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In most of winter wheat producing area, susceptibility to freezing is an important
production-limiting factor. Pearce et al. ( 2013 ) screened ten SHW and identifi ed
only one accession having nine-gene deletion at a major cold tolerance locus Fr-B2.
The deletion is associated with freezing susceptibility and was contributed by the
durum parent ‘Altar-84’ of the SHW. Winter wheat breeding programs interested in
using SHW and improving freezing tolerance may benefi t from preliminary screen-
ing of SHW accessions for those that do not carry deletions at the Fr-B2 locus.
Alpha-amylase (α-Amylase-amy1) gene plays a key role in seed germination and
its activity determines levels of starch degradation, seed germination, and pre-
harvest sprouting (PHS), which is a serious problem in wheat production. Yang
et al. ( 2014 ) isolated and characterized high α-Amylase coding genes from the
wheat cultivar Chuanmai32 (PHS susceptible) and the synthetic wheat SHW-L1
(PHS resistant). Expression profi ling of amy1indicated that mRNA transcript accu-
mulation began at a late stage of grain development. amy1 transcript accumulation
in Chuanmai32 was 4.32- and 18.36-fold higher than observed in SHW-L1 at
DPA25 and DPA30, respectively. Two signifi cant expression quantitative trait loci
(eQTLs) on chromosome 1BS and one on 3DS were characterized by expression
analysis of amy1 transcripts and genetic analysis of SHW-L1/Chuanmai32-derived
500400Leaf 3 Na* concentration (μmol gDW-1
)300200100Commercial bread wheatSynthetic derivatives(Yitpi)0Fig. 10.6 Synthetic backcross-derived lines w ith lower Na + exclusion than the recurrent elite
Australian wheat cultivar, “Yitpi” from Ogbonnaya et al. 2013
A. Börner et al.