SSR loci characterization and molecular marker development based on Anthurium andraeanum L. transcriptomes

【Objective】This study aimed to discover SSR loci of Anthurium andraeanum L. through transcriptome sequencing and develop polymorphic EST-SSR molecular markers， providing reliable tools for evaluating germplasm resources， constructing genetic maps， and molecular breeding in Anthurium andraeanum L.【Method】Transcriptome sequencing of spathes of Anthurium andraeanum L. cultivars of five colors using Illumina， and MISA was employed to screen SSR loci， analyze their types， frequency， and distribution characteristics. EST-SSR primers were designed using Primer 3.0. A total of 120 pairs of primers were randomly selected. After preliminary screening of three representative cultivars， PCR amplification was conducted for 22 Anthurium andraeanum L. cultivars， with calculation of polymorphism information content （PIC）. Finally， the effectiveness of EST-SSR markers was validated by unweighted pair group method with arithmetic mean （UPGMA） using NTSYSpc 2.10e.【Result】Transcriptome sequencing of Anthurium andraeanum L. generated 22381 unigenes， with the total length of 34872210 bp， from which 11324 SSR loci were detected， distributed across 7705 unigenes， with an occurrence frequency of 50.60% and an average distribution distance of 3.08 kb. The predominant repeat motifs were mononucleotide （24.55%）， dinucleotide （46.41%）， and trinucleotide （27.69%）， with the predominant nucleotide repeat type of A/T （21.59%）， AG/CT （37.73%）， and AC/GT （6.30%）. SSR locus lengths were primarily between 12-20 bp， with repeat numbers predominantly ranging from 5 to 12. A total of 7705 primers containing SSR loci were designed for unigenes， 7456 pairs of EST-SSR primers were obtained. Polymorphic detection was performed for the 120 pairs of EST-SSR primers， in which 107 pairs successfully amplified （with the success rate of 89.17%）， with 75 pairs of primers showing polymorphism. A total of 20 pairs of primers were further selected， and the DNA of 22 Anthurium andraeanum L. cultivars was taken as templates for validation， yielding 16 pairs of highly polymorphic primers （PIC>0.5000）. These primers demonstrated excellent discriminatory capability for the 22 Anthurium andraeanum L. cultivars that were classified into four groups， consistent with traditional morphological classification.【Conclusion】SSR loci of Anthurium andraeanum L. transcriptomes exhibit high abundance and polymorphism， which can be used for efficient molecular marker development. The developed EST-SSR markers show characteristics such as high polymorphism and stability， providing effective tools for germplasm evaluation， genetic map construction， and breeding assisted by molecular markers， which can facilitate genetic elucidation and cultivar improvement of major ornamental traits of Anthurium andraeanum L.