Abstract
A sudden death syndrome was observed on one-year-old date palm plants cv. Zaghlol during 2016 summer season in Egypt. Wilt symptoms began in outer leaves, then whole leaves were dried within several days. In addition, yellowish, brown discoloration, soften rot of shoot base and root were developed. Bacterial isolates were isolated and purified on Cetrimide's agar medium. Pathogenicity test was verified on 6-months old date palm seedlings and the bacterial isolates were re-isolated from diseased tissue. They were identified based on the morphological and molecular characteristics. Four bacterial isolates caused wilt symptoms on shoot and brown discoloration on root of date palm seedlings. Based on 16S rRNA gene sequencing, the identity of the bacteria were Alcaligenes faecalis and Pseudomonas aeruginosa. The 16S rRNA nucleotides sequences were conserved in the GeneBank with specific accession numbers. Concerning genetic relationships among the four isolates and the cluster analysis, the dendrogram illustrated that the genotypes Z-Kh-B land Z-Kh-B3 which assumed to be highly related of genetic distance were grouped together in one cluster, but the other genotypes Z-Kh-B2 and Z-Kh-B4 were highly diverged and located in another cluster. This is first world report about A. faecalis and P. aeruginosa as the causal agents of bacterial root rot of date palm plants. (C) 2020 Friends Science Publishers