SHARMA, RASHMI1* and RAKESH, C. VERMA2. 1Department of Botany, Center of Excellence in Environmental Biology, Vikram University, Ujjain, India. present address, Department of Physiology, Tulane University Health Sciences Center, New Orleans, LA, 70112, USA; 2Department of Botany, Center of Excellence in Environmental Biology, Vikram University, Ujjain, India.. - In Vitro flowering in induced colchitetraploid Phlox drummondii: a differential genotype-dependent response.
Phlox is a beautiful winter ornamental and shows great deal of
natural and induced variations in field. Tissue culture studies in
ornamental plants have assumed a renewed improtance in the light of
tremendous possibilities of commercial exploitation of the techniques
for micropropagation, improvement of strains, genetic manipulation,
somaclonal variations. There has been scant reports on culture and
regeneration of Phlox drummondii. Nodal explant of
colchitetraploids Phlox drummondii on MS medium gave good
response when supplemented with IAA, Kinetin and BAP. We have been
able to successfully produce various colchitetraploid mutants for
genetic improvement of Phlox. These variants are unique but
many of them failed to produce seeds and could not be propagated. To
overcome this problem tissue culture methods were resorted. In
vitro flowering was induced with nodal explants with multiple
shoot formation. This method could be of significance to regenarate
seedless Phlox and is of floricultural and industrial value.
The protocol developed offers an in vitro method to regenerate
Phlox from nodes and obtain several plantlet from a single node
and help facilitate the study to control flowering. Interestingly,
colchitetraploid plants were more responsive than diploids. The
observed difference in response of diploid and colchitetraploid may be
genotype-dependent.
Key words: colchitetraploid, in vitro flowering, Phlox drummondii, Phlox