EMS-inducced Translocatio in Nigella damascena L

Abstract

Two morphological variants (P-11/2/2 and P-9/2/3) showing translocation were isolated in an EMS treated M₁ population of Nigella damascena L. The plant P-11/2/2 exhibited complex chromosomal translocations forming ring of four, six and twelve chromosomes and chain of four and six chromosomes, while the plant P-9/2/3 manifested interchange involving four chromosomes in chain configruation only. Possibly, multiple translocation observed in the plant P-l 1/2/2 has resulted in complete pollen and seed sterility following unbalanced microspore formation and concomitant disturbances in fertilization. On the contrary, 78.64% pollen and total seed sterility noted in the plant P-9/2/3 may be ascribed to changes in the genomic balance or physiological disturbances as a consequence of chromosomal interchanges induced by the mutagen or can be attributed to defective female gametogenesis.