Abstract

Four cultivars of bean (Lyamungo 90, Jesca, Flora de Mayo and CAB 19) were tested under differing NaCl concentration to assess their performance in a salt rich medium. The aim was to select salt tolerant bean cultivars. The seeds of these cultivars were inoculated with rhizobium strain (Rhizobium leguminosarum biovar phaseoli) and grown in the greenhouse. After the establishment of the seedlings, plants were administered with doses of saline solutions at varying concentrations of NaCl (0, 2.5, 5.0, 10.0 mM) and collected 10 and 20 days after NaCl treatment. Results showed that higher NaCl concentrations reduced plant height, dry matter yield and also altered the leaf colour and promoted their leaf injury. The more severely affected bean cultivars were Lyamungo 90 and CAB 19 at > 5.0 mM NaCl compared to the control. Cultivars Jesca and Flora de Mayo showed better results in these parameters than cultivars Lyamungo 90 and CAB 19. The results suggest that some cultivars are more tolerant to high salinity than others; those tolerant cultivars can sustain plant growth and exhibit less signs of leaf injury and colour loss when compared to more susceptible cultivars in high salinity conditions.

Key words: Leaf color damage, leaf injury, Phaseolus vulgaris, plant cultivars, salt stress.