Evidence of a Strong Domestication Bottleneck in the Recently Cultivated New Zealand Endemic Root Crop, <i>Arthropodium cirratum</i> (Asparagaceae)

<div><p>We use chloroplast DNA sequencing to examine aspects of the pre-European Māori cultivation of an endemic New Zealand root crop, <i>Arthropodium cirratum</i> (rengarenga). Researching the early stages of domestication is not possible for the majority of crops, because their cultivation began many thousands of years ago and/or they have been substantially altered by modern breeding methods. We found high levels of genetic variation and structuring characterised the natural distribution of <i>A</i>. <i>cirratum</i>, while the translocated populations only retained low levels of this diversity, indicating a strong bottleneck even at the early stages of this species’ cultivation. The high structuring detected at four chloroplast loci within the natural <i>A</i>. <i>cirratum</i> range enabled the putative source(s) of the translocated populations to be identified as most likely located in the eastern Bay of Plenty/East Cape region. The high structuring within <i>A</i>. <i>cirratum</i> also has implications for the conservation of genetic diversity within this species, which has undergone recent declines in both its natural and translocated ranges.</p>