Improving fertiliser acquisition and mineral content in
vegetable Brassicas
John Hammond, Martin Broadley, Graham King, Philip White
Outline
1. Improving fertiliser acquisition efficiency
2. Improving crop mineral quality
Drivers for improving fertiliser use
Water quality
- diffuse pollution - eutrophication
- Agricultural contribution = 11,800 tonnes P per year*
Climate change and energy usage
- 4.9 x 109 GJ yr-1
- 318 x 106 t CO2 yr-1
Crop yield and quality
- economic optimum
Phosphorus is not recycled
- non-renewable
- estimated 100-200 years
- Increased prices
*White and Hammond, Journal of Environmental Quality, 38:13–26
Timelines / approaches
2002
– Definitions / Background
2003
– C-genome diversity analysis
2004
– C-genome QTL mapping
2006
– AC-genome diversity analysis
2007/8 – Root traits dissection
2008/9 – A-genome trait / eQTL / tilling
1.2
Shoot P (%DW)
1.0
0.8
0.6
0.4
0.2
0.0
BraIRRI maaping population
2008/9 – C-genome fine mapping
Definitions / Background: P-use efficiency
Current inputs,
higher yields
Current system
Lower inputs,
same yields
Definitions / Background: P-use efficiency
C-genome diversity analysis
Phosphorus use efficiency in Brassica C-genome
Glasshouse experimental design:
2 levels of P
3 replicates per DFS line (376 accessions)
9 replicates per F1 (74 accessions)
Field experimental design:
4 levels of P
3 replicates per F1 (74 accessions)
Wide distribution for shoot [P] in Brassica C-genome
0.6
Shoot-P (%DW)
0.5
0.4
0.3
0.2
0.1
0.0
Low P
High P
DFS
Low P
High P
Low P
Commercial
cultivars
Hammond et al., (2009) Journal of Experimental Botany, 60, 1953-1968
High P
AGDH
Agronomic P use efficiency
(g DM g-1 Pf)
Agronomic PUE in Brassica C-genome
120
80
40
0
-40
DFS
Commercial cultivars
Hammond et al., (2009) Journal of Experimental Botany, 60, 1953-1968
Current breeding is selecting for PUE
Non-efficient and
responsive
Mean shoot DW
APE (g DM g-1 Pf)
150
NER 66 (9)
159 (51)
ER
100
Mean APE
50
0
NENR 114 (8)
-50
0.0
Non-efficient and
Non-responsive
Responsive and
Efficient
0.2
0.4
83 (6)
0.6
0.8
1.0
1.2
Shoot dry weight (g) at low [P]ext
ENR
1.4
Efficient and
Non-responsive
…but it is driven by yield not improved use or acquisition
C-genome diversity analysis: P-use efficiency
APE (g DM g-1 Pf)
150
100
50
0
ca
ul
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ow
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Br
br
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o
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C
hi eco
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Ko le
hl
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Sa
ab i
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ba
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ca ge
bb
ag
e
-50
Bred for quality
Hammond et al., (2009) Journal of Experimental Botany, 60, 1953-1968
Bred for yield
Timelines / approaches
2002
– Definitions / Background
2003
– C-genome diversity analysis
2004
– C-genome QTL mapping
2006
– AC-genome diversity analysis
2007/8 – Root traits dissection
2008/9 – A-genome trait / eQTL / tilling
1.2
Shoot P (%DW)
1.0
0.8
0.6
0.4
0.2
0.0
BraIRRI maaping population
2008/9 – C-genome fine mapping
PUE in Brassica C-genome has high genetic component
Potential genetic contribution (%) to variation in PUE
Shoot [P]
Agronomic
PUE
P uptake
efficiency
Δ shoot [P]/
P applied
Physiological PUE
Yield/
Shoot [P] at
low P
Yield/
Shoot [P] at
high P
Variance
component
Low P
High P
Δ Yield/
P applied
Experimental
35.1
64.3
37.3
36.5
65.1
55.6
Genetic
29.2
11.0
15.1
8.0
8.9
14.7
Residual
35.7
24.7
47.6
55.5
26.0
29.7
Hammond et al., (2009) Journal of Experimental Botany, 60, 1953-1968
C-genome QTL mapping: P-use efficiency
Hammond et al., (2009) Journal of Experimental Botany, 60, 1953-1968
AG double haploid mapping
population grown in compost
Significant QTL on O3 associated with tissue PUE at high P
1000
800
5% l.s.d
-1
Tissue PUE (g DW g [P]shoot) at high P
1200
2
600
5% l.s.d
400
200
0
2 3 8 9 0 1 2 3 7 9 4 7 8 1 8 0 1 5 a b 9 3
A1 GD3 L11 L11 L12 L12 L12 L12 L12 L12 L13 L13 L13 L14 L15 L16 L16 L16 168 168 L16 L17
S S S S S S S S S S S S S S S S SL L S S
AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AGS AG AG
AGSL141 substitution at bottom of O3 – consistent with –ve effect of ‘A’ allele
AGSL134 substitution at top of O3 – consistent with +ve effect of ‘A’ allele
Timelines / approaches
2002
– Definitions / Background
2003
– C-genome diversity analysis
2004
– C-genome QTL mapping
2006
– AC-genome diversity analysis
2007/8 – Root traits dissection
2008/9 – A-genome trait / eQTL / tilling
1.2
Shoot P (%DW)
1.0
0.8
0.6
0.4
0.2
0.0
BraIRRI maaping population
2008/9 – C-genome fine mapping
Dissecting PUE - selection of extreme phenotypes
Hammond et al., (2009) Journal of Experimental Botany, 60, 1953-1968
Quantifying root traits – quickly and easily
= 1 cm
= 1 cm
= 1 cm
B. oleracea var. italica
B. oleracea var. acephala
B. oleracea var. capitata
Non-responsive
Low tissue PUE
Responsive
High tissue PUE
Responsive
High tissue PUE
Plants grown for 10 days on vertical glass plates supported on blue blotter paper and supplied with a modified MS
nutrient solution containing 0.006 µM P
Lateral root traits correlate with yield and PUE
Timelines / approaches
2002
– Definitions / Background
2003
– C-genome diversity analysis
2004
– C-genome QTL mapping
2006
– AC-genome diversity analysis
2007/8 – Root traits dissection
2008/9 – A-genome trait / eQTL / tilling
1.2
Shoot P (%DW)
1.0
0.8
0.6
0.4
0.2
0.0
BraIRRI maaping population
2008/9 – C-genome fine mapping
A-genome mapping and eQTL
R500 annual
Yellow
Sarson seed
oil (R500)
(ssp.
tricolaris),
USA (8 wks)
1.2
IMB211
Rapid
cycling
(ssp.
pekinensis)
, Japan (6
wks)
Shoot P (%DW)
1.0
0.8
IMB211
R500
0.6
0.4
0.2
0.0
BraIRRi mapping population
Defra WQ0119
Timelines / approaches
2002
– Definitions / Background
2003
– C-genome diversity analysis
2004
– C-genome QTL mapping
2006
– AC-genome diversity analysis
2007/8 – Root traits dissection
2008/9 – A-genome trait / eQTL / tilling
1.2
Shoot P (%DW)
1.0
0.8
0.6
0.4
0.2
0.0
BraIRRI maaping population
2008/9 – C-genome fine mapping
Outline
1. Mineral nutrient acquisition efficiency
2. Improving crop mineral quality
Dietary calcium (Ca) and magnesium (Mg) deficiencies
Relatively large amounts of Ca and Mg required in the human diet
Numerous health disorders associated with low Ca and Mg status
e.g. Ca… bone-related (osteoporosis, rickets), etc.
e.g. Mg… heart dysfunction, hypertension, diabetes, pre-eclampsia, etc.
Soft-tissue biomarkers of Ca/Mg status unreliable, intake used to identify risk
http://www.eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/
Dietary calcium (Ca) and magnesium (Mg) deficiencies
~6 million UK adults <LRNI for Mg
Calcium RNI = 700 mg d-1; LRNI = 400 mg d-1.
~3 million UK adults <LRNI for Ca
UK diet high in dairy + mandatory Ca-fortification of non-wholemeal flour
Many more at risk globally?
Brassica as a good target for Ca and Mg biofortification
Brassica as a good target for Ca and Mg biofortification
2006 production:
68.9 Mt yr-1 cabbages / other brassica
18.1 Mt yr-1 cauliflowers / broccoli
cf. 64.4 Mt yr-1 onions and shallots
"Cabbage & other brassica"
production (Mt)
80
60
40
20
Brassica oleracea
"Cauliflower and broccoli"
production (Mt)
0
15
10
5
0
19
97 998 999 000 001 002 003 004 005 006
1
1
2
2
2
2
2
2
2
http://faostat.fao.org/
Timelines / approaches
2002
– Definitions / Background
2003
– C-genome diversity analysis
2004
– C-genome QTL mapping
2006
– AC-genome diversity analysis
2007/8 – Root traits dissection
2008/9 – A-genome trait / eQTL / tilling
1.2
Shoot P (%DW)
1.0
0.8
0.6
0.4
0.2
0.0
BraIRRI maaping population
2008/9 – C-genome fine mapping
Leaf Ca (%DW)
Potential for genetic improvement of Brassica
3
n=429
2
0
Leaf Mg (%DW)
0.8
0.6
0.4
0.0
AGDH
DFS and F1s
Broadley MR et al. 2008. Plant Physiology, 146, 1707-1720.
c
i
ap
a
a
a
a
s
a
a
is
la
ta
ta aud labr ifer ellic hud talic tryt pha lode
i
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b
m
g
b
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sa lbo em sa tron
g
a
go
Timelines / approaches
2002
– Definitions / Background
2003
– C-genome diversity analysis
2004
– C-genome QTL mapping
2006
– AC-genome diversity analysis
2007/8 – Root traits dissection
2008/9 – A-genome trait / eQTL / tilling
1.2
Shoot P (%DW)
1.0
0.8
0.6
0.4
0.2
0.0
BraIRRI maaping population
2008/9 – C-genome fine mapping
Leaf Ca (%DW)
Potential for genetic improvement of Brassica
3
n=90
2
0
Leaf Mg (%DW)
0.8
0.6
0.4
0.0
AGDH
DFS and F1s
Broadley MR et al. 2008. Plant Physiology, 146, 1707-1720.
c
i
ap
a
a
a
a
s
a
a
is
la
ta
ta aud labr ifer ellic hud talic tryt pha lode
i
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b
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g
b
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sa lbo em sa tron
g
a
go
Potential for genetic improvement of Brassica
Variance
component
Ca
Mg
K
P
Zn
Fe
Genotype (VA)
36.0
37.7
22.2
7.4
18.5
7.1
[P]ext
0.2
4.0
2.2
43.1
7.2
3.5
[P]ext /
genotype
1.4
1.1
1.4
0.5
2.5
0.0
‘other’
62.4
57.2
74.2
49.0
71.8
89.4
High heritability in AG population
(alboglabra X italica)
Broadley MR et al. 2008. Plant Physiology, 146, 1707-1720.
C2
C6
C7
C8
•1B
•1B•2A•1B
•3D
•5D
•5A
•1C
•1A
•4B
•5E •1E •D •3B
C9
•4A
•5B
•5B
•5F •1D
Quantitative trait loci (QTL)
for Ca and Mg
•5E
Broadley MR et al. 2008. Plant Physiology, 146, 1707-1720.
Potential for genetic improvement of Brassica
2.6
A
2.5
Shoot-Ca (%DW)
2.4
2.3
*
**
***
2.2
**
***
C
2.1
•C8 •C9
2.0
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
0.0
2 3 8 9 0 1 2 3 7 9 4 7 8 1 8 0 1 5 a b 9 3
A1 GD3 L11 L11 L12 L12 L12 L12 L12 L12 L13 L13 L13 L14 L15 L16 L16 L16 168 168 L16 L17
S S S S S S S S S S S S S S S S SL L S S
AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AGS AG AG
B
Shoot-Mg (%DW)
0.6
*
*
** * *
*
0.5
***
0.4
0.0
2 3 8 9 0 1 2 3 7 9 4 7 8 1 8 0 1 5 a b 9 3
A1 GD3 L11 L11 L12 L12 L12 L12 L12 L12 L13 L13 L13 L14 L15 L16 L16 L16 168 168 L16 L17
S S S S S S S S S S S S S S S S SL L S S
AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AGS AG AG
Broadley MR et al. 2008. Plant Physiology 146, 1707-1720
Potential for genetic improvement of Brassica
2.6
A
2.5
Shoot-Ca (%DW)
2.4
2.3
*
**
***
2.2
**
***
C
2.1
•C8 •C9
2.0
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
•C8 •C9
0.0
2 3 8 9 0 1 2 3 7 9 4 7 8 1 8 0 1 5 a b 9 3
A1 GD3 L11 L11 L12 L12 L12 L12 L12 L12 L13 L13 L13 L14 L15 L16 L16 L16 168 168 L16 L17
S S S S S S S S S S S S S S S S SL L S S
AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AGS AG AG
B
Shoot-Mg (%DW)
0.6
*
*
** * *
*
0.5
***
0.4
0.0
2 3 8 9 0 1 2 3 7 9 4 7 8 1 8 0 1 5 a b 9 3
A1 GD3 L11 L11 L12 L12 L12 L12 L12 L12 L13 L13 L13 L14 L15 L16 L16 L16 168 168 L16 L17
S S S S S S S S S S S S S S S S SL L S S
AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AG AGS AG AG
Broadley MR et al. 2008. Plant Physiology 146, 1707-1720
Potential for genetic improvement of Brassica
AGSLs introgressed into maternal A12 ‘rapid’ cycling background (B1F2s)
Acknowledgements
Duncan Greenwood
Kefeng Zhang
Helen Bowen
Rory Hayden
Will Spracklen
Tracey Overs
Philip White
Martin Broadley
Graham King