HTP SSR genotyping elucidates extensive genetic diversity in the biofuel plant Jatropha curcas

Jatropha curcas is a subtropical bioenergy crop, which produces high quality oil that can be processed as a feedstock for biodiesel, renewable jet fuel or specialty products.  Because it is a non-edible feedstock and can be effectively harvested on marginal land that is considered undesirable for food crops, it does not compete with global food supplies.  Jatropha is essentially a wild, undomesticated plant with origins tracing back to Central America. As with any crop, successful domestication and generation of elite cultivars requires breeding of genetically diverse germplasm. Recent publications have shown limited genetic variation in JC germplasm collections from Brazil, India, China, South-East-Asia and more.  

Microsatellite (SSR) markers have been widely used in genetic diversity studies and have been commonly analyzed by fragment size separation via gel electrophoresis. For this study we have developed a HTP accurate SSR genotyping strategy, which reveals high level of polymorphism in SGB’s Central American JC germplasm collection. The methods involve High Resolution Melt (HRM) of SSR loci followed by DNA sequencing for absolute allele confirmation. HRM was found to be sensitive, reproducible and accurate method for determination of homozygous and heterozygous alleles. Life Technologies Viia7 enables high throughput processing; 96 DNA samples can be screened against 4 markers per day.