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.

High-density genetic linkage map construction and identification of fruit-related QTLs in pear using SNP and SSR markers

Abstract: Pear (Pyrus spp) is an important fruit crop, grown in all temperate regions of the world, with global production ranked after grape and apples among deciduous tree crops. A high-density linkage map is a valuable tool for fine mapping quantitative trait loci (QTL) and map-based gene cloning. In this study, we firstly constructed a high-density linkage map of pear using SNPs integrated with SSRs, developed by the rapid and robust technology of restriction-associated DNA sequencing (RADseq). The linkage map consists of 3143 SNP markers and 98 SSRs, 3241 markers in total, spanning 2243.4 cM, with an average marker distance of 0.70 cM. Anchoring SSRs were able to anchor seventeen linkage groups to their corresponding chromosomes. Based on this high-density integrated pear linkage map and two years of fruit phenotyping, a total of 32 potential QTLs for 11 traits, including length of pedicel (LFP), single fruit weight (SFW), soluble solid content (SSC), transverse diameter (TD), vertical diameter (VD), calyx status (CS), flesh colour (FC), juice content (JC), number of seeds (NS), skin colour (SC), and skin smooth (SS), were identified and positioned on the genetic map. Among them, some important fruit-related traits have for the first time been identified, such as calyx status, length of pedicel, and flesh colour, and reliable localization of QTLs were verified repeatable. This high-density linkage map of pear is a worthy reference for mapping important fruit traits, QTL identification, and comparison and combination of different genetic maps.

Pesticide Use and Farm Worker Health in Ecuadorian Potato Production

Abstract: Potatoes are a dietary staple in Ecuador as they have been for thousands of years. In 1992, about 50,000 hectares of potatoes were grown in Ecuador, mostly by small farmers. Almost all potato farmers in Ecuador rely on chemical fertilizers and pesticides to increase yields. Potato farmers are perceived as overusing pesticides, both in quantity and quality, with mixtures of chemicals, known locally as cocktails, being the favored form of application. As in many other countries, there is growing popular concern about the environmental and health impacts of agricultural chemical use. Residue testing on fresh vegetables in Ecuador found levels above those recommended by the FAO-WHO food safety guide, Codex Alimentarius. Human poisoning data were slowly accumulated during the 1980s after pesticide poisoning became a notifiable illness under the public health surveillance system. Focused surveys found widespread ignorance of the symptoms of pesticide poisoning and little use of personal protective equipment among farmers and farmworkers. With the widespread use of backpack sprayers (versus tractor or aerial application in developed countries), these groups are most likely to be at risk of excessive exposure. The research results presented here are from a case study to assess impacts of pesticide use in potato production. This case study follows methodological guidelines laid out by Antle and Capalbo to quantify the interaction between production technology, environmental quality, and human health. Two adjacent watersheds totaling about 150 kilometers in Montufar Canton in Carchi Province in a cool moist highland zone in northern Ecuador served as the case

Potato systematics and germplasm collecting, 1989–2000

Abstract: This paper reviews the systematics of wild potatoes over the past 11 years, in reference to the latest comprehensive taxonomic treatment by Hawkes (1990. The potato: evolution, biodiversity and genetic resources. Belhaven Press, Washington, D.C.). Included here is information on monographs and floras, new germplasm collections made since 1988 compared to total potato distributional data, new taxonomic changes (including synonymy and new species descriptions), ingroup and outgroup relationships, intraspecific studies, diversity studies, and fingerprinting. In addition, data supporting taxonomic changes and phylogeny from ploidy levels, Endosperm Balance Numbers, and morphological studies of taxonomically important characters are reviewed. A revised list of 206 species is presented (from 232 in Hawkes) that incorporates recent synonymy of names, recognition of new names, and new species descriptions. New germplasm collections of 58 potato taxa were collected that did not occur in genebanks before 1988.

Genetic analysis of the cultivated potato Solanum tuberosum L. Phureja Group using RAPDs and nuclear SSRs

Abstract: The Solanum tuberosum L. Phureja Group consists of potato landraces widely grown in the Andes from western Venezuela to central Bolivia, and forms an important breeding stock due to their excellent culinary properties and other traits for developing modern varieties. They have been distinguished by short-day adaptation, diploid ploidy (2n = 2x = 24), and lack of tuber dormancy. This nuclear simple sequence repeat (nSSR or microsatellite) study complements a prior random amplified polymorphic DNA (RAPD) study to explore the use of these markers to form a core collection of cultivar groups of potatoes. Like this prior RAPD study, we analyzed 128 accessions of the Phureja Group using nuclear microsatellites (nSSR). Twenty-six of the 128 accessions were invariant for 22 nSSR markers assayed. The nSSR data uncovered 25 unexpected triploid and tetraploid accessions. Chromosome counts of the 102 accessions confirmed these nSSR results and highlighted seven more triploids or tetraploids. Thus, these nSSR markers (except 1) are good indicators of ploidy for diploid potatoes in 92% of the cases. The nSSR and RAPD results: (1) were highly discordant for the remaining 70 accessions that were diploid and variable in nSSR, (2) show the utility of nSSRs to effectively uncover many ploidy variants in cultivated potato, (3) support the use of a cultivar-group (rather than a species) classification of cultivated potato, (4) fail to support a relationship between genetic distance and geographic distance, (5) question the use of any single type of molecular marker to construct core collections.