Judul: Molecular Markers Development that is Associated with Apomixis Characters and the Strength of Cell Wall Composed Yellow Latex Secretory Duct on Mangosteen (Garcinia mangostana L.).
Abstrak: Mangosteen is one of the excellent export fruit commodity from Indonesia and well-known as Queen of Tropical Fruits. There are two current main development issues of mangosteen, which are apomixis and yellow latex secretion from the fruit caused by destruction of epithelial cell that form yellow latex secretory duct. Therefore, a research to study the aspects of apomixis and cell wall strength that form yellow latex secretory duct in mangosteen should be done. This research consisted of two main topics, the development of molecular marker that is associated with the apomixis characters in Garcinia and molecular marker that is associated with the cell wall strength characters that form yellow latex secretory duct in mangosteen. Mangosteen reproduces through apomixis mechanism. Apomixis is a naturally occurring mode of reproduction that results in embryo formation without the involvement of meiosis or fertilization of the egg. Seed-derived progeny of an apomictic plant is genetically identical to the maternal parent. In Garcinia, apomixis form is called as adventitious embryony, which is divided into obligate and facultative apomixis. Identification and characterization of those apomixis in Garcinia is important for conservation and utilization of Garcinia members. The development of specific molecular markers that associated with apomixis is necessary. The developed markers can then be used as a tool for identification, characterization and selection of Garcinia germplasms. The first part of this research aimed to develop molecular markers related to apomixis character. The DNA ampilication was carried out using primer developed by Ozias-akins et al. (1998) based on the sequence of Pennisetum DNA. The primer was used to amplify DNA from four Garcinia species, i.e. : Garcinia mangostana L., G. hambroniana Pierre., G. celebica L. and G. malacensis T. Anderson. The result showed that only G. hambroniana Pierre. DNA could be not amplified, while the others showed the ampilication band with the size of ± 480 bp. The BLAST sequence analysis of the PCR frgment showed that there was no homology with other DNA sequences in database. Three set of primers were then designed based on Single Nucleotide Polymorphism (SNP) among three DNA sequences from those three species (G. mangostana L., G. celebica L. and G. malacensis T. Anderson). This research succesfully developed three set of primers, which were (1) Apo_Fak1 (forward 5‟ACAATAATCACCACCATACC‟3 and reverse 5‟GTCTT TTCCACTTGGGCTGG‟3); (2); Apo_Fak2 (forward 5‟ACAATAATCACCA CCATACC‟3 and reverse 5‟AGGCTTCAACTTAGTTGTCA‟3); (3) Apo_Obli (forward 5‟ACAATAATCACCACCATACC‟3 and reverse 5‟TCATTTCCCA CTTGGGCTGT‟3). Those three set of primers were then verified using three reference species (G. mangostana L., G. celebica L. and G. malacensis T. Anderson) and the result showed two specific bands that related with apomixis character, i.e. : a 300 bp DNA band produced from G. mangostana L. and G. celebica L., while a 317 bp produced from G. malacensis T. Anderson. Forty one species of Garcinia can be separated into three groups based on the developed molecular markers. Fourteen species were identified as obligate apomixis, fourteen species were facultative apomixis with dioecius flowers, and the other thirteen species were facultative apomixis with hermaprodit flowers. Another aspect of mangosteen development that should be considered is how to eliminate
Keyword: apomixis, Garcinia mangostana L.,, Garcinia spp, yellow latex, molecular markers