Microsatellites or simple sequence repeats (SSR) are playing an important role in molecular breeding. This investigation was undertaken to study the genetic diversity among local sorghum accessions from two different agro-ecological zones of Burkina Faso and to assess the polymorphism within local improved varieties and a source (B35) exhibiting the stay-green trait. One hundred and eighty-six local and some exotic accessions were assessed using 26 SSR markers (including 14 markers linked to stay-green QTLs). DNA was extracted using Mixed Alkyl Trimethyl Ammonium Bromide method from dried sample after collection of leaves from three week old plantlets. The average number of alleles per locus was 4 with a medium value of gene diversity (He=0.45) across loci, indicating a low level of dissimilarity among local accessions. The genetic differentiation was significant between local and exotic materials and accessions were grouped according to their racial affiliation. The important finding was the presence of private alleles at markers linked to stay-green loci in the background of some local guinea accessions. The polymorphism between B35 and some local improved varieties for stay-green QTL indicates that most of the linked markers could be used in a breeding program through marker-assisted selection.

Incorporation of stay-green Quantitative Trait Loci (QTL) in elite sorghum (Sorghum bicolor L. Moench) variety through marker-assisted selection at early generation.Objective: The present investigation was undertaken to develop drought tolerant varieties through introgression of stay-green QTLs in order to improve sorghum yield in semi-arid areas of Burkina Faso. Methodology and Result: Marker-assisted selection was carried out to introgress stay-green QTLs into elite sorghum variety. A stay-green donor source, BTx642 (B35), was crossed to the elite variety (Sariaso09) to obtain F1 progenies that were backcrossed to their recurrent parents to obtain the BC1F1 progenies. Seventeen flanking Simple Sequence Repeat (SSRs) polymorphic markers were used for foreground selection and 18 were used for background selection. Eighteen BC1F1 were heterozygous at all target loci for stay-green (stg1, stg2, stg3, stg4 and stgB), 5 progenies (S9B37, S9B43, S9B46 S9B85 and S9B13) had incorporated 3 of these QTLs. 4 plants (S9B34, S9B38, S9B73 and S9B16) incorporated double QTLs (Stg3 and StgB) and three plants (S9B44, S9B48 and S9B20) were heterozygous for Stg1. Conclusions and applications of findings: Among BC1F1 generation, 30 progenies had incorporated at least one stay-green QTL. Two of the introgression lines had high levels of the recurrent parents' genomes and constitute some promising lines to develop drought tolerant varieties that will ensure sorghum production in semi-arid tropics areas and therefore, contribute to ensure food security in Burkina Faso. Despite the small number of genotypes obtained, the results showed the efficiency of Marker Assisted Back Crossing (MABC) versus the conventional backcross procedure.

Parasitic nematodes have been reported as one of the major constraints to soybean production worldwide. The majority of nematodes are so-called "freeliving" and feed mainly on bacteria, fungi, protozoa and other nematodes. In Burkina Faso, the presence of parasitic nematodes has been reported in crops such as rice and sorghum. The objective of this study was to identify the genera and species of nematodes associated with soybean production in Burkina Faso. Investigations were carried out on 24 genotypes of a medium-maturity group of soybean at the Farako-Ba research station. Soil samples were taken from the trial soil before its installation. At harvest, soil samples with roots were taken from each genotype in the elementary plots. The composite sample is represented by 4 lots of soil samples with roots. Extractions and counts of nematodes were performed on the different lots. In total, 7 genera of plantparasitic nematodes associated with soybean were identified. Among these genera, Pratylenchus (100% of infected genotypes), Helicotylenchus (97.28%) and Scutellonema (94.44%) were the most prevalent in terms of frequency and abundance. Some soybean genotypes were less susceptible to the genus Pratylenchus is known to be highly pathogenic in soybean. These were mainly the genotypes TGX2025-10E, TGX2023-3E and TGX2025-14E.

Sweet stalk sorghum has been the subject of very few investigations in Burkina Faso. This study aimed to evaluate the variability of agro-morphological traits and to estimate genetic parameters as well as the correlations between quantitative traits in order to identify appropriate breeding strategies. Eighteen traits were evaluated in 29 sweet sorghum genotypes at Gampèla, using a three-replicate Fisher block design. There was significant variability in Brix, quantitative agro-physiological traits, except for stem diameter (pr.=0.22), and qualitative traits. Brix was positively correlated with plant height (r=0.37) and peduncle length (r=0.41). The Shannon-Weaver diversity index of qualitative traits ranged from 0.452 (exsertion) to 0.910 (grain coverage). The broad sense heritability of quantitative traits ranged from 21.64% (stem diameter) to 96.62% (peduncle length). Seven traits related to panicle dimensions, peduncle length, internode number and length, plant height, and leaf width expressed high broad sense heritability (H2≥80%) and high genetic advance as percent mean (GAM≥20%). These results offer opportunities for improvement by direct selection and could be exploited in Burkina Faso'ssweet sorghum improvement program.