Methods of Dendrobium Rust Detection and Analysis on the Genetic Structure of Dendrobium Rust Populations

Dendrobium, as a rare and precious medicinal material in China, has high medicinal value. With the extension of the cultivating years, one of the main biological factors to affect and restrict its safe production is Dendrobium rust, on which there are very few studies involved currently. Our research has collected a total of 150 rust fungi samples bred from Dendrobium candidum, D. aphyllum, D. crystallinum and D. devonianum from its main producing areas (Honghe and Dehong), and had performed the symptoms observation, pathogenetic identification and ITS sequence analysis, with the results indicated that samples of the all rust fungi of Dendrobium spp. were belonged toBasidiomycetes, Teliomycetes, Uredinales, Coleosporaceae, and Coleosporium. The species will be confirmed in the future. In addition, we had analyzed on the D. candidum population structure in different main producing areas and different species of Dendrobium in the same area by taking advantage of ISSR (Inter-simple sequence repeated, ISSR) molecular markers, with the results showed that the Cladosporium causing the Dendrobium rust in Honghe and Dehong was mainly aggregated regionally, and a small amount of rusts in Honghe was found to be aggregated with that in Dehong, and the Cladosporium bred from different varieties of Dendrobium causing the Dendrobium rust was aggregated individually, which indicated that the rust fungi of Dendrobium had presented a stronger specialization.