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of large numbers of effective FHB QTL in tetraploid wheat, incremental progress is
being made in improving the FHB resistance of durum wheat (Clarke et al. 2004 ;
Comeau et al. 2008 ).
8.2.3 Other Factors
8.2.3.1 Virus Resistance
A large collection of wild diploid and tetraploid wheat was screened for resistance
to a number of insect pests and fungal pathogens (Gill et al. 1983 ). Four out of 25 T.
dicoccoides accessions tested were resistant to WSMV. No resistance was detected
to Hessian fl y or greenbug.
8.2.3.2 Leaf Spotting
The set of Langdon– Triticum dicoccoides durum substitution lines were screened
with three components of leaf spotting disease complex (Singh et al. 2006 ). The
location of genes for resistance to tan spot , caused by Pyrenophora tritici - repentis
was on chromosomes 5B and 3B. The resistance to toxin Ptr Tox A of Stagonospora
blotch was located on chromosome 5A.
8.2.3.3 Storage Proteins
One of the important factors in durum wheat production is that of protein content.
Wild emmer wheat has the potential to transfer this trait to durum wheat. High grain
protein content (GPC) was fi rst reported in T. turgidum var. dicoccoides in 1978
(Avivi 1978 ). Three QTL for GPC were identifi ed on chromosome 5B of T. turgi-
dum var. dicoccoides (Gonzalez-Hernandez et al. 2004 ). In an earlier report, a high
GPC QTL was described on chromosome 6B of the same species (Chee et al. 2001 ).
In addition to high GPC, some dicoccoides accessions also had novel glutamic sub-
units and gliadins, located on chromosome 1B, that could be used to alter storage
protein patterns of durum wheat (Xu et al. 2004 ). Loci controlling levels of storage
proteins in T. dicoccoides were determined by studying T. dicoccoides disomic sub-
stitution lines in a Langdon background (Joppa and Cantrell 1990 ). Disomic substi-
tution lines of dicoccoides chromosomes 6B, 2A and 5B had lower protein levels
than Langdon, while substitution lines 3B, 4B and 7B had higher levels. A gene for
high protein concentration was mapped on chromosome 5B of T. dicoccoides
(Gonzalez-Hernandez et al. 2004 ). A high grain protein locus from T. dicoccoides
was mapped close to the centromere on chromosome 6BS (Joppa et al. 1997 ). PCR
markers were developed for the 6BS QTL (Khan et al. 2000 ).
G. Fedak