Interspecific variations in the habitats of Rhus tripartitum L. populations in Saudi Arabia leading to changes in morphological traits and allelopathic activity

ABSTRACT Background: The objectives of this study are to (i) determine the variations in the soil composition among six different habitats of six Rhus tripartita populations, (ii) identify and compare the variation in the fruit and seeds parameters of these populations, and (iii) evaluate the differences in Rhus tripartita allelopathic activities among populations on the Chenopodium album weed on it as biological control method. Results: The soils analysis of the six habitats of Rhus tripartita populations revealed a significant variation in the soil variables, while salinity, organic matter, and macro-elements (Cl-, HCO3-, Na+, K+, Ca+ and Mg2+) were the most controlling factor. Rhus tripartita fruits and seeds showed that there is an inter-site variability observed between populations. Morphological study indicating a large-scale diversity among the provenances. It is related to the phenotypic characteristics which may be due to the genetic effect. The Rhus tripartita extract concentration, especially population 4 (P4), showed potential allelopathic activity against Chenopodium album, where the germination was strongly inhibited at a concentration of 10 g l-1. Under same concnetration, seedling root length and shoot lenght were seriously affected. Conclusion: These extracts could be used as green source, eco-friendly bioherbicide and to be integrated into the weed control program of weeds. However, further study is needed for characterization of essential oil of Rhus tripartita and their potential allelopathic activities against the Chenopodium album weed or maybe other weeds, and evaluate its valuable economic use on a large scale.