Wild citrus in Oceania: harnessing the diversity

The recent taxonomic change in Citrus indicates that there are 10-11 wild species of Citrus in Oceania (6 in Australia, 4 in PNG, 1 likely in New Caledonia). This represents a significant diversity of close relatives of citrus in the region. Many of these are under severe threat in situ and/or restricted to forest fragments and thus vulnerable under a changing climate. Collection and ex situ conservation of these taxa is required in order to harness the diversity. However seed from these species has not been systematically collected and is not currently represented in national or international ex situ collections. This paper discusses the significance and utilization of the Citrus spp. of Oceania. It also highlights the need for cryopreservation, for long-term ex situ conservation of seed collections of these species to capture the genetic diversity.