Significance of potato biodiversity and other crops in the Andes of Bolivia

By: Jorge A. Rojas Beltrán, Esther L. Rojas Vargas, Pablo Paco Cabrera- Universidad Mayor de San Simón

Although the use of high genetic diversity is a constant in traditional agriculture, in the Andes of Bolivia it is an imposition. Monoculture and genetic uniformity are not viable in Andean agriculture because in this region, agro-ecological conditions (soil, humidity, temperature, etc.) can change in a matter of meters. Then, the Andean farmer faces a complex physical mosaic and has learned that the only way to live with him, is to superimpose a biological mosaic.

However, the possibilities of access to a lesser or greater diversity, is conditioned by the altitude and the conditions of humidity. Lower and wetter places have greater genetic diversity, particularly inter-specific. Thus, for example, in the Raqaypampa Indigenous Peasant Territory (Cochabamba - Bolivia) we have inventoried 26 major cultivated species, the same that to a greater or lesser degree, are sown by each of the farmers. To this amount must be added the different cultivars for each species. In Raqaypampa, up to 39 potato cultivars, 21 wheat cultivars and 37 maize cultivars have been inventoried (table 1), which are the main crops in this region.

Table 1. Historical inventory of cultivars of some species cultivated in the Territory of the Indigenous Native Peasant Autonomy of Raqaypampa (Cochabamba - Bolivia).

Andean farmers not only manage different species and cultivars, but also manage heterogeneous cultivars. That is, there is also a high genetic diversity within the cultivars. For example, traditional quinoa cultivars are more similar to what is technically known as multi-lines. Diversification within cultivars is present even in clonal multiplication species such as potato, goose, etc. In studies conducted in Oca (Oxalis tuberosa), a species that reproduces by tubers, intra-cultivar variability has been demonstrated (Malice et al, 2007; Bonnave et al, 2013).The origin of this variability is the production of tubers of plants that were developed from seeds. These tubers, similar or not to the crop that gave them origin, are not discarded by farmers, rather they are incorporated into the genetic pool they manage. The environment will have the last word. An important aspect to be stressed in this regard is that intra-crop diversification does not translate into a heterogeneous product for use. Obtaining a homogeneous product from a mixture of genotypes, is a remarkable Andean technology that has not been assessed in its proper dimension.

The highest and driest places have less biodiversity. Thus, for example, quinoa is one of the few species, if not the only one, that can produce food in the southern highlands of Bolivia, which is between 3,700 and 4,200 m.a.s.l., and has an average annual rainfall of 190 mm. However, intra-cultivar diversification (there are more than 50 cultivars) and intra-cultivar diversification is very large.

In the heights of the municipality of Sacaba, where the project "Root to Food" is developed, financed by FONTAGRO, the main crop is the potato. These areas are above 3,000 meters above sea level and have an average annual rainfall of more than 500 mm. Although humidity conditions would allow greater diversification, in this case it is the height that limits this possibility. Above 3,000 meters above sea level, the number of species that can thrive is reduced. That is why, in the heights of Sacaba, potato is mainly cultivated, because it is a species that requires some humidity and supports very well the height. In addition, and in a smaller proportion, the smooth potato (Ullucus tuberosus), the goose (Oxalis tuberosa), the isaño (Tropaeolum tuberosum), the oats and the barley are cultivated. However, this does not mean that the diversity is limited because there are as 50 potato cultivars and, what’s more, there are cultivars, such as bitter potatoes, that can develop at 4,000 m.a.s.l., or more. It is also very likely that there is an intra-cultivar diversity in the potato. The same farmers recognize different variants of the same cultivar and we, using molecular markers, have identified at least two variants in one of the most commercial potato cultivars in Bolivia, such as Haycha.

The great genetic diversity of potatoes and other species originates in response to the great diversity of the physical environment where they are sown. As in the Bolivian Andes there are hundreds of combinations of the components of the physical environment, there are also hundreds of cultivated varieties. This agrobiodiversity, which has been fundamental for the development of agriculture in this area, is also being very useful to adapt to climate change. Thus, inter-specific, intra-specific and intra-cultivar diversity is a fundamental pillar of Andean agriculture, not only because it counteracts physical and climatic diversity, but also because it counteracts the negative effects of climate change.

REFERENCES

Bonnave M, Bleeckx G. Rojas-Beltrán J, Maughan P, Flamand MC, Terrazas F, Bertin P (2013) Farmers’ unconscious incorporation of sexually-produced genotypes into the germplasm of a vegetatively-propagated crop (Oxalis tuberosa Mol.) Genet Resour Crop Evol. 

Malice M, Martin N, Pissard A, Rojas-Beltran JA, Gandarillas A, Boudoin JP (2007) A preliminary study of the genetic diversity of Bolivian oca (Oxalis tuberosa Mol.) varieties maintained in situ and ex situ through the utilization of ISSR molecular markers. Genet Res Crop Evol 54: 685–690.