Amani Michel Kouakou - Academia.edu (original) (raw)

Papers by Amani Michel Kouakou

Research paper thumbnail of Identification and validation of QTLs for tuber quality related traits in yam <i>Dioscorea alata</i>

Acta horticulturae, Mar 1, 2023

Research paper thumbnail of Sweetpotato Cultivation: Characteristics, Constraints and Preferred Traits of Producers and Consumers in Côte d'Ivoire

Journal of the Science of Food and Agriculture, Aug 13, 2023

Research paper thumbnail of Quantitative trait loci and candidate genes for physico‐chemical traits related to tuber quality in greater yam (Dioscorea alata L.)

Journal of the Science of Food and Agriculture

BACKGROUNDStarch, dry matter content (DMC), proteins, and sugars are among the major influences o... more BACKGROUNDStarch, dry matter content (DMC), proteins, and sugars are among the major influences on yam tuber quality. Genetic improvement programs need simple, rapid, and low‐cost tools to screen large populations. The objectives of this work were, using a quantitative trait loci mapping approach (QTL) on two diploid full‐sib segregating populations, (i) to acquire knowledge about the genetic control of these traits; (ii) to identify markers linked to the genomic regions controlling each trait, which are useful for marker‐assisted selection (MAS); (iii) to validate the QTLs on a diversity panel; and (iv) to identify candidate genes from the validated QTLs.RESULTSHeritability for all traits was moderately high to high. Significant correlations were observed between traits. A total of 25 QTLs were identified, including six for DMC, six for sugars, six for proteins, and seven for starch. The phenotypic variance explained by individual QTLs ranged from 14.3% to 28.6%. The majority of QT...

Research paper thumbnail of Agronomic evaluation sweet potato (Ipomoea batatas (L) Lam.) genotypes in two agro-ecological zones of Côte d’Ivoire

World Journal of Advanced Research and Reviews

The sweetpotato is the seventh most important crop in the world after wheat, rice, maize, potato,... more The sweetpotato is the seventh most important crop in the world after wheat, rice, maize, potato, barley and cassava. It is produced annually in all regions of Côte d'Ivoire. Sweetpotato plays a role in food security and income generation for rural populations. However, the crop is facing the challenges of climate change leading to a decline in yields of local cultivars. This phenomenon leads to unproductive soils and the abandonment of many crops, including sweetpotato. To address this problem, 15 sweetpotato genotypes from the CNRA and from farmers were evaluated in two agro-ecological zones on the basis of agronomic parameters. Descriptive analysis of the data showed a variation in the agronomic performance of the genotypes from one zone to another. Thus, in Kounontonvogo, yields varied from 3.81 to 30.41 t/ha. The genotypes Irene, CIP-199062-1, TIB-440060 and Fatoni 2 had the best agronomic performance. On the other hand, at CNRA Station, the cultivar Sanfo figui 1 showed a ...

Research paper thumbnail of Vegetative growth and monitoring of diseases and pests of cassava (Manihot esculenta Crantz) hybrids

Agricultural and Food Science Journal of Ghana, 2018

Research paper thumbnail of STABILITY STUDY OF SOME CASSAVA (Manihot esculenta Crantz) VARIETIES RELATIVE TO THE HARVEST PERIOD IN CÔTE D’IVOIRE

Cassava (Manihot esculenta Crantz) is the second largest food crops in Cote d’Ivoire after yam, w... more Cassava (Manihot esculenta Crantz) is the second largest food crops in Cote d’Ivoire after yam, with annual production of 4.2 million tons in 2014. It is both a subsistence crop and income for producers. However, climate hazards and the harvest period influence the yield and quality (dry matter content and starch content) tuberous roots. In addition, assessment of varieties for starch, a very marketable product, was not yet completed. In this context, the study relating to the determination of stable cassava varieties for yield, the dry matter content and the starch content were made from 2007 to 2008. The plant material is composed of 30 cassava varieties. The stability parameters used in eight (8) environments (4 harvest dates combined with two years) are those of Francis and Kannenberg. The harvest date had a significant effect on tuberous root parameters. The harvest at 12 months yielded the best compromise between yield, dry matter content, starch content and time. The stable c...

Research paper thumbnail of Characterization of yam land races in Côte d'Ivoire with respect to food quality and end uses

Journal of Applied …

... International Journal of Poultry Science 7 (5): 474-479. Ashay AO, Fasoyiro SB, Lawal OR, 200... more ... International Journal of Poultry Science 7 (5): 474-479. Ashay AO, Fasoyiro SB, Lawal OR, 2001. Effect of fortification on the compositional and sensory attributes of cowpea-amala. Nutrition & Food Science 31: 88-91. Attaie H, Zakhia N, Bricas N, 1998. ...

Research paper thumbnail of Identification and validation of QTLs for tuber quality related traits in greater yam (Dioscorea alata L.)

Scientific Reports, May 19, 2022

Research paper thumbnail of Development of NIRS and molecular marker to improve breeding efficiency in Greater Yam (Dioscorea alata L.) for key quality traits. ABB1103

Yams (Dioscorea sp.) are important food security crops in tropical and subtropical regions. Diosc... more Yams (Dioscorea sp.) are important food security crops in tropical and subtropical regions. Dioscorea alata, also known as greater yam, is one of the major cultivated species and most widely distributed throughout the tropics. The quality of tubers depends on many internal characters that determine their culinary and nutritional value (e.g., starch content, sugars, dry matter) and some external characteristics (e.g., shape). Conventional breeding for quality traits is essentially carried out based on phenotypic observations and it's difficult, costly and lengthy process. Thus, to facilitate breeding for different quality traits, we are developing different tools including NIRS (Near Infrared Spectroscopy) and molecular markers. The feasibility of use NIRS to predict some physico-chemical (dry matter content, starches, sugars, proteins) and textural characteristics (e.g. hardness, springiness, adhesiveness), is being tested on a panel of 27 contrasted accessions. Also a QTL appro...

Research paper thumbnail of Breeding for improved tuber quality in greater yam (Dioscorea alata L.)

Research paper thumbnail of Detection and diversity of viruses infecting African yam ( Dioscorea rotundata ) in a collection and F 1 progenies in Côte d'Ivoire shed light to plant‐to‐plant viral transmission

Research paper thumbnail of A review of varietal change in roots, tubers and bananas: consumer preferences and other drivers of adoption and implications for breeding

International Journal of Food Science & Technology

This review of the literature on varietal change in sub-Saharan Africa looks in detail at adoptio... more This review of the literature on varietal change in sub-Saharan Africa looks in detail at adoption of new varieties of bananas in Uganda, cassava in Nigeria, potato in Kenya, sweetpotato in Uganda and yams in Côte d'Ivoire. The review explored three hypotheses about drivers of varietal change. There was a strong confirmation for the hypothesis that insufficient priority given to consumer-preferred traits by breeding programmes contributes to the limited uptake of modern varieties (MVs) and low varietal turnover. Lack of evidence meant the second hypothesis of insufficient attention to understanding and responding to gender differences in consumer preferences for quality and post-harvest traits was unresolved. The evidence on the third hypothesis about the informal seed system contributing to slow uptake of MVs was mixed. In some cases, the informal system has contributed to rapid uptake of MVs, but often it appears to be a barrier with inconsistent varietal naming a major challenge.

Research paper thumbnail of Dichotomous key determining varietal groups of yam species Dioscorea alata L

Greener Journal of Agricultural Sciences, 2015

Dichotomous key determining varietal groups of yam species Dioscorea alata L.

Research paper thumbnail of Effect of chemical fertilization on yam preservation in Côte d’Ivoire

Cahiers Agricultures, 1997

An opinion that is widely held by African farmers is that chemical fertilization jeopardizes yam ... more An opinion that is widely held by African farmers is that chemical fertilization jeopardizes yam storage, increasing losses due to spoiling. This problem has not yet been seriously addressed, so the IDESSA outpost in Bouake decided to study it more closely through a series of repeated tests during four successive campaigns from 1985 to 1988. In 1988, the study became more complex by including yams from two different planting periods. Two species that are widely cropped in Cote d’Ivoire were studied simultaneously, Dioscorea alata (cvs Yellow Lisbon and Florido) and D. cayenensis rotundata (cv Krengle). The yam cropfields were fertilized with mineral manure, i.e. 75 N-54 P2O5-94 K2O/ha, and the yams produced were compared with those obtained without fertilizer. Observations in each case concerned a sample of about 220 yams, which were numbered and weighed individually at the start of the trial. This provided baseline numbers and weights that were used to evaluate subsequent losses. T...

Research paper thumbnail of Effect of chemical fertilizers on storage of yams in the Ivory Coast

Cahiers Agricultures, 1997

Research paper thumbnail of The emergence of a new yam variety of Dioscorea alata species, C18, in Côte d'Ivoire

Journal of Applied Biosciences, 2012

Research paper thumbnail of Agronomic Variability of the Sweet Potato Collection (Ipomoea batatas (L.) Lam.) from Côte d'Ivoire

International journal of sciences, 2020

Research paper thumbnail of Biotechnologies végétales et sécurité alimentaire en Afrique : cas des ignames

Cahiers Agricultures, 1999

En Afrique, la securite alimentaire demeure l’une des preoccupations majeures des autorites de ch... more En Afrique, la securite alimentaire demeure l’une des preoccupations majeures des autorites de chaque pays. Les methodes agricoles traditionnelles n’ayant pas permis d’obtenir la securite alimentaire, d’autres voies, comme celles des biotechnologies vegetales, sont envisagees pour atteindre l’objectif vise. Pour les ignames, diverses methodes sont utilisees : microbouturage, cultures de protoplastes, cytometrie en flux, biologie moleculaire (RFLP, RAPD-PCR, etc.), transformation genetique. La collaboration sous-regionale devrait permettre de realiser des fecondations in vitro, a partir des etudes cytogenetiques utilisant la cytometrie en flux, et une meilleure connaissance de la biologie florale. Eu egard aux problemes de biosecurite, la Convention sur la diversite biologique constitue un cadre ideal pour le controle des conditions d’utilisation et de transfert des biotechnologies, ainsi que pour la prevention des risques qui y sont associes.

Research paper thumbnail of Détermination de la période de récolte de huit variétés de patate douce (Ipomoea batatas L Convolvulaceae) à Bouaké au centre de la Côte d’Ivoire

Tropicultura, 2020

Afin de determiner une periode durant laquelle le rendement optimal est atteint avec des racines ... more Afin de determiner une periode durant laquelle le rendement optimal est atteint avec des racines tubereuses de qualite, une evaluation du rendement a ete menee sur quatre periodes de recoltes de patate douce a la Station de Recherche sur les Cultures Vivrieres du Centre National de Recherche Agronomique de Bouake. L’etude a porte sur huit varietes ameliorees de patate douce selon un dispositif en split plot avec pour facteur principal les varietes et pour facteur secondaire la periode de recolte. En general, les parametres mesures (l’indice de la maladie, la severite, le nombre de racines par plant - nombre de petites racines et nombre de grandes racines -) sont influences significativement par la variete a l’exception du rendement et des attaques de charancons et de rongeurs qui suivent la periode de recolte. La recolte faite a quatre mois apres la plantation a donne le meilleur rendement (12,64 t/ha) et les racines tubereuses les moins attaquees par les ravageurs (Incidence des ch...

Research paper thumbnail of Agronomic Characterization of 88 Accessions of the Sweet Potato (Ipomoea batatas (L.) Lam.) Collection of Côte d'Ivoire

The characterization of genetic resources is essential for improvement and conservation programs.... more The characterization of genetic resources is essential for improvement and conservation programs. The objective of this study was to study the morphological and agronomic variability of the sweet potato (Ipomoea batatas (L.) Lam.) collection of the Centre National de Recherche Agronomique (CNRA) of Côte d'Ivoire. The work was carried out with 88 accessions on the basis of 12 agronomic characters according to a Fisher design with two replicates. The correlations observed showed the degree of linkage between the traits. Principal component analysis revealed significant variability between individuals in the four groups formed (1.1, 1.2, 1.3, and 1.4). The most discriminating characters of sweet potato accessions were percentage of productive plants (PPPR), total number of storage roots (SRNU), total storage root weight (SRNU), storage root yield (SRYD), mosaic incidence (VIRD), weevil incidence (SRWE), nematode incidence (SRNE) and rodent incidence (SRRO). The hierarchical cluster...

Research paper thumbnail of Identification and validation of QTLs for tuber quality related traits in yam <i>Dioscorea alata</i>

Acta horticulturae, Mar 1, 2023

Research paper thumbnail of Sweetpotato Cultivation: Characteristics, Constraints and Preferred Traits of Producers and Consumers in Côte d'Ivoire

Journal of the Science of Food and Agriculture, Aug 13, 2023

Research paper thumbnail of Quantitative trait loci and candidate genes for physico‐chemical traits related to tuber quality in greater yam (Dioscorea alata L.)

Journal of the Science of Food and Agriculture

BACKGROUNDStarch, dry matter content (DMC), proteins, and sugars are among the major influences o... more BACKGROUNDStarch, dry matter content (DMC), proteins, and sugars are among the major influences on yam tuber quality. Genetic improvement programs need simple, rapid, and low‐cost tools to screen large populations. The objectives of this work were, using a quantitative trait loci mapping approach (QTL) on two diploid full‐sib segregating populations, (i) to acquire knowledge about the genetic control of these traits; (ii) to identify markers linked to the genomic regions controlling each trait, which are useful for marker‐assisted selection (MAS); (iii) to validate the QTLs on a diversity panel; and (iv) to identify candidate genes from the validated QTLs.RESULTSHeritability for all traits was moderately high to high. Significant correlations were observed between traits. A total of 25 QTLs were identified, including six for DMC, six for sugars, six for proteins, and seven for starch. The phenotypic variance explained by individual QTLs ranged from 14.3% to 28.6%. The majority of QT...

Research paper thumbnail of Agronomic evaluation sweet potato (Ipomoea batatas (L) Lam.) genotypes in two agro-ecological zones of Côte d’Ivoire

World Journal of Advanced Research and Reviews

The sweetpotato is the seventh most important crop in the world after wheat, rice, maize, potato,... more The sweetpotato is the seventh most important crop in the world after wheat, rice, maize, potato, barley and cassava. It is produced annually in all regions of Côte d'Ivoire. Sweetpotato plays a role in food security and income generation for rural populations. However, the crop is facing the challenges of climate change leading to a decline in yields of local cultivars. This phenomenon leads to unproductive soils and the abandonment of many crops, including sweetpotato. To address this problem, 15 sweetpotato genotypes from the CNRA and from farmers were evaluated in two agro-ecological zones on the basis of agronomic parameters. Descriptive analysis of the data showed a variation in the agronomic performance of the genotypes from one zone to another. Thus, in Kounontonvogo, yields varied from 3.81 to 30.41 t/ha. The genotypes Irene, CIP-199062-1, TIB-440060 and Fatoni 2 had the best agronomic performance. On the other hand, at CNRA Station, the cultivar Sanfo figui 1 showed a ...

Research paper thumbnail of Vegetative growth and monitoring of diseases and pests of cassava (Manihot esculenta Crantz) hybrids

Agricultural and Food Science Journal of Ghana, 2018

Research paper thumbnail of STABILITY STUDY OF SOME CASSAVA (Manihot esculenta Crantz) VARIETIES RELATIVE TO THE HARVEST PERIOD IN CÔTE D’IVOIRE

Cassava (Manihot esculenta Crantz) is the second largest food crops in Cote d’Ivoire after yam, w... more Cassava (Manihot esculenta Crantz) is the second largest food crops in Cote d’Ivoire after yam, with annual production of 4.2 million tons in 2014. It is both a subsistence crop and income for producers. However, climate hazards and the harvest period influence the yield and quality (dry matter content and starch content) tuberous roots. In addition, assessment of varieties for starch, a very marketable product, was not yet completed. In this context, the study relating to the determination of stable cassava varieties for yield, the dry matter content and the starch content were made from 2007 to 2008. The plant material is composed of 30 cassava varieties. The stability parameters used in eight (8) environments (4 harvest dates combined with two years) are those of Francis and Kannenberg. The harvest date had a significant effect on tuberous root parameters. The harvest at 12 months yielded the best compromise between yield, dry matter content, starch content and time. The stable c...

Research paper thumbnail of Characterization of yam land races in Côte d'Ivoire with respect to food quality and end uses

Journal of Applied …

... International Journal of Poultry Science 7 (5): 474-479. Ashay AO, Fasoyiro SB, Lawal OR, 200... more ... International Journal of Poultry Science 7 (5): 474-479. Ashay AO, Fasoyiro SB, Lawal OR, 2001. Effect of fortification on the compositional and sensory attributes of cowpea-amala. Nutrition & Food Science 31: 88-91. Attaie H, Zakhia N, Bricas N, 1998. ...

Research paper thumbnail of Identification and validation of QTLs for tuber quality related traits in greater yam (Dioscorea alata L.)

Scientific Reports, May 19, 2022

Research paper thumbnail of Development of NIRS and molecular marker to improve breeding efficiency in Greater Yam (Dioscorea alata L.) for key quality traits. ABB1103

Yams (Dioscorea sp.) are important food security crops in tropical and subtropical regions. Diosc... more Yams (Dioscorea sp.) are important food security crops in tropical and subtropical regions. Dioscorea alata, also known as greater yam, is one of the major cultivated species and most widely distributed throughout the tropics. The quality of tubers depends on many internal characters that determine their culinary and nutritional value (e.g., starch content, sugars, dry matter) and some external characteristics (e.g., shape). Conventional breeding for quality traits is essentially carried out based on phenotypic observations and it's difficult, costly and lengthy process. Thus, to facilitate breeding for different quality traits, we are developing different tools including NIRS (Near Infrared Spectroscopy) and molecular markers. The feasibility of use NIRS to predict some physico-chemical (dry matter content, starches, sugars, proteins) and textural characteristics (e.g. hardness, springiness, adhesiveness), is being tested on a panel of 27 contrasted accessions. Also a QTL appro...

Research paper thumbnail of Breeding for improved tuber quality in greater yam (Dioscorea alata L.)

Research paper thumbnail of Detection and diversity of viruses infecting African yam ( Dioscorea rotundata ) in a collection and F 1 progenies in Côte d'Ivoire shed light to plant‐to‐plant viral transmission

Research paper thumbnail of A review of varietal change in roots, tubers and bananas: consumer preferences and other drivers of adoption and implications for breeding

International Journal of Food Science & Technology

This review of the literature on varietal change in sub-Saharan Africa looks in detail at adoptio... more This review of the literature on varietal change in sub-Saharan Africa looks in detail at adoption of new varieties of bananas in Uganda, cassava in Nigeria, potato in Kenya, sweetpotato in Uganda and yams in Côte d'Ivoire. The review explored three hypotheses about drivers of varietal change. There was a strong confirmation for the hypothesis that insufficient priority given to consumer-preferred traits by breeding programmes contributes to the limited uptake of modern varieties (MVs) and low varietal turnover. Lack of evidence meant the second hypothesis of insufficient attention to understanding and responding to gender differences in consumer preferences for quality and post-harvest traits was unresolved. The evidence on the third hypothesis about the informal seed system contributing to slow uptake of MVs was mixed. In some cases, the informal system has contributed to rapid uptake of MVs, but often it appears to be a barrier with inconsistent varietal naming a major challenge.

Research paper thumbnail of Dichotomous key determining varietal groups of yam species Dioscorea alata L

Greener Journal of Agricultural Sciences, 2015

Dichotomous key determining varietal groups of yam species Dioscorea alata L.

Research paper thumbnail of Effect of chemical fertilization on yam preservation in Côte d’Ivoire

Cahiers Agricultures, 1997

An opinion that is widely held by African farmers is that chemical fertilization jeopardizes yam ... more An opinion that is widely held by African farmers is that chemical fertilization jeopardizes yam storage, increasing losses due to spoiling. This problem has not yet been seriously addressed, so the IDESSA outpost in Bouake decided to study it more closely through a series of repeated tests during four successive campaigns from 1985 to 1988. In 1988, the study became more complex by including yams from two different planting periods. Two species that are widely cropped in Cote d’Ivoire were studied simultaneously, Dioscorea alata (cvs Yellow Lisbon and Florido) and D. cayenensis rotundata (cv Krengle). The yam cropfields were fertilized with mineral manure, i.e. 75 N-54 P2O5-94 K2O/ha, and the yams produced were compared with those obtained without fertilizer. Observations in each case concerned a sample of about 220 yams, which were numbered and weighed individually at the start of the trial. This provided baseline numbers and weights that were used to evaluate subsequent losses. T...

Research paper thumbnail of Effect of chemical fertilizers on storage of yams in the Ivory Coast

Cahiers Agricultures, 1997

Research paper thumbnail of The emergence of a new yam variety of Dioscorea alata species, C18, in Côte d'Ivoire

Journal of Applied Biosciences, 2012

Research paper thumbnail of Agronomic Variability of the Sweet Potato Collection (Ipomoea batatas (L.) Lam.) from Côte d'Ivoire

International journal of sciences, 2020

Research paper thumbnail of Biotechnologies végétales et sécurité alimentaire en Afrique : cas des ignames

Cahiers Agricultures, 1999

En Afrique, la securite alimentaire demeure l’une des preoccupations majeures des autorites de ch... more En Afrique, la securite alimentaire demeure l’une des preoccupations majeures des autorites de chaque pays. Les methodes agricoles traditionnelles n’ayant pas permis d’obtenir la securite alimentaire, d’autres voies, comme celles des biotechnologies vegetales, sont envisagees pour atteindre l’objectif vise. Pour les ignames, diverses methodes sont utilisees : microbouturage, cultures de protoplastes, cytometrie en flux, biologie moleculaire (RFLP, RAPD-PCR, etc.), transformation genetique. La collaboration sous-regionale devrait permettre de realiser des fecondations in vitro, a partir des etudes cytogenetiques utilisant la cytometrie en flux, et une meilleure connaissance de la biologie florale. Eu egard aux problemes de biosecurite, la Convention sur la diversite biologique constitue un cadre ideal pour le controle des conditions d’utilisation et de transfert des biotechnologies, ainsi que pour la prevention des risques qui y sont associes.

Research paper thumbnail of Détermination de la période de récolte de huit variétés de patate douce (Ipomoea batatas L Convolvulaceae) à Bouaké au centre de la Côte d’Ivoire

Tropicultura, 2020

Afin de determiner une periode durant laquelle le rendement optimal est atteint avec des racines ... more Afin de determiner une periode durant laquelle le rendement optimal est atteint avec des racines tubereuses de qualite, une evaluation du rendement a ete menee sur quatre periodes de recoltes de patate douce a la Station de Recherche sur les Cultures Vivrieres du Centre National de Recherche Agronomique de Bouake. L’etude a porte sur huit varietes ameliorees de patate douce selon un dispositif en split plot avec pour facteur principal les varietes et pour facteur secondaire la periode de recolte. En general, les parametres mesures (l’indice de la maladie, la severite, le nombre de racines par plant - nombre de petites racines et nombre de grandes racines -) sont influences significativement par la variete a l’exception du rendement et des attaques de charancons et de rongeurs qui suivent la periode de recolte. La recolte faite a quatre mois apres la plantation a donne le meilleur rendement (12,64 t/ha) et les racines tubereuses les moins attaquees par les ravageurs (Incidence des ch...

Research paper thumbnail of Agronomic Characterization of 88 Accessions of the Sweet Potato (Ipomoea batatas (L.) Lam.) Collection of Côte d'Ivoire

The characterization of genetic resources is essential for improvement and conservation programs.... more The characterization of genetic resources is essential for improvement and conservation programs. The objective of this study was to study the morphological and agronomic variability of the sweet potato (Ipomoea batatas (L.) Lam.) collection of the Centre National de Recherche Agronomique (CNRA) of Côte d'Ivoire. The work was carried out with 88 accessions on the basis of 12 agronomic characters according to a Fisher design with two replicates. The correlations observed showed the degree of linkage between the traits. Principal component analysis revealed significant variability between individuals in the four groups formed (1.1, 1.2, 1.3, and 1.4). The most discriminating characters of sweet potato accessions were percentage of productive plants (PPPR), total number of storage roots (SRNU), total storage root weight (SRNU), storage root yield (SRYD), mosaic incidence (VIRD), weevil incidence (SRWE), nematode incidence (SRNE) and rodent incidence (SRRO). The hierarchical cluster...