Origins of white (Corchorus capsularis L.) and dark (C-olitorius L.) jute: a reevaluation based on nuclear and chloroplast microsatellites

Using a suite of morphological traits and neutral molecular markers, we have reevaluated the origins of the two cultivated jute species. The nine Corchorus species, which are restricted to both Africa and Asia, were phenotyped for bast fibre yield- and quality-linked traits, morpho-phenetically classified based on those traits' similarities, genotyped by nuclear microsatellites and haplotyped by chloroplast microsatellites. The two cultivated jute species contain similar to 70% of the neutral genetic diversity present in their wild relatives. Phylogenetic analyses using 38 highly polymorphic nuclear microsatellites identified C. aestuans as the common ancestor to both the cultivated jute species. C. urticifolius is the nuclear progenitor of C. olitorius (dark jute), but no close nuclear progenitor of C. capsularis (white jute) could be identified. Although either C. aestuans or C. pseudo-olitorius or both appear to be the possible cytoplasmic progenitors of white jute, the matrilineal ancestry of dark jute remains obscure. However, the presence of a single, unique chloroplast haplotype in each of the two cultivated species indicates the involvement of other unknown wild relatives. Taken together with archaeobotanical evidence, our results suggest that dark jute had its origin in equatorial region of east Africa, but was domesticated in India. We could not support an Indo-Myanmar origin of white jute, and possibly it also originated in Africa, but was domesticated in Asia.