|RUBIO-COVARRUBIAS, OSWALDO - Instituto Nacional De Investigaciones Forestales Y Agropecuarias (INIFAP)|
|CADENA-HINOJOSA, M. A. - Instituto Nacional De Investigaciones Forestales Y Agropecuarias (INIFAP)|
|PRAGER, SEAN - University Of California|
|TRUMBLE, JOHN - University Of California|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2017
Publication Date: 2/8/2017
Citation: Rubio-Covarrubias, O.A., Cadena-Hinojosa, M., Prager, S.M., Wallis, C.M., Trumble, J.T. 2017. Characterization of the resistance against zebra chip in tubers of advanced potato lines from Mexico. American Journal of Potato Research. doi: 10.1007/s12230-017-9570-9.
Interpretive Summary: Potato zebra chip (ZC) disease is an emerging threat to North American, Central American, and New Zealand potato growers as it renders tubers unmarketable due to discoloration of fresh market and fried potato products. As a result, four different breeding lines of potato (246, 865, 510, and NAU) were assessed for expression of resistance to ZC and related changes in host physiology. Compared to the highly susceptible cultivar Atlantic, all four breeding lines exhibited reduction in freshly-cut symptoms. However, the breeding lines did not have reduced symptomology when fried. Because the majority of these breeding lines are intended to be consumed fresh and not fried, these breeding lines possibly may be deployed in areas where ZC is endemic to maintain profitability for potato growers in those areas.
Technical Abstract: Potato zebra chip (ZC), which is a threat to potato production in the United States, Mexico, New Zealand, and Central America, is associated with the bacterium “Candidatus Liberibacter solanacearum” (Cls) that is transmitted by the potato psyllid (Bactericera cockerelli Sulc.). ZC control currently depends on insecticide applications, but sustainable control will require development of resistant varieties. This study characterized four promising potato lines (246, 865, 510 and NAU) exposed to Cls-positive adult psyllids in choice and no-choice assays for ZC resistance. Psyllids preferred to settle on Atlantic over 246 and 865, and oviposit on Atlantic compared to 510. However, resistance to ZC appeared more dependent on host responses to Cls infection. All four of these breeding lines exhibited greater ZC resistance in raw tubers compared to a commercially susceptible variety, Atlantic. Expressed resistance was associated with reduced concentrations of phenolic compounds in Cls-infected raw tubers with corresponding reductions in freshly-cut symptoms. However, these four varieties exhibited ZC-linked discoloration of fried tuber slices, which was associated with increased sugar content that occurred following Cls-infection. As a result, these four experiment potato lines could be useful if tubers produced are utilized for fresh, but not processed, markets.