Plant Breeding an Overview

1
Plant Breeding an Overview

• Dr. Vince Pantalone

2
UT students gain valuable experience working with
researchers
3
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6
Molecular marker genotype visualization
RR
RR
RR
rr
rr
rr
rr
Rr
By migrating DNA in an electric field, we can
now see genotypes
7
(No Transcript)
8
What is Plant Breeding?

• The genetic adjustment of plants to the service
  of humankind
• ---Sir Otto Frankel

9
Carrying capacity of the worlds food system
10
Global Population (Billions)1950 - 2050
11
Urban sprawl encroaches rapidly on farmland
How did USA become so successful? How can we
maintain agricultural productivity?
12
Fertility Management and Nutrient Runoff

• Nitrogen fertilizers - revolutionalized agric.
• P, K, and micro-nutrient fertilizers
• Liming

13
Irrigation
WATER continues to be the most limiting factor
in productivity
14
Weed Control, Herbicides
15
Integrated Pest Management
16
Erosion Control
17
Conservation Tillage
18

• Agricultural Engineering
• Mechanistic Crop
• Planting
• Fertilizing
• Spraying
• Harvesting

19
Plant Breeding alone contributes gt 50 of
increased USA Ag productivity
20
Plant breeders need to

• be observant of differences
• understand the genetics
• have imagination to visualize final product
• foresight to predict demand for future plant
  products

21
1. Yield
22
For every 1 Bu/A genetic gain realized, increase
d income to TN producers of 5 to 10 Million
annually
5601T Soybean at Obion, TN
23
USG 5601T Brownsville, TN in 2003
Two hundred twenty acres 61 Bu/A average
Rolling hill
bottom field sixty-five acres 75-80 Bu/A
Outstanding TN Yield Production!
24
(No Transcript)
25
Rapid Development and Deployment of Roundup
Ready Soybeans by Breeders
95 of TN and USA Soybean Acreage was Roundup
Ready in 2007
26
With Traditional Backcross Breeding
2000 F1 50 TN Line BC1F1 75 TN Line BC2F1
87.5 TN Line BC3F1 93.5 TN Line BC4F1
96.9 TN Line BC5F1 98.4 TN
Line BC6F1 99.2 TN Line
2006 one lousy pod!
27
But with Molecular Genetic Markers F1 50 TN
Line BC1F1 80 TN Line BC2F1 98 TN
Line BC3F1 99 TN Line 2003 Winter
plant-row increase 2004 TN Yield Tests
Re-selections 2005 Harvest 100 Bushels
5601T-RR
2002
28
5601T-RR Breeders Seed Increase Milan, TN July
2005
29
USG Allen 1 and better than average in every
county
8.6
10.2
17.4
8.4
10.7
7.5
7.8
30
2. Pest Resistance
31
2004 SDS Regional Test Knoxville, TN
Asgrow A5403 Founding father of every Roundup
Ready Soybean Variety in the World
32
2004 SDS Regional Test Knoxville, TN alerts
breeder field notes at Milan, TN
33
Joint Germplasm Release (Drs. Arelli, Pantalone,
Allen, Mengistu) USDA-ARS and Tennessee
Agricultural Exp. Stn. Release of JTN-5303
Soybean Multiple Disease Resistances SCN
(multiple races) Sudden Death Syndrome Stem
Canker Frogeye Leaf Spot Charcoal Rot
34
3. Quality
35
Dr. Victory Raboy, USDA-ARS Selecting low-phytate
maize for Environmental protection of land and
water quality
36
Motivation for Research
37
Walker et al. 2006. Genetic Mapping of Loci
Associated with Seed Phytic Acid Content in
CX1834-1-2 Soybean. Crop Sci.
?
38
Low phytate donor poor germination, unfavorable
plants
MAS transfer to excellent TN genetic background
39
Chemical structure of linolenic acid

Carboxyl end
?-9c,12c,15c Octadecenoic 18 17 16
15 14 13 12 11 10 9 8
1 CH3CH2CHCHCH2CHCHCH2CHCH(CH2)7COOH 1 2
3 4 5 6 7 8 9 10 11
18 183 (n-3) Methyl (omega) end
Hydrogenation sites
40

• Hydrogenation flavor and oxidative stability
• Trans fats health issues
• FDA label mandate

cis form
saturated
trans form
Hydrogenation

(Source Wilson, 2004)
41
4. Environmental Stress Tolerance
5. Mineral Stress Tolerance
42
6. Adaptation to Mechanization
43
How can we make selections to improve these
traits?

• Biological variation - all organisms have
  biological variation.
• In plants, examples include
• plant height
• plant and leaf morphology
• chemical composition of seed
• seed yield

44
What are the causes of bio-variation?

• 1. Genetic causes
• single genes
• multiple genes
• 2. Environmental
• 3. GxE the interaction between the genotype of
  the plant and the environment in which it grows

45
Phenotype vs. Genotype

• P G E (GxE)
•  
• P is called the phenotypic value, i.e., the
  measurement associated with a particular
  individual
• G is genotypic value, the effect of the
  genotype (averaged across all environments)
• E is the effect of the environment (averaged
  across all genotypes)

46

• If we could measure P in all possible
  environments and regard E as a deviation, then
  the mean of E would be zero and
• P G.
• In a sense, this is what the breeder accomplishes
  before releasing a breeding line as a cultivar.

47
(No Transcript)
48

• Although impossible to evaluate potential variety
  in every possible environment, it is possible
  (within reason) to evaluate in most environment
  types to which the cultivar will likely be
  exposed.
• The mean value over this set of environments is
  as close to the true value of G that breeders can
  achieve.

49
Qualitative traits

• Classified into discrete classes
• Individuals in each class counted
• Some environmental influence on phenotype
• Controlled by a few (lt3) major genes

50
Figure 2.4
(Source Halfhill and Warwick, 2008)
51
Figure 2.5.
A. Monohybrid Cross
B. F1 Self Fertilization
Parent 1
Parent 2
Parent 2
Parent 1
X
X
Yy
YY
yy
Yy
Gametes
Y
Y
y
y
Gametes
Y
y
Y
y
F1 Fertilization
F2 Fertilization
YY Yy
Yy
F2 Plants 75 yellow 25 green
F1 Hybrid Plants 100 yellow
yy
(Source Halfhill and Warwick, 2008)
52
Quantitative traits

• Express continuous variation
• Individuals measured, not counted
• Significant environmental influence on phenotype
• Controlled by many minor (or major) genes, each
  with small (or large) effects

53
AA, bb (6 kg)
aa, BB (6 kg)
X
Aa, Bb (6 kg)
Self-pollinate
4 kg aa, bb
5 kg Aa, bb (x2) aa, Bb (x2)
6 kg Aa, Bb (x4) AA, bb aa, BB
7 kg Aa, BB (x2) AA, Bb (x2)
8 kg AA, BB
Figure 3.1
(Source Tinker, 2008)
54
For the plant breeder patience is a virtue
when working with new genetics
55
Release of New Improved Variety
Utilization of Germplasm Resources
Development of Genetically Diverse Populations
Vigorous Yield Testing
56

• Robust plant population
• Select single plants

Homogeneous or Heterogeneous?
57
Homogeneous or Heterogeneous?
58
Wheat Barley
Rice Soybeans
Maize Beans Peanut Potato
Plantains Yams
Sorghum Millet
59
The Fertile Crescent
60
(No Transcript)
61
Shirreff Scotland. Selected rare off-types in
wheat, oats, and barley from landraces. Uniform
pure lines developed (oat 1824) wheat (1832)
62
Swedish Seed Association Svalof, Sweden. Pure
line method. Conducted progeny tests.
63
Monday is a Holiday! Have a good weekend!