Investigations on Putative Zebra Chip Tolerant Potato Selections

'Candidatus Liberibacter solanacearum' (Lso) has emerged as a devastating pathogen of solanaceous and other vegetable crops. In potato, Lso is the causative agent of zebra chip (ZC) disease, which threatens production in North and Central America and New Zealand. Lso has caused significant economic losses to the potato industry in Texas since the emergence of the disease in 2000. Presently, disease control relies on pesticide applications, but efforts are under way to identify plant resistance. The objective of this work was to validate the most promising cultivars identified as potentially resistant or tolerant to ZC from previous field trials in different Texas locations and in multiple years. An important component of the study was the development of protocols to effectively evaluate resistance or tolerance. Results show that, while none of the tested cultivars displayed resistance against ZC, differences in susceptibility among them were confirmed. Results also demonstrated the importance of performing cage trials in which vector and disease pressure can be controlled.