Submitted to: Proceedings Washington State Potato Conference
Publication Type: Proceedings
Publication Acceptance Date: March 15, 2009
Publication Date: July 17, 2009
Citation: Nitzan, N., Boydston, R.A., Batchelor, D., Crosslin, J., Hamlin, L., Brown, C.R. 2009. Hairy nightshade is an alternative host of Spongospora subterranea, the potato powdery scab pathogen. Proceedings Washington State Potato Conference. Proc. 48th Washington State Potato Conference 103-112. Technical Abstract: Root galls possibly caused by Spongospora subterranea were observed on hairy nightshade (Solanum sarrachoides; HNS). HNS galls and galls from potato were used to artificially inoculate potato and HNS. Eighty-three and 52% potato and HNS plants inoculated with potato inoculum had root galls, respectively. Ten and 31% potato and HNS plants inoculated with HNS inoculum had root galls, respectively. A S. subterranea-specific PCR significantly correlated (P < 0.0001, Phi Coefficient = 0.69) with visual assessment of gall incidence in 34 of 40 samples. Five of 40 samples had no galls, but gave positive PCRs. One of 40 samples had root galls, but gave a negative PCR. More sporosori were produced on potato than on HNS. Therefore, the root galls on HNS were caused by S. subterranea that is able to complete its life cycle on HNS and produce new generations of sporosori that are infectious on potato.