Physio-Anatomical Potentials of Some Vegetable Species for Atmospheric Humidification and Purification in Ojo Area, Lagos, Nigeria

Abstract

The stomatal features of plant species have capacity to release water vapour into the atmosphere. Therefore, the correlation between the  stomatal features and transpiration rate in six vegetable species: Amaranthus cruentus, Capsicum annuum, Celosia argentia,  Corchorus olitorius, Solanum lycopersicum and Talinum fruticosum were examined for their atmospheric humidification and purification.  The leaf epidermal layers were isolated using nail polish; and were observed under the light microscope to examine their stomatal  features. The transpiration rate was carried out using the cobalt chloride method. Results obtained reveal that all the six species are  amphistomatic. The stomatal complex types observed are anisocytic, paratetracytic, staurocytic, brachyparatetracytic, anomotetracytic  and anomocytic. The stomatal density ranged from 52.63 to 153.22 mm-2 on both leaf surfaces. The stomatal index ranged from 31.34 to  71.42% on both leaf surfaces. This investigation showed that stomatal features such as amphistomatic leaf nature, stomatal complex  types (i.e. anomocytic, anomotetracytic, brachyparatetracytic, staurocytic, paratetracytic and anisocytic) with many subsidiary cells, high  stomatal density and high stomatal index were responsible for the high transpiration rate of the studied species. Hence, Capsicum  annuum humidifies the atmosphere most (8.85 × 10^-6), followed by Solanum lycopersicum (8.83 × 10^-6), Celosia argentia (7.29 × 10^-6), Amaranthus cruentus (6.85 × 10^-6), Talinum fruticosum (5.42 × 10^-6), and the least was Corchorus olitorius (5.11 × 10^-6 mol. M-2s ^-1 ).  Conclusively, the stomatal traits showed positive correlations with transpiration rates, thereby enhancing atmospheric humidification and  climate change mitigation (i.e. atmospheric purification).