Impacts of Grapevine Leafroll Disease on Fruit Yield and Grape and Wine Chemistry in a Wine Grape (Vitis vinifera L.) Cultivar.

Grapevine leafroll disease (GLD) is an economically important virus disease affecting wine grapes (Vitis vinifera L.), but little is known about its effect on wine chemistry and sensory composition of wines. In this study, impacts of GLD on fruit yield, berry quality and wine chemistry and sensory features were investigated in a red wine grape cultivar planted in a commercial vineyard.

Discrepancy in compliance between the clinical and genetic diagnosis of choroidal hypoplasia in Danish Rough Collies and Shetland Sheepdogs.

Collie eye anomaly (CEA) is a congenital, inherited ocular disorder which is widespread in herding breeds. Clinically, the two major lesions associated with CEA are choroidal hypoplasia (CH) and coloboma, and both lesions are diagnosed based on ophthalmological examination. A 7.

Impact of extended maceration and regulated deficit irrigation (RDI) in Cabernet Sauvignon wines: characterization of proanthocyanidin distribution, anthocyanin extraction, and chromatic properties.

The impact of extended maceration (EM) was studied in Cabernet Sauvignon grapes sourced from a vineyard subjected to four regulated deficit irrigation (RDI) treatments: (I) 100% replenishment of crop evapotranspiration (100% ETc), (II) 70% ETc, (III) 25% ETc until véraison, followed by 100% ETc until harvest, and IV) 25% ETc. Each vineyard replicate was made into wine with two replicates designated as controls (10-day skin contact) and two as extended maceration (EM, 30-day skin contact). The mean degree of polymerization (mDP), size distribution, concentration, and composition of wine proanthocyanidins (PAs) and monomeric flavan-3-ols of 90 fractions were characterized by preparative and analytical HPLC techniques.

Two independent quantitative trait loci are responsible for novel resistance to beet curly top virus in common bean landrace G122.

Beet curly top virus, often referred to as Curly top virus (CTV), is an important virus disease of common bean in the semiarid regions of the United States, Canada, and Mexico and the only effective control is genetic resistance. Our objective was to determine if dry bean landrace G122, which lacks the Bct gene for resistance to CTV, contains novel resistance to the virus. Two populations, GT-A and GT-B, consisting of 98 F5:7 recombinant inbred lines (RILs) in total were derived from a cross between G122 and the susceptible variety Taylor Horticultural and evaluated for phenotypic response to natural CTV field infection.

A PCR-Based Assay by Sequence-Characterized DNA Markers for the Identification and Detection of Aphanomyces euteiches.

ABSTRACT Polymerase chain reaction (PCR) products were identified and amplified from isolates of Aphanomyces euteiches and A. cochlioides. The products were cloned and sequenced, and the data were used to design pairs of extended PCR primers to amplify sequence-characterized DNA markers.

Generation and Molecular Mapping of a Sequence Characterized Amplified Region Marker Linked with the Bct Gene for Resistance to Beet curly top virus in Common Bean.

ABSTRACT A random amplified polymorphic DNA (RAPD) marker directly linked (0.0 cM) with a resistance gene was identified in a snap bean recombinant inbred population (Moncayo x Primo) consisting of 94 F(5:7) recombinant inbred lines that had uniform segregation for disease reaction to Beet curly top virus (BCTV) across three field locations. Resistance was conditioned by a single dominant allele tentatively designated Bct.

Detection of Erysiphe necator in Air Samples Using the Polymerase Chain Reaction and Species-Specific Primers.

ABSTRACT A polymerase chain reaction (PCR) assay employing species-specific primers was developed to differentiate Erysiphe necator from other powdery mildews common in the northwest United States. DNA was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a Burkard cyclonic surface sampler. To differentiate E.

Development of a Real-Time Polymerase Chain Reaction Assay for Quantifying Verticillium albo-atrum DNA in Resistant and Susceptible Alfalfa.

ABSTRACT A precise real-time polymerase chain reaction (PCR) assay was developed for quantifying Verticillium albo-atrum DNA. The assay was used in a repeated experiment to examine the relationship between the quantity of pathogen DNA detected in infected leaves and shoots and the severity of Verticillium wilt symptoms in several alfalfa cultivars expressing a range of disease symptoms. Plants were visually inspected for symptoms and rated using a disease severity index ranging from 1 to 5, and the quantity of pathogen DNA present in leaves and stems was determined with real-time PCR.

NL-3 K Strain Is a Stable and Naturally Occurring Interspecific Recombinant Derived from Bean common mosaic necrosis virus and Bean common mosaic virus.

ABSTRACT A strain of Bean common mosaic necrosis virus (BCMNV) from Idaho was identified by enzyme-linked immunosorbent assay using monoclonal antibodies and determined to be similar to the NL-3 D strain (of Drifjhout) by reaction of differential bean cultivars. However, this BCMNV strain (designated NL-3 K) caused earlier and more severe symptoms on bean plants representing host groups 0, 4, and 5. The nucleotide sequence encoding the predicted polyprotein of NL-3 K was 9,893 nucleotides (nt) in length, yielding a peptide with a molecular size of 362.

A Strain of Clover yellow vein virus that Causes Severe Pod Necrosis Disease in Snap Bean.

Soybean aphid (Aphis glycines) outbreaks occurring since 2000 have been associated with severe virus epidemics in snap bean (Phaseolus vulgaris) production in the Great Lakes region. Our objective was to identify specific viruses associated with the disease complex observed in the region and to survey bean germplasm for sources of resistance to the causal agents. The principle causal agent of the disease complex associated with extensive pod necrosis was identified as Clover yellow vein virus (ClYVV), designated ClYVV-WI.

Heritability of Resistance to Verticillium Wilt in Alfalfa.

Verticillium wilt of alfalfa, caused by Verticillium albo-atrum, may reduce forage yields by up to 50% in alfalfa-producing areas of the northern United States and Canada. It has been suggested that cultivars require at least 60% resistant plants to afford maximum protection against disease. Our objective was to calculate heritability estimates of resistance to Verticillium wilt in alfalfa.

First Report of Brown Root Rot of Alfalfa Caused by Phoma sclerotioides in Wisconsin.

Brown root rot (BRR) has been associated with winterkill of alfalfa (Medicago sativa L.) in the temperate regions of North America where winters are severe (1). Although suspected, BRR has not been associated with winterkill of alfalfa in the upper Midwestern United States.

Characterization of a New Potyvirus Naturally Infecting Chickpea.

During the 1999 to 2001 growing seasons, symptoms consisting of mosaic, stunting, yellowing, wilting, shortening of internodes, and phloem discoloration were observed in chickpea (Cicer arietinum) grown in the Department of Chuquisaca in southern Bolivia. In some fields, approximately 10% of the plants exhibited viruslike symptoms and suffered greatly reduced seed yields. Lentil (Lens culinaris) was also observed to be infected but not pea (Pisum sativum) or faba bean (Vicia faba) growing in nearby fields.

A Rapid Method Using PCR-Based SCAR Markers for the Detection and Identification of Phoma sclerotioides: The Cause of Brown Root Rot Disease of Alfalfa.

A rapid technique for identification and detection of Phoma sclerotioides, the causal agent of brown root rot of alfalfa, has been developed using polymerase chain reaction (PCR). Amplification products obtained from random amplified polymorphic DNA (RAPD) reactions were cloned and sequenced, and two extended primer sets were designed from the resulting data that were used to detect sequence-characterized DNA markers. A single 499-bp DNA amplification product was consistently obtained from primers PSB12 that was specific for 19 isolates of P.

Nucleotide sequence shows that Bean leafroll virus has a Luteovirus-like genome organization.

The complete nucleotide sequence of the Bean leafroll virus (BLRV) genomic RNA and the termini of its smallest subgenomic RNAs were determined to better understand its mechanisms of gene expression and replication and its phylogenetic position within the Luteoviridae: The number and placement of open reading frames (ORFs) within the BLRV genome was Luteovirus-like. The nucleotide and predicted amino acid sequences of BLRV were most similar to those of Soybean dwarf virus (SbDV). Phylogenetic analyses employing the neighbour-joining method and sister-scanning analysis indicated that the BLRV nonstructural proteins were closely related to those of Barley yellow dwarf virus-PAV (BYDV-PAV), a luteovirus: The region surrounding the frameshift at the junction between ORFs 1 and 2 also contained sequences very similar to those of BYDV-PAV and a Dianthovirus, Red clover necrotic mosaic virus.

First Report of Bean Leafroll Luteovirus Infecting Pea in Italy.

Approximately 5,000 ha of processing peas (Pisum sativum L) are cultivated annually in the Po River Valley of northern Italy. During the 1998 growing season, affected pea plants in this region were observed that exhibited mild chlorosis and mottling, leaf rolling, and stunting symptoms. High aphid populations and disease levels of nearly 100% were observed in susceptible varieties.

First Report of Red Clover Vein Mosaic Carlavirus Naturally Infecting Lentil.

Lentil (Lens culinaris Medik.) is an important legume crop grown in the dryland Pacific Northwest areas of eastern Washington and Oregon, and northern Idaho. Lentil is highly susceptible to pea enation mosaic enamovirus (PEMV) and bean leafroll luteovirus (BLRV), and infection may result in severe yield losses.