In vitro mycorrhization of banana (Musa acuminata) plantlets improves their growth during acclimatization
Banana is amongst the world’s most widely micropropagated plant species. For instance, it is estimated that the production capacity of tissue culture companies in India, the largest world banana producer, is nearly 200 million plants per annum. The in vitro micropropagation of bananas presents several advantages, including high multiplication rate, relatively small space requirement, season-independence, and freedom from pests and diseases. In addition, the plantlets are uniform and represent a good planting material for the establishment of new growing areas or replacement of old plantations. However, the plants are also free from beneficial root inhabitants (e.g. endophytes and arbuscular mycorrhizal fungi (AMF)). These organisms may help plants fend off disease, stimulate growth, crowd out space that would be taken up by pathogens, promote resistance to drought, or influence crop yield by more efficient acquisition of nutrients. Thus, the development of technologies favoring the early colonization of roots by arbuscular mycorrhizal fungi (AMF) may represent an added-value method in plant micropropagation. This paper represents the first report on the in vitro mycorhization of autotrophic banana plantlets and its subsequent effects on plant growth at acclimatization. Heavy root colonization of the plantlets was noticed within the period of in vitro propagation (i.e. 7 weeks). Following transfer to a peat-sand soil substrate, the root system remained highly colonized. Within a period of 5 weeks post-transfer, a relative shoot dry weight increase of > 25% was observed as compared to the non-mycorrhizal plantlets classically propagated on the MS medium. In vitro mycorrhization under autotrophic culture conditions thus represents a promising tool for the pre-adaptation of micropropagated banana plantlets to post-vitro conditions.
Marie Chantal Koffi, Stéphane Declerck. In vitro mycorrhization of banana (Musa acuminata) plantlets improves their growth during acclimatization. In Vitro Cellular & Developmental Biology-Plant 51:265-273, 2015.