Micropropagation of breadfruit (A. altilis) enhanced using a bioreactor system

Abstract

Breadfruit (Artocarpus altilis) is an important starchy food crop with much potential to support livelihoods in the Pacific region. The region has the greatest diversity of breadfruit, with three known species and hybrids. Seeded varieties are largely found in Melanesia and Micronesia, while seedless varieties are found in Polynesia. The seedless varieties are propagated using marcotts, root suckers and root cuttings, and the seeded varieties use seeds. To support increased demands for food for the growing population and to supply market demands, improved methods of propagation are needed. The use of conventional in vitro technology, combined with a temporary immersion bioreactor system, reduced the field-planting readiness time from 44 to 30 weeks. Plantlets produced using the bioreactor were more vigorous, sturdier and taller than those cultured in the conventional semi-solid static tissue culture system. Breadfruit seedlings generated via the bioreactor system are undergoing field evaluation in three breadfruit orchards in Nadi, Fiji, alongside marcotts and root suckers. The analysis is based on the best source of planting material in terms of stem girth, plant height, early fruiting, fruiting patterns, and nutrition and production aspects of varieties. Bioreactor-generated plantlets have also been distributed to Pacific Island countries for evaluation. The research by the Centre for Pacific Crops and Trees (CePaCT) of the Secretariat of the Pacific Community (SPC) based in Suva, Fiji is part of the Pacific breadfruit project funded by the Australian Centre for International Agricultural Research (ACIAR).