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

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.

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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

Plant Pathology Journal ◽

10.3923/ppj.2017.1.11 ◽

2017 ◽

Vol 16 (1) ◽

pp. 1-11 ◽

Cited By ~ 4

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

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QTL identification for cassava bacterial blight resistance under natural infection conditions

Acta Biológica Colombiana ◽

10.15446/abc.v22n1.57951 ◽

2017 ◽

Vol 22 (1) ◽

pp. 19 ◽

Cited By ~ 2

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.

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Prevalence and Distribution of Cassava Bacterial Blight in the Kenyan Coast

Agricultural Science ◽

10.30560/as.v3n1p7 ◽

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.

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Detection of Xanthomonas axonopodis pv. manihotis, the causal agent of cassava bacterial blight diseases in cassava (Manihot esculenta) in Ghana by polymerase chain reaction

European Journal of Plant Pathology ◽

10.1007/s10658-017-1297-3 ◽

2017 ◽

Vol 150 (2) ◽

pp. 471-484

Author(s):

Muntala Abdulai ◽

Hüseyin Basım ◽

Esin Basım ◽

Derya Baki ◽

Nurhan Öztürk

Keyword(s):

Polymerase Chain Reaction ◽

Manihot Esculenta ◽

Bacterial Blight ◽

Causal Agent ◽

Chain Reaction ◽

Cassava Bacterial Blight ◽

Xanthomonas Axonopodis ◽

Polymerase Chain

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ANALYSIS OF GENETIC DIVERSITY OF 26 CASSAVA VARIETIES (Manihot esculenta CRANTZ) WITH DIFFERENT RESPONSES TO WATERLOGGING CONDITIONS BY USING RAPD MARKERS

Journal of Science Natural Science ◽

10.18173/2354-1059.2021-0058 ◽

2021 ◽

Vol 66 (3) ◽

pp. 170-179

Author(s):

Sengsoulichan Dethvongsa ◽

Vu Nguyen Anh ◽

Van Tran Khanh

Keyword(s):

Genetic Diversity ◽

Phylogenetic Tree ◽

Manihot Esculenta ◽

Rapd Markers ◽

Flood Tolerance ◽

Randomly Amplified Polymorphic Dna ◽

Manihot Esculenta Crantz ◽

Rapd Pcr ◽

Cassava Production ◽

Cassava Varieties

RAPD (Randomly Amplified Polymorphic DNA) is an indicator for high and stable polymorphism, widely used in the study of the diversity of cassava. In this paper, the results of using 20 polymorphic primers OPK combined with the establishment of the phylogenetic tree to analyze the genetic diversity of 26 cassava varieties with different responses to waterlogging conditions by using the RAPD-PCR technique were presented. The purpose of this experiment was to show the genetic relevance of the studied cassava varieties. The results showed that the flood tolerance of cassava was not related to the polymorphism and branching characteristics of the stem. This information may be use as a basis for selecting flood-tolerant cassava varieties for cassava production, as well as the basis for selecting genetically different parents for breeding.

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