Development and Cross-genera Transferability of Ginger EST-SSR Markers for Cardamom

Background: Cardamom (Elettaria cardamomum Maton) is an important commodity spice that comes under the ginger family (Zingiberaceae). Several genetic markers are widely being used to analyze plant genomes. However, genetic mapping of cardamom has never been attempted owing to the lack of sufficient number of high quality genetic markers and other pertinent genome information. Objective: The goals of the present study were to design SSR markers from the EST sequences of ginger (Zingiber officinale) and to validate the same in cardamom for demonstrating cross generic transferability. Methods: 38,116 expressed sequence tags of ginger downloaded from the NCBI dbEST database were used to develop and validate co-dominant, multi-allelic SSR markers. Results: A total of 1214 SSRs including mono, di, tri, tetra and hexa repeats were identified in the study. The validation through SSR-PCR followed by agarose gel electrophoresis was carried out for the developed markers. Genetic analysis of the SSR markers showed polymorphism and it clearly differentiated wild genotypes from cultivars and wild escapes from the plantations. Large cardamom, Amomum subulatum Roxb. was used as an outgroup and the newly developed EST-SSR markers were amplified well in this species. Conclusion: The newly developed EST-SSRs could be useful as reproducible markers for cardamom genetic studies.