Population ecology, phenotypic variation and conservation strategy of wild banana Musa acuminata Colla: a case study in Bromo Tengger Semeru National Park, East Java, Indonesia

Musa acuminata is a major wild banana species close-relative to modern bananas. It provides important genetic materials for further banana improvement to address global threats. However, the population ecology, phenotypic variation, and conservation strategies of wild bananas in Indonesia remain poorly understood. This current study, located at Bromo Tengger Semeru National Park (BTSNP) in East Java as a showcase, revealed that wild banana M. acuminata populations were abundantly distributed in clumped patterns on open areas with high light intensities and air humidities from lowland to submontane and montane zones. The population structures were considered healthy and sustainable; dominated by juvenile and mature-vegetative, followed by suckers and a small proportion of mature-generative. The communities were found to be more abundant and had higher phenotypic richness at elevations above 1300 m asl than at lower elevations. Environmental conditions, particularly the light intensity, land slope and soil properties, are factors that contribute significantly to the ecology of wild banana populations. Based on phenotypic characterisation, it was identified as a complex variety of M. acuminata var. rutilifes, nakaii and zebrina. M. acuminata var. rutilifes mostly occupied lower elevations, while var. nakaii and/or zebrina at higher elevations. Phenotypic differentiation was significantly related to elevation as one of the geographical barriers. Based on the SWOT analysis, the suitable conservation strategy for wild banana in BTSNP is assertive or proactive. In-situ, ex-situ and on-farm conservation approaches are suggested. Bioprospecting research on wild bananas is encouraged. Due to the lack of public knowledge about the importance of wild banana conservation, awareness raising is also prioritised as a conservation action.