Direct and indirect in vitro plant regeneration of two commercial cultivars of perennial ryegrass

Abstract

Experiments were conducted on direct and indirect regeneration from
the meristem tip and mature caryopsis explants of Lolium perenne L. ʻNumanʼ and ʻGrasslandʼ. De-husked caryopses were cultured both intact and longitudinally sliced on MS media supplemented with 2,4-D alone, and in combinations with BA. The highest percentage of callus induction obtained from intact-sliced caryopses were 71 and 87% for ʻGrasslandʼ on MS basal medium supplemented with 6 mg L-1 2,4-D+ 0.02 mg L-1 BA, and 5 mg L-1 2,4-D. While, for ʻNumanʼ, the highest callus induction was achieved by the same explants as 55% and 72% with 5 mg L-1 2,4-D + 0.02 mg L-1 BA, and 4 mg L-1 2,4-D + 0.02 mg L-1 BA, respectively.
The best regeneration medium for ʻGrasslandʼ was MS medium supplemented with 10 g L-1 maltose and 2 mg L-1 ABA. In a separate experiment, meristem tip cultures were incubated on two type combination of plants growth regulators along with control treatment. The best regeneration rate was obtained in both cultivars on MS medium supplemented with 0.1 mg L-1 2,4-D + 0.5 mg L-1 Kin. Plantlets with well-developed roots were transferred to greenhouse condition. Four weeks later, all acclimatized plants were survived.