Plant Breeding
Plant Breeding To develop genetically superior cultivars which are adapted to specific environmental conditions and suitable for economic production in a commercial cropping system. These new, and more productive cultivars, are increasingly necessary to fulfil humankind s increasing needs for food, fibre and fuels.
Plant Breeding The basic concept of varietal development is rather simple and involves three distinct operations: Produce or identify genetically diverse germplasm; Carry out selection procedures on phenotypes or genotypes from within this germplasm to identify superior genotypes with specifically and improved characteristics; Stabilize and multiply these superior genotypes and release cultivars for commercial production.
Plant Breeding Genetic modification of crop plants Increase productivity Have better end-use quality Can be produced with fewer input costs, with greater profit
Modern Plant Breeding Began Around the turn of the 20 th Century Darwin Differential breeding of better adaptation (Evolution). Mendel Inheritance of plant characters. Weissman The continuity of germplasm. Johannsen Genotype/phenotype relationships.
What contribution has modern-day plant breeders made to our present day crops
t/ha Winter wheat yield in Idaho 1920 to 1998 6 4 2 0.2236 Mt/year 0 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Year
30 Potato yield in UK 1955 to 1987 20 10 0 0.2193 Mt/year increase 1955 1960 1965 1970 1975 1980 1985 Year
t/ha 9 8 7 6 5 4 3 2 1 0 Wheat and barley yield in UK according to year of introduction Spring wheat Spring barley 1880 1900 1905 1935 1940 1955 1960 1965 1970 1975 1980 1983 Year of Introduction
kg/plot 20 18 16 14 12 10 8 6 4 2 0 Potato Yield in UK according to year of introduction -0.0.38 kg/year decrease 1900 1910 1920 1930 1940 1950 1960 1970 1980 Year of Introduction
What is a Cultivar? Distinctness:.. Shall be clearly distinguishable, by one or more important characteristic, from any other plant variety Uniformity:.. Similar or genetically identical as regards the characteristics, taken as a whole Stability:.. Exhibit its essential characteristics after successive reproductions
What is a Cultivar? Value for Cultivation and Use (VCU):.. constitute either genetically or as far as production in a specific area is concerned, a clear improvement either as regards crop farming or the use made of harvested crops or of products from these crops
Value for Cultivation and Use No statutory VCU trials Reputation of seed companies. Regulatory VCU trials Mistakes are made, and potentially useful cultivars are wrongfully discarded. Only limited numbers of new lines can be tested annually. Tests do not mimic actual agricultural situations. Delays the period of new cultivars being commercialized.
Types of Cultivar Pure-line cultivar: wheat, pea, barley, canola, lentil. Multi-line: wheat, barley, lawn grasses. Clonal cultivar: potato, apple, strawberry. Hybrid cultivar: corn, tomato, canola, carrot, rice, potato. Synthetic cultivar: alfalfa, canola, corn.
Certified Seed Grown under strict quality standards Inspected and tagged by state certification authorities. Genetically pure. Free from weeds. Free from seed borne diseases. Better for agriculture, better end product.
Plant Breeding Operations Identify or create genetic variability Select for desirable recombinants
Artificial Hybridization
Artificial Hybridization
Parental Selection
Parental Combinations High Yield /Disease Susceptible x Low Yield /Disease Resistant High Yield & Disease Resistant
What if I can t find genes for a desirable character from within the crop species that I m working with?
Wide Crossing Interspecific and Intergeneric Hybridization
T. monococcum spp aegilopoides A b A b Ae. Speltoides (cytotype I) SS T. Urartu A u A u Ae. Speltoides (cytotype II) SS T. monococcum spp monococcum A b A b T. turgidum ssp dicoccoides AABB T. timopheevi ssp armeniacum GGA t A t Ae. tauschii DD T. turgidum ssp dicoccon AABB T. timopheevi ssp timopheevi GGA t A t T. aestivum DDAABB T. turgidum ssp durum AABB
Wheat 2n=6x=42 AABBDD or AABB Rye 2n=2x=14 RR Triticale 2n=6x=42 AABBDDRR or AABBRR
[2x = 22] Colchcine [4x = 44] Autotetraploid
[2x = 22] x [4x = 44] [3x = 22] x Sterile [2x = 22] Seedless Watermelon
What if I can t find genes for a desirable character from the crop species or within the relatives of the crop species that I m working with?
Induced Mutation
Practical Considerations Mutagens are indiscriminant agents. Clean up and stabilize mutants. Get rid of undesirable mutants. Selection of desirable mutants. Rapid screen necessary. In vitro screening.
Plant Transformation Possible to transfer single genes from other species and non-plants into plant. Bypass natural barriers which limit sexual gene transfer. Allow breeders to utilize gene from completely unrelated species. Create new variability beyond that currently available.
Applications Herbicide resistant crops glyphosate, glufosinate. Insect resistance mainly using genes from Bacillus thuringiensis (B.t.). Virus resistance coat protein mediated protection. viral replicase genes.
Applications Modified end-use quality. Starch content. Amino acid composition. Oil fatty acid profile. Fruit ripening & improved shelf life. Stress tolerance. Salt. Pharmaceutical. Edible vaccines. Anti-coagulants.
Cautions and Related Issues At present plant transformation is limited to transforming single genes. Techniques can only be applied to genes that have been identified and cloned.
Cautions and Related Issues Identification of suitable promoters for the genes that are to be introduced. Transformation is still largely uncontrolled and many thousands of plants need to be screened to select ones with few deleterious effects.
Selection
Field Testing
Off-Station Field Testing Larger plots Replicated Time consuming Travel Expensive Labor intensive
Molecular Markers
Molecular Markers
High throughput SNP Breeding values & QTL s
Public and Environmental Concerns Public perspective Unsafe for consumption. Frankin Foods Breeders playing God Environmental Upset natural balance Create more troublesome weeds and other pests. Cross pollination with related weedy species.
Top 10 Seed Companies Takii (Japan) DLF-Trifolium (Denmark) Sakata (Japan) Bayer Crop Sci (Germany) KWS Ag (Germany) Land O'Lakes (US) Group1 Limagrain France) Syngenta (Swiss) Dupont (US) Monsanto (US) $347,000,000 $391,000,000 $396,000,000 $,524,000,000 $702,000,000 $917,000,000 $1,226,000,000 $2,018,000,000 $3,300,000,000 $4,964,000,000 Top 10 = 68%, Top 4 = 53%. Top 3 = 47%, Monsanto = 23% world seed 2007
Washington State University Aaron Carter Michael Pumphrey Kim Campbell (USDA) Oregon State University Jim Peterson University of Idaho North Idaho Program Bob Zemetra Southern Idaho Program - Jainli Chen
Idaho SWWW ORCF 102-20% WestBred 528-11% Madsen - 10% Louise - 8% Cultivars Brundage.. 17% ORCF 102. 10% Stephens. 9% WestBred 456. 6% Madsen 5% Stephens 54% Brundage 12% WestBred 470 5% Brundage 96 5% Brundage 44% WestBred 470-25% Stephens 13% WestBred 528-4% Brundage 51% WestBred 456-20% Lambert 6% Brundage 96-5%
ORCF 102 18% Eltan 15% Xerpha - 9% WestBred 528 6% Others (52%) ORCF 101 25% Tubbs 06 19% ORCF 102 15% Goetze 12% Other (39%) Brundage - 17% ORCF 102-10% Stephens - 9% WestBred 456-6% Other (58%)
Washington State University Aaron Carter Michael Pumphrey Kim Campbell (USDA) Oregon State University Bob Zemetra Wayne McPride LimaGrain UI Monsanto WestBred Dow Ag.Sci NW Plant Breeders Syngenta University of Idaho North Idaho Program Southern Idaho Program - Jainli Chen
Factors which influence crop growth Environment Irradiation, Day-length, Temperature, Gases, Water availability. Soil. Water. Nutrients. Pests & Diseases. Weeds. 2012