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locus was found, which carries a premature stop codon, in two
Ae. kotschyi
(UUSS)
accessions. In
Ae. sharonensis
(S
s
hS
s
h) novel haplotypes of
Pina
and
Pinb
were
observed with their possible pseudogenes. The credibility of cDNA of intron-less
genes is questioned due to the lack of cDNA equivalents for some genomic cop-
ies. Recently, Chen et al. (
2009
) studied several accessions of einkorn wheat and
identified 56 sequences encoding the
pina
protein. All the gene sequences from
T.
urartu
grouped together, whereas some sharing by three and two clusters was ob-
served for
T. monococcum
ssp. aegilopoides and
T. monococcum
ssp. monococcum,
respectively. Guzman et al. (
2012
) also identified various alleles for
Pina
and
Pinb
genes including three novel alleles for the
Pinb
locus, P
inb-A
m
1i, Pinb-A
m
1j
and
Pinb-A
m
1k
, from
T. monococcum
.
The breeding of food crops for biofortification with high iron and zinc contents
is primarily important component within the food security nexus, especially in de-
veloping countries. There is need to develop special conventional and molecular
breeding approaches for cost effective nutritional improvement in cereal crops
(Bouis and Welch
2010
). Currently, the cultivated durum and bread wheat varieties
are low in grain iron and zinc contents than the related wild
Triticum
and
Aegilops
species (Chhuneja et al.
2006
). Therefore the wild relatives should be emphasized
for screening for the targeted biofortification traits. Due to ease of genetic transfer,
preference should be given to the
T. monococcum
L.,
Triticum turgidum
L. ssp.
dicoccoides (Korn. ex Asch. et Graebn.) Thell,
Triticum turgidum
L. ssp. dicoccon
(Schrank) Thell., and
Ae. tauschii
accessions. Several QTLs have been identified
for higher grain iron and zinc contents in a
Triticum monococcum
x
T. boeoticum
mapping population consisting of RILs Tiwari et al. (
2009
). Two chromosomes 2A
and 7A were found important for the presence of QTLs controlling iron zinc con-
centrations. Several
Aegilops
species have been identified as potential donors of
useful variability for high iron and zinc concentration Rawat et al. (
2009
). These
species include
Ae. kotschyi
Boiss.,
Ae. peregrina
(Hack.) Maire et Weill.,
Ae. ge-
niculata
Roth,
Ae. ventricosa
Tausch, and
Ae. cylindrica
Host. Recently, Rawat
et al. (
2011
) characterized addition and substitution lines chromosome 1, 2 and 7
from
Ae. kotschyi
which possess genes for high grain micronutrients. Similarly,
Neelam et al. (
2011
) also identified the introgression of group 4 and 7 chromosomes
from
Ae. peregrine
enhances 100-200 % grain iron and zinc density. A series of
wheat-
Ae. longissima
amphiploids were also reported to have high grain iron and
zinc concentrations (Tiwari et al.
2008
) and could be used as immortal sources of
variability for biofortification of wheat for high grain micronutrient concentrations.
Conclusions and Future Perspectives
The implementation of marker-trait combination is pre-requisite for genomics
based wheat improvement. There is rapid advancement in high-throughput protein
and gene analyses techniques offering large scale comparative analysis of genes
from wild and domestication sources. Advances in developing functional markers
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