Root growth media effects on root morphology and architecture in white clover

Abstract

Root morphological and architectural parameters were recorded for Trifolium repens L. cv. ‘Grasslands Huia’, inbreds of cv. ‘Huia’ and cv. ‘Crau’, and selections within ‘Huia’ for contrasting root morphology. The plants were grown in sand and solution culture in a glasshouse experiment. Images of roots were made using a flat‐bed scanner and analysed using WinRhizo™ image analysis software. Mean root topological indices of 0.95 for solution culture and 0.93 for sand culture indicated that root media had little effect on the herringbone pattern of white clover roots. There were root media effects on five root architectural parameters, all explicable as the result of roots branching more frequently in sand. There were clover type × root media type interactions for five root parameters. These were caused by the inbred clovers being less responsive to a change in root medium than the other three clovers. Differences between roots grown in sand or solution culture were relatively small, but we recommend using sand for screening white clover for root parameters when the physical effects of a solid medium on roots is important.