ABSTRACT

Garcinia subelliptica Merr. (called “fukugi” in Japanese) is a dioecious tree species, which has traditionally been planted as windbreak forests in the coast of Ryukyu islands. Although effective afforestation and maintenance of G. subelliptica would greatly be assisted by early sex diagnosis and selection at the seedling stage, the genome and the sex-determination system of G. subelliptica are still poorly understood. In this study, we estimated the genome size of G. subelliptica to be approximately ~ 12 Gb for female and male, based on k-mer analysis. Furthermore, we developed a male-specific DNA marker for G. subelliptica, using the restriction site-associated DNA sequencing (RAD-seq) method. The 660 bp marker fragment, named FSDM (“fukugi” sex determination marker), was amplified in all males but not in the female G. subelliptica genome analyzed so far. In addition, the segregation ratio of the marker was 1:1 among the tested population. The DNA sequence of FSDM showed a significant similarity to the antifungal protein ginkbilobin-2 gene. The development of the sex-specific genetic marker of G. subelliptica may allow more effective conservation of traditional landscape and future design of villages around the northern part of the main island of Okinawa, a promising candidate site for World Natural Heritage.

摘要

藤黄subelliptica大豆- 。（日语中称为“ fukugi”）是一种雌雄异株的树种，传统上是作为琉球群岛海岸防风林种植的。虽然有效造林和维护G. subelliptica将大大早期诊断性和选择在苗期来辅助，基因组和的性别决定系统G. subelliptica仍然知之甚少。在这项研究中，根据k-mer分析，我们估计雌性和雄性亚种G.subelliptica的基因组大小约为12 Gb。此外，我们为G.subelliptica开发了一种雄性特异性DNA标记，使用限制性酶切位点相关的DNA测序（RAD-seq）方法。迄今为止，在所有雄性中扩增了660 bp的标记片段，名为FSDM（“ fukugi”性别确定标记”），但未在雌性G.subelliptica基因组中扩增。另外，在测试人群中，标记的分离比为1：1。FSDM的DNA序列与抗真菌蛋白ginkbilobin-2基因具有显着相似性。椭圆形G.subelliptica的性别特异性遗传标记的发展可能使传统景观得到更有效的保护，并在冲绳主岛北部（该地区有望成为世界自然遗产的候选地）周围的村庄进行未来设计。