Genetic diversity of tropical abalone in Thailand using RAPD-PCR

Abstract

Randomly amplified polymorphic DNA (RAPD) analysis was used to identify species specific genetic markers of three abalone species in Thailand; Haliotis asinina, H. ovina, H. varia. Five decanucleotide primers (UBC101, OPB11, UBC195, UBC197 and UBC271) were selected for genetic analysis of abalone in Thailand. Seventy-two reproducible and polymorphic RAPD fragments (320-2300 bp in length) were generated using primers UBC101 and OPB11. One hundred percent of polymorphic bands were found for both primers. High genetic diversity levels between H. asinina, H. ovina and H varia was observed Genetic diversity of H. asinina were examined using 5 primers (UBC101, OPB11, UBC195, UBC197 and UBC271). One hundred and thirteen reproducible and polymorphic fragments (250-2300 bp in length) were generated. All primers provided high polymorphic levels in this abalone. The percentages of polymorphic bands of H. asinina, H. ovina and H. varia were 84.91, 94.74 and 91.23, respectively. The average similarity index across overall samples resulted from primer UBC101, OPB11, UBC195, UBC197 and UBC271 were 0.7715, 0.6830, 0.8002, 0.8444 and 0.8396, respectively. The average similarity index within samples of H. asinina, H. ovina and H. varia Were 0.7927-0.8496, 0.6010-0.7032 and 0.5259-0.6102, respectively. Average genetic differences within species were 0.2995, 0.4328 and 0.4295 for H. asinina, H. ovina and H. varia, respectively. The average genetic distance of น. asinina in the Gulf of Thailand were 0.0243 implying genetically close relationship compared to Talibong Island from the Andaman Sea and the Philippines samples. A neighbor-joining tree constructed from the average genetic distance between paired geographic samples indicated phylogenetically clear separation between investigated abalone species (using two primers) and geographic samples of H. asinina (using five primers). Phylogeography was obviously observed between H. ovina originating from the Andaman Sea and the Gulf of Thailand. The primer UBC101 yielded a species-specific markers in H. asinina (1700 bp) and the Philippines sample (380 bp). The primer UBC195 showed species-specific nature in H. asinina (1030 and 650 bp). Primer UBC197 provided RAPD markers in H. asinina (1450 and 750 bp). Additional species-specific RAPD markers in H. asinina (680 bp) and H. asinina from Talibong Island (880 bp) were identified by the primer UBC271. No species-specific RAPD markers wereobserved in H. ovina and H. varia.