A. Maamouri, Y. Trifa, K. Kouki , K. Aounallah, C. Karmous
Salinity is one of the main abiotic stresses that affect the development of sensitive vegetable crops such as lettuce (Lactuca sativa L.). High levels of sodium chloride cause not only lower yields but primarily affect product quality. In a first assay based on analysis of in vitro root growth under salt stress, four cultivars of lettuce (two romaine: ‘Verte Maraîchère’ and ‘Blonde Maraîchère’; and two Batavia: ‘Pierre Benite’ and ‘Great Lakes 118’) were sown in MS medium. Seven days-old seedlings were transferred to medium containing different NaCl levels (0, 50, 100, 200, 300, 400 and 500 mM) and placed upside down. After 7 days, seedlings were trans¬ferred again to an NaCl free medium. The screening was based on two parameters: root-bending ratio and root recovery ratio. Results show that for all measured parameters, ‘Great Lakes 118’ is the most tolerant cultivar followed respectively by ‘Verte Maraîchère’, ‘Blonde Maraîchère’ and Batavia ‘Pierre Benite’. The second assay was based on conventional in vitro selection culture to evaluate plant growth under NaCl stress. After 5 days in germination medium, seedlings of Roman lettuce cultivars were transferred to selection medium containing different concentrations of NaCl (0, 50, 100, 200, 300, 400 and 500 mM). In vitro selection culture was based on the evaluation of survival and recovery ratio. The results indicate a superiority of ‘Verte Maraîchère’ in fair agreement with the results based on in vitro root-bending and recovery assay. Our results suggest that in vitro selection assays are simple and reliable methods for rapid screening of salt stress tolerance lettuce cultivars.
Maamouri, A., Trifa, Y., Kouki , K., Aounallah, K. and Karmous, C. (2012). IN VITRO CULTURE USED FOR SCREENING SALT STRESS TOLERANT LETTUCE CULTIVARS. Acta Hortic. 936, 477-484
DOI: 10.17660/ActaHortic.2012.936.64
Lactuca sativa, growth, root recovery, survival ratio, root-bending

Acta Horticulturae