Genetic diversity in Colocasia esculenta and Xanthosoma mafaffa in Togo, West Africa

Damigou Bammite,Paterne Agre,Akouèthê Agbogan,Peter Joseph Matthews,Oluyemi Titilola Akintayo,Yao Dodzi Dagnon,Michael Abberton,Koffi Sodokè Tozo,Komi Odah,Alexandre Dansi

doi:10.36253/ahsc-9689

Abstract

Taro and new cocoyam are root and leaf crops commonly grown in tropical to warm temperate regions. In Togo, they are neglected and underutilised. Here we report the genetic diversity of 26 accessions of taro and 101 accessions of new cocoyam. Analysis of simple sequence repeats revealed low polymorphic information content of 0.43 and 0.25 in taro and new cocoyam, respectively. PCA scatterplots and Neighbour Joining dendrograms based on the SSR data clustered accessions into groups that more-or-less correspond to morphological diversity in both species. AMOVA within and between morphological groups revealed greater variances within groups than between. This indicates weak genetic differentiation between morphological groups, particularly for taro. Genetic diversity was greater among taro cultivars. Taro has a longer history of introduction and dispersal in Africa, and has had more opportunity for multiple introduction and local cultivar development. Different strategies are suggested for future development of these crops in Togo and Africa. For taro, further studies of existing diversity and recent experimental introduction, has spread widely in Africa with little genetic diversity. For this crop, international collaboration is needed to clarify taxonomy, and to introduced further cultivars for evaluation under local conditions in Africa.

Highlights

Received for publication 9 September 2020 Accepted for publication 9 July 2021Root and tuber crops are important sources of food and income for household in rural areas of Africa
Colocasia esculenta (L.) Schott and new cocoyam, Xanthosoma spp., are grown for food and income generation at the household level. Both crops are grown in tropical regions of Africa, Asia, Oceania and America, and taro is common in temperate regions of Africa, Asia, and Oceania (Gonçalves, 2011; Matthews, 2014; Onyeka, 2014; Grimaldi, 2016; Matthews and Ghanem, 2021)
Togolais de Recherche Agronomique (ITRA) located at Davié, at latitude N 6°23’ and longitude E 1°12’ and at 88 m above sea level (Table S2). Accessions of both species were classified in a binary manner based on morphological characters that are observed in the field: taro accessions were identified as either dasheen, or eddoe; new cocoyam accessions were identified as either green or purple

Summary

Introduction

Root and tuber crops are important sources of food and income for household in rural areas of Africa. Colocasia esculenta (L.) Schott and new cocoyam, Xanthosoma spp., are grown for food and income generation at the household level. Both crops are grown in tropical regions of Africa, Asia, Oceania and America, and taro is common in temperate regions of Africa, Asia, and Oceania (Gonçalves, 2011; Matthews, 2014; Onyeka, 2014; Grimaldi, 2016; Matthews and Ghanem, 2021). Taro is considered an ancient crop in Africa, with multiple likely routes of introduction from Asia (Matthews, 2006; Fuller et al, 2011; Chaïr et al, 2016; Grimaldi, 2016). New cocoy am is known to have been introduced to Ghana in 1843 (Karikari, 1971), though earlier introduction fol lowing European contact with America has been sug gested (Bown, 2000)

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