%A Zhang De-yi %T Selection of Nutrient Mutants of Cultured Tobacco Cells %0 Journal Article %D 1978 %J J Integr Plant Biol %R %P -${article.jieShuYe} %V 20 %N 1 %U {https://www.jipb.net/CN/abstract/article_24700.shtml} %8 %X Callus cultures initiated from leaves of haploid and diploid Nicotiana tabacum were transferred to a suspension culture and then treated with 0.25% EMS. Selection of nutrient mutant cells was carried out by planting the culture in a medium with 1% beef extract without any inorganic nitrogen. In this medium the normal cells turned brown and quickly died, while mutant cells remained viable and its fresh weight increased fourteen-fold after 14 days. This trait was stable as mutant cells grown at inorganic nitrogen medium without beef extract for 42 days (subcultures for 6 passages) were still adapted to beef extract medium. The relationship between various levels of beef extract (medium containing no inorganic nitrogen) and growth of normal and mutant cells was studied. Without beef extract, the normal cells were still viable but grew very slowly. The mutant cells were able to growl at 1% while stopped at 4%. It shows that some growth inhibitory factors were contained in the beef extract and the mutant cells were resisted to these growth inhibitory factors. In order to regenerate plants, mutant callus was inoculated onto a beef medium extract containing 2 mg benzyladenine and 0.5 mg NAA per liter. After one month about 10 shoots were obtained (2/3 green shoots, 1/3 albino shoots), while all other mutant calluses could not be regenerated. All the shoots could not produce any roots except those subcultured in the inorganic nitrogen medium.