Micropropagation of Mini Orchid Hybrid Phalaenopsis “Sogo Vivien”

Phalaenopsis “Sogo Vivien” is an orchid hybrid with mini size plant body, and exhibits numerous beautiful pink flowers, that is ideal as ornamental pot plant. Some plants of this orchid exhibit variegated leaves that improve the beauty of the plant, not only because of the flower but also as attracted leaves. This orchid has high economical value, but mass propagation of this orchid has not established yet. An effective method to propagate both the normal and variegated plants is worth to be generated. The objective of this research was to produce a large number of P. “Sogo Vivien” plants, including the variegated plants. The method used seeds from self pollinating variegated plant, and flower stalk nodes. The seeds were sown on three various medium: VW, NP and MS, and flower stalk nodes were planted on VW + BA 10 mg l-1 + active carbon. The results showed that the best medium for in vitro culture of P. “Sogo Vivien” was NP medium, in which all seeds could grew into plantlets. Most plantlets emerged from the seeds were non variegated, only one plantlet out of 1344 seeds was variegated (0.007%). Although all emerged plantlets from flower stalk exhibited variegated leaves. Particularly, the plantlets arised from the second and third basal nodes of flower stalk showed the highest growth rate than that from the other nodes. Histological analysis showed that at 11-13 days after shoot segment plantation on NP medium, the shape of apical cells in the nodes was changed, then followed by the change of cell shape in the basal part of the nodes, produced bipolar pattern, then gradually developed into shoot. These results suggest that mass propagation could be achieved using seed culture, but to get the variegated phenotypes, the second and third nodes of flower stalk from variegated plant were the best explants to be used.

The Use of a Variegated Plant to Determine Adaptations to Altered Light Levels

Variegated Dracaena sanderana plants were grown under 47%, 63%, 80%, and 91% shade cloth. Prior to that, plants were grown under uniform light levels in a greenhouse. Morphological changes which manifested the adaptation to different light levels were not evident until all four leaves present in the apical whorl had expanded. Changes first appeared in a leaf which was 5-15 mm long when plants were placed under the different shade levels. The changes were recognized as alteration in the amount of leaf variegation which gradually changed as new leaves unfolded. After development of four leaves no further morphological changes were apparent. The first `transition' leaf had variegation similar to the preceding leaf and the last `transition' leaf had variegation comparable to the next successive leaf. The amount of variegation was quantified and the changes under different light levels determined. The use of a variegated plant enabled us to readily observe the morphological changes related to light adaptation and showed that a plant is an integrated system which adapts to altered environment over an extended period of time.

INHERITANCE OF A VARIEGATED FOLIAGE CHARACTER IN RUSSIAN WILD RYEGRASS, ELYMUS JUNCEUS FISCH.

Segregation in population derived by crossing heterozygous progeny of Sc.260181, a variegated plant of Russian wild ryegrass, and Sc.25311, a normal plant, showed a 12 normal green:3 variegated:1 albino ratio indicating inheritance according to the dominant epistasis pattern for two factors.