Ejjcct of Cotain Siibsta)ices on Groxuth and Flowering 



539 



A 



B 



C 



D 



Fig. 6. A, Lower part of Perilla plant under short-day conditions. Flower buds in 

 the axils of the lower leaves. B, Lower parts of control Perilla plant under long-day 

 conditions. Small leaves of the growth shoots are visible. No flower buds are present. 

 C, Lower part of Perilla plant under long-day conditions in White's medium with 

 adenine. Flower buds in the axils of the lower leaves. D, Lower part of Perilla plant 

 under long-day conditions in White's medium containing kinetin. Flower buds in 

 the axils of the lower leaves. Magnification x 10. 



Under short-day conditions, which were favorable for generative 

 development of the Perilla plants, their growth was quite rapid; ad- 

 dition of GA and kinetin to the medium retarded root formation 

 and, as a result, growth of aerial parts of the plants was also slower. 

 In all experimental plants, except those treated with kinetin, (in 

 which growth was strongly retarded) differentiation of flower buds 

 was observed 25 to 30 days later, mainly in the axillary shoots of 

 the lower leaves formed before the appearance of roots (Figure 6, A). 



When kept continuously in the dark the plants formed elongated, 

 etiolated shoots consisting of one internode and terminating in two 



