Genetic diversity among endangered rare Dalbergia cochinchinensis (Fabaceae) genotypes in Vietnam revealed by random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) markers
Dalbergia cochinchinensis is a species of legume in the Fabaceae family. This species is popular and valuable in Vietnam and is currently listed on the Vietnam Red List and on the IUCN Red List as endangered. Genetic diversity of the 35 genotypes of D. cochinchinensis species were evaluated by using 52 markers random amplified polymorphic DNA and inter simple sequence repeats (27 RAPD and 25 ISSR). The RAPD primers produced 74 fragments in which 31 were polymorphic with an average of 1.148 polymorphic bands per primer. The number of amplified fragments varied from 1 (OPR15, OPB05, RA142, OPR08, UBC348, OPE14 and OPO04) to 8 (OPP19) and their sizes ranged from 250 to 1600 bp. Amplification of genomic DNA of the 35 genotypes using ISSR analysis yielded 94 fragments of which 64 were polymorphic with an average of 2.560 polymorphic bands per primer. The number of amplified fragments ranged from 1 (ISSR8, ISSR13 and ISSR18) to 6 (ISSR3, ISSR15 and ISSR61) and their size varied from 300 to 2000 bp. The estimated value of molecular diversity parameters within 35 genotypes such as the different number of alleles, effective number of alleles, Shannon’s information index, intralocus gene diversity and Nei’s gene diversity for RAPD were 1.149, 1.125, 0.109, 0.366 and 0.094, respectively; 1.284, 1.246, 0.206, 0.732 and 0.156, respectively in ISSR; 1.225, 1.193, 0.164, 0.542 and 0.124, respectively in RAPD + ISSR. The results indicate that both marker systems RAPD and ISSR, individually or combined can be effectively used in the determination of genetic diversity among D. cochinchinensis.
Keywords: Dalbergia cochinchinensis, endangered, genetic diversity, inter simple sequence repeats, random amplified polymorphic DNA