Context: Some populations of introduced species cause significant undesirable impacts but can also act as reservoirs for genetic diversity. Sambar deer (Cervus unicolor) are ‘Vulnerable’ in their native range and invasive in Australia and New Zealand. Genetic data can be used to determine whether these introduced populations might serve as genetic reservoirs for declining native populations and to identify spatial units for management.

Aims: We aimed to identify the provenance of sambar deer in Australia and New Zealand, and to characterise their genetic diversity and population structure.

Methods: We used mitochondrial control region sequences and 18 nuclear microsatellite loci of 24 New Zealand and 63 Australian sambar deer collected across continuous habitat in each location. We estimated genetic diversity and population differentiation by using pairwise F_ST, AMOVA, and Structure analyses. We compared our data with 27 previously published native and invasive range sequences to identify phylogenetic relationships.

Key results: Sambar deer in Australia and New Zealand are genetically more similar to those in the west of the native range (South and Central Highlands of India, and Sri Lanka), than to those in the east (eastern India, and throughout Southeast Asia). Nuclear genetic diversity was lower than in the native range; only one mitochondrial haplotype was found in each introduced population. Australian and New Zealand sambar deer were genetically distinct but there was no population structure within either population.

Conclusions: The genetic differences we identified between these two introduced populations at putatively neutral loci indicate that there also may be underlying diversity at functional loci. The lack of population genetic structure that we found within introduced populations suggests that individuals within these populations do not experience barriers to dispersal across the areas sampled.

Implications: Although genetic diversity is reduced in the introduced range compared with the native range, sambar deer in Australia and New Zealand harbour unique genetic variants that could be used to strengthen genetic diversity in populations under threat in the native range. The apparent high levels of gene flow across the areas we sampled suggest that localised control is unlikely to be effective in Australia and New Zealand.

背景：一些引进物种种群会造成严重的不良影响，但也可能成为遗传多样性的储存库。水鹿（Cervus unicolor）在其本土地区是“脆弱的”动物，在澳大利亚和新西兰则具有入侵性。遗传数据可用于确定这些引入的种群是否可以作为本土种群数量减少的遗传库，并确定管理的空间单位。

目的：我们的目的是确定澳大利亚和新西兰水鹿的起源，并描述其遗传多样性和种群结构的特征。

方法：我们使用了在每个地点的连续栖息地收集的 24 只新西兰水鹿和 63 只澳大利亚水鹿的线粒体控制区序列和 18 个核微卫星位点。我们通过使用成对F _ST、AMOVA 和结构分析来估计遗传多样性和群体分化。我们将我们的数据与之前发表的 27 个本地和入侵范围序列进行比较，以确定系统发育关系。

主要结果：澳大利亚和新西兰的水鹿在基因上与本土西部（印度南部和中部高地以及斯里兰卡）的水鹿比东部（印度东部和整个东南亚）的水鹿更相似。核遗传多样性低于本地范围；在每个引入的群体中仅发现一种线粒体单倍型。澳大利亚和新西兰水鹿在基因上不同，但两个种群内都没有种群结构。

结论：我们在推定的中性基因座上确定的这两个引入种群之间的遗传差异表明，功能基因座上也可能存在潜在的多样性。我们在引入种群中发现的种群遗传结构的缺乏表明，这些种群中的个体在采样区域内的扩散没有遇到障碍。

影响：尽管与本地范围相比，引入范围内的遗传多样性有所降低，但澳大利亚和新西兰的水鹿拥有独特的遗传变异，可用于加强本地范围内受到威胁的种群的遗传多样性。我们采样地区的基因流动水平明显较高，这表明局部控制在澳大利亚和新西兰不太可能有效。