Optical Fluorescence Diagnostic of Wheat Leaf Rust with Laser Scanning Confocal Microscopy

Abstract

Wheat is the most important grain crop and food source worldwide. The management of diseases and early detection of pathogens is a crucial step in diagnosis programs in wheat. In the primary stage, the symptoms of rust fungus are difficult to identify with visual monitoring and other conventional techniques. In this study, we intended to investigate the early stage leaf rust in wheat crop produced through rust fungus using light fluorescence from laser scanning confocal microscopy (LSCM). The leaf rust and normal samples were analyzed with an excitation of 488 nm wavelength of Ar+ laser without any marker or photosensitizer. The small dark pores instead of stomata appears in leaf due to fungus infection and can be observed after two week of leaf tillering. These spots are orange or brown in the beginning and become black, when plants reach maturity. In recent study, the potential of non-invasive techniques for the detection of plant diseases are demonstrated for the development of a rapid and less complex early stage detection procedure that can be utilized to evaluate the infection structures during fungus infection of wheat. The newly developed rapid procedure will be helpful for early stage detection and management fungal infection before proper development during wheat interaction.