Plant regeneration from protoplasts of Triticum aestivum L. cv. Nakasoushu

A fast-growing, small, granular, embryogenic callus was selected from prima ry calli induced from the Japanese wheat cultivar Nakasoushu and the Austra lian wheat cultivar Bodallin. Regenerable and fine suspension cultures were induced three to six months after liquid culture was initiated and were ch aracterized by dense cytoplasm and active division. These suspension cultur es routinely provided high yields of protoplasts with about 90% viability w hen incubated in a modified KMP (Kao and Michayluk, 1975) medium containing 1 mg l(-1) 2,4-D (2,4-dichlorophenoxyacetic acid), and 1 mg l(-1) zeatin. Nakasoushu and Bodallin protoplasts divided at frequencies of 8.6% and 11.1 %, respectively, in agarose-solidified media. When Nakasoushu protoplasts w ere cultured with effective nurse cells of sorghum and wheat, protoplast di vision increased to 16.9% and 12.6%, respectively. Plating efficiencies var ied from 0.03% to 2.5%. After subculture, protocolonies yielded embryogenic calli and somatic embryos, from which green plants were eventually regener ated. Whole plants obtained from Nakasoushu protoplasts were fertile, demon strating the first report of Japanese cultivars in wheat protoplast culture s.