Mixing Elemental Sulfur or Chlorothalonil with QoI and DMI Fungicides for Management of Late Leaf Spot of Peanut.

Reduced sensitivity to demethylation inhibitor (DMI) and quinone outside inhibitor (QoI) fungicides in Nothopassalora personata, the cause of late leaf spot of peanut (Arachis hypogaea) complicates management of this disease in the southeastern U.S. Mixtures with protectant fungicides may help preserve the utility of members of both DMI and QoI fungicide groups for leaf spot management.

Linkage Mapping and Genome-Wide Association Study Identified Two Peanut Late Leaf Spot Resistance Loci, -1 and -2, Using Nested Association Mapping.

Identification of candidate genes and molecular markers for late leaf spot (LLS) disease resistance in peanut () has been a focus of molecular breeding for the U.S. industry-funded peanut genome project.

Characterization of gene expression patterns in response to an orthotospovirus infection between two diploid peanut species and their hybrid.

Tomato spotted wilt orthotospovirus (TSWV) transmitted by thrips causes significant yield loss in peanut ( L.) production. Use of peanut cultivars with moderate field resistance has been critical for TSWV management.

Evaluation of Wild Peanut Species and Their Allotetraploids for Resistance against Thrips and Thrips-Transmitted Tomato Spotted Wilt Orthotospovirus (TSWV).

Thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) causes spotted wilt disease in peanut ( L.) and limits yield. Breeding programs have been developing TSWV-resistant cultivars, but availability of sources of resistance against TSWV in cultivated germplasm is extremely limited.

Impact of Host Resistance to Tomato Spotted Wilt Orthotospovirus in Peanut Cultivars on Virus Population Genetics and Thrips Fitness.

Thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) is a major constraint to peanut production in the southeastern United States. Peanut cultivars with resistance to TSWV have been widely used for over twenty years. Intensive usage of resistant cultivars has raised concerns about possible selection pressure against TSWV and a likelihood of resistance breakdown.

Defense-Related Gene Expression Following an Orthotospovirus Infection Is Influenced by Host Resistance in .

Planting resistant cultivars is the most effective tactic to manage the thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) in peanut plants. However, molecular mechanisms conferring resistance to TSWV in resistant cultivars are unknown. In this study, transcriptomes of TSWV-susceptible (SunOleic 97R) and field-resistant (Tifguard) peanut cultivars with and without TSWV infection were assembled and differentially expressed genes (DEGs) were compared.

High Throughput Sequencing-Aided Survey Reveals Widespread Mixed Infections of Whitefly-Transmitted Viruses in Cucurbits in Georgia, USA.

Viruses transmitted by the sweet potato whitefly () have been detrimental to the sustainable production of cucurbits in the southeastern USA. Surveys were conducted in the fall of 2019 and 2020 in Georgia, a major cucurbit-producing state of the USA, to identify the viruses infecting cucurbits and their distribution. Symptomatic samples were collected and small RNA libraries were prepared and sequenced from three cantaloupes, four cucumbers, and two yellow squash samples.

Induction of Plant Resistance in Tobacco against Tomato Spotted Wilt Orthotospovirus through Foliar Application of dsRNA.

Thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) continues to be a constraint to peanut, pepper, tobacco, and tomato production in Georgia and elsewhere. TSWV is being managed by an integrated disease management strategy that includes a combination of cultural practices, vector management, and growing virus-resistant varieties where available. We used a non-transgenic strategy to induce RNA interference (RNAi)-mediated resistance in tobacco () plants against TSWV.

Sensitivity of Isolates from Peanut Seeds in Georgia to Azoxystrobin, a Quinone outside Inhibitor (QoI) Fungicide.

infects peanuts and produces a mycotoxin called aflatoxin, a potent human carcinogen. In infected peanuts, it can also affect peanut seed quality by causing seed rot and reducing seed viability, resulting in low germination. In 2020, peanut seeds in Georgia had lower than expected germination and a high frequency of contamination.

Assessment of Quinone Outside Inhibitor Sensitivity and Frogeye Leaf Spot Race of in Georgia Soybean.

Frogeye leaf spot (FLS), caused by the fungal pathogen K. Hara, is a foliar disease of soybean ( L. [Merr.

Effect of In-Furrow Application of Fluopyram on Leaf Spot Diseases of Peanut.

In peanut () production, in-furrow applications of the premix combination of the succinate-dehydrogenase-inhibitor (SDHI) fungicide and nematicide fluopyram and the insecticide imidacloprid are used primarily for management of nematode pests and for preventing feeding damage on foliage caused by tobacco thrips (). Fluopyram is also active against many fungal pathogens. However, the effect of in-furrow applications of fluopyram on early leaf spot () or late leaf spot () has not been characterized.

Adding Epidemiologically Important Meteorological Data to Peanut Rx, the Risk Assessment Framework for Spotted Wilt of Peanut.

Management of disease affecting peanut in the southeastern United States has benefited from extensive field research identifying disease-associated risk factors since the 1990s. An assessment of risk factors associated with tomato spotted wilt (TSW), caused by tomato spotted wilt virus and spread exclusively by thrips, is available to growers through Peanut Rx, a tool developed to inform peanut management decisions. Peanut Rx provides an assessment of relative TSW risk as an index.

Publisher Correction: A recombination bin-map identified a major QTL for resistance to Tomato Spotted Wilt Virus in peanut (Arachis hypogaea).

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A recombination bin-map identified a major QTL for resistance to Tomato Spotted Wilt Virus in peanut (Arachis hypogaea).

Tomato spotted wilt virus (TSWV) is a devastating disease to peanut growers in the South-eastern region of the United States. Newly released peanut cultivars in recent years are crucial as they have some levels of resistance to TSWV. One mapping population of recombinant inbred line (RIL) used in this study was derived from peanut lines of SunOleic 97R and NC94022.

Comparison of transcriptomes of an orthotospovirus vector and non-vector thrips species.

Thrips transmit one of the most devastating plant viruses worldwide-tomato spotted wilt tospovirus (TSWV). Tomato spotted wilt tospovirus is a type species in the genus Orthotospovirus and family Tospoviridae. Although there are more than 7,000 thrips species, only nine thrips species are known to transmit TSWV.

Relating Peanut Rx Risk Factors to Epidemics of Early and Late Leaf Spot of Peanut.

Previous research has demonstrated the efficacy of prescription fungicide programs, based upon Peanut Rx, to reduce combined effects of early leaf spot (ELS), caused by (), and late leaf spot (LLS), caused by (syn. ), but the potential of Peanut Rx to predict each disease has never been formally evaluated. From 2010 to 2016, non-fungicide-treated peanut plots in Georgia and Florida were sampled to monitor the development of ELS and LLS.

Major QTLs for Resistance to Early and Late Leaf Spot Diseases Are Identified on Chromosomes 3 and 5 in Peanut ().

Early and late leaf spots (LLSs) are the major foliar diseases of peanut responsible for severely decreased yield in the absence of intensive fungicide spray programs. Pyramiding host resistance to leaf spots in elite cultivars is a sustainable solution to mitigate the diseases. In order to determine the genetic control of leaf spot disease resistance in peanut, a recombinant inbred line population (Florida-07 × GP-NC WS16) segregating for resistance to both diseases was used to construct a SNP-based linkage map consisting of 855 loci.

Effect of Planting Date and Peanut Cultivar on Epidemics of Late Leaf Spot in Georgia.

Field trials were conducted in 2015 and 2016 in Tifton, GA to determine the effects of planting dates (24 and 27 April, 4, 11, 19, and 26 May 2015; and 11, 18, and 25 April and 2, 9, and 16 May 2016), peanut () cultivar (Georgia-06G and Georgia-12Y), and seed treatment (nontreated and treated with azoxystrobin, fludioxonil, and mefenoxam) on epidemics of late leaf spot (), plant populations, and peanut yield. Final severity and AUDPC of late leaf spot increased with later planting dates in both years. For most planting dates in 2015 and the final planting date in 2016, final leaf spot severity and AUDPC were lower for Georgia-12Y than for Georgia-06G.

Resistance to Thrips in Peanut and Implications for Management of Thrips and Thrips-Transmitted Orthotospoviruses in Peanut.

Thrips are major pests of peanut ( L.) worldwide, and they serve as vectors of devastating orthotospoviruses such as (TSWV) and (GBNV). A tremendous effort has been devoted to developing peanut cultivars with resistance to orthotospoviruses.

High-density genetic map using whole-genome resequencing for fine mapping and candidate gene discovery for disease resistance in peanut.

Whole-genome resequencing (WGRS) of mapping populations has facilitated development of high-density genetic maps essential for fine mapping and candidate gene discovery for traits of interest in crop species. Leaf spots, including early leaf spot (ELS) and late leaf spot (LLS), and Tomato spotted wilt virus (TSWV) are devastating diseases in peanut causing significant yield loss. We generated WGRS data on a recombinant inbred line population, developed a SNP-based high-density genetic map, and conducted fine mapping, candidate gene discovery and marker validation for ELS, LLS and TSWV.

Mapping Late Leaf Spot Resistance in Peanut () Using QTL-seq Reveals Markers for Marker-Assisted Selection.

Late leaf spot (LLS; ) is a major fungal disease of cultivated peanut (). A recombinant inbred line population segregating for quantitative field resistance was used to identify quantitative trait loci (QTL) using QTL-seq. High rates of false positive SNP calls using established methods in this allotetraploid crop obscured significant QTLs.

Late Leaf Spot Severity and Yield of New Peanut Breeding Lines and Cultivars Grown Without Fungicides.

Peanut (Arachis hypogaea) cultivars with resistance or tolerance to Cercospora arachidicola and/or Cercosporidium personatum, the causes of early and late leaf spot, respectively, are needed for organic production in the southeastern U.S. To determine the potential of new breeding lines for use in such production systems, field experiments were conducted in Tifton, GA, in 2014 and 2015 in which nine breeding lines and two cultivars, Georgia-06G and Georgia-12Y, were grown without foliar fungicide applications.

Transcriptome changes associated with Tomato spotted wilt virus infection in various life stages of its thrips vector, Frankliniella fusca (Hinds).

Persistent propagative viruses maintain intricate interactions with their arthropod vectors. In this study, we investigated the transcriptome-level responses associated with a persistent propagative phytovirus infection in various life stages of its vector using an Illumina HiSeq sequencing platform. The pathosystem components included a Tospovirus, Tomato spotted wilt virus (TSWV), its insect vector, Frankliniella fusca (Hinds), and a plant host, Arachis hypogaea (L.

Genetic Dissection of Novel QTLs for Resistance to Leaf Spots and Tomato Spotted Wilt Virus in Peanut ( L.).

Peanut is an important crop, economically and nutritiously, but high production cost is a serious challenge to peanut farmers as exemplified by chemical spray to control foliar diseases such as leaf spots and thrips, the vectors of tomato spotted wilt virus (TSWV). The objective of this research was to map the quantitative trait loci (QTLs) for resistance to leaf spots and TSWV in one recombinant inbred line (RIL) mapping population of "Tifrunner × GT-C20" for identification of linked markers for marker-assisted breeding. Here, we report the improved genetic linkage map with 418 marker loci with a marker density of 5.