Genetic relationship analysis and fingerprint construction of some species in the genus Vanda (Orchidaceae) by interprimer binding site (iPBS) markers

Plants of the genus Vanda exhibit a diverse array of leaf shapes, with the number of flowers varying from a few to many, and a rich palette of colours. These characteristics render them highly valuable for ornamental purposes as tropical orchids. This study employed iPBS molecular markers to analyse the genetic diversity and phylogenetic relationships of 36 species of Vanda and 2 species of Aerides. In addition, DNA fingerprints were constructed. All these works will provide a reference for the identification, variety conservation, and hybrid breeding of species in Vanda. Of the 83 iPBS primers, six were selected because they produced distinct amplification bands, exhibited high polymorphism, and demonstrated good repeatability. These primers were used for polymerase chain reaction (PCR) amplification of genomic DNA from 38 samples, resulting in a total of 210 bands. Among these, all 210 bands were polymorphic, achieving a polymorphism rate of 100%. Using POPGENE 32 software, the mean observed number of alleles (Na) for 38 samples was calculated to be 1.9936, the mean effective number of alleles (Ne) was 1.4243, the mean Nei’s genetic diversity index (He) was 0.2778, and the mean Shannon’s information diversity index (I) was 0.4404. These results indicate a rich genetic diversity among the 38 samples. The genetic similarity coefficients among the samples, calculated using NTSYS-pc 2.1 software, ranged from 0.0345 to 0.6667. Based on these coefficients, unweighted pair group method with arithmetic mean (UPGMA) clustering was performed, and at a similarity coefficient of 0.31, the 38 samples were classified into 7 major groups.250