AFLP analysis reveals exceptionally narrow genetic background in ginger (Zingiber officinaleRosc.)

Ginger (Zingiber officinaleRoscoe), whose rhizome is globally valued as both a medicine and as a spice, is an important cash crop in tropical and subtropical countries. India is a leading producer and exporter of ginger in the world. As many as 50 commercial cultivars of ginger are known in India. The gene pool of this clonally propagated crop species has not been well characterized. We analysed the genetic variability among a collection of 17 ginger clones in India, consisting of released varieties and prominent traditional cultivars, using amplified fragment length polymorphism (AFLP) markers. The 10 AFLP primer pairs tested failed to detect any polymorphism at the 485 loci they screened among the clones examined. The results indicate an extremely narrow genetic base of ginger germplasm in India and suggest that the clones examined are the descendants of a single genotype with wide ecological tolerance. The results are discussed in the context of exclusive asexual multiplication in ginger and its long history of cultivation and trade in India.