GENOME-WIDE ASSOCIATION STUDY TO IDENTIFY CHROMOSOMAL REGIONS RELATED TO THE RESISTANCE TO THE SOIL-BORNE CEREAL MOSAIC VIRUS IN DURUM WHEAT

The soil-borne cereal mosaic virus (SBCMV) is a furovirus that can infect durum (Triticum turgidum ssp. durum) and common (T. aestivum L.) wheat. SBCMV is transmitted to the roots of the host plants by Polymyxa graminis Led., a plasmodiophorid protist that persist in soil up to 20 years. SBCMV is widespread in European countries, and in Italy is present in the northern and central regions, where it causes yield losses on susceptible wheat cultivars often above 50%. The impact of all viruses in wheat may be greater in Europe due to climate change. Notably, a spontaneous mutation of a new variant of SBCMV, that infects plants at high temperatures, was isolated in Japan. In the future, the occurrence of similar mutations may increase due to global temperature increase. Little information is available on genetic determinants for SBCMV resistance and the identification of new sources of resistance is needed. Thus, we are performing a genome wide association study to identify genomic regions related to resistance to SBCMV in durum wheat. Since wild genotypes are an important source of crop genetic diversity, we selected a sub-collection of about 200 landraces from the Global Durum Wheat Panel, already genotyped with Illumina iSelect 90K SNP array technology. Population structure was performed to define the genetic diversity of the sub-collection. The selected genotypes will be grown in greenhouse using a soil infected by SBCMV. Infection will be evaluated by symptoms and by qRT-PCR. The association between genotypic and phenotypic data will be allow us to identify genomic regions and related candidate genes for resistance to SBCMV. This work is supported by Regione Lombardia, d.d.s. n. 4403 28/03/2018, grant n° 42 - SURF.