incorporate resistance from distant relatives. Use of transgenic methods may provide disease resistance in less time. Published protocols...

Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri, vector of Huanglongbing.

Directory of Open Access Journals (Sweden)

Joseph M Patt

Full Text Available Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las. Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri. Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ, a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid

Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing.

Science.gov (United States)

Patt, Joseph M; Robbins, Paul S; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

2018-01-01

Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing

Science.gov (United States)

Robbins, Paul S.; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

2018-01-01

Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected ‘Valencia’ sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

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.

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.

Comparative transcriptional survey between self-incompatibility and self-compatibility in Citrus reticulata Blanco.

Science.gov (United States)

Ma, Yuewen; Li, Qiulei; Hu, Guibing; Qin, Yonghua

2017-04-20

Seedlessness is an excellent economical trait, and self-incompatibility (SI) is one of important factors resulting in seedless fruit in Citrus. However, SI molecular mechanism in Citrus is still unclear. In this study, RNA-Seq technology was used to identify differentially expressed genes related to SI reaction of 'Wuzishatangju' (Citrus reticulata Blanco). A total of 35.67GB raw RNA-Seq data was generated and was de novo assembled into 50,364 unigenes with an average length of 897bp and N50 value of 1549. Twenty-three candidate unigenes related to SI were analyzed using qPCR at different tissues and stages after self- and cross-pollination. Seven pollen S genes (Unigene0050323, Unigene0001060, Unigene0004230, Unigene0004222, Unigene0012037, Unigene0048889 and Unigene0004272), three pistil S genes (Unigene0019191, Unigene0040115, Unigene0036542) and three genes (Unigene0038751, Unigene0031435 and Unigene0029897) associated with the pathway of ubiquitin-mediated proteolysis were identified. Unigene0031435, Unigene0038751 and Unigene0029897 are probably involved in SI reaction of 'Wuzishatangju' based on expression analyses. The present study provides a new insight into the molecular mechanism of SI in Citrus at the transcriptional level. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of postharvest practices including degreening on citrus carpoplane microbial biomes.

Science.gov (United States)

Gomba, A; Chidamba, L; Korsten, L

2017-04-01

To investigate the effect of commercial citrus packhouse processing steps on the fruit surface microbiome of Clementines and Palmer navel oranges. Viable bacteria, yeast and fungi counts, and the pyrosequencing analysis of the 16S rRNA and ITS were used to evaluate the community structure and population dynamics of phylloepiphytic bacteria and fungi associated with commercial postharvest processing. Drenching significantly reduced microbial counts in all cases except for yeasts on navels, while the extent of degreening effects varied between the citrus varieties. Pyrosequencing analysis showed a total of 4409 bacteria and 5792 fungi nonchimeric unique sequences with an average of 1102 bacteria and 1448 fungi reads per sample. Dominant phyla on the citrus carpoplane were Proteobacteria (53·5%), Actinobacteria (19·9%), Bacteroidetes (5·6%) and Deinococcus-Thermus (5·4%) for bacteria and Ascomycota (80·5%) and Basidiomycota (9·8%) for fungi. Beginning with freshly harvested fruit fungal diversity declined significantly after drenching, but had little effect on bacteria and populations recovered during degreening treatments, including those for Penicillium sp. Packhouse processing greatly influences microbial communities on the citrus carpoplane. A broad orange biome was described with pyrosequencing and gave insight into the likely survival and persistence of pathogens, especially as they may affect the quality and safety of the packed product. A close examination of the microbiota of fruit and the impact of intervention strategies on the ecological balance may provide a more durable approach to reduce losses and spoilage. © 2017 The Society for Applied Microbiology.

Biology of the Huanglongbing vector Diaphorina citri (Hemiptera: Liviidae) on different host plants.

Science.gov (United States)

Alves, G R; Diniz, A J F; Parra, J R P

2014-04-01

Although many studies have been conducted on the development and reproductive potential of Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae) in different host species, few have evaluated these parameters on different varieties of the same host species. This study evaluated the influence of five commercial varieties of citrus (Citrus spp. L.)--Hamlin, Natal, Pêra, Ponkan, and Valencia-and orange jasmine [Murraya exotica (L.) Jack] on the development of D. citri. Survival rates for the egg stage were highest on orange jasmine (85.7%) and on Valencia (83.3%). The lowest viability of the nymphal stage was also observed on Hamlin, averaging 57.4%. Values for total viability ranged from 65.9 to 32.6%, and were highest on Valencia. The longest egg-adult development time was on Natal, with a mean of 18.4 d; the shortest total development time was on orange jasmine, with a mean of 17.3 d. Based on the fertility life table, the net reproductive rate (Ro) of D. citri was 2.5 times higher when reared on Valencia than on Hamlin. The other parameters (duration of each generation [T], finite rate of increase [lambda], and innate capacity to increase in number [r(m)]) also demonstrated that Valencia is best suited to this insect. The results obtained for the biological parameters and the fertility life table indicate that Valencia and orange jasmine were the most suitable hosts, whereas Hamlin was least suitable for the development of D. citri. These results provide information for the installation of new citrus groves, especially in the choice of varieties to be planted and the location of different varieties within the groves, with a view toward the management of Huanglongbing or HLB.

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.

Changes in Peroxidase Activity in the Peel of Unshiub Mandarin (Citrus unshiu Marc.) Fruit with Different Storage Treatments

OpenAIRE

Lepeduš, Hrvoje; Jozić, Marko; Štolfa, Ivna; Pavičić, Nikola; Hackenberger, Branimir K.; Cesar, Vera

2005-01-01

The Unshiu mandarin (Citrus unshiu Marc.) is the major Citrus crop in Croatia. Limiting factors for longer consumption of Unshiu mandarin are low storage performance and the appearance of chilling injuries during storage. Previous studies indicated that oxidative stress might be involved in cold-induced peel damage of harvested Citrus fruit. The aim of the present study was to investigate peroxidase distribution, isoenzyme pattern and activity in the peel of Unshiu mandarin fruit. Special goa...

Survey of citrus tristeza virus populations in Central California that react with MCA13 monoclonal antibody

Science.gov (United States)

The Citrus Pest Detection Program (CPDP) of the Central California Tristeza Eradication Agency monitors Citrus tristeza virus (CTV) in Central California. MCA13 is a severe strain discriminating monoclonal antibody used to screen for potentially virulent CTV isolates. MCA13-reactive CTV isolates are...

Resistance of sweet orange Pera (Citrus sinensis) genotypes to Xanthomonas citri subsp. citri under field conditions

Science.gov (United States)

Citrus canker control is based on protection measures and eradication of plants infected with Xanthomonas citri subsp. citri. Although these measures show satisfactory results, the use of resistant genotypes is an important alternative for citrus canker control. The aim of this study was to evaluate...

Adventive plants from ovules and nucelli in Citrus.

Science.gov (United States)

Kochba, J; Spiegel-Roy, P; Safran, H

1972-09-01

1- to 8-week-old ovules and nucelli from three Citrus cultivars-Shamouti and Valencia (Citrus sinensis) oranges and Marsh Seedless (C. paradisi) grapefruit-were cultured in vitro. No embryo differentiation was observed in the explants prior to culture. The Shamouti ovules had degenerated and were apparently unfertilized. Embryoids formed on Murashige and Tucker nutrient medium supplemented with 500 mg/l malt extract. Whole plants developed on the same basal medium supplemented with kinetin and indole-3-acetic acid (IAA), coconut milk or gibberellic acid (GA3). A higher kinetin/IAA ratio or the addition of coconut milk favoured stem elongation more than root formation while a lower kinetin/IAA ratio favoured root formation and inhibited stem elongation. The addition of GA3 to the basal medium stimulated rooting and stem elongation. These results can be of aid in mutation research, allowing irradiation at stages prior to embryonic development.

Citrus huanglongbing in São Paulo State, Brazil: PCR detection of the 'Candidatus' Liberibacter species associated with the disease.

Science.gov (United States)

do Carmo Teixeira, Diva; Luc Danet, Jean; Eveillard, Sandrine; Cristina Martins, Elaine; de Jesus Junior, Waldir Cintra; Takao Yamamoto, Pedro; Aparecido Lopes, Silvio; Beozzo Bassanezi, Renato; Juliano Ayres, Antonio; Saillard, Colette; Bové, Joseph Marie

2005-06-01

Symptoms of huanglongbing (HLB), one of the most serious diseases of citrus in Asia and Africa, have been noticed in March 2004 in the Araraquara region of São Paulo State, Brazil. HLB has not been reported previously from America. The causal HLB bacteria, Candidatus Liberibacter africanus in Africa and Candidatus Liberibacter asiaticus in Asia, can be detected in symptomatic citrus leaves by PCR amplification of their 16S rDNA with previously described primers. When this technique was applied to 43 symptomatic leaf samples from the Araraquara region, all PCR reactions were negative. This suggested that a new pathogen, not detected by the above primers, could be involved in HLB in the State of São Paulo. Indeed, by using universal primers for amplification of bacterial 16S rDNA, a new liberibacter species, Candidatus Liberibacter americanus, has recently been identified. Specific primers for PCR amplification of the 16S rDNA of Ca. L. americanus have been selected. Using these primers, the new liberibacter could be detected in 214 symptomatic leaf samples tested. The leaves of two additional samples were infected with Candidatus Liberibacter asiaticus, and two further samples contained both Ca. L. americanus and Ca. L. asiaticus. The samples came from 47 farms in 35 municipalities. The psyllid vector of Ca. L. asiaticus, Diaphorina citri, is established in South, Central, and North America (Florida and Texas). Ca. L. americanus could be detected by PCR in several batches of D. citri psyllids collected on symptomatic sweet orange trees infected with Ca. L. americanus, strongly suggesting that D. citri is the vector of Ca. L. americanus. The results reported here confirm the presence of HLB in the State of São Paulo. Ca. L. americanus is the most widely distributed pathogen.