CULTIVATION OF HAPLOID PLANTS FROM TOBACCO POLLEN

IF sterile immature anthers of Nicotiana tabacum (2n Combining double low line 48) are cultured in an appropriate nutrient medium, the pollen may develop into plantlets with the haploid number of chromosomes1,2. When the plantlets have developed an adequate root system in the culture medium, they can be transferred to soil and grown to maturity. Reports differ, however, about the developmental stage at which the anthers must be cultured to ensure success. Plantlets were thought1 to be formed only if the pollen is initially in the tetrad condition; but many plantlets have been obtained2 using older anthers which undoubtedly contained separate pollen grains. We have attempted to resolve this difference, and to determine precisely the point at which transition to plantlet formation takes place. At the same time, we have studied the early divisions within the pollen at this transitional point. We now give a brief account of our findings. © 1969 Nature Publishing Group.