Pattern of seedling development and effect of hormones on morphological changes of Geodorum densiflorum (Lam.) Schltr. in vitro

Abstract

In vitro seed culture of Geodorum densiflorum (Lam.) Schltr. was performed on Vacin and
Went (1949) medium supplemented with 150 ml/l coconut water, 50 g/l potato and 20 g/l sucrose.
The results showed that two types of seed germination were investigated. In the first, the rhizome tip
derived from protocorms, curved downward and grew positive orthogravitropically into the culture
medium then regenerated into shoot tip and grew reversely back to the surface of medium. In the
second, the rhizomes continued their earlier diagravitropic movement above the medium surface.
The rhizome sections were also transferred to culture on Murashige and Skoog (MS) 1962 medium
supplemented with different concentrations of BA, TDZ and Kinetin at 0, 0.1, 0.5, 1.0 and 2.0 mg/l
for 12 weeks. The results showed that the highest number of branches per rhizome (2.67) was
obtained when cultured on the medium with 0.1 mg/l TDZ. The rhizome tips were also cultured on
MS (1962) medium with different concentrations of NAA at 0.1, 0.2, 0.5, 1.0 and 2.0 mg/l for 12
weeks. The results indicated that the highest number of branches per rhizome (2.68) and regenerated
shoots (2.25) were obtained when cultured on the medium with 0.5 mg/l NAA. However, different
sizes of young plantlets grew well in the greenhouse with more than 80% of survival.

Keywords: Geodorum densiflorum (Lam.) Schltr., tissue culture, hormones