Understanding the genetic diversity of Durio testudinarius Becc. (Malvaceae) is essential for effective germplasm conservation and genetic resource management; however, molecular information on this wild durian species remains limited. The pertinent study aimed to carry out a comprehensive assessment on genetic diversity of the species D. testudinarius across five populations distributed in five regencies (Sambas, Landak, Sanggau, Sekadau, and Ketapang) in West Kalimantan, Indonesia. In this study, simple sequence repeats also supported barcoding deoxyribonucleic acid of 12 taxa of Durio species. The highest observed and expected heterozygosity values resulted in the Sekadau population (Ho = 0.363 and He = 0.453, respectively), although the species exhibited an overall low level of genetic diversity. DNA barcoding analysis showed the Sambas and Ketapang taxa of D. testudinarius clustered together with strong bootstrap support (93%). Moreover, D. testudinarius formed a distinct lineage that showed a clear separation from D. dulcis, D. zibethinus, D. oxleyanus, D. kutejensis, D. graveolens, D. lanceolatus, and D. acutifolius. The low heterozygosity values revealed limited gene flow among the D. testudinarius populations. Furthermore, the DNA evidence suggested that the germplasm recognized by deoxyribonucleic acid disclosed D. testudinarius accessions were genetically distant from other Durio species in Kalimantan, Indonesia.
D. testudinarius, species, DNA barcoding, morphology, SSR microsatellites
The species D. testudinarius populations in Sambas and Ketapang exhibited distinct groups of Landak, Sekadau, and Sanggau. Based on DNA analysis, five accessions of the D. testudinarius accessions indicated obvious distinctions from seven other species, D. dulcis, D. zibethinus, D. oxleyanus, D. kutejensis, D. graveolens, D. lanceolatus, and D. acutifolius.