Within-species diversity and CWR conservation Jenny Hagenblad
How diverse are organisms?
13 MAY 2016 2 Within-species diversity – Jenny Hagenblad
Populus tremula Oryza sativa
Leffler et al, 2012
Arabidopsis thaliana
How diverse are eukaryotes?
13 MAY 2016 3 Within-species diversity – Jenny Hagenblad
Capsella grandiflora Populus tremula Pinus radiata
Leffler et al, 2012
Arabidopsis thaliana
How diverse are plants?
13 MAY 2016 4 Within-species diversity – Jenny Hagenblad
Leffler et al, 2012
Algae Monocots Dicots
Genetic diversity is correlated with genome and population size
13 MAY 2016 5 Within-species diversity – Jenny Hagenblad
Barton et al, 2007
Genetic diversity depends on the mode of reproduction
13 MAY 2016 6 Within-species diversity – Jenny Hagenblad
Leffler et al, 2012
Genetic diversity – “the clay of evolution”
13 MAY 2016 7 Within-species diversity – Jenny Hagenblad
Crop species contain genetic variation for adaptive traits
13 MAY 2016 8 Within-species diversity – Jenny Hagenblad
Vanhala et al, forthcoming
But HR alleles in Swedish landrace pea are not geographically distributed...
13 MAY 2016 9 Within-species diversity – Jenny Hagenblad
Vanhala et al, forthcoming
Neutral genetic diversity show latitudinal structuring in Fennoscandian landrace barley
13 MAY 2016 10 Within-species diversity – Jenny Hagenblad
Forsberg et al, 2015. Heredity 144: 195 - 206
But putative adaptive genes are invariant in Fennoscandian barley...
13 MAY 2016 11 Within-species diversity – Jenny Hagenblad
Aslan et al, 2015. Crop Sci, 55:2766-2776
Within-population diversity and adaptation
13 MAY 2016 12 Within-species diversity – Jenny Hagenblad
Ma et al, 2010
Plant diversity
13 MAY 2016 13 Within-species diversity – Jenny Hagenblad
How genetically diverse are crops?
13 MAY 2016 14 Within-species diversity – Jenny Hagenblad
Wild progenitor Landraces Modern cultivars
Maize 0.0059 0.0049 0.0048
Maize 0.0210 - 0.0163
Rice 0.0030 0.0024 -
Rice (Indica) 0.0077 - 0.0057
Rice (Japonica) 0.0077 - 0.0037
Foxtail millet - 0.0010 0.0009
Pearl millet 0.0036 - 0.0024
Soybean 0.0030 - 0.0019
Barley 0.0014 - 0.0016
Wheat 0.0070 - 0.0050
Average 0.0067 0.0047
Landrace crops
13 MAY 2016 15 Within-species diversity – Jenny Hagenblad
• Lacking formal improvement
• Locally adapted
• Dynamic population structure
• Distinct identity
• Historic origin
• Associated with traditional farming systems
• Genetically diverse
Swedish historic landraces were not always more variable than modern accessions.
13 MAY 2016 16 Within-species diversity – Jenny Hagenblad
00,05
0,10,15
0,20,25
0,30,35
0,4
Microsatellite diversity
Leino & Hagenblad, 2010. Mol Biol Evol, 27:964-973
Genetic diversity in historical and extant barley and rye landraces.
13 MAY 2016 17 Within-species diversity – Jenny Hagenblad
00,10,20,30,40,50,6
Barley
Extant
Historical
Hagenblad et al, 2012. Genet Resour Crop Evol, 59: 1185 - 199
00,10,20,30,40,50,60,7
Rye
Extant
Historical
The distribution of genetic diversity in crops will depend on mode of reproduction.
13 MAY 2016 18 Within-species diversity – Jenny Hagenblad
barley rye
Hagenblad et al, 2012. Genet Resour Crop Evol, 59: 1185 - 199
The distribution of genetic diversity in crops will depend on the amount of seed exchange.
13 MAY 2016 19 Within-species diversity – Jenny Hagenblad
Leino et al, 2013. Heredity, 110: 338–346
extant accessions
historical accessions
The distribution of genetic diversity in crops will depend on the cultivation practice.
13 MAY 2016 20 Within-species diversity – Jenny Hagenblad
Hagenblad et al, under review
Sampling single individuals may give different impressions of the genetic diversity.
13 MAY 2016 21 Within-species diversity – Jenny Hagenblad
Hagenblad et al, under review
Increased omnivore and predator, but not herbivore abundance in with increased genotypic diversity in evening primrose.
13 MAY 2016 22 Within-species diversity – Jenny Hagenblad
Johnson et al, 2006
Yield advantages of cultivating mixtures
13 MAY 2016 23 Within-species diversity – Jenny Hagenblad
Crop # comparisons Minima Maxima % yield difference mixture and components
Barley 764 -34.9 39.9 2.7 ± 0.28
Oat 558 -10.0 16.5 0.7 ± 0.17
Wheat 745 -26.6 49.7 5.4 ± 0.38
Maize 92 -20.9 16.1 1.1 ± 0.67
Sorghum 63 -8.5 14.5 1.1 ± 0.72
Groundnut 115 -26.9 29.1 1.7 ± 0.92
Soybean 432 -25.6 17.9 0.8 ± 0.29
Other crops 156 -25.6 44.7 5.4 ± 0.89
Smithson & Lenné, 1996
Disease reduction from cultivating mixtures
13 MAY 2016 24 Within-species diversity – Jenny Hagenblad
Crop Disease average % disease reduction
Barley Powdery mildew 38,22
Barley Scald 30,65
Barley Net Blotch 35,70
Barley Rust -23,10
Wheat Leaf Blotch 37,00
Wheat Rust 29,53
Wheat Powdery mildew 52,10
Oat BYDV 47,00
Rice Blast 58,15
Sorghum Leaf Blight 33,50
Common bean Rust 13,80
Common bean Angular leaf spot 13,53
Common bean Anthacnose 6,80
Common bean Halo-blight 16,40
Smithson & Lenné, 1996
Less severe rice blast when susceptible plants were grown together with resistant plants than when grown in monoculture.
13 MAY 2016 25 Within-species diversity – Jenny Hagenblad
Zhu et al, 2000
monoculture
mixture
What do we know about plant within-species diversity?
13 MAY 2016 26 Within-species diversity – Jenny Hagenblad
• Lots of genetic diversity not visible to the naked eye.
• Plant genetic diversity span over a similar range as animal genetic diversity.
• Genetic diversity is correlated with population size.
• Outcrossing plants are more genetically diverse than selfing plants.
• Domestication is associated with a reduction in genetic diversity as is plant improvement.
What do we know about plant within-accession diversity?
13 MAY 2016 27 Within-species diversity – Jenny Hagenblad
• Variable within-accession genetic diversity in landraces.
• Amount of diversity and distribution of diversity depends on
– mode of reproduction
– amount of seed exchange
– cultivation practices
– ...
Why we should care about within-species diversity when it comes to CWR?
13 MAY 2016 28 Within-species diversity – Jenny Hagenblad
• Within-species diversity is a valuable resource in itself!
• Of interest to understand the species’ evolutionary history.
• “The clay of evolution”.
• Allows for adaptation.
• A source of phenotypic variation.
• Can lead to increased production and disease reduction.
Acknowledgements
13 MAY 2016 29 Within-species diversity – Jenny Hagenblad
• People
– Matti Leino
– Tytti Vanhala
– Nils Forsberg
– Selçuk Aslan
– Jenny Zie
– Erik Boström
– Hugo Oliveira
• Funding
– Formas
– Lagersbergs stiftelse
– The Swedish Board of Agriculture
– The Royal Swedish Academy of Agriculture and Forestry (KSLA)
– Carl Tryggers Foundation
– The Nilsson-Ehle foundation
– The Helge Ax:son Johnsson foundation.
www.liu.se
https://people.ifm.liu.se/jehag/HSG/