Overview of Crop Improvement Approaches During the past 100 years, crop improvement came to rely more and more on biology and laboratory methods. In developed countries, research is done by companies that sell seeds. Developing countries rely on the International Research Institutes but their resources are limited.

Where were our crops domesticated Mesoamerica: corn, common bean, squash, sweet potato, tomato, upland cotton Andean region: potato, common bean, peppers, cassava, pineapple, pima cotton African Sahel + Ethiopia: sorghum, African rice, coffee, okra, melon, cowpea Near East: wheat, barley, pea, lentil, chickpea, grape, Eastern India and South-East Asia: mungbean, cucumber, banana and plantain, eggplant, coconut, tea Southern China: Asian rice, soybean, citrus, tea, cabbage

Land races Relative reproductive isolation and differing conditions of soil, nutrients, diseases, insects, water, day length etc created numerous landraces of our crops. Landraces do not have a fixed complement of genes (alleles) because subsistence farmers are always trading seeds and the conditions change over time (hundreds of years). All land races of one species have the same genes (unless deletions occurred), but many different alleles = biodiversity Corn from different fields

The rise of agricultural experiment and plant breeding stations in the 19th Century Established in 1843, Rothamsted it is the oldest agricultural experiment station in continuous existence. The Broadbalk wheat experiment has different crop rotations, levels of fertilizer etc and yields have been measured for 160 years. Analogous fields in the US are the Morrow Plots at the University of Illinois, established in Lower right: Remote sensing of crop growth on the Morrow Plots. Intensities reflect the level of plant growth/fertilizer application University of Illinois Rothamsted Expt. Sta.

The March of Genetic Technology 1860Mendel: making crosses, introducing genes 1920Discovery of hybrid vigor 1950Inducing mutations 1960Tissue culture and embryo rescue 1980Plant transformation and GM crops 2000Genomics (study of all the genes) Gregor Mendel

Lycopersicon esculentum Lycopersicon peruvianum Back- cross series Tomato Cultivar with new trait INTER-SPECIFIC CROSS or INTRA-SPECIFIC CROSS THAT IS NORMALLY FERTILE # 1 Introgression of a specific trait

# 2 Hybridization : To produce a hybrid strain one starts with two “inbreds” (strains that have been self-fertilized for several generations) and then crosses these inbreds. The seeds resulting from this cross are sold to the farmers. They will produce bigger plants with larger ears. However, when the seeds of these ears are planted again the “hybrid vigor” is lost. We do not yet understand the genetic basis of hybrid vigor. Inbred Hybrid Inbred

Maize is a monoecious plant with separate male and female flowers. This makes it much easier to produce hybrids because it is easy to emaculate the plants (remove the pollen producing tassels) and control pollination Tassel = Male flower Produces pollen Silks = Female flower Becomes the ear

Hybrid rice, the result of controlled crossing of two varieties, is raising rice productivity in Asia and elsewhere. Farmers cannot get the yield advantage is they save seed to replant, so the distribution of hybrid seeds is dependent on seed companies. In Africa most farmers are still too poor to buy the hybrid seeds.

# 3 Interspecific hybrids with embryo rescue Triticale, a new “synthetic” cereal, is a cross between wheat and rye produced by embryo rescue of the product of fertilization and a chemically induced chromosome doubling with cochicine Wheat, triticale and rye Triticale is now grown all over the world

Institute of Radiation Breeding Ibaraki-ken, JAPAN 100m radius 89 TBq Cobalt-60 source at the center Shielding berm is 24 ft high # 4 Radiation breeding Hundreds of crop varieties have been produced by radiation breeding. Plants or seeds are irradiated with gamma rays and their progeny examined for agronomically useful traits. This is followed by extensive backcrossing.  -Radiation Field

# 5 Genetic engineering of plants (creation of GMOs) relies on a natural gene transfer mechanism by Agrobacterium tumefaciens from its Ti plasmid to the plant genomic DNA. Discovered by Marc Van Montagu and Jeff Schell in Belgium and by Mary Dell Chilton and Eugene Nester in the USA

Genome Sequencing Important genes identified in one species (Arabidopsis or rice) can immediately be recognized in other species. All this information is public. Expression Profiling Determine the expression of thousands of genes at once on a “chip” Proteomics # 6 Genomics, the most recent genetic technology

Where is plant breeding research done and who does it? Developed countries 1. Large agricultural biotech companies sell seeds and do research aimed at crop improvement through genetic engineering and traditional breeding (Pioneer, Dupont, Monsanto, Bayer). They aim at the crops with big markets (corn, soybeans, potatoes, wheat, cotton). They own many plant breeding sites. 2. Smaller seed companies produce hybrid vegetable seeds. 3. Universities and public institutions (USDA) do much less plant breeding than before, but do all the genomics research and gene discovery. 4. Small biotech companies (Mendel, Ceres etc) do gene discovery research.

Where is plant breeding done and who does it? Developing countries 1. Public domain breeding stations (NARS) 2. C.G.I.A.R. Research Centers CIMMYT Mexico IRRI Philippines The Consultative Group on International Agricultural Research has research centers all over the developing world and employs 8500 scientists and staff, with a $ 340 million annual budget that has to come from “donors”. The centers work with local plant agricultural institutions to improve crops and agric. practices.

Traditionally, CGIAR centers worked on major crops (rice, wheat, corn) but now they work with National Agricultural Research Systems (NARS) and other stakeholders to release improved varieties of minor crops. Newer is better-sorghum grain yields in 20 on-farm trails in Tanzania, 1994/95, show progressive improvements from "first generation" to "second generation" improved varieties New pearl millet varieties consistently out perform traditional varieties in on-farm trials in Malawi and Tanzania Pearl millet in MalawiSorghum in Tanzania

Increase in crop yields in different countries Steady increases in the US started in 1930s with wheat breeding and corn hybridization. Faster yield rise in India are due to double cropping. Genetics is key to raising yields in the world. Other inputs (fertilizers, pest control, irrigation) are also needed

1. Agro-ecological system 2. Resilience/fragility of the environment 3. Ability to purchase inputs 4. Reliability of seed distribution system 5. Food preferences 6. Local food distribution system 7. Export market Genetics, a powerful tool to raise productivity, but must go hand in hand with:

Average annual increase in yields of rice, wheat and maize in developing countries by periods. (Nature 402, C55 - C58 (1999); Feeding the world in the twenty-first century. Gordon Conway and Gary Toenniessen)

Costs and benefits of agricultural research

Agricultural Productivity Increases Benefits Improved per capita production Reduced unit costs and prices Increased incomes and purchasing power for farmers and consumers Restrained expansion into forests, grasslands, and wildlife habitats, helping to avert natural resource degradation Costs Increased soil salinity and lowered water tables in irrigated areas Exacerbated health and environmental problems through inappropriate use of fertilizer and pesticides Displaced tenant farmers may not find employment.

New Research Agenda in the Developing World Production is de-emphasized. More responsive to consumer demand (organic agriculture) More emphasis on “functional foods”. More emphasis on precision farming technology. Developed technologies may not be accessible because of intellectual property rights (IPR). Higher proportion of research in biotech companies that emphasize technologies applicable at home. Smaller growth in funding than years ago.

Implications Pardey, Alston and Pigott, Intl. Food Policy Institute (IFPRI) 1.Less spillover; technologies being developed may not be appropriate for developing countries. 2. Applicable technologies may not be accessible because of intelectual property rights (patents) 3. When appropriate and accessible, technologies will require more development locally and require more sophisticated scientists.