BIODIVERSITAS ISSN: 1412-033X Volume 22, Number 10, October 2021 E-ISSN: 2085-4722 Pages: 4223-4235 DOI: 10.13057/biodiv/d221013 Genetic diversity of eucalypts for germplasm conservation in Forest Area with the Special Purpose of Mount Bromo, Karanganyar, Indonesia RAHAYU 1,♥ , FATIMAH 2 , JAMAL WIWOHO 3 , SUNNY UMMUL FIRDAUS 3 , PUJIYONO 3 , MARIMIN 4 , DWI PRIYO ARIANTO 1 , AHMAD PRAMONO 1 1 Faculty of Agriculture, Universitas Sebelas Maret. Jl. Ir. Sutami 36A, Surakarta 57126, Central Java, Indonesia. Tel./fax. +62-271-663375,  email: rahayu@uns.ac.id 2 Indonesian Center of Biotechnology and Genetic Resources, Ministry of Agriculture. Jl. Tentara Pelajar 3A, Bogor 16111, West Java, Indonesia 3 Faculty of Law, Universitas Sebelas Maret. Jl. Ir. Sutami 36A Surakarta 57126, Central Java, Indonesia 4 Faculty of Cultural Studies, Universitas Sebelas Maret. Jl. Ir. Sutami 36A Surakarta 57126, Central Java, Indonesia Manuscript received: 13 July 2021. Revision accepted: 19 September 2021. Abstract. Rahayu, Fatimah, Wiwoho J, Firdaus SU, Pujiyono, Marimin, Arianto DP, Pramono A. 2021. Genetic diversity of eucalypts for germplasm conservation in Forest Area with the Special Purpose of Mount Bromo, Karanganyar, Indonesia. Biodiversitas 22: 4223- 4235. As a repository of a gene pool, eucalypts germplasm enriches biodiversity, maintains ecosystem sustainability, and aids in conservation. Therefore, this study aims to analyze the genetic diversity of eucalypts ( Corymbia and Eucalyptus) for the development of germplasm conservation in Forest Area with the Special Purpose (KHDTK) Bromo Forest, Karanganyar, Indonesia. In this study, 14 simple sequence repeat (SSR) markers were used to assess the genetic diversity among 20 accessions (Corymbia and 5 Eucalyptus species) from Central and West Java. Subsequently, the genetic parameters were measured and a phylogenetic tree was constructed. The result showed that the SSR markers have high variability, although they belong to different genera. Furthermore, the genetic diversity showed 49 alleles with an average of 3 alleles per locus, while the polymorphism information content (PIC) values were 0.55. There were 4 SSR markers (EMBRA13, EMBRA8, EMCRC11, and EMBRA2) with high PIC value, while the gene diversity (He) of Corymbia and 5 Eucalyptus showed a low level of genetic diversity. The genetic relationship and population structure were divided into genera Corymbia and Eucalyptus. For further application, the eucalypt cultivated in the KHDTK Bromo Forest can contribute as a reference set and 14 SSR markers as a potential marker in combination with morphological characterization to generate a database for germplasm management and conservation. Keywords: Corymbia citriodora, Eucalyptus deglupta, E. globulus, E. pellita, E. urophylla, simple sequence repeat INTRODUCTION Eucalypts is one of the most important industrial forest plantations due to their rapid growth capacity, wider adaptability, and versatile purposes such as pulp, paper, timber, and eucalypt oil production (Sumathi and Yasodha, 2014). Eucalypt belongs to the Myrtaceae family and comprises over 800 species, including 3 closely related genera, namely Angophora, Corymbia, and Eucalyptus (Nicolle 2019). The genus of Angophora consists of only one genus commonly present in New South Wales and Queensland, Australia (Nicolle 2019). Meanwhile, the 2 subgenera of Corymbia (bloodwoods) include Corymbia citriodora which belongs to the Blakella subgenus (Nicolle 2019). The natural distribution of Corymbia extended to northern or eastern Australia (Schuster et al. 2019; Goodine and Oelgemoller 2020). Out of the 9 subgenus of Eucalyptus, Eucalyptus urophylla, E. globulus, E. deglupta, and E. pellita belong to the same subgenus namely Symphyomyrtus (Nicolle, 2019). Similarly, the natural distribution of Eucalyptus species is mostly present in Australia and partly in Papua New Guinea, while E. deglupta Blume and E. urophylla S.T. Blake are the only two species spread in Eastern Indonesia (Nicolle 2019). Plant genetic resources (PGR) need to be continuously enriched, conserved and maintained. Meanwhile, the strategy for preserving of eucalypts germplasm was carried out for ex-situ conservation in Forest Area with the Special Purpose (Kawasan Hutan Dengan Tujuan Khusus, KHDTK) Bromo Forest of Sebelas Maret University, Central Java Province. In forest management, the main focus is for the benefit of forestry research, development, and education (Apriyanto and Kusnandar 2020; Wicaksono et al. 2020). Moreover, the advancement of molecular genetic techniques is becoming increasingly important for studying biodiversity and nature conservation. Molecular tools are also used to decipher distributions and affiliation of a population distribution to identify the populations with immediate conservation concerns (Mukherjee and Ramakrishnan 2018). Microsatellite or simple sequence repeat (SSR) is a DNA marker with a simple sequence consisting of one to six repeated bases, it is commonly present in plant genomes (Brondani et al. 1998). Meanwhile, the high level of polymorphism makes the SSR markers be distributed genetically based on species and individuals (Burke and Long 2012). The characteristics of SSR include the