|Novy, Richard - Rich|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2001
Publication Date: 1/1/2002
Citation: Novy, R.G., Nasruddin, A., Ragsdale, D.W., Radcliffe, E.B. 2002. Genetic resistances to potato leafroll virus (plrv), potato virus y (pvy), and green peach aphid (myzus persicae) in progeny of solanum etuberosum. American Journal of Potato Research. 79:9-18. Interpretive Summary: An increasing prevalence of potato leafroll virus (PLRV) and potato virus Y (PVY) has resulted in significant financial losses to the potato industry. Seed growers have seen an increase in rejected seed lots by certification agencies because of the presence of one or both viruses. PLRV also has impacted commercial potato growers by the expression of net necrosis symptoms in tubers of infected plants. Net necrosis can result in rejection or down-grading by processors and fresh market shippers. The primary transmission agent of these viruses is green peach aphid. One means to control PLRV and PVY is to limit the movement and spread of the viruses by green peach aphid. The control of aphids (green peach primarily) has made them the third most important potato pest with respect to the amount of insecticide applied for their control. The development of potato cultivars with genetic resistances to PVY, PLRV, and green peach aphid would aid in reducing economic losses in the potato industry. A wild potato species, Solanum etuberosum, was used as a source of resistance to PVY, PLRV, and green peach aphid. All three resistances were shown to be present in Etb 6- 21-3 and Etb 6-21-5, two offspring of S. etuberosum and cultivated potato. This unique germplasm should prove useful for the development of virus-resistant potato cultivars.
Technical Abstract: Increasing prevalence of potato leafroll virus (PLRV) and potato virus Y (PVY) has been reported in seed and commercial potato production, resulting in the rejection of potatoes for certification and processing. Host plant resistance to PLRV and PVY and their primary vector, green peach aphid, Myzus persicae, could limit the spread of these viruses. Host plant resistance to PLRV, PVY, and green peach aphid has been identified in non-tuber-bearing Solanum etuberosum (PI 245939), and in its backcross 2 (BC2) progeny. Resistance to green peach aphid involved a reduction in fecundity and adult aphid size. In addition, one BC2 individual was identified as possessing genetic factors that was detrimental to nymph survival. PVY resistance was identified in all five BC2 progenies evaluated in a field screening under intense virus pressure. PLRV resistance was identified in two of the five BC2 progeny. This resistance was stable in field and cage evaluations with large populations of viruliferous aphids. Based on the segregation of virus resistances in the BC2 , PVY and PLRV resistances appear to result from the action of independent genetic mechanisms. Two BC2 individuals, Etb 6-21-3 and Etb 6-21-5 were identified as having multiple resistances to PLRV, PVY, and green peach aphid derived from S. etuberosum. This germplasm could prove useful to potato breeders in the development of virus resistant cultivars.