Evaluation of genetic variability in Spathoglottis species: A model orchid

Abstract

Spathoglottis species are popular terrestrial orchids used as model for orchid studies. Due to alarming threat to species diversity, loss of habitat and increasing popularity, it needs to establish information on morphological characteristics as well as genetic variability for qualitative and quantitative traits to utilize for the genetic improvement programme and conservation of these endangered species. With these objectives an attempt was made to estimate genetic variability in terms of genetic component of variance, heritability and genetic advance in per cent of mean for biometrical traits and qualitative traits of four species viz, Spathoglottis albida Kraenzl., Spathoglottis gracilis Rolfe ex Hook.f., Spathoglottis unguiculata (Labill.) Rchb.f. and Spathoglottis plicata Blume. Results showed that flower colour, the colour and shape of the labellum and bracts were important characteristics used to resolve the morphological difference within Spathoglottis species. Biometrical traits viz, plant height, length of inflorescence, flower size, capsule size, number of flowers / inflorescence etc. involved significant role in the differentiation of species for utilization in the genetic improvement programme. Breeding method selection can be adopted for the genetic improvement programme since the genetic variability estimate revealed statistically significant high phenotypic coefficient of variation, genotypic coefficient of variation, heritability (broad sense) and genetic advance in per cent of mean for most of these biometrical traits.