scholarly journals Silverleaf Nightshade (Solanum elaeagnifolium), a Reservoir Host for ‘Candidatus Liberibacter solanacearum’, the Putative Causal Agent of Zebra Chip Disease of Potato

Plant Disease ◽  
2015 ◽  
Vol 99 (7) ◽  
pp. 910-915 ◽  
Author(s):  
Jenita Thinakaran ◽  
Elizabeth Pierson ◽  
Madhurababu Kunta ◽  
Joseph E. Munyaneza ◽  
Charlie M. Rush ◽  
...  

Zebra chip disease of potato is caused by the bacterial pathogen ‘Candidatus Liberibacter solanacearum’ and is a growing concern for commercial potato production in several countries in North and Central America and New Zealand. ‘Ca. L. solanacearum’ is vectored by the potato psyllid Bactericera cockerelli, which transmits the pathogen to several cultivated and wild solanaceaous host plants. Silverleaf nightshade (SLN), Solanum elaeagnifolium, is a common weed in the Lower Rio Grande Valley of Texas and a host for both the potato psyllid and ‘Ca. L. solanacearum’. SLN plants were successfully inoculated with ‘Ca. L. solanacearum’ under laboratory conditions. Retention studies demonstrated that ‘Ca. L. solanacearum’-infected SLN planted in the field in January 2013, concurrent with commercial potato planting, retained the pathogen under field conditions throughout the year despite extensive dieback during summer. The presence of ‘Ca. L. solanacearum’ was confirmed in leaves, roots, and stolons of SLN plants collected the following year using polymerase chain reaction. Acquisition assays using B. cockerelli adults also revealed that SLN retained the pathogen. Transmission studies determined that B. cockerelli can acquire ‘Ca. L. solanacearum’ within a 2-week acquisition access period on ‘Ca. L. solanacearum’-infected SLN and subsequently transmit the pathogen to potato. These results demonstrate that SLN plants can serve as a reservoir for ‘Ca. L. solanacearum’, providing a source of inoculum for B. cockerelli adults colonizing potato the next season. The presence of SLN plants all year round in the LRGV makes the weed an epidemiologically important host. These findings underscore the importance of eradicating or managing SLN plants growing in the vicinity of potato fields to prevent spread of ‘Ca. L. solanacearum’ and damage caused by zebra chip.

Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 822-829 ◽  
Author(s):  
Jennifer Dahan ◽  
Erik J. Wenninger ◽  
Brandon Thompson ◽  
Sahar Eid ◽  
Nora Olsen ◽  
...  

Zebra chip (ZC) disease, a serious threat to the potato industry, is caused by the bacterium ‘Candidatus Liberibacter solanacearum’ (Lso). Five haplotypes (hapA to hapE) of this pathogen have been described so far in different crops, with only hapA and hapB being associated with ZC in potato. Both haplotypes are vectored and transmitted to a variety of solanaceaeous plants by the tomato/potato psyllid, Bactericera cockerelli (Šulc). Psyllids are native to North America, and four haplotypes have been identified and named based on their predominant geographic association: Northwestern, Central, Western, and Southwestern. Although all psyllid haplotypes have been found in southern Idaho potato fields, data on relative haplotype abundances and dynamic changes in the fields over time have not previously been reported. Here, psyllid samples collected in Idaho potato fields from 2012 to 2015 were used to clarify spatial and temporal patterns in distribution and abundance of psyllid and Lso haplotypes. A shift from hapA toward hapB population of Lso was revealed during these four seasons, indicating possible evolution of Lso in Idaho fields. Although we confirmed that Western psyllids were the most abundant by far during the four seasons of observation, we also observed changes in abundance of other haplotypes, including increased diversity of psyllid haplotypes during 2015. Seasonal changes observed for the Northwestern and Central haplotypes could potentially be linked to psyllid migration and/or habitat changes. South-central Idaho exhibited more diversity in psyllid haplotypes than southwestern Idaho.


Insects ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Koffi Djaman ◽  
Charles Higgins ◽  
Shantel Begay ◽  
Komlan Koudahe ◽  
Samuel Allen ◽  
...  

Potato psyllid (Bactericera cockerelli) is one of the most important pests in potatoes (Solanum tuberosum L.) due to its feeding behavior and the transmission of a bacterium (Candidatus Liberibacter solanacearum) that causes zebra chip disease, altering the quality of the potato tuber and the fried potato chip or french fry. This pest is thus a threat to the chip potato industry and often requires preventive measures including the use of costly insecticides. The objectives of this research were to monitor the variation in B. cockerelli adult abundance and to evaluate the risk of zebra chip disease in northwestern New Mexico, USA. Yellow sticky traps were used to collect the pest at the Agricultural Experiment Station at Farmington, NM and in nearby commercial fields at the Navajo Agricultural Products Industry (NAPI) and Navajo Mesa Farms during the 2017–2019 period. The collected adult pests were analyzed at Texas A & M University for the presence of Candidatus L. solanacearum (Lso). The results showed field infestation by B. cockerelli in early June and that the population peaked during the second half of July and decreased as the potato growing season progressed. However, a second less important peak of the pest was revealed around mid- to late-August, depending on the growing season and field. While the B. cockerelli population increased linearly with average air temperature, it showed strong third order polynomial relationships with the accumulated thermal units and the Julian days. The test of B. cockerelli for the Lso infection revealed a low incidence of the pathogen varying from 0.22% to 6.25% and the infected adult B. cockerelli were collected during the population peak period. The results of this study may be helpful to potato growers in pest management decision-making and control. However, more study is needed to evaluate zebra chip disease in terms of its prevention and economic impact, and to develop economic thresholds and pest management programs for northwestern New Mexico and neighboring regions.


2020 ◽  
Vol 113 (6) ◽  
pp. 2595-2603
Author(s):  
Cesar A Reyes Corral ◽  
W Rodney Cooper ◽  
David R Horton ◽  
Alexander V Karasev

Abstract The potato psyllid, Bactericera cockerelli (Šulc), is a major pest of potato (Solanum tuberosum L.; Solanales: Solanaceae) as a vector of ‘Candidatus Liberibacter solanacearum’, the pathogen that causes zebra chip. Management of zebra chip is challenging in part because the noncrop sources of Liberibacter-infected psyllids arriving in potato remain unknown. Adding to this challenge is the occurrence of distinct genetic haplotypes of both potato psyllid and Liberibacter that differ in host range. Longleaf groundcherry (Physalis longifolia Nutt.) has been substantially overlooked in prior research as a potential noncrop source of Liberibacter-infected B. cockerelli colonizing fields of potato. The objective of this study was to assess the suitability of P. longifolia to the three common haplotypes of B. cockerelli (central, western, and northwestern haplotypes), and to two haplotypes of ‘Ca. L. solanacearum’ (Liberibacter A and B haplotypes). Greenhouse bioassays indicated that B. cockerelli of all three haplotypes produced more offspring on P. longifolia than on potato and preferred P. longifolia over potato during settling and egg-laying activities. Greenhouse and field trials showed that P. longifolia was also highly susceptible to Liberibacter. Additionally, we discovered that infected rhizomes survived winter and produced infected plants in late spring that could then be available for psyllid colonization and pathogen acquisition. Results show that P. longifolia is susceptible to both B. cockerelli and ‘Ca. L. solanacearum’ and must be considered as a potentially important source of infective B. cockerelli colonizing potato fields in the western United States.


Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2587-2591 ◽  
Author(s):  
Jennifer Dahan ◽  
Erik J. Wenninger ◽  
Brandon D. Thompson ◽  
Sahar Eid ◽  
Nora Olsen ◽  
...  

‘Candidatus Liberibacter solanacearum’ (Lso) is an uncultured, phloem-associated bacterium causing a severe tuber disease in potato called zebra chip (ZC). Seven haplotypes of Lso have been described in different hosts, with haplotypes A and B found associated with infections in potato and tomato. In the field, Lso is transmitted by the potato psyllid (Bactericera cockerelli), and between 2011 and 2015, a significant change in Lso haplotype prevalence was previously reported in Idaho: from exclusively A haplotype found in tested psyllids in 2012 to mainly B haplotype found in collected psyllids in 2015. However, prevalence of Lso haplotypes in Idaho was not analyzed in potato tubers exhibiting symptoms of ZC. To fill in this knowledge gap, prevalence of Lso haplotypes was investigated in potato tubers harvested in southern Idaho between 2012 and 2018, and it was found to change from exclusively A haplotype in the 2012 season to an almost equal A and B haplotype distribution during the 2016 season. During the same period, haplotype distribution of Lso in psyllid vectors collected using yellow sticky traps also changed, but in psyllids, the shift from A haplotype of Lso to B haplotype was complete, with no A haplotype detected in 2016 to 2018. The changes in the haplotype prevalence of the Lso circulating in potato fields in southern Idaho may be, among other factors, responsible for a decrease in the ZC incidence in Idaho potato fields between an outbreak of the disease in 2012 and a very low level of ZC afterward.


2012 ◽  
Vol 102 (11) ◽  
pp. 1079-1085 ◽  
Author(s):  
A. Rashed ◽  
T. D. Nash ◽  
L. Paetzold ◽  
F. Workneh ◽  
C. M. Rush

With diseases caused by vector-borne plant pathogens, acquisition and inoculation are two primary stages of the transmission, which can determine vector efficiency in spreading the pathogen. The present study was initiated to quantify acquisition and inoculation successes of ‘Candidatus Liberibacter solanacearum’, the etiological agent of zebra chip disease of potato, by its psyllid vector, Bactericera cockerelli (Hemiptera: Triozidae). Acquisition success was evaluated in relation to feeding site on the host plant as well as the acquisition access period. Inoculation success was evaluated in relation to vector number (1 and 4) on the plants. Acquisition success was influenced by the feeding site on the plant. The highest acquisition success occurred when insects had access to the whole plant. The results of the inoculation study indicated that the rate of successfully inoculated plants increased with the vector number. Plants inoculated with multiple psyllids had higher bacterial titer at the point of inoculation. Although disease incubation period was significantly shorter in plants inoculated with multiple psyllids, this effect was heterogeneous across experimental blocks, and was independent of pathogen quantity detected in the leaflets 3 days postinoculation. Disease progress was not affected by bacterial quantity injected or psyllid numbers.


2013 ◽  
Vol 66 ◽  
pp. 386-386 ◽  
Author(s):  
P.J. Wright ◽  
G.P. Walker ◽  
D.I. Hedderley

Tomato potato psyllid (TPP) (Bactericera cockerelli) vectors Candidatus Liberibacter solanacearum a phloemlimited bacterium that can cause a mottled browning discolouration (zebra chip; ZC) in fried crisps Sulphur is mainly used as a fungicide but is also registered in New Zealand as an insecticide against erineum mite (Colomerus vitis) on grapes A field trial to determine TPP response to foliarapplied sulphur found that weekly applications (no insecticides) significantly reduced psyllid nymph numbers in foliage compared with the control (nosulphur noinsecticide) However the incidence of severe ZC in frycooked tubers was higher in the weekly sulphur treatment than with a commercial insecticide spray programme Tubers from both the nonsprayed control and the weekly sulphur treatment had significantly lower yields and specific gravities than those treated with insecticide Sulphur applied alternately with insecticides gave similar results to the commercial insecticide programme promising for the industrys goal of reducing insecticide applications


2015 ◽  
Vol 68 ◽  
pp. 85-90
Author(s):  
J. Vereijssen ◽  
A.M. Barnes ◽  
N.A. Berry ◽  
G.M. Drayton ◽  
J.D. Fletcher ◽  
...  

Tomato potato psyllid (TPP) Bactericera cockerelli (Scaron;ulc) (Hemiptera Triozidae) was first recorded in the North Island of New Zealand in 2006 Three years later the insect was found in the Oamaru area (South Island) Over the years there has been a rise in TPP numbers trapped in potato crops in Canterbury (South Island) Recently increased prevalence and severity of foliar and tuber symptoms related to plant infection with Candidatus Liberibacter solanacearum (CLso) vectored by TPP have been observed in trials and in commercial potato crops Moreover in the 201314 season the resulting zebra chip disease was observed for the first time in tubers at a processing plant in Canterbury It is concluded that Canterbury has a landscape where hosts are available yearround and a climate that does not seem to hinder TPP development The aim of this paper is to present a stocktake of TPP in Canterbury


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