High frequency plant regeneration from mature embryo explants of highland barley (Hordeum vulgare L. var. nudum Hk. f.) under endosperm-supported culture

Abstract

An in vitro protocol for efficient plant regeneration has been developed from mature embryo explants of highland barley (Hordeum vulgare L. var. nudum Hk. f.) under endosperm-supported culture. Embryos with (endosperm-supported culture, ES) or without endosperm (non-endosperm-supported culture, NES) were excised from mature seeds and cultured on MS medium supplemented with various concentrations of 2,4-D (1–5 mg l−1) for callus induction. The percentage of callus induction from ES explants was significantly (P < 0.05) lower than that from NES. The highest frequency (97.6%) of callus induction was obtained from NES explants on MS medium containing 3 mg l−1 2,4-D. When the primary calli were maintained at a reduced concentration of 2,4-D (0.5 mg l−1) for 3 weeks, embryogenic calli were formed. The embryogenic calli were then transferred to MS medium supplemented with different concentrations of BA (1–5 mg l−1) and 500 mg l−1 casein hydrolysate (CH) for shoot regeneration. However, the capacity of plant regeneration from ES explant-derived calli was significantly (P < 0.05) higher than that from NES. The best response (81.3%) was observed from ES explant-derived calli on MS medium containing 2 mg l−1 BA. Regenerated plantlets with well-developed root systems were transferred to pots where they grew well, attained maturity and produced fertile seeds. This method could be employed for genetic manipulation studies.