scholarly journals Geographical Distribution and Incidence of Cassava Bacterial Blight (Manihot esculenta Crantz) Caused by Xanthomonas axonopodis pv. manihotis in Two Agro-ecological Zones of Cote d'Ivoire

2017 ◽  
Vol 16 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Affery Arthur Mar ◽  
Abo Kouabenan ◽  
Tuo Seydou ◽  
N`Zue Boni ◽  
Kone Daouda
Keyword(s):  
Geographical Distribution ◽  
Cote D'ivoire ◽  
Manihot Esculenta ◽  
Bacterial Blight ◽  
Côte D’Ivoire ◽  
Manihot Esculenta Crantz ◽  
Cassava Bacterial Blight ◽  
Xanthomonas Axonopodis ◽  
Ecological Zones ◽  
Agro Ecological Zones

scholarly journals QTL identification for cassava bacterial blight resistance under natural infection conditions

2017 ◽  
Vol 22 (1) ◽  
pp. 19 ◽  
Author(s):  
Carolina Soto Sedano ◽  
Rubén Eduardo Mora Moreno ◽  
Fernando Calle ◽  
Camilo Ernesto López Carrascal
Keyword(s):  
Manihot Esculenta ◽  
Bacterial Blight ◽  
Natural Infection ◽  
Blight Resistance ◽  
Bacterial Blight Resistance ◽  
Manihot Esculenta Crantz ◽  
Cassava Bacterial Blight ◽  
Xanthomonas Axonopodis ◽  
Qtl Identification

La yuca, Manihot esculenta Crantz, representa la principal fuente de alimento para cerca de 1000 millones de personas. La producción de yuca se ve afectada por diversas enfermedades, una de las más serias es la bacteriosis vascular (CBB) causada por Xanthomonas axonopodis pv. manihotis (Xam). En este estudio se realizó un análisis de loci de rasgos cuantitativos (QTL) para la resistencia a CBB en condiciones naturales de infección, usando una población de mapeo constituida por 99 genotipos de hermanos completos segregantes y un mapa genético altamente denso basado en SNPs. La evaluación fenotípica se llevó a cabo en Puerto López (Meta), Colombia, durante la época de lluvias durante el segundo semestre de 2015. En la población de mapeo fueron detectados individuos con una segregación transgresiva tanto resistentes como susceptibles. A través de un análisis no paramétrico de intervalo simple, se detectaron dos QTL que explican el 10,9 y el 12,6 % de la varianza fenotípica de la resistencia en campo a CBB. Mediante análisis bioinformáticos se identificaron cuatro genes candidatos presentes en los intervalos de los QTL. Este trabajo representa un esfuerzo por dilucidar los mecanismos moleculares implicados en la resistencia de yuca a CBB.

scholarly journals Prevalence and Distribution of Cassava Bacterial Blight in the Kenyan Coast

2021 ◽  
Vol 3 (1) ◽  
pp. p7
Author(s):  
ANTONY Livoi ◽  
A. W. Mwang' ombe ◽  
E. Nyaboga ◽  
D. Kilalo ◽  
E. Obutho
Keyword(s):  
Manihot Esculenta ◽  
Bacterial Blight ◽  
Coastal Region ◽  
Management Program ◽  
Manihot Esculenta Crantz ◽  
Cassava Bacterial Blight ◽  
Xanthomonas Axonopodis ◽  
Major Constraint ◽  
Kenyan Coast ◽  
Cassava Production

Cassava (Manihot esculenta Crantz) is one of the staple food crops grown in Kenya. Diseases remain one of the major constraints for cassava production. Apart from other major viral diseaes Cassava mosaic and Cassava brown streak, Cassava bacterial blight (CBB) caused by Xanthomonas axonopodis pv manihotis and Xanthomonas axonopodis pv cassavae are a major constraint in cassava production in Kenya. This study was done to identify the prevalence, distribution, and farmers' knowledge of cassava bacterial blight in the coastal region of Kenya. A survey was conducted involving 250 farmers who were randomly selected from two regions of Kilifi and Taita Taveta counties. Among the 250 farmers interviewed, 61.6 % identified cassava bacterial blight symptoms in their farms. The main varieties found growing in the region were Tajirika, Karembo, Kibandameno, and Shibe which were all confirmed by farmers as susceptible to cassava bacterial blight. During the survey, plant samples were randomly collected in the field. Out of the 70 samples collected, 40 of them were confirmed positive with X.pv manihotis and X.pv cassavae which cause cassava bacterial blight. The study concluded that there is a widespread of cassava bacterial blight in Kilifi and Taita taveta counties. Kilifi County had the highest incidence of 22% with Taita Taveta having the lowest incidence of 13%. Kilifi County had a higher severity of 8% as compared to Taita Taveta which had 5% Severity. Therefore there is a need for a proper management program to be deployed in managing the disease to enhance cassava production in the region.

AFLP assessment of genetic variability in cassava accessions (Manihot esculenta) resistant and susceptible to the cassava bacterial blight (CBB)

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Gilda Sanchez ◽  
Silvia Restrepo ◽  
Myriam-Cristina Duque ◽  
Martin Fregene ◽  
Merideth Bonierbale ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Manihot Esculenta ◽  
Bacterial Blight ◽  
Multiple Correspondence Analysis ◽  
Aflp Analysis ◽  
Resistance Screening ◽  
Base Resistance ◽  
Cassava Bacterial Blight ◽  
Xanthomonas Axonopodis ◽  
Cassava Varieties

Cassava bacterial blight (CBB) is caused by Xanthomonas axonopodis pv. manihotis (Xam). Resistance is found in Manihot esculenta and, in addition, has been introgressed from a wild relative, M. glaziovii. The resistance is thought to be polygenic and additively inherited. Ninety-three varieties of M. esculenta (Crantz) were assessed by AFLPs for genetic diversity and for resistance to CBB. AFLP analysis was performed using two primer combinations and a 79.2% level of polymorphism was found. The phenogram obtained showed between 74% and 96% genetic similarity among all cassava accessions analysed. The analysis permitted the unique identification of each individual. Two Xam strains were used for resistance screening. Variation in the reaction of cassava varieties to Xam strains was observed for all plant accessions. The correlation of resistance to both strains, had a coefficient of 0.53, suggesting the independence of resistance to each strain. Multiple correspondence analysis showed a random distribution of the resistance/susceptibility response with respect to overall genetic diversity as measured by AFLP analysis. A total heterozygosity index was calculated to determine the diversity within clusters as well as among them. Our results demonstrate that resistance to CBB is broadly distributed in cassava germplasm and that AFLP analysis is an effective and efficient means of providing quantitative estimates of genetic similarities among cassava accessions.Key words: amplified fragment length polymorphism, genetic base, resistance screening, Xanthomonas axonopodis pv. manihotis.

scholarly journals Prospection, Collecte, Nomenclature Paysanne Et Caracterisation Des Variables Qualitatives Des Varietes Locales De Maïs (Zea Mays L.) Cultivees En Cote d’Ivoire

2016 ◽  
Vol 12 (24) ◽  
pp. 298
Author(s):  
Hugues Annicet N’da ◽  
Louise Akanvou ◽  
Arsène Irié Bi Zoro
Keyword(s):  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Cote D’Ivoire ◽  
Ecological Zones ◽  
Côte D'ivoire ◽  
Maize Varieties ◽  
Maize Landraces ◽  
Passport Data ◽  
Agro Ecological Zones

Ivoirian landraces of maize were maintained for several centuries in different ecological conditions, which allowed them to accumulate a large genetic diversity yet little studied. This study aims to make a first inventory of the existing diversity and establish a representative collection of the diversity of this crop in Côte d’Ivoire. Surveys and collection of maize landraces were conducted in three agro-ecological zones of Côte d'Ivoire. Two hundred and forty seven villages were selected and prospect in twentyfour regions. In each village, passport data were collected using the tools and methods of participatory research. A sample of 829 maize accessions were collected. The preliminary characterization of this collection was performed based on the descriptors of maize developed by Bioversity International. The study revealed a significant varietal diversity. Five varieties have been identified based on the color of the grains: yellow maize, white maize, red maize, purple maize and variegated maize. Varieties with yellow grain, with a percentage of 54.16% have been the most prevalent in different areas surveyed. Varieties with purple and red grain have been rare, with respective numbers of 3.38 and 3.62%. Interviews conducted with producers have permitted to inventory 81 local names. The main criteria of farmers to characterize local ecotypes was grains color. The collected accessions are an important gene pool for the present and future generations in the context of plant breeding work.

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