Description of Trichodorus maryland in. sp. (Nematoda: Trichodoridae) from Maryland, USA

Authors: DECRAEMER, WILFRIDA - Ghent University; KANTOR, MIHAIL - Oak Ridge Institute For Science And Education (ORISE); Handoo, Zafar; SUBBOTIN, SERGEI - California Department Of Food And Agriculture

Submitted to: Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2021
Publication Date: 10/7/2021
Citation: Decraemer, W., Kantor, M.R., Handoo, Z.A., Subbotin, S. 2021. Description of Trichodorus maryland in. sp. (Nematoda: Trichodoridae) from Maryland, USA. Nematology. https://doi.org/10.1163/15685411-bja10132.
DOI: https://doi.org/10.1163/15685411-bja10132

Interpretive Summary: Plant-parasitic nematodes are microscopic worms that feed on plants and cause an estimated ten billion dollars of crop losses each year in the United States and 100 billion dollars globally. Stubby-root nematodes are among the most economically important groups of plant-parasitic nematodes worldwide. They can cause a stunted or stubby appearing root system on the plant host. In the present study, ARS, Ghent University, and California Department of Food and Agriculture scientists recovered several known and one new species of Trichodorus nematodes during a survey from natural vegetation in Maryland and California. They distinguished the new species from closely related ones by using molecular and anatomical features, including light microscope and line drawing images. This discovery is significant because new molecular and morphological information obtained from these species will facilitate future identifications of the stubby-root nematodes. Therefore, this research will be used by scientists, growers, action agencies, and extension agencies involved in nematode research and control.

Technical Abstract: During nematode surveys in natural vegetation in Maryland and California, USA, several Trichodorus species were found, among them a new species Trichodorus marylandi n. sp. The new species is about 1 mm long with a medium-sized onchiostyle (54 µm on average). Males are characterized by a single ventromediam cervical papilla located anterior to the secretory-excretory pore, three ventromedium precloacal supplements all located anterior to the retracted spicules and a 42 µm long spicule (average) showing a minor indentation at level of posterior border of capsule of protractor muscles. Females possess a short barrel-shaped vagina when body relaxed, and on each body side two sublateral body pores, one up to four body widths anterior to the vulva and one advulvar in position. A rare observation of a ‘hood’ dorsally attached to a moulting male juvenile was observed and illustrated. Trichodorus marylandi n. sp. is closest to Trichodorus obtusus (syn. T. proximus). Statistical parsimony network shows the phylogenetic relationships between CO1 haplotypes of T. obtusus and T. marylandi n. sp.