Goodyera procera (Kew-Gawl.) Hook is an endangered terrestrial orchid in Hong Kong. Pollination experiments showed that the species is a self-compatible outbreeder, but dependent on pollinators for fruit setting. Bagged plants produced no fruits, and artificial pollinations resulted in 92% fruit set through selfing, 94% through geitonogamous pollination, and 95% through xenogamous pollination; whereas fruit set in the open-pollinated control was 75% at the same sites. Allozyme electrophoresis and random amplified polymorphic DNA (RAPD) were used to evaluate genetic structure of 15 natural populations. Despite its outbreeding system, allozyme data revealed a low level of genetic variation within populations (P = 21.78%, A = 1.22, and H = 0.072) compared with other animal-pollinated outbreeding plant species. At the population level, RAPD variation was P = 55.13% and H = 0.18. At the species level, allozyme variation was low with P = 33%, A = 1.33, and HT = 0.15, and from RAPD data P = 97.03% and HT = 0.29. However, genetic differentiation among populations was much above average for outbreeding species (GST = 0.52 and I = 0.909±0.049 based on allozyme data, and GST = 0.39 and I = 0.859±0.038 based on RAPD data), suggesting that gene flow was limited among sites. Based on this information, the following questions were addressed: 1) How did the species deviate from panmixia in the natural environments? 2) What were the likely causes (genetic drift, geographical isolation, anthropogenic disturbance) for the unexpectedly low level of allozyme variation? and 3) What strategies should be adopted for the protection and management of this species in Hong Kong?

Key words: allozymes, conservation genetics, Goodyera, RAPD, wild orchids