True Yams(Dioscorea):A Biological and Evolutionary Link between Eudicots and Grasses

Abstract

Dioscorea (true yams) is a large genus that contains species important as food (with edible tubers) or as sources of bioactive substances used in a range of applications. Dioscorea is a major staple food in many parts of the world, especially in West Africa and the Pacific islands, and serves as a famine food in many regions. It is a critically important but neglected crop, which is likely to increase in importance as climate change leads to necessary changes in global food systems. It is a herbaceous, climbing, tropical monocot that looks rather like a dicot, and is part of a lineage that is relatively closely related to the phylogenetically derived group containing the grasses. Therefore, it represents an important biological link between the eudicots and grasses--groups that contain all the model flowering plant species--and has the potential to fill gaps in our knowledge of plant biology and evolution. Yams also offer us the possibility to gain new insights into processes such as tuberization and sex determination, which cannot be studied in current model organisms. This combination of rising importance due to its socioeconomic significance and interesting biology and evolutionary position justify its potential as a model organism. This potential remains to be harnessed, and much of the current work on yam is directed toward its role as a food crop. This aspect will remain important, but its potential for answering questions of basic biological interest will be a major motivation for researchers interested in this organism.

Metabolite profiling of yam (Dioscorea spp.) accessions for use in crop improvement programmes

“…Unlike other root and tuber crops, yams may be stored for a period of 4–6 months at ambient temperature (Bricas and Attaie 1997 ; Knoth 1993 ) and as such, yams are vital for the food security of growing regions. To date yams as a food source and cash crop have been understudied and underutilised (Mignouna et al 2009 ; Nkamleu et al 2009 ). This is surprising considering their high yield potential, high food and market values and numerous post-harvest options for storage and utilisation (Asiedu and Sartie 2010 ).…”

Post-Flask Management of Yam (Dioscorea) Plantlets

“…For more information about yams as a model organism, see True Yams (Dioscorea): A Biological and Evolutionary Link between Eudicots and Grasses (Mignouna et al 2009a). For general husbandry procedures, see Yam (Dioscorea) Husbandry: Cultivating Yams in the Field or Greenhouse (Mignouna et al 2009b), and to create tissue culturederived yam plantlets, see Culturing Meristematic Tissue and Node Cuttings from Yams (Dioscorea) (Mignouna et al 2009c).…”

Taxonomic and phylogenetic significance of leaf venation characteristics in Dioscorea plants

“…This group of plants displays many remarkable characteristics that are not often observed in monocots, such as two-furrowed pollens, differentiated twin cotyledons, an apical germ and venation similar to dicots in certain species [13][14][15]. Therefore, Dioscorea is considered a key group in the evolutionary process from dicots to monocots [16,17]. Over 600 species of Dioscorea are found worldwide, and they are divided into 22 Given this variation, leaf morphology, in particular venation, was demonstrated to be prominent in the classification of Dioscorea plants.…”