8th INTERNATIONAL WHEAT CONFERENCE

A QTL was considered to be “stable” if it appeared at least in three environments and
in the overall mean. Additionally, “suggested QTL” have been reported if they appear
at least in two environments and in the overall mean. The LOD scores for the QTLs
mapped ranged between 1.9 (Hi) and 3.4 (Yld). Out of 103 significant QTL identified,
Tgw showed the maximum number (14), where as Tw, Gwe and Ft showed the minimum
(6). Out of 14 stable QTL identified, Ht and Pl showed the maximum number (5),
while Gnts showed the minimum (1). Two QTL (one for Ht and another one for Pl) on
chromosome 3B were stable across all the environments and also in the overall mean.
Out of 10 suggested QTL identified, Gnfs showed the maximum number (3), where Tw,
Gwe and Gnts showed the minimum (1). The phenotypic variation (R 2 ) explained by
individual QTL for all the traits considered ranged from 6.6% (Gnfs) to 45% (Ht). Both
parental lines contributed with favorable alleles for the majority of traits, but the contribution
from UC1113 was higher. Pleiotropic regions were identified for various traits
over nine chromosomes, mainly 2B, 3A, 3B, 4A, 4B and 5A. The co-location of QTL on
chromosome 3B involved ten yield components (Yld, Tgw, Tw, Ht, Pl, Gne, Gwe, Ft, Gnfs,
Gnts), making it as an important region for marker-assisted selection. Positive and highly
significant correlations were found between grain yield and its components. Gne, Gwe,
Gnfs and Gnts showed positive correlations with grain yield in all the environments. Gne
and Gnts showed strong positive correlations with grain yield (r = 0.82). The strongest
positive correlation found was between Ht and Pl (r = 0.91). Indirect selection for these
components can increase the grain yield of durum wheat. The reported QTL can be used
for: introgression of favorable genes and QTLs into interesting plant materials, markerassisted
selection and germplasm screening for the evaluated traits.
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