Transcript Titel
Traditional breeding:
major accomplishments
Bert Visser
Copenhagen, 13 december 2005
Centre for Genetic Resources, the Netherlands
Scope of this presentation
actors
results
the succession of breeders
food security
yields
resistances
hybrids
starting materials
germplasm collections
Centre for Genetic Resources, the Netherlands
Actors: the succession of breeders
domestication started only 10,000 years ago
small breeding enterprise emerged in 19th century
until 19th century all breeders were farmers
(not all farmers were breeders)
breeders became specialists
breeders used genetics
breeding was core business
large mergers accelerated in the rise of biotech
breeding a multidisciplinary affair in multinationals
increasingly, varieties vehicle to sell traits
Centre for Genetic Resources, the Netherlands
Results: food security
current human population levels depend on plant
domestication
Green Revolution (1970s/1980s)
cereal production expanded faster than world population
prevented large-scale famines in e.g. India and China
in 2002 world food supply 20% higher than in 1961
real prices 40% lower
(Borlaug & Dowswell, 2003)
Centre for Genetic Resources, the Netherlands
Food security versus food sovereignty
food security
food may be available, but:
does it reach every person?
is it affordable to all persons?
food sovereignty
deals with autonomy
the right to choose
challenges globalization and food product uniformity
Centre for Genetic Resources, the Netherlands
Results: yield as a complex
yield is the result of several factors
germplasm
irrigation
fertilizer
pesticides
mechanization
Centre for Genetic Resources, the Netherlands
Results: some yield figures (1)
actual yield increases between 1960 and 2000
wheat 208%
rice 109%
maize 157%
potato 78%
cassava 36%
high-yielding semi-dwarf varieties
on 84% of wheat area
on 74% of rice area
harvest index increased from 0.3 to 0.5 (Kush, 2003)
Centre for Genetic Resources, the Netherlands
Results: some yield figures (2)
yield potential (Kush, 2003)
grain production per capita (Kush, 2003)
from 4 to 10 tonnes/ha for rice and wheat
annual growth of wheat potential
in 1984 342 kg, in 1996 321 kg
cropping period from 150 – 180 days to 110 days
drought avoidance
three croppings per year
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Results: new resistances
resistances introgressed from wild relatives
some diseases erased (De Nijs, pers. comm.)
many not available from farmers’ varieties
based on wide crosses
wheat, rice, maize, tomato, lettuce, etc.
cucumber scab
cucumber leaf spot
some pathogens contained
potato nematode species (Globodera rostochiensis)
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Resistances from genebank stocks
resistance against tomato spotted wilt virus (De Ponti)
rust resistance in wheat (CIMMYT)
Hessian fly resistance in wheat
stripe rust in barley
polygenic scab and mildew resistance in apple (BAZ)
grassy stunt resistance in rice (IRRI)
Fusarium wilt in pigeon pea (ICRISAT)
late blight in potato (USDA-ARS)
late blight in potato (CGN)
Centre for Genetic Resources, the Netherlands
Hybrid development
two major motives
agronomic: hybrid vigour
economic: biological property protection
higher yields in hybrids
rice yields up to 10 tonnes/ha (China)
attractive trait combinations from different parents
what if similar investments had been spent on open
pollinating varieties?
Centre for Genetic Resources, the Netherlands
The role of germplasm collections
ex situ collections sources of resistances
major use motive for breeders (CGN questionnaire)
wild relatives major component of collections
utilization in subsequent steps, contributions by several
actors
ex situ collections potential sources of many traits
quantitative traits
non-expressed traits
paradigm shift (Tanksley and McCouch, 1997)
Centre for Genetic Resources, the Netherlands
Conclusions (1)
in developed countries food production taken for
granted
not high on politician’s agenda
in developing countries remaining issue
shift towards sustainability aspects
in developing countries Green Revolution major
impact on food production
more on yield than on sustainability
exclusive focus on staple crops
Centre for Genetic Resources, the Netherlands
Conclusions (2)
immense diversity available through traditional
breeding
not exhausted
GM crops largely technology push and economically
inspired (patentable traits and processes)
GM technology any impact on food security?
currently only four crops, two traits, six countries
only developed for markets with purchasing power
only marketed if patents can be enforced
Centre for Genetic Resources, the Netherlands