Division of Botany, Indian Agricultural Research Institute, Delhi-12
The morphological, anatomical, growth, fertility and cytological characteristics of the C1, C2, C3 and subsequent generations of colchicine-induced autotetraploids of senji (Melilotus indica) were studied. Though the tetraploids had the usual gigas characteristics with reference to individual plant parts, they were poor in growth and vegetative vigour. In addition they were highly susceptible to infestation with aphids and downy mildew. The coefficient of realization of multivalents ranged from 0.38 to 0.53 in different tetraploid plants. There was no clear relationship between either multivalent or univalent formation and seed fertility. The tetraploid population did not offer much scope for selection for the agronomically important characters and senji does not seem to be a favourable material for polyploidy breeding.
