Investigation on genetic traits and selection of interspecific somatic hybrid progenies in tobacco.

The interspecific somatic hybrid plants were produced in 1980 by protoplast fusions between N. tabacum and N. rustica, and N. tabacum and N. glauca. The results of this study on the genetic traits and selection of the hybrid progenies for seven years showed that the performances of the somatic hybrids (SH) were typical intermediate forms of the two species involved in each somatic hybridization, and that segregation began in SH3 and (SH)BC2 generations (the SH1 backcrossed to N. tabacum twice). However, stable lines and male sterile lines from SH1 until the present, were also obtained. The fertilities of the hybrid progenies were generally poor. The characteristics of the recurrent parent were accumulated, and the chromosome numbers of the hybrid plants were gradually decreased as the number of backcrossing generations increased. Some new types of tobacco with certain commercial values have been selected for used in the present study. The conclusion reached, based on our results, is that the somatic hybridization technology has now been successfully utilized to create unique breeding lines of tobacco, and represents a powerful, new tool for crop improvement.