MOLECULAR AND HYPER-SPECTRAL DETECTION OF STAGONOSPORA NODORUM

Stagonospora nodorum (sex. Phaeosphaeria nodorum) is an ascomycete and the causal agent of stagonospora blotch (SNB) disease which is detected mainly on soft and durum wheat, causing consistent losses in quality and quantity in the main world cereal area (Eyal et al., 1987). This study consists in the setup of the fungal growth monitoring by novel analytical techniques during the Stagonospora nodorum pathogenic attack and blotch disease progression on durum wheat. Durum wheat plant, treated or untreated with Folicur, have been inoculated or not (control) both in greenhouse and in the field at different phenotypic stage. Leaf samples have been harvested at different time intervals and used for the subsequent analyses. These analyses consist in two different approach for monitoring and quantifying fungal growth: a spectral images-based analysis and a molecular quantitative (qPCR) method. The first is a no invasive analytical technique, which has recently been used for determining fungal contamination of plant tissues. The latter allow to specifically and quantitatively detect the amount of fungus inside its host. Fungal contamination can be determined by a classical approach (e.g. microscopy) within 120 hours post infection (hpi). The image spectroscopy combined with a robust statistical analysis (ANOVA+Principal Compenents Analysis) indicates 1510 nm as wavelength predictive for unraveling at 48-72 hpi the presence of S. nodorum. Morevoer, the use of specie-specific primers designed on the b-tub sequence of S. nodorum allows the early detection ( 24 hpi) of the pathogen straight from plant tissues. Results indicate that both approach can be used for early detecting S. nodorum in the field.