Physiological and Growth Responses of Several Genotypes of Common Purslane (Portulaca oleracea L.) under Mediterranean Semi-arid Conditions

Abstract

Common purslane (Portulaca oleracea L.) is a drought-tolerant weed cultivated for its fresh leaves and stems. In the present study, a field experiment was conducted to determine plant development and photosynthesis of several common purslane genotypes in a high-density planting system. The experiment was carried out according to randomized complete block design with four replications per treatment. Four local populations and two commercial cultivars of common purslane were studied. During the experiment, plant biomass, plant height, leaf relative chlorophyll content (SPAD values), stomatal conductance (gs) and photosynthetic rate (A) were recorded. From the results of our study significant differences in plant height and biomass were observed among the studied genotypes. The lowest height and biomass were found in genotype ‘Domokos’ whose growth was prostrate to semi-prostrate, whereas all the other genotypes had erect growth. Differences were also observed in physiological parameters. In particular, the relative chlorophyll content (SPAD value) was the highest for genotype ‘Domokos’, whereas stomatal conductance and photosynthetic rates were the lowest for the same genotype. Biomass yield had also positive and significant correlation with photosynthetic rate and plant height. Our results indicate that the tested genotypes had significant differences in growth habit and physiological parameters. Comparing the tested genotypes, it could be suggested that apart from genotype ‘Domokos’ which had lower biomass yield due to its growth habit, the rest of the genotypes could be suitable for commercial purposes and proposed as an alternative crop in semi-arid regions of the Mediterranean basin.