Incidence of potato viruses and their effect on potato production in the Sudan

Viral diseases are among the major factors affecting potato (Solanum tuberosum L.) production in Uganda. Knowledge of the types of viruses and their distribution levels in the country is vital for targeting sound management strategies. The objective of this study was to assess the prevalence and distribution of potato viruses in different potato growing areas in Uganda. Virus diagnostic surveys were conducted across the main potato producing regions and virus detection was done using DAS-ELISA and RT-PCR techniques. The study showed that the most widely distributed and economically important potato viruses were: PVS (31-90.9%), PLRV (2.6-81.3%), PVY (7.1-54.5%) and PVX (8.3 -53.3%); while the least detected viruses were PVM (18.2%) and PVA (9%). The viruses were prevalent either singly or in mixtures. Up to 42.8% of the samples were infected with one virus, 20.9% with two viruses and 4.2% with three viruses; while no virus was detected in 31.3% of the samples. Of the double infections, the PVY+PVS combination was the most common and widely distributed (2.1-18.2%) in 12 districts; followed by PVY+PLRV (1.8-21.3%) occurring in six districts, PVM+PVS (7.9-16.7%), PLRV+PVX (2.4-14.3%) in 5 districts and PVY+PVX (2.4-4.4%) in 3 districts. Triple infections involving PVY+PLRV+PVS were recorded at prevalence levels of 2.2-18.6% in six district. Altitude, temperature, varieties and seed sources showed relationships with the variation in the prevalence of the viruses. There were high virus prevalence and disease severity levels in low altitude areas (1088-1334 m.a.s.l) of mid-western sub-region (Mbarara and Lwengo), Central (Kibaale, Mubende) and Mid Northern (Pader) sub region compared to high altitude areas (>1600 m.a.s.l). The Virus risk Area Modeling results showed the largest area (48.6%; 1,308,160 ha) at moderate risk of virus infection; while 27.3% (732,305 ha) was at high risk of virus infection. Based on the distribution level of the viruses, potato production could be intensified in areas with less virus pressure mainly, in parts of West Nile and Rwenzori regions.

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The effects of monitoring the abundance and species composition of aphids as virus vectors on seed potato production in Serbia

Pesticidi i fitomedicina ◽

10.2298/pif1401009m ◽

2014 ◽

Vol 29 (1) ◽

pp. 9-19 ◽

Cited By ~ 2

Author(s):

Drago Milosevic ◽

Slobodan Milenkovic ◽

Pantelija Peric ◽

Svetomir Stamenkovic

Keyword(s):

Species Composition ◽

Seed Potato ◽

Potato Virus ◽

Potato Virus Y ◽

Potato Production ◽

Control Measures ◽

Seed Potato Production ◽

Potato Viruses ◽

Plant Infection ◽

Haulm Destruction

Aphids are the most important vectors of potato viruses during the crop?s growing season. The most widespread and damaging viruses, the potato virus Y and potato leaf roll virus, are transmitted by aphids in non-persistent and persistent manner, respectively. The two viruses cause the greatest concern of potato producers and a great constraint to seed potato production in Serbia, the region and across the world. Potato virus Y is particularly harmful, given its distribution and spreading rate. Seed potato production systems under well-managed conditions involve a series of virus control measures, including the monitoring of outbreaks of winged aphids, their abundance and species composition, in order to forecast virosis, i.e. potential plant and tuber infection periods. Monitoring the aphid vectors of potato viruses enables determination of optimum dates for haulm destruction when higher than normal numbers of winged aphids as vectors of economically harmful diseases have been observed. Haulm destruction in a potato crop reduces the risk of plant infection and virus translocation from the aboveground parts to tubers, thus keeping the proportion of infected tubers within tolerance limits allowed for certain categories of seed potatoes. This practice has positive effects if used in combination with other viral disease control measures; otherwise, it becomes ineffective. This paper provides an integral analysis of the effects and role of monitoring outbreaks of aphids, their abundance and species composition in timing haulm growth termination to prevent plant infection, virus translocation and tuber infestation in potato crops in Serbia and the wider region.

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Phylogenomic relationship and evolutionary insights of sweet potato viruses from the western highlands of Kenya

10.7287/peerj.preprints.26909v1 ◽

2018 ◽

Author(s):

James M Wainaina ◽

Elijah Ateka ◽

Timothy Makori ◽

Monica A Kehoe ◽

Laura M Boykin

Keyword(s):

Coat Protein ◽

Sweet Potato ◽

Field Isolate ◽

Gene Tree ◽

Potato Production ◽

Sub Saharan Africa ◽

Eastern Africa ◽

Whole Genome ◽

Species Trees ◽

Potato Viruses

Sweet potato is a major food security crop within sub-Saharan Africa where 90 % of Africa’s sweet potato production occurs. One of the major limitations of sweet potato production are viral infections. In this study, we used a combination of whole genome sequences from a field isolate from Kenya and those available in GenBank. Sequences of four sweet potato viruses: sweet potato feathery mottle virus (SPFMV), sweet potato virus C (SPVC), sweet potato chlorotic stunt virus (SPCSV), sweet potato chlorotic fleck virus(SPCFV) were obtained from the Kenyan sample. SPFMV sequences both from this study and from GenBank were found to be recombinant. Recombination breakpoints were found within the Nla-Pro, coat protein and P1 genes. The SPCSV, SPVC and SPCFV viruses from this study were non-recombinant. Bayesian phylogenomic relationships across whole genome trees showed variation in the number of well-supported clades; within SPCSV (RNA1 and RNA2) and SPFMV two well-supported clades (I and II) were resolved. The SPCFV tree resolved three well-supported clades (I-III) while four well-supported clades were resolved in SPVC (I-IV). Similar clades were resolved within the coalescent species trees. However, there were disagreements between the clades resolved in the gene trees compared to those from the whole genome tree and coalescent species trees. However the coat protein gene tree of SPCSV and SPCFV resolved similar clades to genome and coalescent species tree while this was not the case in SPFMV and SPVC. In addition, we report variation in selective pressure within sites of the individual genes across all four viruses; overall all viruses were under purifying selection. We report the first complete genomes of SPFMV, SPVC, SPCFV and a partial SPCSV from Kenya as a mixed infection in one sample. In addition, we reveal their phylogenomic relationships and provide evolutionary insights into these viruses. Our findings demonstrate the need for clean planting materials as the first line of control for these viruses, in particular for smallholder farmers within eastern Africa region.

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Molecular Detection of Potato Viruses in Bangladesh and Their Phylogenetic Analysis

Plants ◽

10.3390/plants9111413 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1413

Author(s):

Mamun-Or Rashid ◽

Ying Wang ◽

Cheng-Gui Han

Keyword(s):

Phylogenetic Analysis ◽

Potato Virus ◽

Control Strategies ◽

Potato Virus X ◽

Potato Production ◽

Chinese Isolate ◽

Potato Virus S ◽

Iranian Isolate ◽

Potato Viruses ◽

Canadian Isolate

Potato (Solanum tuberosum) is a major food source in the whole world including Bangladesh. Viral diseases are the key constraint for sustainable potato production by reducing both quality and quantity. To determine the present status of eight important potato viruses in Bangladesh, tuber samples were collected from three major potato growing regions (Munshiganj, Jessore and Bogra districts) in January–February 2017 and February 2018. Reverse transcription polymerase chain reaction (RT-PCR) with coat protein (CP)-specific primers were used to amplify CP sequences of the respective viruses, and confirmed by sequencing, which were deposited in the GenBank. Results indicated that the tuber samples were subjected to Potato leafroll virus (PLRV), Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus H (PVH), Potato aucuba mosaic virus (PAMV) and Potato virus M (PVM) infection, whereas mixed infections were very common. Phylogenetic analysis revealed that the PLRV from this study was closely related to a Canadian and a Chinese isolate, respectively; PVX was closely related to a Canadian and a Chinese isolate, respectively; PVY was closely related to a Chinese isolate; PVS was closely related to a Chinese and an Iranian isolate, respectively; PAMV was closely related to a Canadian isolate; PVH was closely related to a Huhhot isolate of China; and PVM was closely related to an Indian and an Iranian isolate, respectively. As far as we know, PAMV in this study is the first report in Bangladesh. These findings will provide a great scope for appropriate virus control strategies to virus free potato production in Bangladesh.

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Phylogenomic relationship and evolutionary insights of sweet potato viruses from the western highlands of Kenya

10.7287/peerj.preprints.26909 ◽

2018 ◽

Author(s):

James M Wainaina ◽

Elijah Ateka ◽

Timothy Makori ◽

Monica A Kehoe ◽

Laura M Boykin

Keyword(s):

Coat Protein ◽

Sweet Potato ◽

Field Isolate ◽

Gene Tree ◽

Potato Production ◽

Sub Saharan Africa ◽

Eastern Africa ◽

Whole Genome ◽

Species Trees ◽

Potato Viruses

Sweet potato is a major food security crop within sub-Saharan Africa where 90 % of Africa’s sweet potato production occurs. One of the major limitations of sweet potato production are viral infections. In this study, we used a combination of whole genome sequences from a field isolate from Kenya and those available in GenBank. Sequences of four sweet potato viruses: sweet potato feathery mottle virus (SPFMV), sweet potato virus C (SPVC), sweet potato chlorotic stunt virus (SPCSV), sweet potato chlorotic fleck virus(SPCFV) were obtained from the Kenyan sample. SPFMV sequences both from this study and from GenBank were found to be recombinant. Recombination breakpoints were found within the Nla-Pro, coat protein and P1 genes. The SPCSV, SPVC and SPCFV viruses from this study were non-recombinant. Bayesian phylogenomic relationships across whole genome trees showed variation in the number of well-supported clades; within SPCSV (RNA1 and RNA2) and SPFMV two well-supported clades (I and II) were resolved. The SPCFV tree resolved three well-supported clades (I-III) while four well-supported clades were resolved in SPVC (I-IV). Similar clades were resolved within the coalescent species trees. However, there were disagreements between the clades resolved in the gene trees compared to those from the whole genome tree and coalescent species trees. However the coat protein gene tree of SPCSV and SPCFV resolved similar clades to genome and coalescent species tree while this was not the case in SPFMV and SPVC. In addition, we report variation in selective pressure within sites of the individual genes across all four viruses; overall all viruses were under purifying selection. We report the first complete genomes of SPFMV, SPVC, SPCFV and a partial SPCSV from Kenya as a mixed infection in one sample. In addition, we reveal their phylogenomic relationships and provide evolutionary insights into these viruses. Our findings demonstrate the need for clean planting materials as the first line of control for these viruses, in particular for smallholder farmers within eastern Africa region.

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DIVERSITY AND ABUNDANCE OF LANDING APHIDS IN TWO AREAS OF SEED POTATO PRODUCTION IN TUNISIA; RELATIVE TO THE INCIDENCE OF POTATO VIRUSES

Redia ◽

10.19263/redia-103.20.13 ◽

2020 ◽

Vol 103 ◽

pp. 75-85

Author(s):

AMEN HLAOUI ◽

EMANUELE MAZZONI ◽

REBHA SOUISSI ◽

SONIA BOUKHRIS BOUHACHEM

Keyword(s):

Seed Potato ◽

Potato Virus ◽

Acyrthosiphon Pisum ◽

Viral Infections ◽

Virus Transmission ◽

Potato Production ◽

Climatic Conditions ◽

Seed Potato Production ◽

Potato Viruses ◽

Chi Square Analysis

Aphid flight activities were monitored in 2015 in two areas of seed potato production in Tunisia. Yellow water traps were used to investigate the diversity of aphidofauna and the incidence of aphids involved in potato virus transmission. A total of 9966 specimens belonged to 73 taxa were captured. The cumulative abundance recorded in Douala (first site) was much higher than in El Ogla (second site) (8768 vs 1189 specimens). The most preponderant species in Douala were Aphis spiraecola Patch (66.1%) and Aphis spp. group (13.5%). In El Ogla Rhopalosiphum padi (L.) comprised 58.9% of total catches, followed by Acyrthosiphon pisum (Harris) (12%) and Aploneura lentisci (Passerini) (10.4%). The highest values of diversity indices were recorded on April 23 th [Shannon-Wiener index (H’)=2.58; Simpson index (1-D)=0.88] in Douala and on May 12th (H’=1.70; 1-D=0.75) in El Ogla. The detection of viral infections by DAS-ELISA determined the predominance of Potato virus Y amongst five main potato viruses tested. Overall Chi-square analysis determined significant differences crossing all areas of seed and ware potatoes and season crops. The highest incidence of viruses was recorded in Douala (18.5%) while El Ogla was under the threshold value (4%). This might be attributed to the occurrence of aphids in early season known previously to be efficient vectors of PVY and to the characteristics of area including climatic conditions, altitude and landscape structure. These results provide new evidence for El Ogla as ideal site to produce healthy tubers while conversely Douala is favourable for the propagation of vectors and viruses.

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The pressure of Aphids (Aphididae, Hemiptera), vectors of potato viruses

Archives of Biological Sciences ◽

10.2298/abs1302659v ◽

2013 ◽

Vol 65 (2) ◽

pp. 659-666 ◽

Cited By ~ 4

Author(s):

Andja Vucetic ◽

Ivana Jovicic ◽

Olivera Petrovic-Obradovic

Keyword(s):

Seed Potato ◽

Seed Quality ◽

Potato Production ◽

Plant Viruses ◽

Limiting Factors ◽

Infection Level ◽

Potato Viruses ◽

Pressure Index ◽

Leafroll Virus ◽

Healthy Seed

Plant viruses and aphids as their vectors, are limiting factors in the production of healthy seed potato. Potato Virus Y (PVY) and Potato Leafroll Virus (PLRV) are the two most significant potato viruses in Europe, and seed quality depends directly on the infection level. In order to determine the possibilities for healthy seed potato production in Serbia, aphid flight activities have been monitored for four years in four localities. Over 6400 specimens of aphids have been collected. The number of aphids and vector pressure index varies depending on the localities? altitude. In localities at altitudes under 1000 m, they were high. The highest index was in locality Kotraza in 2007, when the PVY index exceeded the value of 180, while for PLRV it was 60. At high altitudes, above 1100 m, the number of aphids was low, as was the vector pressure index. The lowest index values were recorded in localities on Mt. Golija at 1300 m a.s.l. where the indexes for both viruses never exceeded value 6.

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