scholarly journals Resistance to Candidatus Liberibacter solanacearum in tomato landraces from Mexico

2019 ◽  
Author(s):  
José A. Garzón-Tiznado ◽  
Carlos A. López-Orona ◽  
Luciano Castro-Espinoza ◽  
Sixto Velarde-Félix ◽  
Marely G. Figueroa-Pérez ◽  
...  
Keyword(s):  
United States ◽  
New Zealand ◽  
Central America ◽  
Incubation Time ◽  
Plant Pathogen ◽  
The United States ◽  
Resistant Cultivars ◽  
Wide Range ◽  
Resistant Sources ◽  
United States Mexico

AbstractCandidatus Liberibacter solanacearum (CLso) is an economically important plant-pathogen of tomato (Solanum lycopersicum) crops in the United States, Mexico, Central America, and New Zealand. Currently, there are no reports of resistance to CLso in tomato cultivars. Identification and development of CLso-resistant cultivars may offer the most efficient way to manage this tomato disease. Resistance of 46 tomato landraces collected in different regions of Mexico, representing a wide range of genetic variability from this country was evaluated. Two assays were done in consecutively years to assess the resistance to CLso under greenhouse conditions. Plants from both tests were inoculated with CLso through 20 Bactericera cockerelli insects per plant. In the first trial, landraces FC22 and FC44 showed a significantly higher proportion of resistant plants, less symptoms severity, and longer incubation time, followed by landraces FC40 and FC33 compared with the rest of the 42 landraces and 2 susceptible cultivars 60 days post inoculation (dpi). In the second assay, only landraces FC22 and FC44 had again significantly higher proportion of resistant plants, less symptoms severity, relative lower CLso titers, and longer incubation time in comparison with landraces FC40 and FC33 and the two susceptible cultivars 60 dpi, corroborating their resistance to CLso. Presence of CLso DNA in all resistant plants from both assays discards scape plants and indicates that the methodology used was adequate to discriminate between resistant and susceptible plants. These results confirm that landraces FC22 and FC44 are promising resistant sources for the development of CLso-resistant cultivars of tomato.Author summaryThe bacterium “Candidatus Liberibacter solanacearum” (CLso) is an important plant-pathogen of tomato crops in the United States, Mexico, Central America, and New Zealand. Tomato growers are lacking of cultivars with resistance to this pathogen and the development of resistant cultivars of this crop would make a sustainable business for these growers and healthy tomato consumption for humans. Tomato landraces from countries that are center of domestication of cultivated crops like Mexico, are potentially sources of resistance to plant-pathogens. Therefore, two tests were done looking for resistance sources to this pathogen and we found two tomato landraces (FC22 and FC44) showing high level of resistance to CLso because they had significantly higher resistant plants, less symptoms severity, lower CLso DNA concentration, and delay of the first symptoms in the inoculated plants in comparison with the two commercial cultivars and 44 tomato landraces collected from Mexico 60 days post infection. These landraces are promising resistant sources for the development of CLso-resistant cultivars of tomato.

A BIOSYSTEMATIC REVISION OF THE GENUS MUSCIDIFURAX (HYMENOPTERA: PTEROMALIDAE) WITH DESCRIPTIONS OF FOUR NEW SPECIES

1970 ◽  
Vol 102 (10) ◽  
pp. 1268-1290 ◽  
Author(s):  
Marcos Kogan ◽  
E. F. Legner
Keyword(s):  
United States ◽  
Puerto Rico ◽  
Central America ◽  
New World ◽  
The United States ◽  
Additional Species ◽  
Local Populations ◽  
Morphological Studies ◽  
Scanning Electronmicroscopy ◽  
United States Mexico

AbstractExtensive collections of synanthropic fly parasitoids in animal excrement accumulations in the United States, Mexico, Costa Rica, Puerto Rico, Uruguay, Chile, Denmark, Israel, and South Africa yielded seven forms of a Muscidifurax complex which were totally or partially reproductively isolated. Morphological studies of female and male parasitoids coupled with biological and zoogeographical information permitted the identification of five sibling species. Muscidifurax raptor Girault and Sanders 1910 is redescribed and four additional species are described as new: M. zaraptor, from the southwestern United States; M. raptoroides from Central America and Mexico; M. uniraptor from Puerto Rico, and M. raptorellus from Uruguay and Chile. Biological notes are added to the descriptions, and it was postulated that the genus is undergoing a process of speciation with local populations slowly becoming reproductively isolated and eventually giving rise to morphologically distinguishable entities. Most evidence suggests the establishment of Muscidifurax in the New World, concomitant with or shortly following the establishment of muscoid flies in accumulated excrement. Scanning electronmicroscopy was used in the analysis of some morphological structures.

Frost tolerance of Liquidambar styraciflua native to the United States, Mexico, and Central America

1971 ◽  
Vol 49 (9) ◽  
pp. 1551-1558 ◽  
Author(s):  
George J. Williams, III ◽  
Calvin McMillan
Keyword(s):  
United States ◽  
Central America ◽  
The United States ◽  
Frost Tolerance ◽  
Liquidambar Styraciflua ◽  
United States Mexico ◽  
Amo 1618 ◽  
The U.S ◽  
Collection Sites ◽  
Selection Of

Seedlings derived from field-collected seed from the United States, Mexico, and Central America were tested for frost hardiness under laboratory conditions. U.S. seedlings grown under four controlled conditions demonstrated greatest frost hardening under cool temperatures and short day lengths. Seedlings representing northernmost U.S. collection sites developed greater frost tolerance than seedlings representing southern U.S. collection sites. In comparing United States, Mexico, and Central America seedlings, the U.S. material showed greatest frost tolerance with Mexico and Central America demonstrating similar hardiness. The application of plant hormones (natural gibberellic acid and artificial AMO-1618) produced opposite effects on U.S. seedlings derived from Connecticut and Florida seed. The Connecticut seedlings demonstrated greatest frost tolerance in all treatments. Demonstrated frost tolerance differences among United States, Mexico, and Central America populations strongly indicate selection of frost hardy races in habitats with severe frost conditions.

scholarly journals Organic Apple Production in Two Humid Regions: Comparing Progress in Pest Management Strategies in Iowa and New Zealand

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Kathleen Delate ◽  
Andrea McKern ◽  
Robert Turnbull ◽  
James T.S. Walker ◽  
Richard Volz ◽  
...  
Keyword(s):  
United States ◽  
New Zealand ◽  
Pest Management ◽  
Management Strategies ◽  
Codling Moth ◽  
The United States ◽  
Organic Production ◽  
Population Increase ◽  
Resistant Cultivars ◽  
Integrated Fruit Production

By 2003, organic apple [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] production had increased to 5626 ha in the United States and to 2964 ha in New Zealand by 2002. Common problems facing organic apple growers in the humid regions of New Zealand and the United States include effective management strategies for apple scab [Venturia inaequalis (Cooke)] and insect pests. Experiments conducted in Iowa in 2003–2004 demonstrated the effectiveness of a kaolin clay- and spinosad-based insecticide program in maintaining codling moth [Cydia pomonella (L.)] damage levels to less than 5% in the scab-resistant cultivars Enterprise, Liberty, Redfree, and Gold Rush. Similar pest management systems have been developed in New Zealand to comply with export standards and quarantines. The use of codling moth granulosis virus and a spinosad-based insecticide have led to reduced pest pressure and to an increase in organic exports with a 41% premium price over conventional apples. However, an association between spinosad use and woolly apple aphid [Eriosoma lanigerum (Hausmann)] population increase was observed in organic orchard surveys in 2006. An alternative to spinosad applications, insect disinfestation through controlled atmosphere (CA) treatment, was investigated to control quarantined pests and to extend the storage potential of scab-resistant cultivars. A CA treatment of 9 weeks of 2% O2 and 2% CO2 at 0.5 °C was determined to maintain firmness ratings to export standards in CA-stored, scab-resistant ‘Pinkie’ apples and to decrease internal ethylene concentration by 84% compared with apples stored in air. In addition, new scab-resistant cultivars with ‘Pinkie’ background under development in New Zealand show promise for organic production in humid regions. Few fruit quality differences were determined between ‘Pinkie’ fruits from integrated fruit production and organic production systems, although premium prices exist only for certified organic apples.

Synthesis of Results from the North American Monsoon Experiment (NAME) Process Study

2007 ◽  
Vol 20 (9) ◽  
pp. 1601-1607 ◽  
Author(s):  
Wayne Higgins ◽  
David Gochis
Keyword(s):  
United States ◽  
Central America ◽  
North American ◽  
The United States ◽  
Background Information ◽  
North American Monsoon ◽  
The North ◽  
Process Study ◽  
Monsoon System ◽  
United States Mexico

Abstract An international team of scientists from the United States, Mexico, and Central America carried out a major field campaign during the summer of 2004 to develop an improved understanding of the North American monsoon system leading to improved precipitation forecasts. Results from this campaign, which is the centerpiece of the North American Monsoon Experiment (NAME) Process Study, are reported in this issue of the Journal of Climate. In addition to a synthesis of key findings, this brief overview article also raises some important unresolved issues that require further attention. More detailed background information on NAME, including motivating science questions, where NAME 2004 was conducted, when, and the experimental design, was published previously by Higgins et al.

scholarly journals Pathogenicity, Virulence, and Vegetative Compatibility Grouping of Verticillium Isolates from Spinach Seed

Plant Disease ◽  
2013 ◽  
Vol 97 (11) ◽  
pp. 1457-1469 ◽  
Author(s):  
Angela M. Iglesias-Garcia ◽  
Maria I. Villarroel-Zeballos ◽  
Chunda Feng ◽  
Lindsey J. du Toit ◽  
James C. Correll
Keyword(s):  
United States ◽  
New Zealand ◽  
The Netherlands ◽  
Pacific Northwest ◽  
Its Region ◽  
The United States ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Groups ◽  
Wide Range ◽  
Seed Crops

In 2005, Verticillium dahliae was first reported to be pathogenic to spinach seed crops in the Pacific Northwest, with symptoms only developing after initiation of the reproductive stage of plant growth, and to be prevalent on commercial spinach seed lots produced in Denmark, The Netherlands, and the United States. In this study, the genetic diversity, pathogenicity, and virulence were examined for a collection of isolates of Verticillium spp. from spinach as well as other hosts (alfalfa, cotton, lettuce, mint, peppermint, potato, radish, and tomato) from various countries and from different vegetative compatibility groups (VCGs). Of a total of 210 isolates of V. dahliae obtained from spinach seed produced in Denmark, the Netherlands, New Zealand, or the United States, 128 were assigned to VCG 4B (89% of 91 U.S. isolates, 86% of 42 isolates from the Netherlands, 19% of 43 Denmark isolates, and 8% of 13 New Zealand isolates), 65 to VCG 2B (92% of the New Zealand isolates, 79% of the Denmark isolates, 14% of the Netherlands isolates, and 9% of the U.S. isolates), and 3 to VCG 2A (2% of each of the Denmark and U.S. isolates, and 0% of the Netherlands and New Zealand isolates); 14 isolates could not be assigned to a VCG. Although little variation in the sequence of the internal transcribed spacer (ITS) region of ribosomal DNA was observed among isolates within each Verticillium sp., the ITS region readily differentiated isolates of the species V. dahliae, V. tricorpus, and Gibellulopsis nigrescens (formerly V. nigrescens) obtained from spinach seed. Greenhouse pathogenicity assays on spinach, cotton, lettuce, and tomato plants using isolates of V. dahliae (n = 29 to 34 isolates), V. tricorpus (n = 3), G. nigrescens (n = 2), and V. albo-atrum (n = 1) originally obtained from these hosts as well as from alfalfa, mint, peppermint, potato, and radish, revealed a wide range in virulence among the isolates. Isolates of V. tricorpus and G. nigrescens recovered from spinach seed and an isolate of V. albo-atrum from alfalfa were not pathogenic on spinach. In addition, isolates of V. dahliae from mint and peppermint were not pathogenic or only weakly virulent on the hosts evaluated. Although there was a wide range in virulence among the isolates of V. dahliae tested, all of the V. dahliae isolates caused Verticillium wilt symptoms on spinach, lettuce, tomato, and cotton. None of the isolates of V. dahliae showed host specificity. These results indicate that Verticillium and related species associated with spinach seed display substantial variability in virulence and pathogenicity to spinach and other plants but the V. dahliae isolates were restricted to three VCGs.

Cytogenetic and isozyme studies of wild and cultivated Capsicum annuum

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 279-282 ◽  
Author(s):  
C. Conicella ◽  
A. Errico ◽  
F. Saccardo
Keyword(s):  
United States ◽  
Gene Duplication ◽  
Central America ◽  
Capsicum Annuum ◽  
Alternative Explanation ◽  
The United States ◽  
Central Mexico ◽  
Hybridization Test ◽  
Translocation Heterozygosity ◽  
United States Mexico

The esterase isozymes of 15 wild and cultivated accessions of Capsicum annuum from different geographic areas throughout the United States, Mexico, Central America, and South America showed three patterns. All accessions from central Mexico, including the cultivated type, and some from the United States, had pattern A. Other accessions from the United States, those from Central America, and those from Peru had pattern B; those from Colombia had pattern C. Pattern C had more bands, apparently identical with those in the hybrids between A and B. F1 plants between the Colombian accession used in a hybridization test and accessions with patterns A and B showed associations of four or six chromosomes at metaphase I of meiosis. The hypothesis is discussed that pattern C resulted from a process of gene duplication. The alternative explanation of permanent translocation heterozygosity is excluded because in the Colombian accessions no multivalents were observed at meiosis.Key words: Capsicum, geographic distributions, duplication, translocation, isozymes.

Effectiveness of Programs for the Prevention of Child Sexual Abuse

2020 ◽  
Vol 25 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Amaia Del Campo ◽  
Marisalva Fávero
Keyword(s):  
United States ◽  
Sexual Abuse ◽  
New Zealand ◽  
Critical Analysis ◽  
Prevention Programs ◽  
The United States ◽  
Sexual Abuse Prevention ◽  
Negative Effects ◽  
The United Kingdom ◽  
Methodological Considerations

Abstract. During the last decades, several studies have been conducted on the effectiveness of sexual abuse prevention programs implemented in different countries. In this article, we present a review of 70 studies (1981–2017) evaluating prevention programs, conducted mostly in the United States and Canada, although with a considerable presence also in other countries, such as New Zealand and the United Kingdom. The results of these studies, in general, are very promising and encourage us to continue this type of intervention, almost unanimously confirming its effectiveness. Prevention programs encourage children and adolescents to report the abuse experienced and they may help to reduce the trauma of sexual abuse if there are victims among the participants. We also found that some evaluations have not considered the possible negative effects of this type of programs in the event that they are applied inappropriately. Finally, we present some methodological considerations as critical analysis to this type of evaluations.

The Politics of Precaution

2012 ◽  
Author(s):  
David Vogel
Keyword(s):  
United States ◽  
Animal Feed ◽  
The United States ◽  
Hazardous Substances ◽  
Risk Regulation ◽  
Scientific Certainty ◽  
European Public ◽  
Wide Range ◽  
Regulatory Controls ◽  
Milk Hormones

This book examines the politics of consumer and environmental risk regulation in the United States and Europe over the last five decades, explaining why America and Europe have often regulated a wide range of similar risks differently. It finds that between 1960 and 1990, American health, safety, and environmental regulations were more stringent, risk averse, comprehensive, and innovative than those adopted in Europe. But since around 1990 global regulatory leadership has shifted to Europe. What explains this striking reversal? This book takes an in-depth, comparative look at European and American policies toward a range of consumer and environmental risks, including vehicle air pollution, ozone depletion, climate change, beef and milk hormones, genetically modified agriculture, antibiotics in animal feed, pesticides, cosmetic safety, and hazardous substances in electronic products. The book traces how concerns over such risks—and pressure on political leaders to do something about them—have risen among the European public but declined among Americans. The book explores how policymakers in Europe have grown supportive of more stringent regulations while those in the United States have become sharply polarized along partisan lines. And as European policymakers have grown more willing to regulate risks on precautionary grounds, increasingly skeptical American policymakers have called for higher levels of scientific certainty before imposing additional regulatory controls on business.

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