Asexual Reproduction to Propel Recovery Efforts of the Critically Endangered Hayun Lagu Tree (Serianthes nelsonii Merr.)

The natural distribution of the critically endangered tree Serianthes nelsonii (H (a) over circle yun l (a) over circle gu) is restricted to 33 known individuals located on the islands of Rota and Guam, Mariana Islands. Major risks of extinction are a limited range, a minimal number of individuals, and a lack of recruitment. The potential for grafting and air-layering propagation was evaluated to reveal new approaches, by which species recovery efforts may be achieved. Root formation occurred on 100% of the air-layered S. nelsonii stems. Using Serianthes kanehirae as rootstock, graft success was 100% for approach graft and 25% for traditional veneer graft techniques. These results have shown that asexual reproduction is highly successful for this woody legume species and is available to address the restrictions on species recovery caused by limited seed availability. These propagation strategies open up new prospects for conserving contemporary genetic diversity and reversing the failures in S. nelsonii recovery efforts, since the 1994 recovery plan was published.