Plant regeneration from cultured immature embryos of early and late barley cultivars: 1. Plant regeneration in the primary callus derived from immature embryos.

摘要

The frequency of multiple plant regeneration (MPR) of cultured primary calli derived from developing embryos of 22 barley cultivars differing in ripening time (the period between seedling emergence and spike formation) was determined. The capacity for MPR was lower in the early-ripening cultivars than late-ripening ones. Changes in embryo transparency within an intact spike (an index characterizing embryo development) were monitored visually between 6 and 12 days after artificial pollination in a climatic chamber. During this period, completely transparent embryos became opaque at the axis, then at the scutellum, and finally became completely opaque. This process proceeded more rapidly in early-ripening cultivars. It is suggested that the cause ofthe lower level of MPR in early-ripening cultivars was the accelerated development of their embryos and as a result, the shortening of the period for which they were capable of MPR.