Fructan storage and regeneration of perennial weeds: Cirsium arvense (L.) Scop and Tussilago farfara (L.)

Summary

Carbohydrate storage in underground organs of perennial weeds will increase because of the increasing temperatures and CO2 concentrations that increase photosynthesis. The objective of this study was to understand the effects of temperature and shoot age on the storage of fructan, the main carbohydrate storage, and the depletion associated with regeneration during the early growth. We subjected juvenile and mature plants of Canada thistle and Coltsfoot to different temperatures, in growth chambers, and we measured fructan in roots/rhizomes. After temperature treatment, roots/rhizomes were replanted to assess their regenerative ability. Juvenile plants subjected to lower temperatures did not store fructan. While Canada thistle showed higher fructan storage at lower temperature, Coltsfoot did not show differences in storage of fructan. Proximal root fragments had higher amount of fructan than distal fragments in Canada thistle but this was not observed for coltsfoot. The regenerative ability was associated to temperature and age. We concluded that fructan storage is temperature dependent and it starts four weeks after emergence. Differences in fructan levels at different ages and positions on horizontal roots/rhizomes are responsible for a progressive emergence of shoots and these complicate the determination of the best time for perennial weeds control.