Researchers at University of Tsukuba have investigated the genetic diversity and future distribution of Shorea macrophylla (Dipterocarpaceae), an important tree species endemic to Borneo. They found that populations in northeastern Borneo represent the species' origin. Climate change projections suggest that suitable habitat for this tree will expand in the future.

Tsukuba, Japan—High-quality oil can be extracted from the seeds of tengkwang, a dipterocarp species. Shorea macrophylla, a tengkwang tree endemic to Borneo, produces large seeds and grows into a tall tree. It is therefore an important resource for seed oil extraction as well as timber production and is cultivated through afforestation.

In this study, the researchers analyzed natural forest populations of S. macrophylla in the Indonesian part of Borneo (Kalimantan) using two types of DNA markers: single-nucleotide polymorphisms (SNPs) and simple sequence repeats (SSRs). Both markers revealed distinct genetic structures among northeastern, central, and southwestern populations. The northeastern population showed the highest genetic diversity and is considered the ancestral population of S. macrophylla.

On the basis of these findings, the researchers recommend conserving the three populations of S. macrophylla as separate management units, since each carries unique genetic characteristics. Projections of suitable habitats for S. macrophylla in 2070 under climate change scenarios indicate an expanded range, reinforcing the need to produce seedlings within each management unit and to conduct afforestation in ways that avoid mixing populations.

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This study was partly supported by the JSPS KAKENHI program (grant no. 24405034) and the Science and Technology Research Partnership for Sustainable Development (SATREPS; JPMJSA2101).

Original Paper

Title of original paper:

Genetic diversity and population structure of Shorea macrophylla using genome-wide single-nucleotide polymorphisms and microsatellite markers in Indonesia for conservation

Journal:

Ecological Research

DOI:

10.1111/1440-1703.70010

Correspondence

Professor Emeritus TSUMURA Yoshihiko
Institute of Life and Environmental Sciences, University of Tsukuba

Related Link

Institute of Life and Environmental Sciences