Allelopathic effects of aqueous extracts of Cyperus papyrus L on bacteria in root nodules of Pisum sativum L.

We determined the allelopathic effect of papyrus (Cyperus papyrus L) extracts (0,5,10 %) on growth and root nodules and their bacteria of two pea (Pisum sativum L) cultivars (Iraqi and Turkish, Local varieties). The extracts reduced the Plant height, root length, dry weight of shoot and root by 23.5 %, 42.30 %, 45.65 % and 50 %, respectively, in Iraqi variety. The aqueous extract of papyrus at the highest concentration of 10 % decreased the root nodules numbers in both varieties, the highest decrease (88.88 %) was in Iraqi variety. Morphological, biochemical and molecular analyses were performed on two bacterial strains isolated from the root nodules of the control sample and from the aqueous extract of papyrus leaves at 5 % concentration for the Iraqi variety, while no isolates were recorded at 10 % concentration. Sequence analysis using DNA BLAST showed 97 % similarity with bacterial isolates from the genus Siccibacter (strain Siccibacter colletis N16, accession number MN555377.1) and 99 % similarity with isolates from the genus Staphylococcus (strain Staphylococcus warneri Dk131, registered with NCBI). All isolates with 16S rRNA sequences were registered as new strains in Mosul in Gene Bank (NCBI) and the phylogenetic tree of these isolates was constructed using MEGA 6.