High corolla color variation of Hoya coronaria Blume in Belitung Island: Potential use and conservation

Abstract

Genus Hoya (Apocynaceae: Asclepiadadoideae) has become popular as an ornamental plant due to the beauty of its shiny, waxy, star-shaped corolla with various color. Normally, each species has specific corolla and corona color. However, some species have variations in corolla color, for example, Hoya coronaria Blume. Normally, H. coronaria has white with pinkish dotted corolla color, rarely with red corolla color. H. coronaria is distributed from South Thailand, Malay Peninsula, Java, Borneo, and Sumatra as well as in Belitung Island. We surveyed the population and corolla color of H. coronaria in Belitung Island in June 2019. The RHS color chart was used to determine the color. We found eight accessions with different corolla and corona color variation of H coronaria in Belitung Island, ranging from white, cream, pink, peach, deep pink, yellow, red, and deep red. This variation was very high, and the population of Hoya coronaria was well developed in the heath forest habitat of Belitung Island. Further utilization was suggested as a domesticated ornamental plant with proper characterization to support further breeding program. H coronaria was also a component of the heath forest habitat of Belitung Island, which is very fragile. Thus the ex-situ and in situ conservation were suggested for sustainability.