The leafy vegetable Telfairia occidentalis is a tropical vine grown in West Africa; it is indigenous to Southern Nigeria and is usually subjected to extreme salt stress in Southern Nigeria as well as in the world that results in significant loss of T. occidentalis production. Therefore, the present investigation was aimed at evaluating the response of T. occidentalis seedlings inoculated with arbuscular mycorrhizal fungi (Glomus geosporum) in saline soil and further to determine the threshold of T. occidentalis salinity tolerance in association with G. geosporum. The total photosynthetic pigments contents in saline soil treatment were significantly (p=0.05) reduced as well as percentage arbuscular mycorrhizal fungi colonization (53.97 to 22.41%). Mycorrhizal dependency was significantly (p=0.05) higher in saline soil treatments compared to control (100.00% to 15.13%). Mineral analysis of T. occidentalis leaves revealed increased uptake and accumulation of Na+ (500.00 mg/kg in control to 2920.13 mg/kg in saline soil treatment). Saline soil treatments significantly (p=0.05) reduced the K, Mg, N, P and Ca. AM Fungi significantly (p=0.05) increased the photosynthetic pigments and minerals both in saline and non-saline soil treatments. Using different mechanisms T. occidentalis by association with G. geosporum showed better salt tolerance thank the uninoculated plants. G. geosporum was able to impose some physiological and root morphological changes such as an extensive network of the mycorrhizal-plant roots to improve water and mineral nutrient uptake. Physiologically G. geosporum inoculation enriched T. occidentalis vigour, attuned the rate of K+/Na+ which restored nutrient and water balance in the plant and directly resulting in the enhancement of salt tolerance in T. occidentalis seedlings, thus improving growth and yield.

The leafy vegetable Telfairia occidentalis is a tropical vine grown in West Africa; it is indigenous to Southern Nigeria and is usually subjected to extreme salt stress in Southern Nigeria as well as in the world that results in significant loss of T. occidentalis production. Therefore, the present investigation was aimed at evaluating the response of T. occidentalis seedlings inoculated with arbuscular mycorrhizal fungi (Glomus geosporum) in saline soil and further to determine the threshold of T. occidentalis salinity tolerance in association with G. geosporum. The total photosynthetic pigments contents in saline soil treatment were significantly (p=0.05) reduced as well as percentage arbuscular mycorrhizal fungi colonization (53.97 to 22.41%). Mycorrhizal dependency was significantly (p=0.05) higher in saline soil treatments compared to control (100.00% to 15.13%). Mineral analysis of T. occidentalis leaves revealed increased uptake and accumulation of Na+ (500.00 mg/kg in control to 2920.13 mg/kg in saline soil treatment). Saline soil treatments significantly (p=0.05) reduced the K, Mg, N, P and Ca. AM Fungi significantly (p=0.05) increased the photosynthetic pigments and minerals both in saline and non-saline soil treatments. Using different mechanisms T. occidentalis by association with G. geosporum showed better salt tolerance thank the uninoculated plants. G. geosporum was able to impose some physiological and root morphological changes such as an extensive network of the mycorrhizal-plant roots to improve water and mineral nutrient uptake. Physiologically G. geosporum inoculation enriched T. occidentalis vigour, attuned the rate of K+/Na+ which restored nutrient and water balance in the plant and directly resulting in the enhancement of salt tolerance in T. occidentalis seedlings, thus improving growth and yield.

This study evaluated the influence of Arbuscular Mycorrhizal (Rhizophagus irregularis) fungi inoculation (M) on the growth ofCucurbita maximaand as a buffer against phytoextraction of selected heavy metals (HM) (Zn, Cu, Cr, Cd and Pb) from a soil contaminated with crude oil (C). The experiment was set up using four soil treatments, each with three replicates C+ M-, C+ M+, C-M+ and C-M- (control without oil and inoculum). The shoot length, petiole length, number of nodes, leaf area and percentage germination ofC. maximawere significantly (p=0.05) reduced in uninoculated crude oil treatment (C+ M-), unpolluted mycorrhizal inoculated treatments (C-M+) showed remarkable response in growth parameters above the control (C-M-), while the polluted and inoculated treatment (C+ M+) showed significant (p=0.05) increase in growth parameters when compared to the polluted uninoculated treatment (C+ M-). Heavy metals analysis revealed a significant (p=0.05) difference in the heavy metal accumulation ofC. maxima. The heavy metals analyzed in this study are present thus inC. maxima; Zn>Cu>Cr>Pb>Cd. Crude oil polluted uninoculated treatment (C+ M-) recorded the highest concentrations of heavy metals than crude oil polluted inoculated (R. irregularis) treatment (C+ M+). Mycorrhizal inoculated unpolluted treatment (C-M+) and unpolluted uninoculated treatment (C-M-) indicated the lowest heavy metal concentrations. Inoculation withR. irregularissignificantly (p=0.05) reduced heavy metals uptake byC. maximaas observed in this study. Also, the negative effect of crude oil on AMF root colonization ofC. maximabyR. irregulariswas observed in polluted and inoculated treatment. HM often accumulate in the top layer of soil, therefore, are available for uptake by plants via roots, which is a major entry point of HM that ultimately affects different physiological processes. AM fungi can impinge on the chemical properties of heavy metals in the soil, their absorption by the host plant, and their allocation to different plant parts, affecting plant growth and the bioremediation process, thus making the AM fungi a suitable buffer for mitigating heavy metal stress onC. maxima.

The effect crude oil pollution and amendment treatments using decomposed green manure (Calopogonium muconoidesDesvaux andAspilia africana(Person) C.D.Adams) on the growth and neutraceutical (minerals, proximate and vitamins A and C) ofCucurbita maximawere studied. Crude oil polluted soils were obtained by mixing thoroughly 10 kg of sandy-loam soil with 10, 20, 30, 40 and 50 ml of crude oil, 0 ml served as control. The amendment treatment with green manure ofC. muconoidesandA. africanawas carried out by adding the different levels of crude oil polluted soils (10 – 50 ml) with 4 kg of the compost manure. The experimental work was carried out in the green house using plastic buckets. Measurement of selected growth parameters such as percentage germination, vine length, leaf area, internode length, leaf number and petiole length was carried out after nine (9) weeks. The results indicated that crude oil pollution significantly (p=0.05) reduced the growth parameters ofC. maxima. Mineral content, proximate composition and vitamin A and C contents ofC. maximaalso showed pronounced reduction with increase in crude oil concentration. The addition of amendment treatment with green manure ofC. muconoidesandA. africanato ameliorate the impeding condition in the crude oil polluted soil significantly (p=0.05) improved the growth parameters and neutraceutical composition ofC. maximawhen compared to the pollution treatment. This study revealed that crude oil pollution negatively affected the growth and neutraceutical composition and generally the productivity ofC. maxima. From this study, it is evident thatC. muconoidesandA. africanaenhanced the growth and quality ofC. maxima.Therefore,C. muconoidesandA. africanashould be used for effective and efficient bioremediation practices.