Genetic Diversity, Cytology, and Systematic and Phylogenetic Studies in Zingiberaceae

Members of the Zingiberaceae, one of the largest families of the plant kingdom, are major contributors to the undergrowth of the tropical rain and monsoon forests, mostly in Asia. They are also the most commonly used gingers, of which the genera Alpinia, Amomum, Curcuma, and Zingiber, followed by Boesenbergia, Kaempferia, Elettaria, Elettariopsis, Etlingera, and Hedychium are the most important. Most species are rhizomatous, and their propagation often occurs through rhizomes. The advent of molecular systematics has aided and accelerated phylogenetic studies in Zingiberaceae, which in turn have led to the proposal of a new classification for this family. The floral and reproductive biology of several species remain poorly understood, and only a few studies have examined the breeding systems and pollination mechanisms. Polyploidy, aneuploidy, and structural changes in chromosomes have played an important role in the evolution of the Zingiberaceae. However, information such as the basic, gametic, and diploid chromosome number is known for only a few species. In this review we highlighted the need to undertake concentrated efforts to address poorly known areas and perform phylogenetic studies to achieve a consensus on the number of genera and species in the family; investigate the pollination biology and breeding system in members of this family; conduct cytological studies to acquire reliable information regarding basic, gametic, and somatic chromosome numbers and ploidy levels in different species; and perform genetic diversity studies to determine the genetic base of the existing genetic resources in the Zingiberaceae. _____________________________________________________________________________________________________________