Studies on a few indigenous species of orchids of north-east India and two hybrids through isozyme analysis

The orchids represent one of the largest and highly evolved groups of flowering plants with tremendous genetic variation. In order to study a few indigenous orchid species of north-east India and hybridity of two inter-generic hybrids involving four species of three genera, isozyme analysis was performed to identify and confirm hybridity. The experiment was conducted at Assam Agricultural University, in the Department of Horticulture, Jorhat, Assam during 2000–2001. Two enzyme systems namely, MDH and esterase were used for the confirm hybridity and identification of different variety/species. Different species and hybrids used for the experiment were Spathoglottis plicata (light purple), S. plicata (deep purple), S. plicata (deep purple) x Dendrobium densiflorum, D. densiflorum, Arundina graminifolia, D. moschatum var. moschatum x Arundina graminifolia, D. moschatum var. moschatum, D. moschatum var. unguipetalum and Rhynchostylis retusa and R. albiflora. Only single zone of MDH activity viz., MDH 1 was recorded in the gel, depending upon the electrophoretic mobility of the bands. The number of bands in the zone varied between one to three. Three zones of esterase activity viz., Est. 1, Est. 2 and Est. 3 were recorded in the gel depending upon the electrophoretic mobility and their bands.