부산대학교 도서관

Syzygium P. Browne ex Gaertn. (Myrtaceae) is a mega-diverse plant genus in Southeast Asia. Due to its immense species richness, Syzygium has been selected in this study as a model organism to investigate species radiations utilising genome-based approaches. A total of 292 Syzygium and Myrtaceae accessions were examined and mapped against a newly assembled chromosome-level reference genome of Syzygium grande (Wight) Walp. It is shown here that Syzygium grande is a paleotetraploid that shares a lineage-specific whole genome duplication (WGD) event with all Myrtales taxa. Biogeographic reconstructions suggest Syzygium originated in Sahul (Australia-New Guinea) and later diversified eastward to the Pacific Islands and westward to Sunda (peninsular and insular Southeast Asia), mainland Asia, the Indian Ocean islands and Africa. Multiple independent migrations into Sunda have occurred and these radiations involved rapid bursts of speciation events. New Guinea is one of the last remaining frontiers with about 90% of its land area remains forested. As Syzygium is the largest tree genus recorded for New Guinea, there is an immediate urgency to enumerate all species occurring on the island before they go extinct due to anthropogenic activities. An annotated checklist for the Bird's Head Peninsula is presented here. This work is based on dried herbarium specimens, as well as three field expeditions undertaken in West Papua and Papua Provinces, Indonesia. In total, 38 Syzygium species are recorded for the Bird's Head Peninsula, all of which are native except Syzygium polyanthum (Wight) Walp. Twenty-five species are New Guinean endemics and of these, five are narrow endemics restricted to the Bird's Head Peninsula. A new species and a new combination are made here. Twenty-one names are lectotypified, while six names are neotypified. Five unidentified but distinct taxa are also enumerated. A taxonomic key to all 38 Syzygium species is provided.