Genotypic differences in callus induction and plant regeneration from mature embryos of barley (Hordeum vulgare L.)

An efficient induction system and regeneration protocol based on mature barley embryos were developed. Embryos isolated from mature seeds, dehusked by hand and inoculated with longitudinally bisected sections, showed low contamination and high primary callus-forming capability. The influences of nine culture media on primary callus induction and germination from the mature embryos of barley cultivars Golden Promise and Zaoshu 3 were analyzed. The results showed that the two cultivars had much higher values of primary callus induction in the B16M6D medium as compared to the other eight medium formulations, with a frequency of 74.3% and 78.4% for Golden Promise and Zaoshu 3, respectively. Furthermore, Zaoshu 3 demonstrated particularly high stability in callus induction over the different media, indicating its potential utilization in callus induction and regeneration for its good agronomic traits and wide adaption. There were significant differences amongst 11 barley genotypes in terms of primary callus induction in the optimum medium, with percentages of callus induction and germination response ranging from 17.9% to 78.4% and 2.8% to 47.4%, respectively. Green plantlets of Dong 17, Golden Promise, and Zaoshu 3 were successfully developed from primary calli through embryogenesis, with green plant differentiation frequencies ranging from 9.7% to 21.0% across genotypes.