Plant regeneration from cultured immature embryos of early and late barley cultivars: 2. Morphological differentiation of embryos as an indicator of their competence for plant regeneration.

摘要

The frequency of multiple plant regeneration (MPR) was studied in calli derived from the embryos of three early-ripening and three late-ripening barley cultivars differing in size, degree of transparency and morphological differentiation. The loss of embryonic cell capacity for plant regeneration in vitro coincided with the termination of morphological differentiation in the embryonic axis. In the early-ripening cultivars, the differentiation of embryonic axes terminated earlier, at smaller sizes and higher transparency of embryos. In all cultivars, the termination of the differentiation of embryonic axes into plant organs was accompanied by changes in the coleoptile shape from spherical into semispherical and by the loss of the coleoptile capacity for staining bright blue-green with toluidine blue. These coleoptile characteristics were chosen for the workable markers of embryo morphological differentiation in selecting the embryos with a high potential for plant regeneration in vitro.