Pathogen Identification and Phylogenetic Analysis of Sugarcane Rust in Plateau Areas at Low Latitudes

[Objectives]This study was conducted to clarify the species,occurrence and distribution characteristics of sugarcane rust pathogens in low-latitude plateau sugarcane rust areas of Yunnan Province and the phylogenetic relationship between the pathogens and that between them and other rust fungi of the genus Puccinia.[Methods]Fifty seven sugarcane rust samples collected from the sugarcane areas of Baoshan,Lincang,Menghai,Menglian,Ximeng,Lancang and Wenshan in Yunnan were subjected to molecular identification.[Results]The four sugarcane rust samples from Haiyin1 hao in Menghai,Yunnan Province belonged to orange rust of sugarcane,and the pathogen was Puccinia kuehnii Butler.;and other 53 samples of sugarcane rust belonged to brown rust of sugarcane,and the pathogen was Puccinia melanocephala Syd.et P.Syd.The rDNA sequences of other rust fungi from the genus Puccinia were downloaded from GenBank and used for the construction of an NJ tree for systematic evolution analysis together with the sequences obtained in this study.The results showed that the four P.kuehnii sequences obtained in this study were clustered with Puccinia polysora(GenBank accession number:GU058024)into one group,and they were close genetically;the 53 P.melanocephala sequences were clustered with P.nakanishikii(GenBank accession number:GU058002),P.rufipes(GenBank accession number:AJ296545),Aecidium deutziae(GenBank accession number:KU309317)and P.coronata(GenBank accession number:DQ354526)into one group,and they had a close genetic relationship;and the genetic relationship of the two species of sugarcane rust fungi identified in this study was relatively distant.[Conclusions]This study provides a scientific basis for sugarcane rust epidemic prediction,disease resistance breeding,and precise prevention and control.