In vitro studies pertaining to rooting in Bambusa balcooa
Student name: Ms Bhavya Khullar
Guide: Dr Anandita Singh
Year of completion: 2010
Host Organisation: The Energy and Resources Institute (TERI) Micropropagation Technology Park (MTP), Gual Pahari, Harya
Supervisor (Host Organisation): Dr Sanjay Saxena
Abstract: In vitro propagation of Bamboo is imperative owing to the numerous constraints possessed by
conventional methods of breeding viz. planting rhizomes or offsets, layering, nodal-cuttings,
marcotting; and the inability of the same to meet the increasing demands in the future. Protocols for
micropropagation have been developed but they are limited by the low rooting frequency, poor root
quality and low survival rate of the tissue culture-raised plants. An attempt has been made to
understand the various factors that affect in vitro rooting; and select some of them for further
experimentation, that could increase rooting frequency without compromising on the shoot quality
of bamboo. The existing protocol for in vitro rooting of Bambusa balcooa at TERI MTP (MS with
half strength major/macro nutrients supplemented with 1 mg/l IBA, 1 mg/l IAA, 1mg/l NAA and 3%
w/v sucrose that is gelled using 0.2% w/v Gelrite®) is reported to have a rooting frequency of
approx. 15-40 % (as the experimental control) and a low survival rate because of the deterioration
of shoot quality after rooting. Various treatments viz. phloroglucinol, QL and DR media, activated
charcoal, coumarin, pulse with varying periods of induction and various combinations of auxin (s);
have been tried to enhance in vitro rooting in Bambusa balcooa, which is a difficult-to-root species.
The emphasis is laid down to improve shoot quality and plant survival. The experiments that have
been performed in the present study had been shown to enhance rooting in other species by other
researchers. Positive results have been achieved with pulse treatment in B. balcooa i.e. inoculation
of shoots in a media containing high concentration of auxins (MS basal supplemented with 50mg/l
IBA or 20 mg/l IBA and 20mg/l NAA) followed by transfer to a media containing lower
concentration of auxins (experimental control); that has increased rooting frequency to approx. 95-
100% without compromising on the shoot quality. Inoculation of shoots in a higher concentration of
auxins for a period of 4 or 5 days caused root induction and transfer to the control caused root
elongation. It is observed that the above mentioned pulse treatment for rooting followed by
culturing the rooted shoots in MS basal liquid media supplemented with 0.5mg/l BAP results in
100% plant survival in hardening. The same experiments were performed with B. tulda but no
similar success was achieved in B. tulda. Wherever no positive results are obtained in B. balcooa,
the emphasis has been to find a suitable reason for such an observation. The objectives of the study
have been to study the factors affecting in vitro rooting and to select a few amongst them to enhance
in vitro rooting in Bambusa balcooa.
Keywords: Bamboo, in vitro rooting, difficult-to-root, pulse treatment,
micropropagation
