Evaluation of Genetic Diversity among and within Mangosteen (Garcinia mangostana L.) Trees

Mangosteen is reproduced through apomixis, from which the seed develops without fertilization. Many tropical fruit species are facultative apomicts, while the mangosteen is an obligate apomict and it is believed that all of its progenies may have same genotype as their mother plant. In an effort to get a better understanding about such a possibility, research to evaluate the genetic variation among mangosteen accessions as well as among progenies from one mother plant were conducted. The plant material used were six mangosteen accessions from West Sumatra and 18 progenies from one mother plant. The progenies consisted of nine seedlings derived from polyembryonic seeds and nine from mono-embryonic seeds. Genetic observation was conducted using the Random Amplified Polymorphic DNA (RAPD) technique. Four primers were used to amplify the genomic DNA of mangosteen. Based on DNA polymorphisms, it was found that genetic variations occurred among accessions and also among progenies within one mother plant. The six mangosteen accessions were separated into five different genotypes that could be further divided into two groups. Genetic similarity of the accessions ranged from 42 to 100%. Parent and offspring analysis showed that 14 of 18 progenies were found to be non-maternal, while the four others were maternal genotypes. Genetic variations were found among the progenies from both poly-embryonic seeds and mono-embryonic seeds. Their genetic similarities to their mother plant ranged from 59 to 100%. These results support previous findings concerning the existence of genetic variation in apomictic mangosteen.