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Cowpea is one of the most important crops in West Africa and is essential for the region’s food and nutrition security and economic development. Consequently, improving its agronomic performance and yield is a desirable goal. Brown blotch disease, caused by the fungal pathogen Colletotrichum capsici, is an important constraint of cowpea productivity, and at present, only limited genetic resources are available for breeding improved brown blotch-resistant varieties. The current study has characterized the genetic basis for brown blotch resistance conferred by the cowpea cultivar KN1 and identified a major dominant quantitative trait locus (QTL) for resistance on chromosome Vu02. A segregating F2 population (n = 200), derived from a cross between KN1 and brown blotch-susceptible Tiligre (KVx775-33-2G), was developed and scored for disease severity following controlled inoculation. A subset of the population (n = 94) was genotyped with 99 newly developed allele-specific polymerase chain reaction (AS-PCR) markers, and multiple interval mapping was performed. One major and three minor QTL were identified. This is the first reported mapping of QTL conferring resistance to C. capsici in cowpea, and it is expected that the markers identified here will be a valuable resource for developing elite cowpea cultivars with resistance to brown blotch.Electronic supplementary materialThe online version of this article (10.1007/s11032-018-0867-1) contains supplementary material, which is available to authorized users.

La production du riz au Burkina Faso est limitée par certaines maladies fongiques transmises par les espèces du genre Fusarium. A cet effet, l’importance de ces champignons a été évaluée sur 59 échantillons provenant de 7 variétés de riz par la méthode du papier buvard. Les sites sont répartis dans les 13 régions administratives situées en fonction des 3 zones agroécologiques du pays. Fusarium spp. a été identifié dans 81,35% des échantillons à des taux d’infection de 1 à 41%. Fusarium spp. est présent dans toutes les zones agroécologiques avec des taux de prévalence variant de 78,2 à 83,87%. Les échantillons provenant de la zone Soudano-Sahélienne et Soudanienne ont été plus infectés (respectivement 6,74% et 5,34%) que ceux de la zone Sahélienne (1,40%). Ces champignons ont été rencontrés dans toutes les régions du pays avec des taux d’infections de semences variant de 0,5 à 15,25%. Les régions les plus attaquées étant le Centre-Sud (15,25%), le Centre (11,75%) et la Boucle du Mouhoun (11,5%). L’étude montre un taux d’infection global des semences par Fusarium spp. de 5,74%. Une identification des espèces rencontrées sur le riz est impérative. L’évaluation de leur pathogénicité permettra de déterminer celles impliquées dans le gigantisme du riz. Mots clés : Fusarium spp., prévalence, taux d’infection, semences de riz Incidence of Fusarium spp. associated with rice seeds (Oryzae sativa L.) in Burkina Faso Rice production in Burkina Faso is limited by some fungal diseases transmitted by species from the genus Fusarium. To this end, the importance of these fungi was assessed on 59 samples from 7 rice varieties using the blotting paper method. The sites were distributed in the 13 administrative regions located according to the 3 agro-ecological zones of the country. Fusarium spp. was identified in 81.35% of the samples at infection rates ranging from 1 to 41%. Fusarium spp. is present in all agroecological zones with prevalence rates ranging from 78.2 to 83.87 %. Samples from the Sudano-Sahelian and Sudanian zones were more infected (6.74% and 5.34% respectively) than those from the Sahelian zone (1.40%). These fungi were found in all regions of the country with seed infection rates ranging from 0.5 to 15.25%. The most affected regions were the Centre-South (15.25%), the Centre (11.75 %) and the “Boucle du Mouhoun” (11.5%). The study shows an overall seed infection rate of Fusarium spp. of 5.74%. Identification of the species found on rice is imperative. Evaluation of their pathogenicity will make it possible to determine which species are involved in the rice's gigantism.Keywords: Fusarium spp., prevalence, infection rate, rice seed

The diversity and genetic differentiation of populations of Fusarium species associated with sorghum fields, both endophytes obtained from sorghum performing and non performing plants and isolates obtained from two sampling periods were investigated. Fusarium specific Internal Transcribed Spacer 2 (FITS2) primers set were used to assess genetic variability of 32 isolates from susceptible Fusarium spp. endophytes from Sorghum tissues. Fusarium thapsinum (Gibberella thapsina) with 68.75% of the isolates constituted the majority of Fusarium spp. isolated in performing plants. Gibberella thapsina species identified are described as non-pathogenic and associated to performing plant of sorghum. Previously, some species of Fusarium thapsinum have been recognized as pathogenic and responsible for yield losses in several cereal crops including Sorghum bicolor produced in Burkina Faso. The other Fusarium spp. identified in this study including Fusarium subglutinans, Fusarium chlamydosporum, Gibberella intermedia, Fusarium dlaminii, Fusarium oxysporum, Fusarium proliferatum, and Fusarium spp. An additional unknown fungi species were also identified. A diverse population of 10 sequence types was found, although 8 sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within Fusarium spp., and endophytic isolates were not monophyletic. Phylogenetic analysis from Neighbor-Joining/UnWeighted Neighbor-Joining showed a high genetic relationship among these 32 isolates of Fusarium spp. and high variation in FITS sequence of them. The use of specific phylomarker of the genus Fusarium allowed to identify the endophytic species of this genus and to establish the phylogenetic relationships between the endophytic species of Fusarium. The phylogenetic analysis revealed three groups of the fungi. However, no relationship between these groups and the geographical origins of these fungi has been established.