3. Genetic diversity
Genetic diversity is the heritable variability
Is the basis of selection and crop improvement
An important resource in plant breeding
5. Reduction of genetic variability:
domestication and selection
Wild
Adaptation
Domestication
Selection
The extent and distribution
of genetic diversity depends
on its evolution, past
bottlenecks and human
factors
6. Genetic diversity
Nikolai Vavilov
plants were not domesticated somewhere
in the world at random but there are
regions where the domestication started.
The center of origin is also considered the
center of diversity.
7. Centres of origin of food and
agricultural areas
J. Diamond (2002). Nature 418
11. UK; 2237
FR; 1054
BE; 1314
CZ; 256
IT; 421 SWE;195
Selection of accessions in
germplasm collections
UK
310
FR
274
BE
296
CZ
253
IT
232
SWE
195
5,477 accessions in
germplasm collections
1,560
accessions with
phenotypic
observations
APPLE
Removing synonyms and triploids
IT-RO; 943
IT-MI; 575
FR; 764
ISP; 303
CH; 300
2,885 accessions in
germplasm collections
1,296 accessions
with phenotypic
observations
Removing synonyms and selecting
diversity
PEACH
IT-RO
178
IT-MI
140
FR
343
SP
353
CH
282
12. Phenotypic data in the
FruitBreedomics database
APPLE
37,818 informative data entries in the
phenotypic database
PEACH
UK FR BE CZ IT FRIT-RO IT-MI SP CH
81,206 informative data entries in the
phenotypic database
13. Molecular markers
Traditionally, variability has been described visually,
however, over the past few years molecular markers have
been used
Allow a more efficient breeding by the use of genetic
markers that ‘tag’ traits of interest that sometimes are
difficult to select for
14. Study of peach genetic
variability in FruitBreedomics
germplasm collections
15. 1300 varieties genotyped with the 9K IPSC SNPs chip
PEACH GENETIC VARIABILITY
16. PEACH GENETIC VARIABILITY
Most representative K is 3:
• Occidental breeding material (352 accessions)
• Chinese / oriental material (58 accessions)
• Occidental old / non breeding material (165 accessions)
• Admixed accessions [Q < 0.8] (665 accessions)
OCCIDENTAL ORIENTAL
18. Results: apple genetic variability and
population structure
Nb of
genotypes
Nb of
accessions
Belgium 190 209
CZ 120 132
France 225 225
Italy 167 184
Sweden 158 160
UK 271 271
2 countries 78 171
3 countries 20 72
4 countries 12 58
1241 1482
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91 94 97 100103106109
Duplicates - diploids Belgium Czech_Republic France Italy Sweden United_Kingdom
Diploids
19. Results: apple genetic variability and
population structure Diversity –
Partner’s collection
20. CONCLUSIONS
Is the bases of selection and crop improvement
Evolution, past bottlenecks and human factors have reduced
dramatically the genetic variability in cultivated plants
Genetic diversity should be safely conserved and efficiently used
In FruitBreedomics we have set peach and apple Core
Collections
Phenotypic data into a database
Genetic variability studies on these CC will help to preserve
variability and will allow a more efficient breeding