Conservation of an important montane bamboo Thamnocalamus falconeri, Hook.f. ex Munro through axillary bud proliferation

Abstract

Thamnocalamus falconeri, Hook.f. ex Munro., an important bamboo species belonging to the family Poaceae, locally known as Ringal, occurs in the hills of Uttarakhand, India. This species has been traditionally exploited by local communities to support their livelihoods. Increasing needs of the hill villages impose unsustainable pressure on natural stands of Ringal in the Uttarakhand hills and forests have been degraded. The long history of excessive cutting of Ringal from natural forests and the lack of replanting threaten villager livelihoods. Replanting is required to conserve the species. We propose a protocol for generation of planting material through axillary bud proliferation for multiplication and conservation of this species. We collected offsets/rhizomes from a natural stand of T. falconeri in the Chopta Mandal areas (Chamoli district, India). These were planted at sites of varied elevation and fresh single nodal segments were collected from them as explants. Different sterilization treatments were assessed to combat contamination. Among these, treatment of 0.1 % HgCl₂ followed by 5 % NaOCl, proved best. Among two cytokinin treatments, viz. BAP and Kinetin, singly or in combination, BAP alone (5 mg L⁻¹) proved superior and resulted in 100 % bud break. BAP-supplemented MS media yielded maximum vigorous shoot formation (90 %) and maximum number of shoots (8.9). Subculturing of shoots on the same medium with similar BAP treatment (5 mg L⁻¹ BAP) enabled continuous production of healthy shoots at similar frequency. Maximum rooting (100 %) was recorded on half-strength MS medium supplemented with 5 mg L⁻¹ IBA. Micropropagated plants were hardened and acclimatized in soil mixture (2:1:1) and then transplanted to field sites (Magra, Uttarakhand, 1,834 m). Eight to ten months after field transplantation we recorded 100 % survival of transplanted material. This micropropagation protocol could be used successfully for raising a stock of genetically homogenous plant material in bulk for field plantations and for conservation of the species.