The barley Frost resistance-H2 locus.
Frost resistance-H2 (Fr-H2) is a major QTL affecting freezing tolerance in barley, yet its molecular basis is still not clearly understood. To gain a better insight into the structural characterization of the locus, a high-resolution linkage map developed from the Nure × Tremois cross was initially implemented to map 13 loci which divided the 0.602 cM total genetic distance into ten recombination segments. A PCR-based screening was then applied to identify positive bacterial artificial chromosome (BAC) clones from two genomic libraries of the reference genotype Morex. Twenty-six overlapping BACs from the integrated physical-genetic map were 454 sequenced. Reads assembled in contigs were subsequently ordered, aligned and manually curated in 42 scaffolds. In a total of 1.47 Mbp, 58 protein-coding sequences were identified, 33 of which classified according to similarity with sequences in public databases. As three complete barley C-repeat Binding Factors (HvCBF) genes were newly identified, the locus contained13 full-length HvCBFs, four Related to AP2 Triticeae (RAPT) genes, and at least five CBF pseudogenes. The final overall assembly of Fr-H2 includes more than 90 % of target region: all genes were identified along the locus, and a general survey of Repetitive Elements obtained. We believe that this gold-standard sequence for the Morex Fr-H2 will be a useful genomic tool for structural and evolutionary comparisons with Fr-H2 in winter-hardy cultivars along with Fr-2 of other Triticeae crops.
Department of Life Sciences, University of Modena and Reggio Emilia, Via Amendola 2, Pad. Besta, 42122, Reggio Emilia, Italy, marianna.pasquariello@unimore.it.
Marianna
M
Pasquariello
Delfina
D
Barabaschi
Axel
A
Himmelbach
Burkhard
B
Steuernagel
Ruvini
R
Ariyadasa
Nils
N
Stein
Francesco
F
Gandolfi
Elena
E
Tenedini
Isabella
I
Bernardis
Enrico
E
Tagliafico
Nicola
N
Pecchioni
Enrico
E
Francia
D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D005615:Freezing; D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics*; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010802:Phylogeny; D020161:Physical Chromosome Mapping