Agrobiodiversity: Let's grow and eat more diverse.

What is agrobiodiversity?

Agrobiodiversity is all wild and domesticated diversity of plants, animals, fungi and microorganisms, including the landscapes in which they are found (Casas and Vallejo, 2019). This heterogeneity allows for an amalgam of interlinked processes, which are affected and at the same time affect human activities. The FAO (2004) tells us that when talking about agrobiodiversity we are also including the diversity of unharvested species that support production, for example: predators and pollinators. These elements underpin the agro-ecosystems in all its forms: agricultural, pastoral, forestry and aquatic.

La variety and variability in agrobiodiversity are extremely important elements. Variety is the diversity that exists within individuals of the same species, for example if we think of the different types of corn that exist in Mexico: cacahuacintle, mushito from Michoacán, blue, olotón or conical (among many others). On the other hand, the variability It is a tendency for the genotypes of a population to differentiate, that is, the variation in the genetic material of a species or population (Rimieri, 2017). Variability can occur due to mutations (which is any change in a DNA sequence) or to a combination of genes that occurs during gamete reproduction.

As you can imagine, all this would not be possible without the intervention of the human being for approximately 10,000 years; this relationship between the human being and the ecosystem where they live is known as ethnoecology. In turn, it gives rise to the local knowledge of our original peoples that is transmitted from generation to generation.

Mexico is a center of origin and domestication

To contextualize, a center of origin is the geographical space where the origin of a species or population occurred. When these species disperse, reproduce or mutate, they give rise to new species that form centers of diversification, so a diversification center may not be your center of origin (CONABIO, 2020). On the other hand, a domestication center It is an area in which the wild population is selected in terms of its genetics or phenotype; the process requires a long time and sometimes it is necessary to start several times depending on the intervention of the human being. For domestication to happen, farmers select and sow the seeds of the plants they consider to be of the best quality, which is part of customary knowledge. Each agricultural cycle changes them and they are genetically differentiated from other regions. This is one of the reasons why there are 64 varieties of corn in Mexico (Sánchez et. al., 2000).

Between 1920 and 1940, a Russian agronomist-geneticist named Nikolai I Vavilov carried out unique expeditions in the world and collected information on the variation of the different cultivated species. At that time, his work would serve the government of the Union of Soviet Socialist Republics (USSR), but his study really helped everyone to marvel at the endemism on the planet and the ancient activities of domestication. After his extensive study, Vavilov proposed eight centers of origin:

1. China,

2. India and the Indo-Malaya region,

3. Central Asia, including Pakistan, Punjab, Kashmir, Afghanistan and Turkestan,

4. Near East,

5. Mediterranean,

6. Ethiopia,

7. Southern Mexico and Central America,

8. South America (in Ecuador, Peru, Bolivia, Chiloé in Chile and the Brazil-Paraguay region).

Mexico's biological wealth and why it matters

Mexico is a mountainous tropical country with a high number of endemic species (species characteristic of a specific geographical space) and has temperate marine environments in the Pacific and tropical in the Gulf of Mexico and the Caribbean (Plascencia et.al., 2011), which means that in our country there is a privileged variety of ecosystems and species.

For this reason, Mexico is part of a select group of countries worldwide that are called megadiverse countries because they are home to 70% of all species of flora and fauna on the planet; only Mexican territory houses 10% of the planet's biological wealth (INECOL, 2021). This vast biological wealth includes agrobiodiversity, which represents not only the varied diet of Mexicans but also traditional medical knowledge, the raw materials used to make certain products and that collective knowledge about climate and planting. To illustrate the importance of agrobiodiversity in our country, 15.4% of all the species that make up the world's food system are found in Mexico (Boege, 2009:18) Think about how much wealth there is in our land!

In addition, agrobiodiversity helps maintain hydrological cycles, soil fertility through the nutrient cycle and organic decomposition, controls erosion and contributes to the regulation of pests and pollination. In short, it favors the resilience of socio-ecosystems when faced with catastrophes.

Agrobiodiversity in Mexico faces several threats such as climate change, technicalized monoculture agriculture, soil degradation, pollution, the intensive and increasing use of agrochemicals, the overexploitation of soil and water, the introduction of exotic species -species that belong to a different ecosystem-, the disappearance of arable areas due to migration, and above all, purchasing preferences, which is a decisive factor for agricultural production since local varieties are replaced by modern varieties, causing genetic erosion. This is another essential element to consider; genetic erosion refers to the loss of individual and combination genes. Because farmers replace existing varieties with commercial varieties in traditional cultivation, these are reduced and give way to new pests for the ecosystem.

Globally, food consumption habits have become increasingly similar to each other. We rely mainly on three crops: corn, wheat and rice. As a result of this pattern, thousands of cultivated plants are no longer used, despite having high nutritional values. As a result, the loss of this enormous variety of plants impairs not only our nutrition, but also the resilience of agricultural ecosystems in the face of the threats described above.

How can we contribute to mitigating the threats faced by agrobiodiversity in our country?

Some years ago, it was considered that the best way to conserve agrobiodiversity was ex situ, that is, outside the space where the seed is cultivated, mainly in germplasm banks. It is currently recognized that the optimal way to conserve, improve and take advantage of agrobiodiversity is on site, in their habitat. Even better if it is on the same plot making use of seeds, since it is also a strategy for agricultural species to continue evolving.

However, as consumers we can do a lot. In the first instance, expand our knowledge about the extensive agrobiodiversity in Mexico, reflect on our buying habits and seek ways to connect directly with producers.

References

Boege, E. (2009). Centers of origin, indigenous peoples and the diversification of maize Ciencias, No. 92 - 93, October-March, pp. 18-28 National Autonomous University of Mexico, Mexico.

A. & M. Vallejo Houses, 2019. Agroecology and Agrobiodiversity. In: Merino P. L. Environmental crisis in Mexico. Route for change. National Autonomous University of Mexico, Mexico pp.99-117.

Centres of origin and diversification | CONABIO. Mexican Biodiversity. (2021). Consulted 7/10/2021. Retrieved from: https://www.biodiversidad.gob.mx/genes/centrosOrigen.

Rimieri, P. (2017). Genetic diversity and genetic variability: two different concepts associated with germplasm and plant genetic improvement. BAG. Journal of basic and applied genetics, 28 (2), 7-13. Consulted 07/10/21. Retrieved from http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1852-62332017000300001&lng=es&tlng=es.

Plascencia, R.L.; Castañón A.; Raz-Guzmán, A. (2011). Biodiversity in Mexico: its conservation and biological collections Sciences, No. 101, January-March, pp. 36-43 National Autonomous University of Mexico, Mexico.

Sanchez, J; Goodman, M; and Stuber, W. (2000). Isozymatic diversity of the races of maize of the Americas. Magidica 45:185-203.