Liquid culture in the bioreactor for efficient in-vitro propagation of lingonberry

Micropropagation is an advanced vegetative propagation technology employed to produce a large number of high-quality plants in limited time and space, and has been used extensively in Vaccinium species. Lingonberry (Vaccinium vitis-idaea L.) is a health-promoting fruit crop containing a high number of antioxidant properties. Different types of medium and bioreactors are available to produce high-quality propagation material. However, the effectiveness of the propagation system is not the same for different species. Here we compare the shoot proliferation of two lingonberry genotypes on a semi-solid medium and in two liquid cultures consisting of stationary bioreactor and temporary immersion bioreactor systems. Shoot regeneration from leaf explants was achieved on an agar gelled semi-solid medium containing 1mg/L zeatin, keeping two weeks in the dark and six weeks under the light. Nodal segments obtained were evaluated for shoot proliferation on a semi-solid medium and in a liquid medium using a stationary bioreactor or temporary immersion bioreactor system after eight weeks of culture. Shoots per explant and leaves per shoot were counted, shoot height was measured, shoot vigour was scored, and hyperhydric plants were expressed in percentage. Cultures in a liquid medium producing 3-4 times more number shoots than on a semi-solid medium were found to be effective for shoot proliferation. However, there were differences between the bioreactors in the liquid cultures for some parameters, and the effect was genotype specific.