Location: Horticultural Crops ResearchTitle: The relationship between temperature and development in Globodera ellingtonae
|KIEREN, SHANNON - Oregon State University|
Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2015
Publication Date: 12/1/2015
Citation: Phillips, W.S., Kieren, S.R., Zasada, I.A. 2015. The relationship between temperature and development in Globodera ellingtonae. Journal of Nematology. 47:283-289.
Interpretive Summary: The potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida occur worldwide and can cause over 80% yield loss of potato. Both of these nematodes are regulated pests in the U.S. Recently, a very similar nematode to PCN, G. ellingtonae was found in Oregon and Idaho. Little information exists regarding the developmental biology of this nematode. To address this question, growth chamber experiments were conducted and the development of G. ellingtonae on potato at different temperatures was monitored. It was found that the amount of time required for the nematode to complete development decreased with increasing temperatures. Additionally, the upper and lower temperatures at which development does not occur were determined. These observations allowed for the comparison of G. ellingtonae to other PCN. Temperature ranges for successful development of G. ellingtonae were more similar to G. rostochiensis than G. pallida. This research will be used by scientists and regulators to make decisions regarding the regulation of this nematode in the U.S.
Technical Abstract: A new cyst nematode species, Globodera ellingtonae, was recently described from populations in Oregon and Idaho; this nematode has been shown to reproduce on potato. Because of this nematodes close relationship to the potato cyst nematodes, G. rostochiensis and G. pallida, an understanding of the risk of potential spread of this new nematode, including prediction of potential geographical distribution, is required. To determine the development of G. ellingtonae under different temperatures, we conducted growth chamber experiments over a range of temperatures (10°C to 26.5°C) and tracked length of time to various developmental stages, including adult females bearing the next generation of eggs. The time to peak population densities of G. ellingtonae life stages generally increased with decreasing temperature. Regression of the inverse time in days to weighted mean peak population densities of second-stage (J2) and third-stage (J3) juveniles yielded different base temperatures: 6.3°C and 4.4°C for J2 and J3, respectively. Setting a base temp of 6°C allowed calculation of the degree days (DD6) over which different life stages occurred. The largest population densities of J2 were found in roots between ~50 and 200 accumulated DD6. Population densities of J3 peaked between 200 and 300 DD6. Once present in the soil, 300 to 400 DD6, adult males remained detectable for approximately 500 DD6. The DD6 until 50% of eggs contained vermiform juveniles ranged from 784 to 884. Given the similarity in temperature ranges for successful development we found between G. ellingtonae and G. rostochiensis, G. ellingtonae populations likely could survive in the same geographic range in which G. rostochiensis now occurs.