Plant Regeneration of Pampas Grass from Immature Inflorescences Cultured in Vitro

Abstract

A micropropagation system to obtain plants from inflorescences of pampas grass (Cortaderia selloana Schult. `Pumila') was developed. Factors examined included developmental stage of inflorescence cultured and growth regulator combinations and concentrations that support explant establishment, shoot regeneration, and rooting. Immature inflorescences ≈300 mm long formed many shoot primordia when initially cultured on Murashige and Skoog basal medium containing 4.5 μ m 2,4-D and 8.9 μ m BA and subcultured to medium with 0.4 μ m 2,4-D and 4.4 μ m BA. Thereafter, monthly transfer to a medium without growth regulators yielded about three shoots per tube per month for more than 6 months. Most shoots rooted spontaneously and were easily hardened to greenhouse conditions. Field-tested plants flowered within 2 years and nearly all appeared identical to the parent cultivar. With this technique, several thousand plants can be obtained from a single inflorescence in 1 year. Chemical names used: N -(phenylmethyl)-1 H -purine-6-amine (BA); (2,4-dichlorophenoxy)acetic acid (2,4-D).