Vegetative reproduction and root anatomy of Solanum centrale J.M.Black (Australian bush tomato)

The aim of this study was to describe the morphology, anatomy and function of underground structures associated with colonies of Solanum centrale J.M.Black (Australian bush tomato), a perennial sub-shrub found in arid areas of Australia and an important traditional staple food for Aboriginal people. It is known that this species forms clonal communities, but there is little understanding of the mechanisms of formation in either natural or cultivated situations. The underground connections within seven clonal communities from Central and South Australia were documented and samples of secondary roots, thick lateral roots and stems were examined under both laboratory and glasshouse conditions. Clonal communities were observed at all sites with individual ramets arising from lateral roots (root-suckers) that ranged from 2-10 mm in diameter growing in a network 5-15 cm below the soil surface. Lateral roots have dicotyledonous root anatomy and rapidly resprout to form new clonal ramets. They also have the capacity to accumulate starch in parenchyma cells. The morphology and root-suckering ability resemble those of weedy Solanum spp. from other parts of the world, as well as species from a variety of genera adapted to arid climates. Methods to capitalise on the ability of lateral roots to form clonal ramets in cultivated situations, particularly given the difficulties in establishing crops from seed, are discussed.