Département de Biologie et Physiologie Végétales, Unité de Formation et de Recherche en Sciences de la vie et de la Terre, Université de Ouagadougou, 03 BP 7021 Ouagadougou 03, Ouagadougou, Burkina Faso
Jatropha curcas L. is a perennial oleaginous plant which is known for its multiple uses. The oil extracted from its seeds is used in the manufacture of biodiesel and soap. The plant also has therapeutic virtues and insecticidal properties. In Burkina Faso, the species remains under exploited. Despite its potentialities, the genetic diversity of this phytogenetic resource is badly known. This study was conducted to determine the level and the structuring of the genetic variability of a collection of 70 accessions coming from the various phytogeographical sectors of the country and to estimate the genetic parameters of the various characters. Thus, an agro-morphological evaluation of the collection was carried out during the rainy season 2014. Eleven (11) quantitative characters relating to the vegetative development and the potential of production of the plant were used. This study revealed the existence of variability within accessions. The characters related to the yield showed greater variability than those related of the vegetative development. The analysis of the structuring of variability showed that plants which have an important vegetative development are more productive than those of little size.The estimate of the genetic parameters revealed a weak difference between the phenotypic and genotypic coefficients of variation and high broad sense heritability for all the characters. The characters related to the yield expressed the highest expected genetic advance, phenotypic and genotypic coefficients of variation. The results of the study can be exploited in Jatropha curcas' improvement program.
The climatic changes and the irregularity of the seasons of rain involved the adoption by the farmers of the varieties more plastic and adapted in their zone of culture that the improved varieties. In the objective to measure the response of the ecotypes to photoperiodism, a study of the sensitivity of 120 ecotypes of sorghum of Burkina Faso to the photoperiod was made using a test comprising two dates of sowing. These ecotypes come from the germplasm of the University of Ouagadougou, made up between 1984 and 1986 within the framework of the safeguarding of the diversity of the sorghum. It comes out from this study that all the studied ecotypes are photoperiodic and systematically reduce their cycle at the time of a delay the semi one. Also let us note that 46 % of the ecotypes showed a sensitivity moderate to the photoperiod (0<K?0,3), 38% a relatively significant sensitivity (0,3<K?0,6) and 16 % a strong sensitivity (0,6 < K?0,9). The flowering of the ecotypes occurred in the 25 days which preceded the average date by end of the rain season and floral initiation started and finished during the time to which the day is shorter than the night. We retain as this study as at the time of a delay of 3 weeks sowing the ecotypes lose 10 to 96% their seeds with an average of 66%.
The objective of this study is to contribute to a better knowledge of the agromorphological diversity of Cleome gynandra L. of the West of Burkina Faso. Hundred accessions, collected in the vegetable gardens and the natural populations of the sahelo-soudan zone and the soudan zone of Burkina Faso, was evaluated according to a Latinized Alpha-Plan design. Observations and Biometrical measurements were carried on 23 variables. The study revealed a great agromorphological variability within the accessions from the vegetable gardens and those collected in the natural populations. 17 characters - 11 quantitatives and 6 qualitatives discriminate the studied accessions. Highly significant differences at 1% were observed between the accessions of the two climatic zones and between the accessions from the vegetable gardens and those collected in the natural populations. The agronomical performances of the accessions from the sahelo-soudan zone are higher than those of the accessions from the soudan zone. Also, the performances of the accessions from the vegetable gardens are higher than those from the natural populations. Several positive correlations were observed. The study of the structuring of the diversity of the accessions revealed two great sets. The first set is mainly constituted with cultivated accessions and accessions from the sahelo-soudan zone. The second set is mainly constituted with accessions collected in the natural populations and of accessions from the soudan zone. Thus, the growing practices and the climatic zones were the determining factors in the structuring of the diversity of the studied accessions.