Conservation status assessment of banana crop wild relatives using species distribution modelling

Aim: Crop wild relatives (CWR) are an essential source of genetic material for the improvement of certain traits in related crop species. Despite their importance, increasing public, scientific and political support, large gaps exist in the amount of genetic material collected and conserved of many CWR. Here, we construct a dataset on the distribution of wild banana species (Musa spp.) and assess their risk and conservation status. We deal with the questions (1) what areas are potentially suitable for wild banana species (2) how much of the wild banana diversity is currently at risk or insufficiently conserved ex- and in-situ. Location: Native distribution area of wild banana species, ranging from the northeastern states of India to northeastern Australia. Methods: We assessed the potential environmental range of wild species using a species distribution modelling approach with MaxEnt. Extinction risk was evaluated following IUCN criterion B and the ex- and in-situ conservation status was assessed using an indicator for biodiversity and sustainable development targets. Results: We found that 11 out of 59 assessed species can be considered as vulnerable and nine as endangered. Highest species richness was found along the border of south China and northern Vietnam, in the northeastern states of India and on the Malayan peninsula. Our distribution modelling approach indicates that the northern Indo-Burmese region has the highest environmental suitability for most wild banana species and that lowland rainforests in general are highly suitable for bananas. Assessment of in- and ex-situ conservation status indicates that 56 out of 59 assessed species are currently insufficiently conserved ex-situ and that 49 are of high priority for further conservation. Additional in-situ conservation is of high priority for six species and of medium priority for 40 species. Main Conclusions: To date, little of the banana CWR are sufficiently conserved both in- and ex-situ.研究背景与目标：作物野生近缘种（Crop Wild Relatives, CWR）是改良相关作物特定农艺性状的核心遗传资源。尽管其科研与应用价值日益凸显，并获得了愈发广泛的公众、科研及政策支持，但当前多数CWR的遗传材料收集与保藏仍存在显著缺口。本研究构建了野生芭蕉属（Musa spp.）物种的分布数据集，并对其濒危风险与保护现状展开评估，旨在解答两大科学问题：（1）哪些区域具备野生芭蕉属物种的潜在适宜生境？（2）当前有多大比例的野生芭蕉多样性面临灭绝风险，或在迁地与就地保护层面存在不足？ 研究区域：野生芭蕉属物种的原生分布范围，覆盖从印度东北部各邦至澳大利亚东北部的广阔区域。 研究方法：本研究采用最大熵模型（MaxEnt）的物种分布建模方法，推演野生芭蕉属物种的潜在适宜环境区间。灭绝风险评估依据世界自然保护联盟（International Union for Conservation of Nature, IUCN）标准B开展，迁地与就地保护现状则通过生物多样性及可持续发展目标相关评价指标进行量化分析。 研究结果：本次评估的59个芭蕉属物种中，11个被归类为易危等级，9个被归类为濒危等级。物种丰富度最高的区域集中于中国南部与越南北部交界地带、印度东北部各邦以及马来半岛。分布建模结果显示，印缅北部区域对多数野生芭蕉属物种具备最高的环境适宜性，而低地热带雨林整体上为芭蕉属物种提供了优质的生存生境。保护现状评估表明，59个评估物种中有56个的迁地保护现状未达标准，其中49个物种亟需开展针对性保护行动。此外，6个物种亟需新增就地保护措施，另有40个物种的就地保护优先级为中等。 主要结论：截至目前，仅有极少量芭蕉属野生近缘种同时实现了充分的就地与迁地保护。