Nicotiana tabacum L-as a source of cytoplasmic male sterility in interspecific cross with N. alata Link & Otto

A new source of cytoplasmic male sterility (CMS) in tobacco with interspeci fic origin is reported. In traditional selection wild tobacco species have been used as donors of cytoplasm. In the present study the cultivated speci es Nicotiana tabacum L. (n = 24) is a source of CMS. It was used as female parent and N. alata (n = 9) was involved as a pollinator. The F-1 hybrid of this cross was completely sterile. Tissue culture method was applied to re store the female fertility. Regenerants obtained from the 5th passage were successfully pollinated with N. tabacum and seed-containing capsules were f ormed. All BC1P1 plants were male sterile. They possessed normally develope d corollas, three-loculed or deformed pistils, and 1-2 stamens modified int o secondary pistils. In some plants stamenless flowers were observed. Male sterility of BC1P1 was preserved in BC2P1-BC7P1 progenies confirming its cy toplasmic nature.