Location: Emerging Pests and Pathogens ResearchTitle: An evaluation of two H1-linked markers and their suitability for selecting Globodera rostochiensis resistant potatoes in the New York breeding program
|PARK, JAEBUM - Cornell University - New York|
|DEJONG, WALTER - Cornell University - New York|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2017
Publication Date: 12/22/2017
Citation: Park, J., Yang, H., Dejong, W.S., Wang, X. 2017. An evaluation of two H1-linked markers and their suitability for selecting Globodera rostochiensis resistant potatoes in the New York breeding program. American Journal of Potato Research. 95:170-177.
Interpretive Summary: As a worldwide recognized quarantine pest, the golden cyst nematode (Globodera rostochiensis) was first detected on Long island in New York in 1941 and is still present in eight NY counties. Golden nematode is a serious pest that can cause greater than 60% potato yield reduction when not controlled. Resistant potato cultivars containing the H1 gene need to be planted in infested fields in order to control the nematode. The traditional bioassay method for screening potato clones for golden nematode resistance is laborious and time consuming. In this study, we evaluated two known H1-linked molecular markers for their suitability for selecting resistant clones in the NY potato breeding program. Our results showed that the ability of both markers to predict resistance was extremely high (greater than 98%), suggesting that both markers may be introduced into the NY breeding program to aid the acceleration of breeding of potatoes resistant to the golden nematode.
Technical Abstract: The golden cyst nematode (Globodera rostochiensis) is a serious pest that can dramatically reduce potato crop yield. Pathotype Ro1 of G. rostochiensis was first detected in the United States in 1941 and is still present on several farms in New York State. The H1 gene confers high levels of resistance to pathotype Ro1 but screening for it with a bioassay is time consuming and expensive. In this study two known molecular markers, 57R and TG689, were evaluated for their ability to identify resistant clones among 38 global cultivars and 350 New York breeding clones. The ability of either marker to predict resistance was high – 99.7% and 98.3% for 57R and TG689, respectively – but the ability to predict susceptibility was much lower, 47% and 41% respectively. As resistance is the trait of interest, either of these markers is sufficient to make selection decisions in a practical breeding program. Cases exhibiting discordance between marker response and bioassay results were investigated further. Recombination, inflow of other resistance genes, and occasional failure of marker- and/or bio-assays are discussed as potential causes.