Molecular Characterization of Spirogyra from Northern Thailand using Inter Simple Sequence Repeat (ISSR) Markers

Aims: This study is aimed at determining the molecular identification and genetic relationships of Spirogyra collected from northern Thailand using the genotyping of ISSR markers.

Study Design: The 13 Spirogyra specimens in northern Thailand will be investigated by profiling the specimens via a two-step analysis process, which includes morphological and molecular methods using ISSR markers.

Place and Duration of Study: The 13 Spirogyra specimens were collected randomly from all parts of Thailand from February 2009 to May 2011, specifically including Phrae, Nan, Chiang Rai, Chiang Mai, Tak, Mae Hong Son, Lampang, Lamphun and Phayao Provinces.

Methodology: The morphological characteristics of each sample were recorded. These characteristics included the cell dimensions (width and length) and the number and arrangement of the chloroplast spiral/granules. In addition, with regard to the molecular study, the 10 ISSR primers were amplified in order to examine the DNA fingerprints of all Spirogyra specimens.

Results: The Spirogyra specimens were classified by 5 distinct patterns as follows; Pattern 1: condensed and slightly compacted chloroplast spirals, Pattern 2: short cells with scattered chloroplast spirals, Pattern 3: long cells with fewer chloroplast spirals, Pattern 4: short cells with fewer chloroplast spirals and Pattern 5: long cells with condensed and compacted chloroplast spirals. Morphological characteristics were found to be significantly different through an examination of 5 specific traits (p< 0.05) among all of the specimens using Turkey’s criteria. The major criterion for classification involved the number and arrangement of the chloroplast spirals. Moreover, 61 fragment sizes from ISSR-PCR were analyzed using the UPGMA method. They can be separated and represented by 5 groups of the Spirogyra according to their morphology in this study. These results correspond to the morphological study, so it can be concluded that the ISSR PCR can be applied for the accurate identification of Spirogyra populations.

Conclusion: The results of both methods were used to successfully divide the Spirogyra specimens collected from northern Thailand into 5 distinct groups. The phylogenetic analysis used in this study presented useful information in the confirmation of the taxonomy of Spirogyra, which can be compared to the taxonomy that was achieved based on morphological observations that were made during molecular identification. All of which can be of significant use with regard to Spirogyra classification in Thailand.