Diagnostics of Major Fungal Pathogens of Rice

Rice (Oryza sativa L.) stands as one of the foremost cereals cultivated across diverse agro-climatic regions globally. However, the rice crop faces numerous challenges from both biotic and abiotic factors. Fungal diseases, in particular, pose a significant impediment to rice production, affecting the crop at various growth stages. Therefore, prompt detection and accurate identification of pathogens are essential for effectively managing the disease. Conventional methods for detecting fungal pathogens of rice typically involve isolating the presumed pathogen on a suitable nutrient medium, followed by microscopic examination of spores and spore-bearing structures, and identification based on taxonomic characteristics. These processes are time-consuming and labor-intensive and can yield inconsistent results, often requiring significant expertise in fungal taxonomy. In contrast, the identification of certain rice fungal pathogens through their biochemical and physiological characteristics offers greater certainty compared to isolation-based methods. Indeed, nucleic acid–based techniques, such as polymerase chain reaction (PCR), along with its variations like real-time PCR and loop-mediated isothermal amplification (LAMP), offer rapidity and consistency in results. Notably, they exhibit enhanced specificity, sensitivity, and reliability. These advanced methods facilitate the detection, differentiation, and quantification of rice fungal pathogens, whether present in symptomatic or asymptomatic rice plants, as well as in seeds.