Clonal micro-garden formation of Bambusa vulgaris: effect of seasonality, culture environment, antibiotic and plant growth regulator on in vitro culture

ABSTRACT

Background:

We have developed a micropropagation technique methodology to clonal micro-garden formation of Bambusa vulgaris selected adult plant. Collection site (i.e., stock plant cultivated in different environments) and seasonality of shoot collection (i.e., months of the year) effects on in vitro culture were evaluated. Explants that showed normal development were ex vitro rooted in mini-incubator system, and three culture media (WPM, MS and deionized water + agar) supplemented with plant growth regulators (IBA, NAA and BAP) and antibiotic (streptomycin sulphate and culture medium free - control) were evaluated. Micropropagated plants were acclimatized in a shadow house and transferred to a semi-hydroponic system for establishment of a clonal micro-garden. The efficacy of the cloning protocol was determined with genetic fidelity analysis by ISSR molecular markers.

Results:

Considering all inoculations, 21.9% of nodal segments were in vitro established in nine shoot collections. The rooting percentage was 36.6%, and no interactions were observed between the use of culture medium and antibiotic. Culture medium free antibiotic resulted in 80.0% of survival and 50.0% of adventitious rooting. Micropropagated plants presented adequate growth and adaptation to ex vitro conditions in the clonal micro-garden. Molecular analyses by ISSR markers indicated the absence of genetic variations, and histological analyses revealed normal adventitious root formation originating from meristematic cells.

Conclusion:

The formation of a clonal micro-garden was demonstrated, proving the feasibility of the tested technique. Our results contribute to the development of a clonal propagation protocol for B. vulgaris selected adult plants.

Keywords:
Bamboo; Clonal multiplication; In vitro culture; Genetic fidelity; Adventitious rooting

HIGHLIGHTS

Seasonality and stock plant culture environment influences the in vitro establishment of nodal segment.

Fungal contamination is the main factor responsible for explant mortality on in vitro establishment phase.

Multiplication and elongation phases occur simultaneously.

Ex vitro adventitious rooting is not influenced by the culture medium and antibiotic.

ISSR molecular markers were efficient for clonal identification.

Clonal micro-garden of bamboo is possible to be established.