Agro-Morphological Characterization and Assessment of Variability within a Germplasm of Benin Rice (Oryza sativa L.) Varieties

Abstract

A b s t r a c t A r t i c l e I n f oThe knowledge of the agro-morphological diversity within a crop and its distribution across agro-ecological zones could be of a great help in the management of its germplasm and the development of strategies for its improvement. In this study the phenotypic diversity within a germplasm of 127 accessions of Benin rice varieties is assessed through agro-morphological characterisation with 24 qualitative and 20 quantitative variables. Within the quantitative parameters, the most variable were plant height (PlH), leaf length (LeafL), panicle leaf length (FlagLL), number of tillers (NberTillers), yield (GrYield), sowing to heading cycle (SHC), sowing-to-maturity cycle (80%SMC), leaf width (LeafW), while the less variable were grain length, grain width, panicle length. Within the qualitative ones, form of the caryopses, attitude of ramifications and color of apex (1) expressed the higher variability. A large phenotypic diversity as measured by the Shannon-Weaver diversity index, was observed within accessions (H= 0.72) and across agro-ecological zones (0.29) and phenotypic groups (0.48). Lowland accessions being less diverse than those cultivated in highland. With the country, Zone IV including Boukoumbé, Djougou, Kobli, Matéri, Sinendé and Tanguiéta is the main area of high diversity. Multivariate analysis classified accessions into three groups (Gp1, Gp2 and Gp3) of different characteristics.