Phylogeographic and Phylogenomic Structure of the Quarantine Plant Pathogen , Including New Reports in the United States.

Global agricultural trade has accelerated the emergence and re-emergence of new plant pathogens. In the United States, the fungal pathogen is still considered a foreign quarantine pathogen that affects ornamental plants (i.e.

Quantitative field testing Heterodera glycines from metagenomic DNA samples isolated directly from soil under agronomic production.

A quantitative PCR procedure targeting the Heterodera glycines ortholog of the Caenorhabditis elegans uncoordinated-78 gene was developed. The procedure estimated the quantity of H. glycines from metagenomic DNA samples isolated directly from field soil under agronomic production.

Quantitative field testing Rotylenchulus reniformis DNA from metagenomic samples isolated directly from soil.

A quantitative PCR procedure targeting the β-tubulin gene determined the number of Rotylenchulus reniformis Linford & Oliveira 1940 in metagenomic DNA samples isolated from soil. Of note, this outcome was in the presence of other soil-dwelling plant parasitic nematodes including its sister genus Helicotylenchus Steiner, 1945. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from soil.

First Report of Bipolaris oryzae Causing Leaf Spot of Switchgrass in Mississippi.

'Alamo' switchgrass (Panicum virgatum L.) seedlings growing in a soilless mix exhibiting dark brown, irregular-shaped foliar lesions with black borders were submitted to the Mississippi State University Plant Disease Diagnostic Laboratory in the summer of 2009 from a local forest products company. Symptomatic tissues were plated onto water agar (WA) and incubated for 21 days on a laboratory bench top with a 12-h photoperiod at 22°C.

First Occurrence of Laurel Wilt Disease Caused by Raffaelea lauricola on Redbay Trees in Mississippi.

Laurel wilt is a lethal, nonnative vascular wilt disease of redbay (Persea borbonia), sassafras (Sassafras albidum), and other trees in the Lauraceae (1,4). It is caused by a fungus (Raffaelea lauricola) and transmitted by the redbay ambrosia beetle (Xyleborus glabratus), a nonnative insect first detected in Georgia in 2002 (1,2). Since introduction of the pathogen and vector (presumably from Asia), laurel wilt has caused extensive mortality to redbays in Georgia, Florida, and South Carolina (1).