Abstract only

Durum wheat production in the Mediterranean basin is plagued by a range of biotic stresses. Among those, septoria tritici blotch that is caused by the fungus Mycosphaerella graminicola has become an important disease. The high genome plasticity of the pathogen and its specialization features (differential pathogenicity towards durum and bread wheat) hinder the identification and exploitation of resistance genes across diverse growing areas. The genetic variation of the response to M. graminicola and the chromosomal location of resistance factors were studied in a durum wheat panel of 183 accessions of diverse origin suitable for association mapping (Maccaferri et al. 2006, Plant Genetics Resources 4: 79-85). The panel was evaluated for two consecutive years (2008 and 2009) in three environments: Tunisia (Beja), Mexico (Toluca) and Italy (Argelato and Ferrara). The accessions were then inoculated under controlled conditions with ten M. graminicola isolates from durum wheat collected over a range of Mediterranean countries. The germplasm collection has been genotyped with approximately 300 SSR markers of known map position and about 900 durum wheat DArT markers. Based on the field and the seedling inoculation assay data (percentages necrosis and pycnidia on primary leaves), significant marker-trait associations pointing to specific chromosome regions have been obtained. A preliminary analysis highlighted some chromosome regions consistently involved in resistance to septoria tritici blotch in bread wheat, particularly in chromosomes 1BL, 2AL and 4AL that accounted for a sizeable portion of phenotypic variation among accessions. The detailed results will be presented and discussed.

Genetic Resources Program|Global Wheat Program

English

Lucia Segura

INT2585|CCJL01

CIMMYT Staff Publications Collection