Allelopthic Effects of Ziziphus jujuba and Z. lotus Leaf Extracts on Triticum durum and Lens culinaris

Abstract

Ziziphus species were known for their widespread uses in folk medicine. This work aimed to determine the secondary metabolites (total phenols, flavonoïds, and tannins) of aqueous leaf extracts of two Ziziphus species (Z. jujuba and Z. lotus) from different origins (Mahres, Mahdia, Kairouan, or Rouhia) and their allelopathic effects on Triticum durum and Lens culinaris. The germination percentage, plumule and radicle lengths were recorded after seven days. Total phenols and flavonoïds varied from 10 to 14.03 mg EAG/g DW (total phenols) and from 4.63 to 7 mg QE/g DW (flavonoïds) for Z. jujuba and Z. lotus, respectively. Tannin contents varied from 4.4 (Z. jujuba) to 6 mg CE/g DW (Z. lotus). The radicle length was strongly inhibited by 69.38% in T. durum and by 43.29% in L. culinaris especially when treated with Ziziphus spp. leaf extracts at 100 mg/ml concentration. Root length of T. durum was more inhibited (86.75%) by Z. lotus leaf extract than that of L. culinaris. High levels of phenolic compounds detected especially in Z. lotus leaf extract could justify its inhibitory effect on germination rate and seedling length. Z. lotus leaf extract could be used as herbicide to delete undesirable weeds.

Keywords

• Allelopathy
• leaf extract
• phenolic compounds
• Ziziphus species