Diversity and food quality properties of farmers' varieties of sorghum from Bénin

Farmers' varieties of sorghum from three communities in different regions of northern Bénin were analysed for their food quality and agro-morphological properties, and also for their genetic diversity using amplified fragment length polymorphism (AFLP). Farmers' varieties of sorghum differed greatly with respect to their morphology and agronomic and food traits. Most of the varieties had long (>200 cm) stems (87%), loose panicles (79%) and a red or pink colour (52%). Most were susceptible to drought (54%) and to attacks by striga (79%), insects (99%) and birds (77%). Farmers evaluated the quality of the seeds for preparing porridges as being high for 60% of the varieties and 26% of the varieties were regarded as suitable for making beverages. Late-maturing, large-seeded, red or pink varieties are preferred by farmers for porridges and beverages. Gene diversity among varieties within regions, as measured by neutral markers, was similar for the three regions (0.211-0.240). However, across regions the short (<150 cm) stem varieties showed relatively high genetic diversity compared with long or medium stem varieties (0.378 vs 0.184-0.216 for long-medium stem varieties). Genetic differentiation (Fst) among regions and among stem lengths of varieties was significant and ranged between 0.086 and 0.135. Grain colour, stem length and panicle shape varied significantly with the region/stem length and correlated with the genetic differentiation of regions. No relationship could be detected between the genetic differentiation of the varieties and their food quality as expressed by the farmers. Implications of the findings for crop conservation and breeding are discussed. © 2006 Society of Chemical Industry.