A first genome assembly of the barley fungal pathogen Pyrenophora teres f. teres

The total assembly was 41.95 Mbp and contains 11,799 gene models of 50 amino acids or more. Comparison against two sequenced BACs showed that complex regions with a high GC content assembled effectively. Electrophoretic karyotyping showed distinct chromosomal polymorphisms between isolates 0-1 and 15A, and cytological karyotyping confirmed the presence of at least nine chromosomes. The genetic map spans 2477.7 cM and is composed of 243 markers in 25 linkage groups, and incorporates simple sequence repeat markers developed from the assembly. Among predicted genes, non-ribosomal peptide synthetases and efflux pumps in particular appear to have undergone a P. teres f. teres-specific expansion of non-orthologous gene families.This study demonstrates that paired-end Solexa sequencing can successfully capture coding regions of a filamentous fungal genome. The assembly contains a plethora of predicted genes that have been implicated in a necrotrophic lifestyle and pathogenicity and presents a significant resource for examining the bases for P. teres f. teres pathogenicity.Net blotch of barley (Hordeum vulgare) is caused by Pyrenophora teres Drechsler (anamorph Drechslera teres [Sacc.] Shoem.). P. teres is an ascomycete within the class Dothideomycetes and order Pleosporales. This order contains plant pathogens responsible for many necrotrophic diseases in crops, including members of the genera Ascochyta, Cochliobolus, Pyrenophora, Leptosphaeria and Stagonospora. Net blotch is a major disease worldwide that causes barley yield losses of 10 to 40%, although complete loss can occur with susceptible cultivars in the absence of fungicide treatment [1]. In Australia the value of disease control is estimated at $246 million annually with average direct costs of $62 million annually, making it the country's most significant barley disease [2].Net blotch exists in two morphologically indistinguishable but genetically differentiated forms: P. teres f. teres (net form of net blotch,