Cultivating biodiversity: Sorghum example
Climate, environment and competition between species are well-known factors in the genetic evolution of plants. But crop plants are subject to an additional force: human action. A Franco-Kenyan research team has demonstrated this fact for Sorghum and therewith reveals interesting new hints for the conservation of biodiversity, too.
It is difficult
to distinguish the human impact on the effects of natural factors on
the evolution of crop plants. A Franco-Kenyan research team has managed
to do just that for sorghum, one of the main cereals in Africa. The
scientists demonstrated how three societies living on the slopes of
Mount Kenya have shaped the geographic distribution and structure of the
genetic diversity of local varieties. Because of their practices for
selecting and exchanging crop seeds for harvesting, the farmers in each
ethnic group maintain varieties which are unique to them. These prove to
be genetically and phenotypically differentiated, despite their close
geographical proximity. This study sheds light on the debate on the
ownership and redistribution of benefits from genetic resources.
Three societies, the same environment
Climate, environment and competition between species are well-known
factors in the genetic evolution of plants. But crop plants are subject
to an additional force: human action. Up to now, few studies have been
able to distinguish the results of the domestication of the effects of
natural constraints on crop diversity. To shed some light on this
question, a Franco-Kenyan research team became interested in a
particular territory: the eastern slopes of Mount Kenya. This territory
offers both an ecologically homogeneous environment and brings together
different ethnic groups, the Chuka, Mbeere and Tharaka peoples, making
it possible to compare the influence of their different agricultural
practices and traditional knowledge on the diversity of sorghum, a very
important cereal in this area.
Practices that shape each variety
Researchers from the IRD, Cirad and KARI in Kenya have
carried out field surveys of each ethnic group to specify their social
organization, the traditional methods for selecting and exchanging seeds
from one harvest to another, the importance of the market in such
trading, etc. These investigations revealed that the Chuka, Mbeere and
Tharaka peoples each grow a mixture of sorghum varieties that is unique
to each group. Certain varieties dominate based on ethnic preferences
and practices (cooking, etc.), or according to their agricultural
strategies for dealing with natural hazards (long or short crop cycle
varieties). In addition, local seed varieties are traditionally
transmitted in a very compartmentalized way within the same ethnic
group. These practices limit the genetic and phenotypic standardization
of the varieties grown on the slopes of Mount Kenya. So, despite a
common local market, sorghum populations are very different there.
Each ethnic group leaves its genetic "signature"
At the same time, the researchers inventoried and sampled the
different varieties of sorghum grown by 130 Chuka, Mbeere and Tharaka
households. DNA analysis of the 300 plants gathered has identified four
genetic groups of sorghum. Two of them correspond to two introduced
varieties. These are varieties that were genetically improved by NGOs or
the national agricultural extension services. One of these varieties,
which was introduced almost 15 years ago, seems to be more genetically
diverse among the Chuka than with the other ethnic groups. This suggests
that the practices of the three communities leave their "signature" in
the genomes of sorghum populations.
Using this multidisciplinary approach bringing together
anthropologists, geneticists and agronomists, this work shows the role
of human societies in the geographic distribution and evolution of the
genetic diversity of crop plants. Identifying the factors that shape
biodiversity locally helps to preserve them better in the future.
Furthermore, this confirms the influence of local practices and
knowledge on the diversity of life, which is a central issue in the
debate on the ownership and redistribution of benefits from the use of
The above story is based on materials
provided by Institut de Recherche pour le Développement (IRD)
Vanesse Labeyrie, Monique Deu, Adeline Barnaud, Caroline Calatayud,
Marylène Buiron, Peterson Wambugu, Stéphanie Manel, Jean-Christophe
Glaszmann, Christian Leclerc. Influence of Ethnolinguistic Diversity on the Sorghum Genetic Patterns in Subsistence Farming Systems in Eastern Kenya. PLoS ONE, 2014; 9 (3): e92178 DOI: 10.1371/journal.pone.0092178
This article was published at ScienceDaily here
Picture: © IRD / A. Barnaud
Tags: Biodiversity Management | Biodiversity policy | Forestry and paper | Agriculture and food
Other articles you might be interested in:
Private Investment in Conservation Reaches $8.2 Billion
The private sector channeled $8.2 billion (B) of private capital in to investments that seek measurable environmental benefits – in addition to financial returns – between 2004 and 2015 according to a report released by Forest Trends’ Ecosystem Marketplace.
Voluntary Sustainability Standards and Biodiversity
Understanding the potential of agricultural standards for biodiversity protection - This policy brief provides a summary of the findings of joint research conducted by International Institute for Sustainable Development in collaboration with the Convention for Biological Diversity Secretariat analyzing the potential contribution of voluntary sustainability standards to support biodiversity protection.
Aidenvironment Study: Sustainability Issues and Solutions in the Rubber Sector
Low prices drive natural rubber producers into poverty and serious violations of working rights are common. This is the harsh reality revealed in a new study conducted by Aidenvironment. The comprehensive review of literature reveals numerous cases of inadequate safety standards, inappropriate use of toxic chemicals, discrimination and structurally long working hours and child labour. It points to the need for more responsible sourcing practices by the rubber industry with particular attention to fair trading conditions.