Cold and salt tolerance of somatic hybrid calli between barley (Hordeum vulgate L.) and carrot (Daucus carota L.)

Abstract

Three somatic hybrid plants (no. 1, no. 2 and no. 3) were obtained from fused protoplasts between barley (Hordeum vulgare L.) and carrot (Daucus carota L.) (Kisaka et al. 1997). They closely resembled carrot in terms of morphology. In the present study, cold and salt tolerance of the somatic hybrid calli which were induced from these somatic hybrid plants were investigated to know whether both tolerances were transferred. No. 2 was more tolerant to cold than carrot and other somatic hybrids. Furthermore, NaCl and KCl tolerance of no. 2 was as high as that of barley, while those of no. 3 were intermediate between those of barley and carrot. However, no. 1 was not tolerant to NaCl and KCl, as was carrot. Levels of betaine in no. 2 and no. 3 were higher than that in carrot, and the levels of betaine were increased by treatment with NaCl, as in barley. The calli induced from hybrids and their parents grew very well in medium supplemented with betaine, but the betaine was not effective in reducing the inhibition of cell growth by NaCl. These results indicate that the cold- and salt-tolerant traits might have been transferred from barley by protoplast fusion in the somatic hybrid (no. 2).