BSc-MSc (Integrated)

The research work entitled “Development of functional SSR markers for D- Limonene content and analysis of genetic polymorphism in cardamom (Elettaria cardamomum Maton)” was carried out at the Biotechnology and Bioinformatics Division of Jawaharlal Nehru Tropical Botanical Garden and Research Institute (JNTBGRI), Palode during the academic year 2017-2018.
Elettaria cardamomum Maton, commonly known as green or true cardamom, is one of the most economically important spice crop owing to its very pleasant aroma and taste. It is highly valued from ancient time both for its medicinal as well as culinary uses. The study was carried out with an aim to analyse the genetic diversity inherent in the cardamom landraces and wild genotypes using cardamom specific SSR markers and the estimation and validation of its D-Limonene content.
The genetic diversity inherent in the cardamom germplasm were analysed with cardamom specific SSR markers. Thirty accessions including popular and non- popular cultivars, wild varieties, landraces and one large cardamom (as outgroup) were included in the present study. For the diversity analysis, six cardamom specific SSR markers were employed and POPGENE was used to estimate the genetic variation. The Limonene percentage in four samples was estimated through GC- MS. The present study has shown that D- Limonene, is the antimicrobial, antioxidant, and tumour suppressive constituent in cardamom essential oil, is found to be high in the current popular cultivars, Njellani and Green bold (2.76 and 1.73% respectively) compared to other cardamom varieties (Palakkudi, 0.31% and Pathumuriyan, 0.1%). For validating the results of GC-MS, gene specific primers for limonene were designed from the conserved regions of selected plant species. Thirty accessions were validated with these primers, in which the sample Pathumuriyan has shown distinct variation in the PCR products resolved using horizontal agarose gel electrophoresis which clearly demonstrates the variation in the genes involved in the biosynthesis of D- Limonene in this cultivar. The molecular marker and chemical analysis successfully validated the genetic variability within the species as well as established potential of the two popular cultivars in production of essential oil with high D-Limonene content. The present study can be further elaborated to metabolic pathway analysis with respect to essential oil content and would lead to the development of elite cardamom varieties with increased D- Limonene content through hybridisation techniques.