QTL Analysis for Salt Tolerance in Barley
Said Abdul Wali Dadshani1, Annette Weidner2, Gerhard H. Buck-Sorlin3,
Andreas Börner2, Folkard Asch1
1 University
of Bonn, Institute of Plant Nutrition, Germany,
2
Institute of Plant Genetics and Crop Plant Research (IPK), Germany,
3
Brandenburgisch-technische Universität (BTU)
Introduction
Soil salinity, often combined with overgrazing, threatens vast
areas of agriculturally productive land, particularly in semi-arid
regions. Barley is potentially tolerant to salinity and is an
important food and fodder crop. Given the appropriate genotypes,
reclamation of degraded soils could be envisaged using barley
pastures.
The objective of this study was to identify the genetic basis of salt
tolerance traits in barley (Hordeum vulgare L.) using as a start the
Oregon Wolfe Barley (OWB) mapping population and number of
Afghan barley cultivars.
Germination and early seedling growth were used to evaluate the
salinity tolerance expression in the mapping population. QTL
analysis was used to identify chromosome regions related to
those traits.
Afghanistan
Methodology
seeding tray with 7 lines
grazing & erosion
marker assisted breeding
Germination and early seedling growth in response to different levels of salinity
differed strongly among the lines of the OWB population. At low salt
concentrations almost all lines germinated. With increasing NaCl concentration
germination rate decreased. About 20% of the lines performed better than the
REC parent and about 35% performed worse than the DOM parent.
OWB 59
120
120
2% NaCl
2.5% NaCl
DOM
cumulative salinity score
1.5% NaCl
barley cropping
Results & Discussion
The marker saturated Oregon-Wolfe barley mapping population (94
lines + 2 parents) was subjected to 4 different concentrations of
NaCl solution (0, 1.5, 2, 2.5%) for ten days. Seed was sown in
seeding trays containing 10 grains per line in climate chambers
(20°C, 100% rH, 12h PP). Salinity responses of 10 individual
seedlings were scored after ten days for leaf and root development
on a scale from 1 (poorest) to 6 (best). Results were correlated with
markers using the Qgene program of Nelson (1997) resulting in the
identification of QTLs for salinity tolerance in the germination stage.
100
Aqua dest.
salinity
2.5 % NaCl
2.0 % NaCl
100
1.5 % NaCl
80
80
DOM
40
60
Overall mean
20
40
REC
60
0
1
OWB 73
20
0
REC
12 40 21 19 73 29 33 10 84 35 62 56 4 53 1 41 70 27 15 13 20 14 7 90 11 36 61 9 50 39 47 68 78 92 2 52 75 79 88 93 60 64 22 25 48 77 85 95 30 16 49 80 76 3 63 54 82 28 69 81 46 17 66 71 24 6 26 58 5 55 65 91 94 96 72 87 42 18 31 57 38 51 74 89 32 43 23 67 44 37 8 86 45 83 34 59
OWB line number
Three chromosome regions were found to correlate with salinity evaluation scores
of the OWB population. Two on chromosome 5H and one on chromosome 7H
(red arrows in figure below.) The likelihood for QTLs related to salinity tolerance on
the centromere region of chromosome 5H increased with the salt concentration
(LOD scores at the specific regions). The increase of the LOD score on chromosome 7H at higher salt concentration was less.
OWB 59
7H
OWB 73
Contact
Contact at
at DTT
DTT 2004
2004
Dr. Folkard Asch
University of Bonn
Inst. f. Plant Nutrition
Karlrobert-Kreiten Str. 13
53115 Bonn
fa@uni-bonn.de
Acknowledgements
Acknowledgements
Photos from Afghan pastures were found at:
http://postconflict.unep.ch/photos. htm
Pictures from the OWB population were obtained
from:
Outlook
p Identification of chromosome regions carrying traits for resistance or tolerance
to salinity in barley will allow to test of a large number of accessions for specific
traits with little experimental effort.
and IPK Gatersleben
p In our quest for barley cultivars suitable for the target country Afghanistan,
adapted to semi-arid conditions and resistant to salinity, the QTL analyses
shown here will help identify suitable cultivars from local germplasm.
References
References
p The QTLs identified in this study will be validated for the vegetative and
reproductive stage in a field trial in Afghanistan under saline and non-saline
conditions including Afghan barley varieties.
http://wheat.pw.usda.gov/ggpages/OWB_gallery/in
dex.htm
Mano Y and Takeda K (1997). Mapping
quantitative trait loci for salt tolerance at
germination and the seedling stage in barley
(Hordeum vulgare L.).Euphytica 94: 263-272.
Nelson JC (1997) QGENE: software for mapping based genomic analysis and
breeding. Mol Breed 3: 239-245.
Please
Please take
take aa copy....
copy....
QTLs for salt tolerance at germination have been described for the Harrington /
TR306 population on chromosomes 1H and 5H and for the Steptoe / Morex
population on chromosomes 4H, 5H and 6H (Mano et al. 1997). In contrast to
Mano et al. who found QTLs on chromosome 5HL, we located the QTLs in the
centromere region of chromosome 5H, between the molecular markers BmAc0047
and ABC302 (LOD=9.66) which accounted for 41% of the total variance. In line
with earlier reports, QTLs found on the chromosome 7H were located at the
centromere region.
p Results will be used to select Afghan barley genotypes, resistant to salinity that
can be developed further to serve as multi-purpose crop to feed either humans
or livestock.
"Deutscher
"Deutscher Tropentag
Tropentag 2004"
2004" --- 5.
5. –– 7.
7. October
October in
in Berlin
Berlin