International Potato Center

About: International Potato Center is a facility organization based out in Lima, Peru. It is known for research contribution in the topics: Population & Phytophthora infestans. The organization has 1036 authors who have published 1460 publications receiving 47183 citations.

Multiscale assessment of spatial precipitation variability over complex mountain terrain using a high-resolution spatiotemporal wavelet reconstruction method

Abstract: Studying precipitation variability in the Peruvian Andes is a challenge given the high topographic variability and the scarcity of weather stations. Yet previous research has shown that a near-linear relationship exists between precipitation and vegetation in the semi-arid central Andes. We exploit this relationship by developing a new, spatially highly resolved spatio-temporal precipitation reconstruction method, using daily precipitation time series from in situ weather stations, and dekadal (10 calendar days) normalized difference vegetation index (NDVI) fields. The two data sets are combined through a wavelet decomposition method. A 4° x 4° region around Quelccaya ice cap (QIC), the world's largest tropical ice cap located in the central Peruvian Andes, was selected as study area, due to its importance for climatic, glaciologic and paleoclimatic research. The reconstructed end product, a ~1 km2 gridded precipitation data set at dekadal temporal resolution, was validated against independent rain gauge data and compared with the Tropical Rainfall Measuring Mission (TRMM) 3B42 version 7 product. This validation showed a better overall performance of our own reconstruction than the TRMM data. Additionally, a comparison of our precipitation product with snowfall measurements at the QIC summit (5670 m) shows a regionally coherent signal at the dekadal scale, suggesting that the precipitation falling at QIC is driven by regional- rather than local-scale convective activity. We anticipate that this methodology and the type of data generated in this study will be useful for hydrological and glaciological studies, as well as for validation of high-resolution downscaling products in mountain regions.

Consumer Preference Testing of Boiled Sweetpotato Using Crowdsourced Citizen Science in Ghana and Uganda

Abstract: Crowdsourced citizen science is an emerging approach in plant sciences. The triadic comparison of technologies (tricot) approach has been successfully utilised by demand-led breeding programmes to identify varieties for dissemination suited to specific geographic and climatic regions. An important feature of this approach is the independent way in which farmers individually evaluate the varieties on their own farms as ‘citizen scientists’. In this study, we adapted this approach to evaluate consumer preferences to boiled sweetpotato (Ipomoea batatas (L.) Lam) roots of 21 advanced breeding materials and varieties in Ghana and 6 released varieties in Uganda. We were specifically interested in evaluating if a more independent style of evaluation (home tasting) would produce results comparable to an approach that involves control over preparation (centralised tasting). We compiled data from 1,433 participants who individually contributed to a home tasting (de-centralised) and a centralised tasting trial in Ghana and Uganda, evaluating overall acceptability, and indicating the reasons for their preferences. Geographic factors showed important contribution to define consumers’ preference to boiled sweetpotato genotypes. Home and centralised tasting approaches gave similar rankings for overall acceptability, which was strongly correlated to taste. In both Ghana and Uganda, it was possible to robustly identify superior sweetpotato genotypes from consumers’ perspectives. Our results indicate that the tricot approach can be successfully applied to consumer preference studies.

Badnaviruses of sweetpotato: symptomless co-inhabitants on a global scale

Abstract: Sweetpotato is among the most important root-crops worldwide, particularly in developing countries, and its production is affected severely by a variety of virus diseases During the last decade a number of new viruses have been discovered in sweetpotatoes from different continents through next generation sequencing studies, among them belonging to the genus Badnavirus and collectively assigned to the species Sweet potato pakkakuy virus (SPPV) We determined the complete genome sequence of two SPPV isolates and show the ubiquitous presence of similar viruses in germplasm and field material from around the globe We show SPPV is not integrated into the sweetpotato genome, occurs only at extremely low titers but is nevertheless efficiently transmitted through seeds and cuttings They are unaffected by virus elimination therapy and lack any discernible symptoms in sweetpotatoes or indicator host plants Nevertheless, they show considerable variation in their nucleotide sequences and correspond to several genetic lineages Studies of their interaction with the two most important sweetpotato viruses showed only limited synergistic increase in the titres of one of two SPPV isolates We contend that these viruses may pose little threat to sweetpotato production and more likely represent a new type of persistent virus in a possibly commensal or mutualistic relationship with sweetpotato

Effects of heat tolerance on expression of resistance to Pseudomonas solanacearum E.F. Smith in potato.

Abstract: Twelve potato clones with different genetic background for resistance to bacterial wilt and adaptation were tested for resistance to a race 1 and a race 3 isolate of the pathogen at three locations in the Philippines representing different ranges of ambient temperature. The results showed that the genes for heat tolerance are crucial for resistance. Stability analysis indicated that clones with both resistance and heat tolerance genes displayed higher and more stable resistance to the race 1 isolate than those clones having only resistance genes. The latter group tended to have higher values of both regression of disease index on environmental index and deviation from the regression in the stability analysis. Host — pathogen interaction effects were found to be statistically significant but small compared to main effects of isolates and clones. The involvement of genes with different effects on wilt resistance is discussed. Introduction