Afforestation of post-fire Pinus brutia Ten. forests: Effects of Eucalyptus camaldulensis Dehnh., P. brutia and Pinus pinea L. leaf extracts on cell division in P. brutia seeds

We investigated the allelopathic potential of Eucalyptus camaldulensis Dehnh., Pinus pinea L. and Pinus brutia Ten. leaf extracts [(0 (control), 25, 50 and 100%)] on cell division and chromosome structure during the seed germination and seedling development of P. brutia.. The effects on P. brutia mitotic index, phase indices and genotoxicity index were scored and statistically interpreted. The results showed that these species used in afforestation of post-fire had positive and negative effects on the growth of P. brutia seeds. The 100 % leaf extract of E. camaldulensis and 50 % of P. brutia increased the mitotic activity and cell division in the meristematic root tip cells of P. brutia seeds than control. The leaf extract of E. camaldulensis at lowest concentration (25%) were most cytotoxic due to changes in the aberrant chromosome structure of P. brutia cells. While, the P. brutia leaf extracts (25 % and 100 % concentrations) were highly allelopathic and reduced the mitotic activity, affecting the seedling development in P. brutia. Consequently, the results suggested that treatments EC-100 (18 %), PB-50 (14 %) and PP-25 (13.6 %) were very successful to alleviate genotoxic effects of leaf extracts compared to the mitotic index. These groups have a cytoprotective role to protect the stability of chromosome structure during the cell division for P. brutia regeneration.