Publications

Sweet potato (Ipomoea batatas (L.) Lam., Convolvulaceae) counts among the most widely cultivated staple crops worldwide, yet the origins of its domestication remain unclear. This hexaploid species could have had either an autopolyploid origin, from the diploid I. trifida, or an allopolyploid origin, involving genomes of I. trifida and I. triloba.

Crop wild relatives of sweetpotato [Ipomoea batatas (L.) Lam., I. series Batatas] have the potential to contribute to breeding objectives for this important root crop. Uncertainty in regard to species boundaries and their phylogenetic relationships, the limited availability of germplasm with which to perform crosses, and the difficulty of introgression of genes from wild species has constrained their utilization.

The best known ARTCs include arracacha, achira, yacon, mauka, and ahipa from the interAndean valleys; and ulluco, oca, mashua, maca, and 8 potato species from the highlands. These crops are grown from southern Venezuela to northwestern Argentina with the highest varietal diversity and uses in the region between central Peru to central Bolivia

The Andean tuber-bearing species, Oxalis tuberosa Mol., is a vegetatively propagated crop cultivated in the uplands of the Andes. Its genetic diversity was investigated in the present study using the inter-simple sequence repeat (ISSR) technique. Thirty-two accessions originating from South America (Argentina, Bolivia, Chile, and Peru) and maintained in vitro were chosen to represent the ecogeographic diversity of its cultivation area.

Oxalis tuberosa is an important crop cultivated in the highest Andean zones. A germplasm collection is maintained ex situ by CIP, which has developed a morphological markers system to classify the accessions into morphotypes, i.e. groups of morphologically identical accessions.

Genetic diversity of ulluco (Ullucus tuberosus), maintained ex situ and originating from Peru and North Bolivia, has been analysed using morphological traits and inter-simple sequence repeat (ISSR) markers, along with passport data. With regard to morphological and ISSR variation, our study revealed a high number of morphotypes and genotypes.

Glucosinolates (GSL) are secondary metabolites found in several families of dicotyledonous angiosperms, including the Brassicaceae and a large number of other edible species (Wang et al. 2002, Robbelen et al. 1989)

This paper analyzes the genetic diversity of mashua cultivars grown in six communities in the Cusco region of Peru, of non-cultivated forms collected in the same region, and a sample of cultivars from the germplasm collection at the International Potato Center (CIP). From the DNA fingerprinting generated by SRAP markers, it is clear that mashua is a genetically variable crop with a range of similarity ranging from 65 to 99%.

The sesquiterpene lactones (STLs) content of glandular trichomes from the leaves of twenty-five yacon (Smallanthus sonchifolius, Asteraceae) accessions, obtained along a latitudinal gradient from Ecuador to northwest Argentina, was characterized by gas chromatography/mass spectroscopy (GC/MS). While accessions from Ecuador, Bolivia and Argentina proved to be very chemoconsistent, significant variation was found in quantitative composition of STLs from accessions in central Peru, the probable region of origin for the species.

Yacon, an Andean root crop, is a plentiful source of fructooligosaccharides (FOS) and phenolic compounds. Its consumption has been related to the prevention of chronic diseases (dyslipidemia and insulin resistance), colon cancer, constipation, among other properties.

The sesquiterpene lactones (STLs) content of glandular trichomes from the leaves of twenty-five yacon (Smallanthus sonchifolius, Asteraceae) accessions, obtained along a latitudinal gradient from Ecuador to northwest Argentina, was characterized by gas chromatography/mass spectroscopy (GC/MS). While accessions from Ecuador, Bolivia and Argentina proved to be very chemoconsistent, significant variation was found in quantitative composition of STLs from accessions in central Peru, the probable region of origin for the species.

Syrup obtained from yacon roots could be well positioned as a nutraceutical product due to its high fructooligosaccharides content. We examined the beneficial effects and tolerance of yacon syrup on human health.

Yacon is a root crop which contains high amounts of fructooligosaccharides (FOS). The aim of this study was to investigate the effects of yacon syrup on colon transit time in healthy volunteers.

Yacon (Smallanthus sonchifolius [Poepp. & Endl.] H. Robinson) is an under-exploited native root crop of the Andes, which stores oligofructans (fructo-oligosaccharides, FOS) as its main component of dry matter (DM). FOS are of increasing economic interest because of their low caloric value in human diets and bifidogenic benefits on colon health.

Maca (Lepidium meyenii Walpers) hypocotyls are reported to have a favorable biological activity in man. Th e presumed bioactive constituents seem to vary among maca hypocotyl color types, but the residual variation is large. Th is study tested the hypothesis that, apart from color types, environmental factors have a distinct infl uence on the concentration of characteristic secondary metabolites in maca.

: Maca is an Andean crop of the Brassicaceae family which is mainly known for its fertility-enhancing properties following consumption. The hypocotyls display various colours ranging from white to black. Each colour has different biological effects. The aim of this study was to analyse the concentrations of major secondary metabolites in hypocotyls and leaves of maca in a controlled planting experiment in the Peruvian Andes at 4130 m above sea level. The effects of colour type and of previous cultivation of the field were examined.

Relationships between Arracacia species were studied according to 28 morphological discriminant characters, in 90 accessions: 83 Arracacia (Arracacia elata, A. incisa and A. xanthorrhiza), and seven accessions of Neonelsonia acuminata, which has been confused with A. elata. The geographic distribution of the Arracacia species was determined from the passport data of the 90 accessions. A. elata was clearly differentiated from N. acuminata according to morphological characteristics.

A study of genetic diversity was conducted among four wild Arracacia species (A. elata, A. equatorialis, A. incisa and A. xanthorrhiza), using three accessions per species, 20 plants per accession referred to as a population, 100 morphological characters and five AFLP primer combinations producing 202 AFLP markers. Genetic diversity was well described using these morphological descriptors and AFLP markers. Analysis of molecular variance showed a total variation of 49.5% which was attributed to differences between species; variation between populations within species amounted for 25.8%, while variation within populations accounted for 24.6%.

Cryobanks are becoming increasingly important particularly for the secure longterm conservation of clonally propagated plant genetic resources. Low maintenance costs for cryopreserved accessions, optimized space usage, extended conservation periods (theoretically for hundreds of years), low risk of mixing or losing accessions, genetic stability, minimal selection pressure and a high probability of maintaining accessions pathogen-free longterm are some of the primary advantages of cryopreserving plant genetic resource collections.

The effect of cold and sucrose pretreatment for increasing tolerance to cryopreservation was evaluated with eight diverse genotypes, six cultivars belonging to the cultivated species, Solanum tuberosum spp., S. tuberosum subsp. andigena, S. x juzepczukii and S. x ajanhuiri, and two genotypes from the wild species, S. commersonii. In vitro plantlets were cultured at either 6 or 22 C in media supplemented with either 0.07 or 0.3 M sucrose prior to droplet PVS2 cryopreservation.

The value of potato as a food and agroindustrial crop is indisputable. For centuries, this crop has played an important role in reducing hunger and malnutrition around the world.

17,618 accessions of potato, sweetpotato, and ARTC germplasm are being stored in Huancayo (Perú) and other places (EMBRAPA, CIAT, and Svalbard) to protect the world’s food supply from epidemics, disasters or wars that might wipe out irreplaceable crops.

This is the duplication of a genetically identical sub-sample of the accession to mitigate the risk of its partial or total loss caused by natural or man-made catastrophes. The safety duplicates are genetically identical to the base collection and are referred to as the secondary most original sample (Engels and Visser, 2003). Safety duplicates include both the duplication of material and its related information, and are deposited in a base collection at a different location, usually in another country. The location is chosen to minimize possible risks and provides the best possible storage facilities.