In vitro culture and somatic embryogenesis of four Trifolium species

Callus cultures were induced from hypocotyl sections of Trifolium incarnatum L., T. vesiculosum Savi., T. ambiguum Bieb., and T. repens L. Callus production was the greatest for T. incarnatum and T. ambiguum on Phillips and Collins L2 medium with 0.06 mg/l picloram and 0.1 mg/l 6-benzylaminopurine and for T. vesiculosum and T. repens on Gamborg B5 medium with 1.25 mg/l 2,4-dichlorophenoxyacetic acid (2.4-D), 0.5 mg/l naphthaleneacetic acid (NAA), and 0.5 mg/l 6-furfurylaminopurine (kinetin). Proembryos or somatic embryos were formed in all four species though germination and subsequent plantlet formation only occured in t. incarnatum and T. vesiculosum. Mature plants were obtained via somatic embryogenesis for T. incarnatum. The regenerated plants were fertile and had the normal diploid number of chromosomes (2n = 14).