Project Number: 1907-22000-021-00
Project Type: Appropriated

Start Date: Feb 26, 2012
End Date: Feb 25, 2017

Objective:
1: Improve detection and management for potato cyst nematode (PCN) and potato virus Y (PVY). 1.1: Develop management options for emerging pathotypes of PCN (G. rostochiensis). 1.2: Reduce PVY incidence in seed stocks and the potato crop. 2: Discover and characterize genes and proteins that influence virus-vector-host or nematode-host interactions for potato and grain crops. 2.1: Characterize candidate nematode parasitism genes and their associated host proteins contributing to plant parasitism. 2.2: Develop biomarkers for circulative virus transmission competence in aphid populations. 2.3: Define how luteovirus proteins orchestrate virus movement within plants and aphid vectors. 3: Develop potatoes resistant to virus or nematode infection. 3.1: Determine the resistance of potato cultivars and clones to pathotypes of PCN (G. rostochiensis). 3.2: Determine the susceptibility of potato cultivars to potato tuber necrotic ringspot disease (PTNRD) caused by some necrotic strains of PVY.

Approach:
Viruses and cyst nematodes present the United States potato industry with its most severe regula-tory problems. This project primarily focuses on potato cyst nematodes (PCN), Potato virus Y (PVY), and Luteoviruses including Potato leafroll virus (PLRV) and the viruses causing barley yellow dwarf disease of cereal crops. The two species of PCN (Globodera rostochiensis and G. pallida) are quaran-tine pests that cause direct crop losses, increase pest control costs, constrain cropping patterns, de-value property, and interfere with domestic and international trade of potato and many other soil-associated crops. PVY and PLRV cause crop losses, interfere with marketing and trade of potato, and are the major diseases targeted by seed potato certification programs. Additionally, management options for vector-borne viruses are extremely limited and an understanding of the mechanisms by which viruses are carried between hosts by insects will lead to new targets of opportunity to control these pathogens. In recent years, PCN and the necrotic strains of PVY have been spreading to new areas. It has been determined that the population genetics of PCN and viral pathogens are far more dynamic than previously thought, and these genetic shifts profoundly influence disease detection and management strategies. The overarching research goal is to develop an understanding of the major genetic and environmental factors that drive the dynamics of nematode and virus diseases. Multifaceted objectives needed to accomplish this research goal include: the improvement of detection and management strategies of the various pathogen populations, the identification of genetic mechanisms that regulate nematode and virus pathogenicity and pathogen movement within the crops, and the development of new sources of resistance in potato germplasm. Approaches include epidemiological and etiological studies to identify major factors contributing to the spread and diversification of these pathogens, fundamental studies of the mechanisms of pathogenesis and transmission of PCN and viruses, respectively and the collaborative development of potato germplasm with effective resistance to PCN and viruses. Rapid identification and containment, coupled with new strategies for management of nematode and virus diseases will help the U.S. potato industry remain viable and allow them to expand market share.