Potato and Tuber Crops

Colocasia -Origin and Classification

Origin and Classification

• Colocasia and Xanthosoma together are known as coco yam.
• In Colocasia, leaves are peltate and sterile appendage is at top of spadix.
• In Xanthosoma, leaves are sagitate and sterile appendage is absent.
• Taro (Colocasia) originated in South East Asia including India and Malaysia. Plucknett (1983) differentiated Colocasia esculenta into two types:
  1. Calocasia esculenta var. esculenta
     • Produces a large main corm with a few cormels. This includes wild types and is grown under a wide range of moisture conditions from flooded to rainfed upland conditions.
     • This group has 28 chromosomes and are diploids.
     • Leaves are generally elongated. Sterile appendage of spadix is shorter than male part.
     • Eddoe types With cormels bigger than mother corm belong to this group.
     • Naga Kaju of Nagaland, Khasi Bhunga of Meghalaya, Kovur of Andhra Pradesh, local cultivars like Panch Mukhi, Koni Kachu and White Gauriya belong to var. esculenta.
  2. Calocasia esculenta var. antiquorum
     • This includes both cultivated and wild forms. It has small or medium sized main corm and a larger number of side cormels which are edible.
     • It is raised as an irrigated or rainfed upland crop.
     • Plants have 42 chromosomes and are always triploids and do not set seeds.
     • Leaves are almost round. Sterile appendage is larger than male part.