ICARDA annual report 2004

ICARDA Annual Report 2004
22
Pullman, Washington, USA, during
the 1997/98, 1998/99, and 1999/00
growing seasons. Ninety-four F6 to
F8 RILs were scored for 56 Random
Amplified Polymorphic DNA
(RAPD), 106 Inter Simple Sequence
Repeat (ISSR), and 94 Amplified
Fragment Length Polymorphism
(AFLP) markers, and three morphological
traits: plant height, fall
growth habit, and leaflet size. Of
these 256 markers, 84 were excluded
from the QTL analysis because
of lack of linkage, incomplete data,
or distorted segregation.
Five independent QTLs were
detected for winter survival at
Haymana in 1997/98: one on linkage
group 4 and two each on linkage
groups 3 and 6. Together, these
QTLs explained 33.4% of the total
phenotypic variation in winter survival.
Under harsh winter conditions
at Pullman, where mortality
was 95%, one QTL was detected on
linkage group 4. In the mild winter
conditions at Haymana in 1999/00,
three putative QTLs were detected:
two on linkage group 1 and one on
linkage group 4. Together the QTLs
explained 22.9% of phenotypic
variation. The QTL located on linkage
group 4 was common to all
environments and years, but the
effect and position differed across
environments. The two QTLs on
linkage groups 4 and 6 were detected
when winter-survival data from
all sites were combined and subjected
to QTL analysis. (Fig. 9).
Of the four QTLs identified for
winter survival, three were located
on linkage group 1 and one on linkage
group 4. These four QTLs
accounted for 42.7% of the variation
in winter injury. Three of the
QTLs conditioning winter injury
were located in the same genomic
regions as QTLs for winter survival.
The QTL on linkage group 1
at positions 39 cM and 129 cM were
also detected at Haymana, and the
QTL on linkage group 4 was proba-
Fig. 9. Quantitative trait loci (QTLs) detected for winter survival (WS) and winter injury
(WI) in lentil, at Haymana and Sivas in Turkey and at Pullman, USA; recombinant
inbred lines from the WA8649090/Precoz population grown during four cropping seasons
(1997/98 to 1999/00). LG = linkage group.
bly the same QTL at all locations.
Therefore, although five QTLs were
detected for winter survival, only
one (the QTL on linkage group 4
for winter survival) was expressed
across all environments.
On the basis of the QTL analyses,
candidate molecular markers
for winter survival were identified
for use in marker-assisted selection
programs. ISSR marker ubc808-12
(linkage group 4) was consistent
across environments. Another ISSR
marker (ubc840-3) was associated
with winter injury at Pullman and
Haymana. Marker-assisted selection
will accelerate selection for
‘Morton,’ a lentil cultivar
with QTLs for winter-hardiness,
recently
released by Dr Rick
Short (right) of
Washington State
University, in USA.
winter-hardiness, particularly
when mild or extremely unusual
winter conditions occur.
Identifying dual-season
chickpea cultivars for winter
and spring planting
Farmers in WANA usually plant
chickpea in the spring, making use
of water retained in the soil following
winter rainfall. However,
ICARDA researchers have shown
that winter planting can almost
double yields, mainly because of
increased water-use efficiency.