Potato In Peru Research Articles

Traditional potato tillage systems in the Peruvian Andes impact bacterial diversity, evenness, community composition, and functions in soil microbiomes

The soil microbiome, a crucial component of agricultural ecosystems, plays a pivotal role in crop production and ecosystem functioning. However, its response to traditional tillage systems in potato cultivation in the Peruvian highlands is still far from understood. Here, ecological and functional aspects of the bacterial community were analyzed based on soil samples from two traditional tillage systems: 'chiwa' (minimal tillage) and 'barbecho' (full tillage), in the Huanuco region of the Peruvian central Andes. Similar soil bacterial community composition was shown for minimal tillage system, but it was heterogeneous for full tillage system. This soil bacterial community composition under full tillage system may be attributed to stochastic, and a more dynamic environment within this tillage system. 'Chiwa' and 'barbecho' soils harbored distinct bacterial genera into their communities, indicating their potential as bioindicators of traditional tillage effects. Functional analysis revealed common metabolic pathways in both tillage systems, with differences in anaerobic pathways in 'chiwa' and more diverse pathways in 'barbecho'. These findings open the possibilities to explore microbial bioindicators for minimal and full tillage systems, which are in relationship with healthy soil, and they can be used to propose adequate tillage systems for the sowing of potatoes in Peru.

Identifying priority sites for the on-farm conservation of landraces and systematic diversity monitoring through an integrated multi-level hotspot analysis: the case of potatoes in Peru

IntroductionEffective monitoring of the in situ conservation status and change dynamics of landrace populations in their centers of origin ideally requires the identification of sites that are complementary in terms of the richness, uniqueness and coverage of genetic diversity.MethodsWe applied a 4-step approach to identify sites of high potato landrace diversity which will guide the set-up of a network of complementary prospective conservation observatories in Peru, the potato center of origin. A GIS mapping approach was used to determine which combination of sites would provide the most comprehensive and complementary genepool coverage. A landrace inventory was developed from 49 sources, comprising 47,272 landrace records, 97.1% with coordinates, which was used to derive landrace, cultivated species, and cultivar group richness. Data on known indicators of agrobiodiversity, including potato wild relative concurrence, cultivated area, ecogeographic diversity, and ethnolinguistic diversity were included in the spatial overlay analysis, which was used in conjunction with expert opinion data to provide further insight to hotspot selection.ResultsThirteen hotspots with high, unique, and complementary levels of landrace diversity were identified. We recommend that robust baselines are established, documenting current diversity in these sites using semi-standardized methods and metrics for future tracking.DiscussionOur results, while being the most robust of their kind to date, were inevitably affected by data gaps, infrastructure and hotspot biases. New documentation efforts should record landrace diversity in uncovered regions, as well as explore complementary mechanisms to track the conservation status of unique endemic landraces that occur in coldspots.

Size, color, and freshness: Standards and heritage of native potatoes in Peru

Peru is the center of origin and diversity of more than 3,000 varieties of native potatoes although only a few varieties are typically consumed beyond the Andean region. Drawing on 14 months of ethnographic research, I explore the role of standards of size, quality, and colors as well as documents like invoices in formalizing and mobilizing the potatoes in the market. I argue that these standards and documents together with economic sociability serve as an important strategy to add value to native potatoes from their production in Ayacucho to their distribution in Lima. By keeping the ethnographic eye on the construction and negotiation of those standards, I show the fragility, the risks, the opportunities, and the power relationships that emerge along the native potato chain.

Potato Virus A Isolates from Three Continents: Their Biological Properties, Phylogenetics, and Prehistory.

Forty-seven potato virus A (PVA) isolates from Europe, Australia, and South America's Andean region were subjected to high-throughput sequencing, and 46 complete genomes from Europe (n = 9), Australia (n = 2), and the Andes (n = 35) obtained. These and 17 other genomes gave alignments of 63 open reading frames 9,180 nucleotides long; 9 were recombinants. The nonrecombinants formed three tightly clustered, almost equidistant phylogroups; A comprised 14 Peruvian potato isolates; W comprised 37 from potato in Peru, Argentina, and elsewhere in the world; and T contained three from tamarillo in New Zealand. When five isolates were inoculated to a potato cultivar differential, three strain groups (= pathotypes) unrelated to phylogenetic groupings were recognized. No temporal signal was detected among the dated nonrecombinant sequences, but PVA and potato virus Y (PVY) are from related lineages and ecologically similar; therefore, "relative dating" was obtained using a single maximum-likelihood phylogeny of PVA and PVY sequences and PVY's well-supported 157 CE "time to most common recent ancestor". The PVA datings obtained were supported by several independent historical coincidences. The PVA and PVY populations apparently arose in the Andes approximately 18 centuries ago, and were taken to Europe during the Columbian Exchange, radiating there after the mid-19th century potato late blight pandemic. PVA's phylogroup A population diverged more recently in the Andean region, probably after new cultivars were bred locally using newly introduced Solanum tuberosum subsp. tuberosum as a parent. Such cultivars became widely grown, and apparently generated the A × W phylogroup recombinants. Phylogroup A, and its interphylogroup recombinants, might pose a biosecurity risk.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Plant-parasite coevolution: A weak signature of local adaptation between Peruvian Globodera pallida populations and wild potatoes.

Plant–parasite coevolution has generated much interest and studies to understand and manage diseases in agriculture. Such a reciprocal evolutionary process could lead to a pattern of local adaptation between plants and parasites. Based on the phylogeography of each partner, the present study tested the hypothesis of local adaptation between the potato cyst nematode Globodera pallida and wild potatoes in Peru. The measured fitness trait was the hatching of cysts which is induced by host root exudates. Using a cross‐hatching assay between 13 populations of G. pallida and root exudates from 12 wild potatoes, our results did not show a strong pattern of local adaptation of the parasite but the sympatric combinations induced better hatching of cysts than allopatric combinations, and there was a negative relationship between the hatching percentage and the geographical distance between nematode populations and wild potatoes. Moreover, a strong effect of the geographic origin of root exudates was found, with root exudates from south of Peru inducing better hatching than root exudates from north of Peru. These results could be useful to develop new biocontrol products or potato cultivars to limit damages caused by G. pallida.

Characterization of distinct strains of an aphid-transmitted ilarvirus (Fam. Bromoviridae) infecting different hosts from South America

Potato yellowing virus (PYV, original code SB-22), an unassigned member of the Genus Ilarvirus Family Bromoviridae, has been reported infecting potatoes in Peru, Ecuador and Chile. It is associated with symptomless infections, however yellowing of young leaves has been observed in some potato cultivars. Thirteen potato and yacon isolates were selected after routine screening of CIP-germplasm and twenty-four were identified from 994 potato plants collected in Peru whereas one was intercepted from yacon in the UK. These isolates were identified using high throughput sequencing, ELISA, host range and RT-PCR. Here we report the sequence characterization of the complete genomes of nine PYV isolates found infecting Solanum tuberosum, four complete genome isolates infecting Smallanthus sonchifolius (yacon), and in addition 15 complete RNA3 sequences from potato and partial sequences of RNA1, 2 and 3 of isolates infecting potato and yacon from Ecuador, Peru and Bolivia. Results of phylogenetic and recombination analysis showed RNA3 to be the most variable among the virus isolates and suggest potato infecting isolates have resulted through acquisition of a movement protein variant through recombination with an unknown but related ilarvirus, whereas one yacon isolate from Bolivia also had resulted from a recombination event with another related viruses in the same region. Yacon isolates could be distinguished from potato isolates by their inability to infect Physalis floridana, and potato isolates from Ecuador and Peru could be distinguished by their symptomatology in this host as well as phylogenetically. The non-recombinant yacon isolates were closely related to a recently described isolate from Solanum muricatum (pepino dulce), and all isolates were related to Fragaria chiloensis latent virus (FCiLV) reported in strawberry from Chile, and probably should be considered the same species. Although PYV is not serologically related to Alfalfa mosaic virus (AMV), they are both transmitted by aphids and share several other characteristics that support the previous suggestion to reclassify AMV as a member in the genus Ilarvirus.

Proyección de la producción de papa en Puno. Una aplicación de la metodología de Box-Jenkins

Potato is the fourth most important food crop in the world that serves as a diet for the rich and the poor. Puno is the department with the highest production of potatoes in Peru, a country where more than 4,000 of the 5,000 existing varieties are found in the world and where the cultivation originated. The main objective of this research was to identify the best seasonal ARIMA model (or SARIMA) to model and forecasting potato production in Puno, using the Box-Jenkins methodology. The study considered monthly data on potato production in Puno between 2007 and 2017. The best model found for the modeling and forecasting of potato production in Puno is SARIMA (1, 1, 2)(1, 0, 1)12 using the Akaike Information Criterion (AIC) and Schwarz Criteria (SC). Finally, the twelve-month forecasting of potato production is presented to be used for policy decisions in the agricultural sector.

FIRST REPORT OF POTATO YELLOWING VIRUS INFECTING PEPPER IN ECUADOR

Pepper (Capsicum annum L.) is a solanaceous species originating from South and Central America. Potato yel- lowing virus (PYV), an unclassified putative member of the genus Ilarvirus, was first found in potato in Peru (Fuentes et al., 1993), later in wild potato (Solanum fernandezianum) in Chile (Valkonen et al., 1992) and more recently in a native potato (Solanum phureja) in Ecuador (Silvestre et al., 2011). In December 2014, foliar mosaic and necrotic spotting of leaves and stems accompanied by bud and fruit necrosis were observed in pepper fields of Puembo, in the Pichincha prov- ince of Ecuador. Based on the symptomatology, the occur- rence of PYV was suspected and confirmed in symptomatic leaves by DAS-ELISA with a specific antiserum provided by G. Muller, International Potato Center, Lima, Peru, and by RT-PCR using universal primers for members of the family Bromoviridae (Untiveros et al., 2010). The 300 bp amplicon obtained from a symptomatic pepper was purified, custom- sequenced (Macrogen, South Korea) and the nucleotide se- quence was deposited in GenBank (KP772263). Sequence analysis (BioEdit v. 7.05) showed 93.1-97% and 78-90% iden- tity with other PYV isolates at the nucleotide and amino acid levels, respectively. A phylogenetic tree constructed at the nucleotide level using MEGA version 4.1 showed that the Ecuadorian PYV isolate from capsicum was closely related to isolate Loja 2 from S. phureja in Ecuador (HQ141056). Solanum isolates Canete (HQ141057), Russia (KM244740), Loja 1 (HQ141053) and Azuay (HQ141054) formed a sepa- rate cluster. To the best of our knowledge, this is the first report of PYV on Capsicum in Ecuador.

Plants, People, and the Conservation of Biodiversity of Potatoes in Peru

Plants, People, and the Conservation of Biodiversity of Potatoes in Peru

Resistance to metalaxyl-M and cymoxanil in a dominant clonal lineage of Phytophthora infestans in Huánuco, Peru, an area of continuous potato production

Fifty-eight isolates of Phytophthora infestans were evaluated in vitro and on detached leaves of potato for their sensitivities to metalaxyl-M and cymoxanil. The isolates belonged to the clonal lineage, EC-1, which is dominant on potato in Peru and Ecuador. All isolates were collected in Huanuco, Peru, an area of year-round potato production, where the potential for development of fungicide resistance is high. All isolates were resistant to metalaxyl-M, with in vitro EC50 values ranging from 468.30—813.57 mg l−1. In contrast, we found no evidence for resistance to cymoxanil for which in vitro EC50 values ranged from 0.03—1.11 mg l−1. Resistance to each fungicide was also evaluated for five isolates in a detached leaf assay in which the fungicide was sprayed on the leaf surface prior to inoculation. With metalaxyl-M, the range of EC50 values was 158.85—828.29 mg l−1, similar to that for the in vitro assay. For cymoxanil, EC50 values ranged from 1.41 to 2.31 mg l−1, which was higher than in the in vitro assay but still two orders of magnitude lower than the concentration applied by farmers in the field.

Diversity of Ralstonia solanacearum causing potato bacterial wilt in Iran and the first record of phylotype II/biovar 2T strains outside South America

The diversity of 40 strains of Ralstonia solanacearum causing bacterial wilt of potato in the major potato‐growing areas of Iran was assessed. Based on rep‐PCR genomic fingerprinting, strains fell into two distinct groups. The first group contained 37 of the 40 strains and the second consisted of three strains from a narrow tropical region in Iran. The three strains from the narrow tropical region were found to be phenotypically and genotypically most similar to R. solanacearum biovar 2T strains, whereas all other strains were phenotypically and genotypically identified as being R. solanacearum biovar 2/race 3. Phylogenetic analysis of endoglucanase gene sequence information of two of the strains from the tropical region revealed that they belonged to phylotype II of the R. solanacearum species complex and had 100% sequence similarity to a biovar 2T strain from potato in Peru. This is the first report of the presence of R. solanacearum phylotype II/biovar 2T in Iran and the first report of the existence of this group of R. solanacearum outside South America.

Molecular variability of sweet potato feathery mottle virus and other potyviruses infecting sweet potato in Peru

Several potyviruses are found infecting sweet potato (Ipomoea batatas) in Peru, of which sweet potato feathery mottle virus (SPFMV, genus Potyvirus) is the most common. However, sequence data for these viruses are not available from Peru. In this study, the 3'-terminal approximately 1,800 nucleotide sequences of 17 potyvirus samples collected from the six main sweet potato-producing areas of Peru over the past 20 years were determined and analyzed. Results of sequence comparisons and phylogenetic analysis showed that three of the four recognized SPFMV strain groups, including the East African strain, are established in Peru as well as two other potyviruses: sweet potato virus G (SPVG) and sweet potato virus 2 (SPV2). The analysis further revealed that SPFMV, SPVG and SPV2 are related and form an Ipomoea-specific phylogenetic lineage within the genus Potyvirus and identified for the first time recombination events between viruses from different strain groups of SPFMV.

Host Specialization not Detected Among Isolates of the EC-1 Lineage of Phytophthora infestans Attacking Wild and Cultivated Potatoes in Peru

To determine whether populations of Phytophthora infestans attacking wild and cultivated potatoes in the highlands of Peru are specialized on their hosts of origin, we characterized isolates using several neutral markers, metalaxyl resistance and for aggressiveness in a detached leaf assay. One hundred and fifty-three isolates were collected from the northern and central highlands of Peru from different potato cultivars (both modern and native cultivars) and from different species of wild, tuber-bearing potatoes. All the isolates analyzed belonged to one of four clonal lineages that had been described previously in Peru: EC-1, US-1, PE-3 and PE-7. The EC-1 lineage (n = 133) was dominant and present in similar frequencies on wild and cultivated potatoes. PE-3 (n = 14) was found primarily on cultivated potatoes, with only one isolate coming from a wild host. US-1 (n = 2) and PE-7 (n = 4) were rare; all but one (PE-7) occurred on wild potatoes. Isolates from the EC-1 lineage from modern cultivars were compared in three separate detached leaf inoculation assays with EC-1 isolates from the wild potato species S. sogarandinum, S. bill-hookerii or S. huancabambense, respectively. No significant interactions between isolate type (from wild or cultivated potato) and host type (wild or cultivated) were measured for any assay. It appears that the pathogen genotypes in the EC-1 lineage indiscriminately attack both wild and cultivated tuber-bearing solanaceous hosts in Peru, and breeders should be able to select for resistance using the common EC-1 lineage.

Potential adoption and management of insect-resistant potato in Peru, and implications for genetically engineered potato

This paper analyzes some important issues surrounding possible deployment of genetically engineered (GE) insect-resistant potato in Peru, based on a large farmer survey held in Peru in 2003. We found that the formal seed system plays a limited role compared with the informal seed system, especially for smallholder farmers. Although 97% of smallholder farmers would buy seed of an insect-resistant variety, a majority would buy it only once every 2 to 4 years. Survey data show that farmers would be willing to pay a premium of 50% on seed cost for insect resistant varieties. Paying price premiums of 25% to 50%, farmers would still increase their net income, assuming insect resistance is high and pesticide use will be strongly reduced. Of all farmers, 55% indicated preference for insect-resistant potato in varieties other than their current varieties. The survey indicates that smallholder farmers are interested to experiment with new varieties and have a positive perception of improved varieties. Based on these findings, and considering the difficulties implementing existing biosafety regulatory systems such as those in place in the U.S. and E.U., we propose to develop a variety-based segregation system to separate GE from conventionally bred potatoes. In such a system, which would embrace the spread of GE potatoes through informal seed systems, only a limited number of sterile varieties would be introduced that are easily distinguishable from conventional varieties.

<I>Spodoptera ochrea</I> (Lepidoptera: Noctuidae): a New Host Record (Asparagus) from Peru and Description of the Female Genitalia

Spodoptera ochrea (Hampson) was recently reared on a new host, asparagus (Asparagus officinalis L.), in Peru. Other host plants include cotton, tobacco, and potatoes in Peru. Distribution is restricted to the dry west coast of southern Ecuador and Peru. The female genitalia is illustrated and described for the first time. Additional records of asparagus feeding Spodoptera are discussed.

Anastomosis Groups, Pathogenicity, and Other Characteristics of Rhizoctonia solani Isolated from Potatoes in Peru

Anastomosis Groups, Pathogenicity, and Other Characteristics of Rhizoctonia solani Isolated from Potatoes in Peru

A Previously Undescribed Nepovirus Isolated from Potato in Peru

A Previously Undescribed Nepovirus Isolated from Potato in Peru

Oca Strain of Arracacha Virus B from Potato in Peru

Oca Strain of Arracacha Virus B from Potato in Peru

Host range and properties of potato black ringspot virus

SUMMARYPotato black ringspot virus (PBRV), obtained from cultivated potato in Peru, was found to have a very wide host range resembling that of tobacco ringspot virus (TRSV‐B), to which PBRV is distantly related serologically. However, PBRV caused the more severe symptoms in many species and, unlike TRSV B, infected Lycopersicon esculentum and Cyamopsis tetragonoloba. In Solanum tuberosum, PBRV caused necrotic spots and ringspots in systemically infected leaves in the year of infection and was readily transmitted through tubers to progeny plants, most of which developed no obvious symptoms although systemically infected. TRSV‐B infected non‐inoculated S. tuberosum leaves only sporadically, did not induce symptoms in them and was not transmitted through tubers to progeny plants.PBRV was cultured in Nicotiana clevelandii and infectivity was assayed in Cheno‐podium amaranticolor or C. quinoa. Virus particles were purified from leaf extracts, after clarification using chloroform, by precipitation with 6% polyethylene glycol and differential centrifugation. Purified preparations contained 25 nm diameter isometric particles with somewhat angular outlines, sedimenting as three components (T, M and B) at 49, 84 and 117 S, and containing a single protein species of mol. wt 59 000. Preparations of PBRV nucleic acid contained two species, estimated by polyacrylamide gel electrophoresis in non‐denaturing conditions to have mol. wt of about 25 106 (RNA‐1) and 15 106 (RNA‐2). Infectivity was associated with B particles, preparations of which contained RNA‐1 and RNA‐2, presumably in different particles. M particles contained RNA‐2, were not infective and enhanced infectivity only slightly when added to B particles. Similar relative amounts of RNA‐1 and RNA‐2 were extracted from unfractionated virus using phenol or Pronase, but preparations obtained using phenol were much the more infective.PBRV has properties typical of nepoviruses; its present cryptogram is (R/1):2–5/41 + 15/28 or 2 1 5/46:S/S:S/*, nepovirus group.

Fertilizer Response Information and Income Gains: The Case of Potatoes in Peru

AbstractYield response to different levels of fertilizer on various soils is estimated by a generalized response function. Average new income generated by use of optimum levels is estimated at over $800 per hectare. The social gain to Peru is estimated to be as much as $50 million annually.