Induced tillering of Lolium multiflorum in vitro.

Four growth regulators incorporated into Murashige and Skoog's basal medium were tested for their effect on the rate of tillering of Lolium multiforum plantlets in culture. Tillering was stimulated in the presence of 1-2 mg l ^-1 6-benzylaminopurine, but 1 mg l ^-1 gave less plantlet distortion and the tillers could be separated easily. Small shoot tips were considered to be best for establishing aseptic cultures for propagation, but individual tillers were best for transferring to the tiller inducing medium, both initially and at subculturing. Tillering rate was affected by culture vessel, temperature and light intensity. Of the variations tested, the optimum conditions were to culture whole tillers onto a medium containing 1 mg l ^-1 BAP in 30-ml universal tubes at 20°C with continuous white fluorescent light at 12,000 lx for 4-5 weeks. Rates in excess of 40 tillers per month were obtained in culture compared with 5-12 in the glasshouse.