Abstract

Soybean [(Glycine max (L.) Merr.] is the most important grain legumes in the world in terms of total production. But only a fraction of its accessions has been characterizedbased on origin, morphometric traits, agronomic performance and seed composition. This crop is now cultivated to a very limited extent in twenty one sub-Saharan African countries. The main objective of the present study is to characterize morphologically and agronomically the soybean accessions from the Democratic Republic of Congo (DR-Congo) gene pool. The results of the present study highlight the high level of variability in the soybean gene pool in the DR-Congo. In general 41% of soybean accessions from this collection have lanceolate leaves, 35.3% rhomboid-lanceolate, 14.7% oval, and 8.8% rhomboid. More than 65% of accessions have pod color that fit in within a variation of light brown. Almost 62% of accessions have seed with light beige color, 27% curry, and 12% pink beige. There were significant differences among accessions for all the quantitative traits analyzed. In the DR-Congo collection, all the accessions were less than 0.5 m tall with 75% shorter than 0.4 m. In general, plant height, stem diameter at first internodes and number of leaves per plant were significantly correlated to each other. Significant correlation was also observed between leaflet length and plant height. Grain yields were highly and significantly correlated to the number of pods and seeds per plant. Based on grain yield and disease resistance over the two years of trials at different locations, ten accessions have been identified as adapted to the local conditions of the main growing soybean region in the DR-Congo.

Key words: Glycine max, soybean collection, morphometric traits, Democratic Republic of Congo (DR-Congo), in situ conservation, agronomic performance.