English

Bakayoko Lassana,Timothee Koutouan Tchimon,Adebola Patrick,Simon Pierre N’Guetta Assanvo,Mubalama Mondo Jean,Pierre Zohouri Goli,N’Zue Boni,Sidoine Essis Brice,Agre Paterne,N’Da Pokou Desire,Evrard Brice Dibi Konan,Michel Kouakou Amani,Bakari Kouassi Abou

doi:10.5897/ajar2021.15637

Abstract

Yam anthracnose disease (YAD), caused by the fungus Colletotrichum gloeosporioides Penz, is the most damaging fungal disease of Dioscorea alata yam worldwide. Local yam varieties, which sustain Côte d'Ivoire’s farmers and other end-users livelihoods, are highly susceptible to this pathogen. Thus, there is a need for developing new yam cultivars to sustain yam production in Côte d'Ivoire. To achieve such objective, identifying and selecting sources of resistance within the existing germplasm is crucial prior to the establishment of a breeding program. This study, therefore, aimed at determining the field resistance to C. gloeosporioides of 115 D. alata landrace varieties. Field experiments were conducted at the Research Station for Food Crops (SRCV) of the CNRA, Bouaké City, in Central Côte d'Ivoire, for three growing seasons. Results showed that symptoms of the anthracnose disease were more noticeable four months after planting (P3): high disease severity and incidence scores. At this period, ‘Betebete’ group (DSS = 3.40 and DI = 99.81%) was the most sensitive to anthracnose disease across years. In contrast, ‘Brazo’ (DSS = 2.24 and DI = 94.81%) and ‘Florido’ (DSS = 2.59 and DI = 97.23%) groups were the least sensitive. This finding indicates that local yam accessions from Côte d’Ivoire have different sensitivity levels to anthracnose disease attacks. Therefore, the genetic diversity from this work should be further exploited by yam breeding and genetic improvement programs for developing cultivars, combining resistance to YAD, high yield potential, and superior tuber quality to meet producers and consumers’ needs. Key words: Anthracnose, Côte d'Ivoire, disease resistance, environment, Dioscorea alata, plant breeding.

Highlights

Yam (Dioscorea spp.) is an economically important staple food crop for over 300 million people in tropics and subtropics (Kutama et al, 2013; Reddy et al, 2015; Adifon et al, 2019)
The experiment was conducted at the Research Station for Food Crops (SRCV) of the National Center of Agronomic Research (CNRA) located in the Bouaké City, in central Côte d'Ivoire (7°44‟ N latitude and 5°04‟W longitude)
Characteristics of anthracnose symptoms observed on the leaves of D. alata accessions

Summary

Introduction

Yam (Dioscorea spp.) is an economically important staple food crop for over 300 million people in tropics and subtropics (Kutama et al, 2013; Reddy et al, 2015; Adifon et al, 2019). It is a perennial herbaceous vine, mainly cultivated for its starchy underground tubers. Yam is an important source of income for famers and significantly contributes to achieving food security in the yam production areas of West Africa (Sartie and Asiedu, 2014; Mulualem et al, 2018). Two cultivated yam species are dominant for their economic importance: Dioscorea rotundata Poir. and Dioscorea alata L. (Mignouna et al, 2008)

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Conclusion