New bioassay method to find the allelopathic potential of wheat cultivars on rye (Secale cereale L.) seedlings

This experiment was done to develop a new simple and valid method for allelopathy studies and facilitating the use of image analysis in such research. A special transparent growth box containing black fabric enclosed inside was used to provide the seedbed to allow diffusion of allelochemichals from each side to opposite side. The allelopathy potential of 9-wheat cultivars was evaluated against rye (Secale cereale L.) to examine the suitability of this method. Images were captured every 12 h to evaluate the effects of wheat cultivars on rye seedling growth over time. The rye seedling growth was significantly affected by allelopathy of different wheat cultivars. The root surface area and spread (root architecture) of rye was decreased by more allelopathic cultivars in the growing medium. There was a clear correlation between the root spread of rye and seedling growth, suggesting the potential of root spread as an important parameter of allelopathic activity. Root spread measurement could be precisely done by using one photograph taken from the expanded roots. This method provided a consistent and reliable tool for analyzing the changes in root architecture of allelochemical receiver plants during the exposure to allelopathic neighbours.