Molecular Identification and Phylogenetic Analysis of Sugarcane Yellow Leaf Phytoplasma ( SCYLP ) in E gypt

Samples of sugarcane leaves were collected from different commercial fields and breeding stations in E gypt. Aetiology of sugarcane phytoplasma disease was investigated using nested PCR . Phytoplasma‐specific primers ( P 1/ P 7 and R 16 F 2n/ R 16 R 2) were used to amplify a fragment of the 16 S r RNA gene. Sequencing and restriction fragment length polymorphism analyses revealed that the tested phytoplasmas belonged to the 16 S r I (aster yellows phytoplasma) group. Phylogenetic analyses of 60 screened accessions of 16 S ribosomal RNA gene sequences of C andidatus phytoplasmas comprising those collected from E gypt (this study) and those extracted from G en B ank showed that they split into two distinct clusters. All the phytoplasmas form a stable phylogenetic subcluster, as judged by branch length and bootstrap values of 100% in the 16 S group cluster. Results of phylogenetic analyses indicated that these phytoplasmas are closely related and share a common ancestor. Conversely, based on the analysis of the 16 S ‐23 S region, examined isolates segregated into four different clusters suggesting a notable heterogeneity between them. These results are the first record of the presence of phytoplasma in association with sugarcane yellow leaf in E gypt.