First Report of Zebra Chip and ‘Candidatus Liberibacter solanacearum’ on Potatoes in Nicaragua

Abstract

In September 2011, potato (Solanum tuberosum) tubers grown in Nicaragua outside of Estelí and Jinotega were observed with internal discoloration suggestive of zebra chip (ZC); and the plants showed foliar symptoms of chlorosis, leaf scorching, wilting, vascular discoloration, swollen nodes, twisted stems, and aerial tubers (3). Disease incidence ranged from 50 to 95% in eight fields ranging from 5 to 12 ha in the Estelí and Jinotega regions of Nicaragua. Leaf samples and psyllids were collected from two fields, and total DNA was purified from the leaves of 17 symptomatic and 10 asymptomatic plants. DNA was also extracted from 20 individual potato psyllids. Primers specific for 16S rDNA (OA2 and OI2c) and the surface antigen gene (OMB 1482f and 2086r) of Candidatus Liberibacter solanacearum (CLs) were used to confirm the presence of the pathogen in infected potatoes and insects (2). All symptomatic potato leaf samples tested positive for the presence of CLs using both primers, and no asymptomatic plants had positive results. Seven insects tested positive for the presence of CLs. 16S rDNA sequences obtained for all positive samples (1,071 bp) were identical and showed 99 to 100% identity to a number of rDNA sequences of CLs in GenBank (Accession Nos. HM246509 and FJ957897). 16S rDNA sequences from two CLs-infected plants, one from Estelí, Nicaragua (JX559779) and one from Jinotega, Nicaragua (JK559780), were deposited in GenBank. Identity of insects was done using a morphological key, and then verified as Bactericera cockerelli using a real-time PCR assay with melt temperature analysis of the cytochrome c oxidase 1 gene, as described by Chapman et al. (1). Sequencing of the amplified DNA yielded an approximately 63-bp read, with 100% homology to reference sequences of B. cockerelli (AY971886) and those obtained from psyllids collected in McAllen, TX, in 2010. B. cockerelli samples were collected from both locations. Similar to previous reports of ZC in new locations, foliar and tuber symptoms associated with ZC were observed in all eight fields in these two Nicaraguan potato-growing regions, specific PCR amplification with two primer pairs was completed, 16S rDNA sequence analyses showed 100% similarity to reference sequences of CLs, and the presence of potato psyllids which tested positive for the presence of CLs provide evidence that ZC is now present in Nicaragua. Potatoes rank in the top 20 commodities produced in Nicaragua, resulting in >$4.5M annual revenue. Because CLs has caused significant economic damage to potatoes in the United States, Mexico, Guatemala, and Honduras, this finding has significance for potato production in Central America. References: (1) R. I. Chapman et al. Southwest. Entomol. 37:475, 2012. (2) J. M. Crosslin. Southwest. Entomol. 36:125, 2011. (3) L. W. Liefting et al. Internat. J. Syst. Evol. Microbiol. 59:2274, 2009.

A Novel Interaction of Nesidiocoris tenuis (Hemiptera: Miridae) as a Biological Control Agent of Bactericera cockerelli (Hemiptera: Triozidae) in Potato

“…This bacterial pathogen causes diseases in several solanaceous crops, including zebra chip (ZC), an economically important disease in potatoes in the United States, Mexico, and New Zealand [32,[45][46][47][48][49]. Zebra chip disease has also been documented to occur in Guatemala, Honduras, El Salvador, and Nicaragua [45,50,51], and most recently in Ecuador [31]. The losses from ZC disease in potato cultivation were initially sporadic.…”

A comprehensive review of zebra chip disease in potato and its management through breeding for resistance/tolerance to ‘Candidatus Liberibacter solanacearum’ and its insect vector

“…By 2000 it had been observed in potato fields in Texas, USA 4,6,11 . Since then, ZC or infected psyllids have been detected in major potato growing regions of the USA, Canada, Mexico, Central America, New Zealand, Australia, and South America 12–22 . CLso has also been linked to disease in multiple solanaceous crops, including tomatillo, peppers, tomato, and numerous solanaceous weeds, 23–28 and in carrot and celery in Europe, the Middle East, and Africa 29–38 …”

Jornadas de salud para plantas en Intibucá, Honduras: El efecto sobre el conocimiento y las prácticas de control de paratrioza en papa

“…En los últimos años, la paratrioza y la bacteria han comenzado a causar daños en otros países en la región y se han reportado en otros cultivos. En Guatemala y México existen reportes en papa, mientras que los hay en tabaco en Honduras y Nicaragua, tomate en El Salvador y berenjena en Honduras (Bextine et al 2013a;Bextine et al 2013b;Munyaneza et al 2009;Munyaneza et al 2013a;Munyaneza et al 2013b;Palmieri et al 2012). Es por esto que se deben aunar esfuerzos, tanto en Honduras como en la región centroamericana, para que el agricultor pueda controlar la plaga y así evitar propagar la enfermedad y causar aún mayores pérdidas.…”