Isolation of a White Flowered Mutant through Seed Culture in Spathoglottis plicata Blume

Abstract

Spathoglottis plicata Blume, a terrestrial orchid having prolonged inflorescence with beautiful lilac (pinkish purple) coloured flowers, is commercially important. Treatment of its seeds with sodium azide induced strikingly attractive flower colour modification exploiting seed culture protocols. Vacin and Went (VW) (1949) medium stimulated seed germination and after supplementation with ripe banana extract yielded maximum germination frequency in all cases; it was followed with ripe tomato extract and yogurt water (semi-solid liquor from fermented milk) in untreated and post-treated seeds respectively. The magnitude, however, reduced in treated seeds. Germination initiated usually on the 20th day of inoculation, while addition of yogurt water induced earlier germination by 9 days in the treated and 7 days in untreated samples. Repeatedly subcultured 60 days old plantlets were gradually acclimatized growing inside a hardening chamber and subsequently in a glass house. A treated plant with deep green leaves showed conspicuous variation from the mother strain by its charming milk-white flower colour and green floral bracts in contrast to lilac coloured flower and floral bracts in the latter. VM2 progeny retained the mutant phenotype and genetic uniqueness as indicated by specific PAGE protein banding profile. The mutant having completely different flower colour modification with milky whiteness possesses special floricultural significance and may, therefore, be treated as a new horticultural variety.