Construction of new EST-SSRs for Fusarium resistant wheat breeding

Surveying Fusarium resistance in wheat with easy applicable molecular markers such as simple
sequence repeats (SSRs) is a prerequest for molecular breeding. Expressed sequence tags (ESTs) are
one of the main sources for development of new SSR candidates. Therefore, 18.292 publicly available
wheat ESTs were mined and genotyping of newly developed 55 EST-SSR derived primer pairs
produced clear fragments in ten wheat cultivars carrying different levels of Fusarium resistance. Among
the proved markers, 23 polymorphic EST-SSRs were obtained and related alleles were mostly found on
B and D genome. Based on the fragment profiling and similarity analysis, a 327bp amplicon, which was
a product of contig 1207 (chromosome 5BL), was detected only in Fusarium head blight (FHB) resistant
cultivars (CM82036 and Sumai) and the amino acid sequences showed a similarity to pathogen related
proteins. Another FHB resistance related EST-SSR, Contig 556 (chromosome 1BL) produced a 151bp
fragment in Sumai and was associated to wax2-like protein. A polymorphic 204bp fragment, derived
from Contig 578 (chromosome 1DL), was generated from root rot (FRR) resistant cultivars (2-49;
Altay2000 and Sunco). A total of 98 alleles were displayed with an average of 1.8 alleles per locus and
the polymorphic information content (PIC) ranged from 0.11 to 0.78. Dendrogram tree with two main
and five sub-groups were displayed the highest genetic relationship between FRR resistant cultivars (2-
49 and Altay2000), FRR sensitive cultivars (Seri82 and Scout66) and FHB resistant cultivars (CM82036
and Sumai). Thus, exploitation of these candidate EST-SSRs may help to genotype other wheat
sources for Fusarium resistance.