Andean Tuber Research Articles

Germplasm conservation of oca (Oxalis tuberosa Mol.) through botanical seed. Seed formation under a system of polymorphic incompatibility

Seven clonal accessions representing all three stylar morphs of tristylous oca were intercrossed and selfed in a complete diallelic crossing design. The four traits total capsule production, total number of seeds/capsule, total number of seeds containing an embryo/capsule, and percent seeds containing an embryo of all seeds per capsule were recorded. Both capsule and seed production were highest in the legitimate pollinations (in which styles are pollinated with pollen of the corresponding anther level), but also in illegitimate pollinations of mid-styled seed parents with long-level anther pollen of short-styled accessions. All 18 types of pollination, consisting of 6 legitimate, 6 illegitimate intermorph, and 6 illegitimate intramorph pollinations, expressed gradually different levels of capsule and seed production. Intramorph pollinations and selfs of mid-styled seed parents were less incompatible than intramorph pollinations and selfs of the long- and short-styled morphs. All accessions studied expressed an intact system of heteromorphic stylar incompatibility despite their exclusive clonal propagation for millennia. A maximum of 16,3 seeds/capsule containing an embryo was obtained in an individual legitimate cross of two accessions, although an average of 25 ovules are present in a flower of O. tuberosa. The results are discussed in relation to the establishment of a genebank based on botanical seed of this clonally propagated, valuable Andean tuber crop.

Comparative Morphology of Starch of Three Andean Tubers

AbstractThe starch of three Andean tubers have been studied (Oxalis tuberosa, Ullucus tuberosus, Tropaeolum tuberosum). Qualitative optical methods, scanning electron microscopy and quantitative analytical microscopy have been used. Statistical tests have been applied to the results. The comparative study of starch grains morphology provides important characters for their identification. As a result, starch would be an element of high value in the determination of material recovered from archaeological sites in different preservation conditions or used in food elaboration.

Chemical composition and protein quality of some local Andean food sources

The chemical composition of tubers of Tropaeolum tuberosum, Oxalis tuberosa, Iliacus tuberosum and the seeds of Chenopodium quinua, Chenopodium padillicaule, Amaranthus caudatus and Lupinus mutabilis was studied. The protein efficiency ratios (PER) of quinua, amaranth and lupin were also investigated. The results show that the native Andean tubers constitute sources of highly digestible carbohydrates, whereas the cereal-like grains are characterized by a protein content higher than that found in cereals, and an excellent protein quality. The Andean lupin possesses the advantage of an extremely high protein and energy density, although protein quality is low; this advantage, however, can be overcome by mixing with other traditional Andean food crops. It can be concluded that diets based on well-combined local food sources constitute an inexpensive, ecologically useful and physiologically adequate contribution to combat widespread malnutrition in the Andean area.

Cultivation of minor tuber crops in Peru and Bolivia

A collection mission of three Andean tuber crops, oca (Oxalis tuberosa, Oxalidaceae), ulluco (Ullucus tuberosus, Basellaceae) and añu (Tropaeolum tuberosum, Tropaeolaceae), was carried out in southern Peru, Bolivia and northern Argentina. This article deals with the observations made during this mission. 55 ulluco fields were visited. In general, the fields are small, 240m2 on average, and they are mostly situated on mountain slopes. The fields are fertilized with animal dung; chemical fertilizers are quite rare. In the fields, people work with hoes ang ploughs as they did hundreds of years ago. Mechanization of agriculture would prevent full utilization of the mountainous area of the Andes. Ulluco is usually interplanted with other crops, usually, many forms of ulluco in one field. Because of crop rotation description of the fields is partly valid for the cultivation of other crops, too. Due to drastic climatic variation, cultivation of mixed varieties maybe the best way to guarantee some yield. When results of the investigations are wished to benefit developing countries, knowledge of social, agricultural and environmental factors is of great value.

Nutritional evaluation of three underexploited andean tubers:Oxalis tuberosa (Oxalidaceae),Ullucus tuberosus (Basellaceae), andTropaeolum tuberosum (Tropaeolaceae)

Three species of edible tubers endemic to and domesticated in the Andes were studied for their nutritional value. Collected samples ofOxalis tuberosa, Ullucus tuberosus, andTropaeolum tuberosum show a high amount of variation in both percent protein and quality of essential amino acids. A protein difference of120% is present amongT. tuberosum cultivars and a protein difference of 300% is present among the three species. The data indicate that previous published Andean tuber crop food values may need revision. The introduction of "improved" crop varieties and less nutritious foodstuffs threatens the base ofcultivar diversity that has been selected by Andean agriculturists over centuries. This rapid erosion of Andean tuber diversity indicates the importance of identifying and conserving Andean tuber cul-tivars throughout the Andes.

Four Endemic Andean Tuber Crops: Promising Food Resources for Agricultural Diversification

Four Endemic Andean Tuber Crops: Promising Food Resources for Agricultural Diversification