A TEMPERATURE-DEPENDENT MORPHOLOGICAL MUTANT OF TOBACCO

A recessive temperature dependent shooty mutant (tds) of Nicotiana tab acum L. (W38) is described. The mutant phenotype is expressed at low t emperature (21 degrees C). Mutant characteristics include thick, narro w leaves with abnormal mesophyll cells, short internodes, and near abs ence of apical dominance. Most plants remain vegetative and the occasi onal flower has petaloid stamens. High temperature (30 degrees C) reve rses the mutant phenotype, with formation of normal leaves and restora tion of apical dominance. However, many flowers still have petaloid st amens. Reciprocal grafting and auxin-cytokinin interaction experiments do not suggest shifts in auxin-cytokinin balance. Overall, this mutan t bears some resemblance to transgenic tobacco overexpressing homeodom ain genes from maize and Arabidopsis.