Genotyping of Tanzanian rice genotypes

Tanzania is the second largest rice producer in the Eastern and Southern Africa region. However, its average yield remains low partly due to the fact that Tanzanian farmers still continue growing their traditional rice varieties which have low yield potential. In order to better exploit these landraces in rice breeding programs, a collection was made in different regions of Tanzania Mainland, Zanzibar and Pemba islands. A total of 162 landraces were collected and characterized at KATRIN for agromorphological traits and genetic diversity of the collection was assessed using 95 single nucleotide polymorphism (SNP) markers. Agro-morphological characterization showed high phenotypic variability within the collection. Landraces grouped in 3 main clusters irrespective of the collection region but instead correlated with ecologies of adaption ‐ rainfed upland and lowland/irrigated lowland. The genetic diversity study revealed 3 major groups of landraces ‐ 47% of the collection (76 landraces) -- clustered with known O. sativa japonica varieties, 46% (75 landraces) with O. sativa indica varieties and 7% were in an isolated group (exclusively landraces, 11) with none of the known varieties tested. Genetic distance matrix showed some redundancy within the collection with 5 landraces showing similarity. Loci containing aroma genes were successfully identified using SSR molecular markers. Information generated from this work will contribute significantly to rice breeding and improvement programmes in the country.