Identification of powdery mildew disease and genetic improvements in hazelnut

Official URL: https://risc01.sabanciuniv.edu/record=b2553598 _(Table of contents)

Corylus avellana L. (hazelnut) is an economically important nut crop worldwide due to its nutritional and nutraceutical properties. Powdery mildew is a fungal infection caused by obligate biotrophic fungal plant pathogens distributed nearly worldwide and infects a wide range of plants. Being a highly contagious pathogen that effects the crop quality, a fast and correct genetic diagnosis efforts are highly demanded. In the content on this thesis work initial effort is given to identify the types and characteristics of two pathogens of powdery mildews that mostly infects hazelnut leaves in Turkey. As a result of unique microscopy analysis and genetical ancestor tracing they have been identified as Erysiphe corylacearum and Phylactinia guttata where first is more abundant and destructive and latter is less frequently observed. In order to be able to diagnose the type of pathogen on-field, a novel fast and cost-effective methodology based on the use of newly designed E. corylacearum and P. guttata specific primers is developed. Results suggest that the proposed approach reduces the pathogen diagnosis time 10 to 1 when compared with diagnosis with the use of conventional ITS primers. Focusing specifically on E. corylacearum specific primers limit of detection is identified quantitatively with calculation of pathogen copy number. Loop Mediated Isothermal Amplification (LAMP) method is employed with E. corylacearum specific 28S-LAMP primers that enables the on-field identification of pathogen. Lastly, the genome sequencing of Corylus avellana cv. Tombul have been correctly sequenced that enabled the identification of resistant gene family Mildew Locus O (MLO) that paves way to powdery mildew resistant hazelnut crops