Tainan, Taiwan
June 12, 2009
 Source:
AVRDC - The World Vegetable
Center - Newsletter
Vegetable production in the
developing world requires hardier, more productive, and more
nutritious varieties able to thrive as the world’s climate
changes. Dr. Andreas Ebert, the Center’s Global Theme Leader for
Germplasm, collects and protects vegetable genetic resources;
plant breeders use this germplasm to develop
improved vegetable varieties. At stake is the health and
economic well-being of millions of poor farmers, their families,
and communities.
Why does the Center maintain
core collections?
Genebank curators aim to preserve the widest possible range of
genetic diversity within a given crop species. However, large
collections are difficult to manage and use; AVRDC’s genebank,
for instance, has 15,314 accessions of vegetable soybean alone.
A core collection is small in size, but contains maximum
diversity. If the core accessions are well-selected, 10 percent
of the original or base collection can retain 70 to 80 percent
of all alleles present in the whole collection. At AVRDC, we are
just beginning to form representative core collections of
our major crops.
Genotype or phenotype: Which is more important?
Plant diversity can be considered on many different levels.
Phenotypic variation is important to identify plants for
agricultural and industrial purposes. The analysis of variations
in genotype highlights the genetic basis of phenotypic
variation. The genotype is the genetic code—the inheritable
information carried by all living organisms, plants, animals,
and microbes. The phenotype is the outward physical
manifestation of this inheritable information in interaction
with the environment. Plant breeders deal with traits such as
yield, color, fruit shape, pest and disease resistance; these
traits, in turn, are influenced by biotic and abiotic stress,
and by the interaction of genes. Breeders have to scan the total
variation in the breeding population (phenotypes)
and partition it into genetic (heritable) and environmental
components. Hence, genotypes and phenotypes are both essential
components of any breeding effort.
The Genetic Resources and Seed Unit has amassed a great deal
of information about each accession. How is that information
organized and shared?
All relevant data about the Center’s germplasm collection is
stored in the AVRDC Vegetable Genetic Resources Information
System (AVGRIS). It links all operations associated with
germplasm conservation and management,
from registration, characterization, evaluation, and seed
inventory to seed distribution to end-users. This
information is freely accessible on the AVRDC website for users
worldwide. The AVRDC genebank is also part of the System-wide
Information Network for Genetic Resources (SINGER), an
information exchange network of
the Consultative Group on International Agricultural Research
(CGIAR).
Why are indigenous vegetables receiving more attention?
Indigenous vegetables play a significant and increasingly
important role in human diets and the rural economy in most
countries in Asia and sub-Saharan Africa. Indigenous vegetables
are locally adapted and hardy, they can be grown with minimal
external inputs, and they are often tolerant to drought and
heat, and thus are valuable assets as the climate changes. Many
indigenous vegetables are highly nutritious and are the most
important source of micronutrients for the poorest of the poor.
In recent years, AVRDC has recognized the true value of
indigenous vegetables and has embarked on germplasm exploration
and collecting missions in collaboration with national programs,
especially in Southeast Asia. Meanwhile, the Center has
assembled nearly 12,000 accessions of about 200 different
species of indigenous vegetables.
Can genebanks halt the loss in biodiversity?
With multiple threats to agricultural biodiversity worldwide,
including population growth, reduction of arable land, habitat
fragmentation and loss, and modern plant breeding—which led to
the replacement of thousands of
farmer-developed landraces by just a few high-yielding crop
cultivars— genebanks are essential to the
preservation of valuable germplasm for the survival of mankind.
It has been estimated that over six million
samples of seeds are currently being conserved in more than 1300
genebanks. The 11 CGIAR genebanks and AVRDC’s genebank of
vegetable germplasm are pivotal to the global conservation
effort; they currently hold more than 660,000 accessions of
important crops for food and agriculture and, in contrast to
many national
genebanks, are easily accessible to plant breeders and other
scientists worldwide. Ideally, ex situ conservation should be
combined with in situ conservation in natural habitats or
on-farm, which allows for the continuous adaptation of plants to
the changing environment.
What is the procedure for making deposits or withdrawals?
A Material Transfer Agreement (MTA) or a Germplasm Acquisition
Agreement (GAA) describes the materials to be deposited. These
agreements confirm that the provider is legally free to provide
the germplasm and related
information to AVRDC, and that all necessary national
permissions have been obtained. The GAA further states that
AVRDC undertakes to use and conserve the germplasm for the
purposes of research, breeding, and training for food and
agriculture and that the Center is free to make the germplasm
and related information available to any third party for
agricultural conservation, research, breeding, and training
purposes.
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