EFFECT OF CRUDE OIL SPILLAGE ON THE FOLIAGE ANATOMICALCHARACTERISTICS OF PIGEON PEA (CAJANUS CAJAN (L.)) MILLSPIMPLICATION FOR PHYTOREMEDIATION

Abstract

The effect of crude oil pollution on the foliage anatomical characteristics of C. cajan Millsp was investigated. Seedlings were polluted with 20 ml, 40 ml, 150 ml and 750 ml (separate) of crude oil, 60 days after planting (DAP). Sections (μ) microns ofthe leaves of both polluted and unpolluted  (control)  plants,  harvested  at  63  and   106  (DAP),  were  examined  (x  400 magnification) to determine the thickness of the leaf, thickness of the adaxial and abaxial epidermises, the number of stomata and the stomatal pore dimensions at the adaxial and abaxial leaf surfaces. The number of palisade and spongy cells per field view and the number of chloroplasts per palisade and spongy cells were counted, while the length and the diameter of xylem lumen were measured. The results showed that pollution with 20 ml to 150 ml of crude oil significantly (p ˂ 0.05) increased the leaf thickness, number of spongy cells (40 and 150 ml), chloroplasts (40 – 750 ml), stomata (150 and 750 ml), stomatal pore width at abaxial leaf surface (150 and 750 ml), size of xylem lumen length and width (40 and 150 ml) for 106 DAP but not for 63 DAP. However, 750 ml of crude oil significantly (p ˂ 0.05) reduced the thickness of the leaf, adaxial and abaxial epidermal thickness, number of spongy and palisade cells, chloroplast per spongy cell (106 DAP only), number of stomata at abaxial leaf surface (106 DAP only) than other treatments. C. cajan neither showed any serious toxicity symptoms nor was it poisoned or killed by crude oil pollution, instead, the growth in different cells was enhanced. The ability ofC. cajan to withstand crude oil pollution is an indication of the possible use of the plant for phytoremediation of crude oil polluted soil.