Variability in cooking time, iron and zinc content in common bean (Phaseolus Vulgaris L.) genotypes

Prolonged cooking time leads to structural changes at the grain cellular level, resulting in loss of nutrients such as iron (Fe) and zinc (Zn) which are among the main nutrients important in addressing micronutrient malnutrition. The aim of this study was to evaluate the diversity of cooking time, Fe and Zn content in a total of 152 common bean (Phaseolus vulgaris) genotypes from around Eastern Africa, in order to identify short cooking genotypes with high Fe and Zn content. Field trials were conducted at CIAT-Uganda research station over two seasons in 2016. Cooking time was estimated using an automated Mattson cooker at CIAT-Uganda while Fe and Zn content was determined using XRF analysis at Rwanda Agricultural Board (RAB) in Rubona. A wide variability was evident from the test genotypes both for cooking time and mineral concentration. Cooking time exhibited a continuous distribution ranging from 35-100 minutes for the first season and 43–122 minutes for the second season. Seventy-three percent of the test genotypes had Fe levels higher than the low Fe check, CAL 96 (55mg/kg) which is popularly known as ‘Nambale’ and a popular commercial variety in Uganda. A total of 15 genotypes (Amahunja, Awash melka, Bihogo, CAB 2, ECAPAN021, G858, Icaquimbaya, KK20, NABE12C, NABE4, NABE6, ROBA-1, RWR1873, RWV3006) were consistent in short cooking time for the two seasons and had a Fe content above the low Fe check (CAL96 – 55mg/kg). A high correlation (r = 0.71) was observed between Fe and Zn whereas a low correlation between cooking time and Fe (r = -0.04) and Zn (r = 0.04) was observed. Great variability was evident for both traits indicating possible improvement by breeding and thus the possibility of having short cooking common bean genotypes with high Fe and Zn content

Prevalence of viruses infecting cowpea in Uganda and their molecular detection

The main areas for cowpea cultivation in Uganda were surveyed in June and October 2006 for viruses affecting the crop. Seed and leaf samples from symptomatic and asymptomatic plants were collected from farmers’ fields and analysed for infecting viruses using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The viruses detected in the leaf and seed samples were: cucumber mosaic cucumovirus (CMV), cowpea mild mottle calarvirus (CPMMV), cowpea mottle carmovirus (CPMoV), Cowpea chlorotic mottle bromovirus (CCMV), Cowpea yellow mosaic comovirus (CYMV), cowpea severe mosaic comovirus (CPSMV), cowpea aphid-borne mosaic potyvirus (CABMV) and Southern bean mosaic sobemovirus (SBMV). CPMV was detected only in leaf samples. CMV and CABMV were later confirmed using reverse transcription polymerase chain reaction (RT-PCR). Of the viruses detected in leaf samples, 53.26% occurred as single infections, 24.46% dual and 22.28% multiple infections. Similarly, analysis of seed samples revealed infection of 40.6, 34.6 and 24.8% for single, dual and multiple infections, respectively. Multiple virus infections were associated with more disease severity and higher yield losses. The seed transmission levels of 23.0, 20.3 and 16.4% were recorded for CMV, CPMMV and CABMV, respectively. This study identified six more viruses in addition to what was previously reported in the country, of which eight were seed-borne. This necessitates the need for the production and use of virus-free seeds, development of virus resistant genotypes and adoption of efficient seed certification systems.Keywords: Vigna unguiculata, disease incidence, seed-borne viruses, ELISA, (RT-PCR

Comparing the efficiency of base and multiplicative selection indices for yield and quality traits in Cassava: Article Retracted by the Authors

The efficiency of two selection indices; base index and the multiplicative index was compared to determine the effectiveness of each in identifying superior genotypes in cassava (Manihot esculent Crantz) population. Genotypic data on various yield and quality traits among 570 cassava genotypes were used to construct these selection indices. The efficiency of these indices was compared by determining the performance means of each genotype for studied traits and computing selection differentials of each index. Best linear unbiased predictions (BLUPs) for dry matter content and harvest index were also used for comparison of the two selection indices.  The base index produced high-performance means of all five studied traits and proved to be more efficient compared to the multiplicative index in the improvement of cassava genotypes. In addition, the base index produced high selection differentials for three out of five studied traits. It was concluded that the base index is useful in cassava germplasm selectio

Magnitude of genotype x environment interaction for bacterial leaf blight resistance in rice growing areas of Uganda

Bacterial leaf blight (BLB) of rice ( Oryzae sativa L.), caused by Xanthomonas oryzae pv. oryzae, is a major constraint in most lowland rice producing areas of Uganda. The disease is widely distributed in all irrigated and rainfed lowland rice ecosytems in the country. The pathogen (Xoo) is highly variable and its control is rather difficult. Development and deployment of host resistance is the only effective means of BLB management. The objective of this study was to determine the magnitude of genotype by environment (G x E) interaction for resistance to bacterial leaf blight in rice in Uganda. A study comprised of two sets of germplasms, a total of 30 rice genotypes comprising of 13 lines with varying levels of BLB resistance, and 17 F4 lines that had been previous generated through crossing 7 parental lines, and then advanced in bulk from F1, was conducted in Namulonge-Wakiso, Olweny-Lira and Kibimba- Bugiri districts in Uganda. The study also included 7 parental lines and 6 popular varieties used in most farmers\u2019 fields. Variety IR 24 had been used as a universal check against BLB in Asian rice populations. Results revealed differential reactions on a set of near isogenic lines in the background of IR24, and some national and regional cultivars. IRBB1 (Xa1), IRBB2 (Xa2) and IRBB14 (Xa14) showed moderate susceptibility to susceptibility towards field pathogen populations in the three locations. Whereas genotype IRBB4 with gene Xa4 differentiated pathotypes of Kibimba and Lira from that of Namulonge, IRBB10 (Xa10) and IRBB11 (Xa11) differentiated pathotypes of Lira from the rest. Genotypes that had been pyramided with BLB genes of resistance, showed similar reactions to the three field populations. Generally, the near isogenic lines IRBB1, IRBB2, IRBB11 and IRBB14, had the highest leaf area damaged by disease attack. The highest was shown by IRBB11 with the Kibimba pathotypes for which disease attack was 43%. Low attack was observed on pyramided genotypes in all locations and two with single gene, i.e. IRBB8 and IRBB21, respectively. Interestingly, IR24 was as resistant as any of the pyramided combinations. Results also revealed different reactions of the tested genotypes in the three locations. The analysis of variance by AMMI partitioned the main effects of treatments into genotype, environment, and genotype x environment (G x E) interactions. Results also revealed that, the mean sum of squares due to treatments, genotypes, environments and genotype x environment interaction were significant, and contributed 48.2, 15.3, 19.3 and 13.3%, respectively, PCA1 accounted for 73.02% of the total G x E sum of squares.La br\ufblure foliaire bact\ue9rienne (BLB) est caus\ue9e chez le riz ( Oryzae sativa L.) par Xanthomonas oryzae pv. oryzae qui est un probl\ue8me majeur dans la plupart des basfonds ou on produit le riz en Ouganda. La maladie est largement r\ue9pandue dans tous les \ue9cosyst\ue8mes ou le riz est produit, soit par irrigation ou par les pluies. L\u2019agent pathog\ue8ne (Xoo) pr\ue9sente une tr\ue8s grande diversification, et tr\ue8s difficile a Controller. Le d\ue9veloppement et d\ue9ploiement d\u2019h\uf4tes r\ue9sistants est le seul moyen efficace pour le control du BLB. La pr\ue9sente \ue9tude visait \ue0 d\ue9terminer l\u2019effet de l\u2019interaction g\ue9notype-environnement (GxE) sur la r\ue9sistance \ue0 la bact\ue9rie de brulure foliaire chez le riz en Ouganda. Une exp\ue9rimentation a \ue9t\ue9 conduite sur 30 g\ue9notypes de riz, dont 13 lign\ue9es avec des niveaux de r\ue9sistance vari\ue9s \ue0 BLB et 17 lign\ue9es F4 g\ue9n\ue9r\ue9es en croissant 7 lign\ue9es parentales dont les F1 ont \ue9t\ue9 avances a Namulonge-Wakiso, Olweny-Lira et Kibimba- Bugiri en Ouganda. L\u2019\ue9tude a aussi pris en compte 7 lign\ue9es parentales et 6 vari\ue9t\ue9s populaires utilis\ue9es dans la plupart des champs. La vari\ue9t\ue9 IR 24 a \ue9t\ue9 utilis\ue9e comme r\ue9f\ue9rence universelle r\ue9sistante au BLB dans les populations de riz asiatiques. Les r\ue9sultats ont r\ue9v\ue9l\ue9 des r\ue9actions diverses sur une s\ue9rie de lign\ue9es isog\ue9niques par rapport \ue0 IR24, et quelques accessions nationales et r\ue9gionales. IRBB1 (Xa1), IRBB2 (Xa2) et IRBB14 (Xa14) se sont montre peu ou tr\ue8s susceptibles au BLB dans les trois localit\ue9s. Tandis que le g\ue9notype IRBB4 qui porte le g\ue8ne Xa4 a r\ue9agi de fa\ue7on diff\ue9rente vis \ue0 vis des pathotypes de Kibimba et de Lira compare \ue0 ceux de Namulonge, IRBB10 (Xa10) et IRBB11 (Xa11) ont diff\ue9renci\ue9 les pathotypes de Lira par rapport au reste. Les g\ue9notypes portant des cumuls de g\ue8nes de r\ue9sistance ont exhibes des r\ue9actions identiques dans toutes les trois populations. G\ue9n\ue9ralement, les lign\ue9es presque isog\ue9niques IRBB1, IRBB2, IRBB11 et IRBB14, ont pr\ue9sent\ue9 les pourcentages les plus \ue9lev\ue9s de dommages foliaires. Les dommages les plus importants \ue9taient observ\ue9s chez IRBB11 en contact avec les pathotypes de Kibimba, pour lesquels on a not\ue9 43% d\u2019attaque foliaire. Dans toutes les localit\ue9s, les d\ue9g\ue2ts \ue9taient mod\ue9r\ue9s sur les g\ue9notypes \ue0 plusieurs g\ue8nes de r\ue9sistance et deux avec un seul g\ue8ne. Par exemple, IRBB8 et IRBB21, respectivement. Fort heureusement, IR24 \ue9tait autant r\ue9sistant que tous les autres g\ue8nes cumul\ue9s. Il a \ue9t\ue9 aussi observe que les r\ue9actions sur les g\ue9notypes testes varient d\u2019une location a une autre. L\u2019analyse de variance par AMMI a partitionne les effets des traitements en effet dus aux g\ue9notypes, a l\u2019environnement et a leur interaction. Aussi, il a \ue9t\ue9 observe que les sommes des carr\ue9s moyens due au traitements, g\ue9notypes, environnement et interaction g\ue9notype-environnement, \ue9taient significatives et contribuent respectivement 48.2, 15.3, 19.3 et 13.3% a la variation totale. L\u2019axe PCA1 a expliqu\ue9 73.02% de la variation totale due \ue0 l\u2019interaction G x E

Genetic progress achieved in bean breeding in Uganda

Several cultivars of common bean (Phaseolus vulgaris L.) have been released in Uganda over a period of five decades, but the genetic gain to selection in respect of yield and agronomic characteristics has not been determined. This study was conducted to estimate the gain in selection over the 1960 - 2016 period, of common bean breeding in Uganda. Twenty nine bush and eleven climbing type cultivars were evaluated for yield and yield components, in three locations, during 2017B and 2018A cropping seasons. The study was carried out at the National Crop Resources Research Institute (NaCCRI), Nakabango Research Institute in central and Kwachwekano Zonal Agriculture Research Institute in southwestern Uganda. The design used was a randomised complete blocks with three replicates for the climbing types; and a 3x10 Alpha lattice design with three replicates for bush types. Significant differences (P<0.001) were recorded among cultivars for most traits in both bush and climbers, except seed number per pod (NSP). The range of genetic gain in grain yield was between 1,505 to 2,418 kg ha-1 for bush type cultivars, and 1,641 to 2,687 kg ha-1 for the climbing types. Yield has increased by16.3 and 26.3 kg ha-1 per year for bush and climbers, respectively; with a relative gain of 1.27%/year for bush types and 1.54%/year for the climbing types. Biomass yield and harvest index explained most of the variation in grain yield and number of pods per plant in climbing types. Among climbing types, biomass yield was significantly and positively correlated with grain yield per plant and grain yield per ha (P<0.05, and r= 0.87) and with grain yield per ha (P<0.01 r = 0.98) for bush types, biomass yield was significantly and positively correlated with grain yield per plant (P<0.05, and r= 0.59) and with grain yield per ha (P<0.01 r = 0.80) and harvest index (P<0.5 r = 0.80)

PREVALENCE OF ANGULAR LEAF SPOT DISEASE AND SOURCES OF RESISTANCE IN COMMON BEAN IN EASTERN DEMOCRATIC REPUBLIC OF CONGO

Angular leaf spot ( Pseudocercospora griseola Crous U, Brown) is one of the most important diseases hindering common bean ( Phaseolus vulgaris L.) production in the Great Lakes Region of Africa, including the Democratic Republic of Congo. The disease causes extreme yield losses, estimated at 384.2 tonnes per year, in Sub-Saharan Africa. Little is known about the distribution, severity and incidence of the disease and the effect of agronomic practices and environmental factors on the disease prevalence in the country to facilitate interventions. A field survey was conducted during two crop seasons, February to June and September to January, in two main beans growing zones of eastern DRC namely; sub-humid highland and sub-humid mid altitude at low latitudes, in South and North Kivu, respectively. Severity and incidence of angular leaf-spot and other occurring diseases were assessed on common bean plants in farmers\u2019 fields. Angular leaf spot in these fields had an average severity index (PSI) of 49.9%. PSI was significantly different (P<0.05) between districts and seasons. Using multiple regression analysis, independent variables: growth stage, cropping system, districts and altitude were shown to have significant influence on the observed PSI (P<0.05) with R2 = 96.2%. The highest severity (PSI=59.7%) was observed in Kabare district, and the lowest in Uvira district (PSI=39.5%). Screening of a set of 37 released common bean varieties in DRC using virulent Andean and Mesoamerican isolates identified four resistant bean varieties; ARA 4, COD MLV 059, MLV 224/94B, LSA 144 and Mexico 54. Some of these varieties possess useful traits, in addition to acceptable seed market class, and are hence recommended as suitable parents for ALS resistant variety development and promotion in ALS prone environments.La tache angulaire ( Pseudocercospora griseola Crous U, Brown) est l\u2019une des maladies les plus importantes qui entravent la production de haricot commun ( Phaseolus vulgaris L.) dans la r\ue9gion des Grands Lacs d\u2019Afrique, y compris la R\ue9publique D\ue9mocratique du Congo. La maladie provoque des pertes de rendement extr\ueames, estim\ue9es \ue0 384.2 tonnes par an en Afrique Sub-Saharienne. Ily a encore peu de connaissance sur la distribution, la gravit\ue9 et l\u2019incidence de la maladie et l\u2019effet des pratiques agronomiques et des facteurs environnement aux sur la pr\ue9valence de la maladie dans le pays pour faciliter les interventions. Une enqu\ueatesur le terrain a \ue9t\ue9men\ue9e pendant deux saisons de r\ue9colte, de F\ue9vrier \ue0 Juin et de Septembre \ue0 janvier, dans deux zones principals de culture de haricots de l\u2019est de la RDC, \ue0 savoir: Sous-humides de haute altitude et sous-humides \ue0 basse altitude, au Sud et au Nord-Kivu. La gravit\ue9 et l\u2019incidence de la tache angulaire des feuilles et d\u2019autres maladies ont \ue9t\ue9 \ue9valu\ue9es sur les plants de haricots dans les champs des agriculteurs. Ces champs \ue9taient infest\ue9s par la maladie, avec unindice de gravit\ue9 moyen (IPS) de 49.9%. PSI \ue9tait significativement diff\ue9rent (P <0.05) entre districts et saisons. En utilisant l\u2019analyse de r\ue9gression multiple, les variables ind\ue9pendantes: stade de croissance, syst\ue8me de culture, districts et altitude ont montr\ue9 une influence significative sur le PSI observ\ue9 (P <0.05) avec R2 = 96.2%. La s\ue9v\ue9rit\ue9 plus \ue9lev\ue9e (PSI = 59.7%) a \ue9t\ue9 observ\ue9e dans le district de Kabare et la plus faible dans le district d\u2019Uvira (PSI = 39,5%). La s\ue9lection d\u2019un lot de 37 vari\ue9t\ue9s de haricot distribu\ue9es en RDC utilisant des isolats virulents Andins et M\ue9soam\ue9ricains a permis d\u2019identifier quatre vari\ue9t\ue9s de haricots r\ue9sistants; ARA 4, COD MLV 059, MLV 224 / 94B, LSA 144 et Mexique 54. Certaines de ces vari\ue9t\ue9s pr\ue9sentent des traits utiles en plus de son acceptabilit\ue9 sur lemarch\ue9 des semences, et sont donc recommand\ue9s comme des parents appropri\ue9s pour le d\ue9veloppement et la promotion des vari\ue9t\ue9s r\ue9sistantes ALS

Characterization of elite maize inbred lines for drought tolerance using Simple Sequence Repeats markers

The development of drought tolerant maize has been limited by the suggested complexity of the environment on drought phenotypic traits. However, some simple sequence repeats (SSRs) molecular markers linked to drought tolerance via quantitative trait loci (QTL) have been identified in maize but their use requires validation on newly developed elite maize inbred lines. This study therefore aims to validate 19 selected SSR markers linked to maize drought tolerance and determine the genetic diversity of sixty-eight elite maize inbred lines. Genomic DNA was extracted with a CTAB method and the PCR products were separated on agarose gel with auto radiograms visually scored for polymorphic bands to establish a data matrix. Assessment of the genetic links among the inbred lines was carried out using cluster analysis. The 68 maize inbred lines were clustered based on a matrix of genetic similarity Jaccard using the UPGMA algorithm. Some of the markers that were informative included P-bnlg238, Phi037, P-bnlg1179 and Umc2214 and these showed significant group differentiation among the inbred lines. Marker Umc1447, Umc1432 and Umc2359 were among the markers with monomorphic bands, while Phi034, Bnlg1074 and P-umc1542 showed no characterized bands. The polymorphism information content (PIC) value of the informative markers ranged from 0.13 (Bnlg434) to 0.76 (P-bnlg238). The cluster analysis classified the maize inbred lines into four groups based on the SSR data. The exploitation of information of genetic diversity among the inbred maize lines to develop drought tolerant hybrids is hereby discussed

Development, promotion and dissemination of improved Fusarium wilt resistant pigeon pea lines in drought prone areas of Uganda

Pigeon Pea (Cajanus cajan) remains a relatively untapped food legume crop in Uganda and in many parts of Africa mainly due to lack of promotion and availability of varieties that meet producer and consumers needs. The crop is a rich source of protein, fixes nitrogen in the soil and is tolerant to drought conditions. This makes it an ideal crop for the semi-arid areas of Africa. This project is using a participatory breeding approach to develop and promote consumer/market preferred pigeon pea varieties resistant to Fusarium wilt disease (Fusarium udum) and drought among farmers in northern Uganda. To do this, a collection of landraces and elite materials from Uganda, Malawi and ICRISAT is being screened for farmer desired qualities. Promising lines will be analyzed for performance under Fusarium wilt infection and drought, and thereafter selected lines will be entered into a breeding program. All research activities have been designed as part of two students' M.Sc. thesis research, involving a Ugandan and a Malawian studen

Feasibilty of zein proteins, simple sequence repeats and phenotypic traits for background selection in quality protein maize breeding

Widespread adoption of quality protein maize (QPM), especially among tropical farming systems has been slow mainly due to the slow process of generating varieties with acceptable kernel quality and adaptability to different agroecological contexts. A molecular based foreground selection system for opaque 2 (o2), the cause of enhanced lysine content in maize exists. Background selection systems albeit, are poorly developed in spite of the mapping of putative loci associated with kernel modification and knowledge on causes of modification. The aim of this study was to develop background selection systems for o2 introgression into locally adapted genotypes. Experiments were conducted at Makerere University Agricultural Research Institute, Kabanyolo (MUARIK), in Uganda on backcross progeny (BC1F1) and BC2F2), derived from a locally adapted line 136R and a QPM donor CML176. We tested the use of zein proteins known to influence modification as well as DNA markers and phenotypic descriptors as tools for background selection for recurrent parent genome and modifier loci in locally adapted maize genotypes. Simply inherited traits such as maize streak virus disease resistance were suitable for background selection. Other traits include plant and ear heights. The simple sequence repeats markers mapped to chromosomes 3, 5, 7, respectively and associated with quantitative trait loci (QTL) conditioning resistance in maize to grey leaf spot and anthesis to silking interval were suitable for assay of recurrent parent genome. The 27-kDa g zein protein levels was suitable for background selection for kernel modification. It should, however, be used along with other zeins such as the 22 kDa and 19 kDa zein proteins.L'adoption du ma\uefs de prot\ue9ne de qualit\ue9 (QPM), sp\ue9cialement parmi les syst\ue8mes culturaux tropicaux a \ue9t\ue9 lente principalement due au processus lent de g\ue9n\ue9ration de vari\ue9t\ue9s avec de grains acceptables de qualit\ue9 et d'adaptabilit\ue9 \ue0 diff\ue9rents contextes agro\ue9cologiques. Il existe une cause du contenu am\ue9lior\ue9 de la lysine dans le ma\uefs, un syst\ue8me bas\ue9 sur la s\ue9lection mol\ue9culaire opaque 2 (o2). Malgr\ue9 les syst\ue8mes de s\ue9lection de fond, ceux-ci sont pauvrement d\ue9velopp\ue9s en d\ue9pit du "mapping" du loci associ\ue9 avec la modification du grain et la connaissance sur les causes de modification. L'objet de cette \ue9tude \ue9tait de d\ue9velopper les syst\ue8mes de s\ue9lection de fond pour l'introgression o2 dans les g\ue9notypes localement adapt\ue9s. Des essais \ue9taient conduits sur la prog\ue9nie de "backcross" (BC1F1) et BC2F2), d\ue9riv\ue9s de lign\ue9es adapt\ue9es 136R et un QPM doneur CML176. Nous avons test\ue9 l'usage des prot\ue9ines z\ue9ines capables d'influencer de modifications des marqueurs d'ADN et descripteurs ph\ue9notypiques comme mat\ue9riel de s\ue9lection de fond pour parent de g\ue9nome recurrent et modifiant de loci dans les g\ue9notypes de ma\ubfs localement adapt\ue9s. Des traits simplement h\ue9rit\ue9s dont la r\ue9sistance \ue0 la maladie de virus de m\ue8che \ue9taient appropri\ue9s pour la s\ue9lection de fond. D'autres traits incluaient la hauteur de plants et la taille de l'\ue9pis. Les marqueurs SSR repr\ue9sent\ue9s sur les chromosomes 3,5,7, respectivement et associ\ue9s aux traits quantitatifs loci (QTL) conditionnant la r\ue9sistance dans le ma\ubfs \ue0 la maladie de t\ue2che grise de feuilles ansi que l'intervalle de l'anthesis jusqu'\ue0 la s\ue9cr\ue9tion du "silk" \ue9taient appropri\ue9s pour \ue9valuation du g\ue9nome parent recurrent. Les niveaux de prot\ue9ines z\ue9ines 27-kDa g \ue9taient appropri\ue9s pour la s\ue9lection de fond pour la modification de grains. Ceci pourra \ueatre utilis\ue9 \ue0 c\uf4t\ue9 d'autres z\ue9ines telles que les prot\ue9ines z\ue9ines 22 kDa et 19 kDa

EFFICIENT SCREENING PROCEDURE FOR BLACK SIGATOKA DISEASE OF BANANA

Current methods for screening for reaction of Mycosphaerella fijiensis are mostly field based and subject to variability caused by weather conditions. The objective of this study was to develop an efficient screening procedure for black sigatoka disease in order to provide a reliable controlled environment screening method. A fragmented mycelia-based infection system was developed using weighed mycelia suspensions, in 0.18% water agar. Consistent and repeatable black sigatoka infection was achieved in cv. Gross Michel as a reference susceptible cultivar. The infection system developed was used to validate screenhouse reaction of banana genotypes to M. fijiensis. Three East African highland genotypes (AAA-EA), one plantain genotype (ABB), two dessert (AAB and AAA) and one hybrid genotype (AAAA) were tested. Inoculum of M. fijiensis was adjusted to 15 mg ml-1 fragmented mycelium and applied to the abaxial surfaces of the first two open leaves. Plants were evaluated for 6 weeks post inoculation (PI). Significant differences in the response of the different genotypes, to M. fijiensis infection were observed at 3, 4, 5 and 6 weeks PI. All East African highland and dessert genotypes were susceptible. M9 hybrid and Psang awak (ABB) expressed resistance, characterised by high disease incubation period and slow rate of symptom development, with Psanag awak being the most resistant. Artificial inoculation of in vitro plants with weighed fragmented mycelial suspension, was practicable for determining resistance to M. fijiensis. This is the first report demonstrating that use of weighed fragmented mycelial inoculum spread over the entire leaf surface, can be used to quantitatively assess reaction of banana genotypes to M. fijiensis under screenhouse conditions.Les m\ue9thodes actuelles de d\ue9pistage de Mycosphaerella fijiensis sont essentiellement bas\ue9es sur des \ue9valuations dans le champ et sont souvent sujets \ue0 des variabilit\ue9s climatiques. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9velopper une proc\ue9dure efficace de d\ue9pistage de la maladie foliaire du bananier Sigatoka dans le but de proposer une m\ue9thode de d\ue9pistage non influenc\ue9e par l\u2019environnement. Un syst\ue8me d\u2019infection a \ue9t\ue9 d\ue9velopp\ue9 en se servant de myc\ue9lium en suspension dans 0,18% de solution agar. Des infections consistantes et r\ue9p\ue9t\ue9es ont \ue9t\ue9 r\ue9alis\ue9es in cv. La vari\ue9t\ue9 Gross Michel a \ue9t\ue9 utilis\ue9e comme r\ue9f\ue9rence susceptible. Le syst\ue8me d\u2019infection d\ue9velopp\ue9 a \ue9t\ue9 utilis\ue9 pour valider la r\ue9action des accessions de bananiers en serre \ue0 M. fijiensis. Trois g\ue9notypes de bananiers adapt\ue9s aux hautes altitudes en Afrique de l\u2019Est (AAA-EA), un g\ue9notype de type plantain (ABB), deux d\ue9serts (AAB and AAA) et un hybride (AAAA) ont \ue9t\ue9 test\ue9s. Des inocula de M. fijiensis ont \ue9t\ue9 doses \ue0 15 mg ml-1 et appliqu\ue9s sur la face dorsale des deux premi\ue8res feuilles ouvertes. Les plants ont \ue9t\ue9 \ue9valu\ue9s pendant 6 semaines apr\ue8s inoculation (PI). Des diff\ue9rences significatives ont \ue9t\ue9 observ\ue9es dans les r\ue9ponses des g\ue9notypes \ue0 l\u2019infection \ue0 diff\ue9rents stages apr\ue8s inoculation (3, 4,5 et 6 semaines) de M. fijiensis. Tous les g\ue9notypes de haute altitude et les d\ue9serts ont \ue9t\ue9 r\ue9v\ue9l\ue9s susceptibles. L\u2019hybride M9 et Psang awak (ABB) se sont montr\ue9s r\ue9sistants, ils sont caract\ue9ris\ue9s par une longue p\ue9riode d\u2019incubation et un taux bas de d\ue9veloppement de sympt\uf4mes, Psanag awak s\u2019est r\ue9v\ue9l\ue9 le plus r\ue9sistant. L\u2019inoculation artificielle in vitro des plants avec des suspensions de fragments myc\ue9liens, a \ue9t\ue9 pratique dans la d\ue9termination de la r\ue9sistance \ue0 M. fijiensis. Ceci est le premier r\ue9sultat d\u2019\ue9tude scientifique ayant d\ue9montr\ue9 que cette technique peut \ueatre utilis\ue9e pour l\u2019\ue9valuation de la r\ue9action des g\ue9notypes de bananiers \ue0 l\u2019infection de M. fijiensis dans des conditions d\u2019exp\ue9riences en serre.