In vitro induction and characterisation of tetraploid drumstick tree (Moringa oleifera Lam.)

Artificial induction of polyploidy is widely used in breeding programmes to improve the agronomic traits. The drumstick tree (Moringa oleifera Lam.) has a range of potential commercial uses, as the vegetative organs have high nutritional, medicinal, and feed values. In the present study, in vitro tetraploidisation in drumstick tree was performed by treating leaf segments with colchicine and subsequently verifying the ploidy levels. For polyploidisation, explant survival and regeneration rates were affected more by exposure time than by colchicine concentration, and the highest polyploidisation efficiency was observed at 500 mg/L colchicine for 3 days, which yielded 21% tetraploids. The morphological characteristics and contents of seven fodder-related nutrients (crude protein, ether extract, ash, acid detergent fibre, neutral detergent fibre, calcium, and phosphorus) in the leaves and shoots were compared between tetraploid and diploid drumstick trees. The resulting tetraploids showed significantly enhanced leaf and stomatal size. In addition, the contents of seven fodder-related nutrients were higher, although to varying degrees, in tetraploids than in diploids. The results indicated that the tetraploid produced in this study exhibited superior agronomical traits and improved biomass yield than diploids, and may represent excellent raw materials for fodder to enhance biomass and nutrition.