Research progress of methods on grass fungal endophyte detection

After the initial discovery of perennial ryegrass and tall fescue lead poisoning of farm animals, the responsible endophytic fungi in the grass was identified; further study confirmed the presence of endophytic fungi not only led to livestock poisoning, but significantly improved the competitive ability of the host in the community. The ecological and physiological functions of grass endophytic fungi have established this field as a popular research topic worldwide, which has provided opportunities for the development of endophytic fungi detection technology. Generally, well-established detection methods for pathogenic fungi have been used for the detection grass endophytic fungi, such as microscopic detection with staining. However, the accuracy of results was easily influenced by different host species, phenophases, and tissues. The rapid development and application of molecular biology, genetics, enzyme linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), real-time PCR methods, and other modern molecular techniques has enabled the continuous improvement of the detection methods of endophytic fungi, which can compensate for the shortage of traditional methods. The rapid and efficient determination of the existence, distribution, classification, and position of the endophytic fungi, requires an accurate and reasonable selection of specific detection methods, such as qualitative or quantitative detection combined with classical microscopy staining to determine the endophytic fungi. In this paper, we reported recent research on the detection methods of endophytic fungi and also discuss the development of classical detection method of other microbes, which are important for the development of specific detection technologies for endophytic fungi and can quantitatively determine the existence and the activity of endophytic fungi. Specific endophytic fungi detection technologies, which are no longer limited to only the identification of the presence of endophytic fungi, but can simultaneous quantify the activity of endophytic fungi detection, are an important focus for the technological development.