Cytoplasms of several Nicotiana species - N. amplexicaulis , N. bigelovii , N. debneyi , N. eastii , N. exigua , N. glauca , N. glutinosa , N. goodspeedii , N. knightiana , N. occidentalis , N. plumbaginifolia , N. raimondii , N. suaveolens , N. undulata - were bred into the N. tabacum genomic background of flue cured tobacco cv. Zamojska 4. The collection includes also a cytoplasmic male sterile (cms) analogue of cv. Zamojska 4 with mutated cytoplasm of N. tabacum . Some of the alloplasmics were originally obtained in this laboratory ( N. amplexicaulis , N. eastii , N. exigua , N. glauca , N. knightiana , N. raimondii ). The remaining ones were acquired from other laboratories and backcrossed into Zamojska 4. All alien cytoplasms except that of N. knightiana produced full male sterility in Zamojska 4. The extent of male organ modifications varied from complete absence of stamens ( N. suaveolens , N. tabacum ) to petaloid and stigmatoid structures (most common effect) to malformed stamens ( N. amplexicaulis , N. glauca ) to apparently normal stamens ( N. raimondii , N. knightiana ). The majority of the alloplasmics showed response to tentoxin that was compatible with the cytoplasm donor. The exceptions were those involving N. exigua , N. raimondii , ( N. raimondii I) and the cytoplasmic mutant of N. tabacum . There was some variation in growth and morphology among the alloplasmic variants of Zamojska 4. Under field infestation alloplasmics with the cytoplasm of N. plumbaginifolia and N. eastii showed symptoms of blue mold whereas the remaining alloplasmics and cv. Zamojska 4 were highly tolerant of that disease.