Corchorus olitorius (L.) is one of the main crops for fibre production, cultivated in tropical and subtropical environments, from Africa to Japan, across the Middle East and India. In developing countries, the leaves are used as a medicine and also as food. In this study, we evaluated the physiological responses of nine accessions of C. olitorius in order to nominate the most suitable one for introduction into southern Europe. African and Asian accessions obtained from the Leibniz Institute IPK gene bank were analysed for their photosynthetic variables and quality traits during cultivation. Accessions from Africa, in particular those from Egypt and Libya, showed higher intrinsic water-use efficiency. However, at high temperatures, the Japanese accession also showed a high level of water-use efficiency, as evidenced by the high carbon fixation rate. Chinese and Indian accessions showed a reduction in growth performance, although a high concentration of antioxidants in the leaves and biomass accumulation have been reported in those accessions. C. olitorius demonstrated an intrinsic attitude to adaptation; according to their subtropical origin, all of the plants grew at sub-optimal status (Fv/Fm). These data, however, do not seem to compromise the potential of these plants as a crop for growing in southern Europe. Moreover, their introduction can be based solely on their biochemical quality traits.
