Development Of EST-SSR Markers In Phalaenopsis And Their Transferability To Cymbidium

Phalaenopsis, a kind of Orchid aceae Phalaenopsis Blume plant, is among the most rewarding orchids to grow. Nine polymorphic primer pairs were developed from8188ESTs of Phalaenopsis from NCBI and used to analysis genetic diversity of16common Phalaenopsis cultivars on the market to find out their diversity and relationship and provided reference for the future breeding.The developed primer pairs were further applied to PCR amplification in17Cymbidium cultivars. The results of this study are as follows:1. There were8188ESTs of Phalaenopsis from NCBI were screened using SSRIT software, according to the standard of repeat motif number above eight. The results showed that261SSRs were mined from246ESTs with a frequency of3.19%. Dinucleotide repeats EST-SSRs were dominant, accounting for94.25%in all SSRs.(TA)n and (GA)n were the most frequent motifs, accounting for26.42%and25.61%in dinucleotide repeats, followed by (TC)n,(AT)n and (AG)n. Thirty-two primer pairs were designed.2. Sixteen primer pairs had expected products using the template of cultivar’V31’ The sixteen workable primer pairs were chosen to PCR amplification in16Phalaenopsis cultivars and45alleles loci were detected across9EST-SSR loci. The average number of alleles per EST-SSR locus was5with a range from2to12. The value of allelic polymorphism information content(PIC) ranged from0.527to0.981, on an average of0.755per EST-SSR marker. The genetic similarity of paired varieties ranged from0.550to0.875, with average0.728. The results showed that the commom Phalaenopsis cultivars on the market had closer genetic relationgship with each other.3. Cluster analysis based on the UPGMA method indicated that the16Phalaenopsis cultivars could be divided into four groups at similarities coefficient of0.73, which was generally consistent with color. The Group Ⅰ included ten cultivars, such as Dtps. Queen Beer ’Red Sky’, Dtps. Jiuhbao Red Rose, et al. The Group Ⅱ included four cultivars, such as P. Taida Salu, P. Fuller’s Sunset, Dtps. Chain Xen Queen, Dtps. Shin-yaun Golden Beauty. The Group Ⅲ included one cultivar P. Brother Sara Gold. The Group IV included one cultivar P. amabilis cv.formosum.4. Fourteen primer pairs had products using the template of3chinese orchid cultivars ’chunlan no. one’,’huilan no. one’and’molan’. The results indicated that SSR markers developed from Phalaenopsis EST had a certain transitivity in Cymbidium.