Cytogenetic studies in two induced leaf mutant lines of Nigella sativa L.

Abstract

Four extremely dwarf plants having identical leaf phenotype as their progenitor were recovered from the selfed progeny of the feathery leaf mutant isolated in the M2 generation following 2 hours treatment with 0.5% EMS. Meiotic studies revealed the characteristic presence of paired fragments in the parent (M2) and multi-valents in the dwarf mutant plants (M3). Such dwarf mutant plants have been designated as “telescopic mutant” by the authors. Multivalents noted in the telescopic mutant plants have arisen possibly due to deletion in the M2 plant, followed by an inter-change. Four such telescopic mutant plants could be raised in the selfed M3 progeny of the telescopic plants; one of which showed prevalence of ring like multivalent (quadrivalent) associations but the others forming normal bivalents. The cyto-genetically marked M4 telescopic mutant was found to be semi-sterile. Origin of the telescopic mutant line has been ascribed to deficiency of genes as an outcome of chromosomal deletion in the parent.