The Protoplast Culture of Brassica campestris ssp. pekinensis and Plant Regeneration via Somatic Embryogenesis
结球白菜下胚轴原生质体培养及其体细胞胚植株再生

Some factors blocking the protoplast regeneration of Brassica campestris ssp. pekinensis include genotype-dependent cell browning and low frequency of shoot induction. Screening for a genotype that is easy to culture and establishing an experimental system for efficient shoot induction will greatly benefit the genetic innovation of B. campestris ssp. pekinensis via somatic hybridization. Hypocotyl protoplasts of several varieties of B. campestris ssp. pekinensis were cultured, and factors influencing cell division and browning were studied. Cell division and browning were influenced heavily by genotypes of materials and the culture media used. KM8P medium effectively reduced the browning tendency of the cells and was a good medium for protoplast culture of B. campestris ssp. pekinensis. Activated charcoal had a specific function of reducing cell browning and promoting the star-shaped microcalli formation. The somatic embryos were observed on calli of the genotype Asko in shoot-inducing medium containing 3 mg.L-1 AgNO3, with a frequency of about 5%. Intact plants were developed easily from the embryos. This procedure has advantages in easily regenerating plants with relatively high frequency via a somatic embryogenesis pathway.