Does winter affect the regrowth potential of white clover buds?
Est-ce que l'hiver affecte la croissance potentielle des bourgeons du trèfle blanc ?
Résumé
In order to compare the growth potential of buds of white clover (Trifolium repens L.) we used a method to assess the potential for activity of shoot buds and root primordia. Two contrasting cultivars (cv. AberHerald and Grasslands Huia) were tested. The growth potential was evaluated following the excision of individual stolon nodes sampled in the field on experimental plots located in eastern part of France. Two populations of nodes were sampled : 1) the yungest node emerged from the apical bud (node 1). 2) the third node behind the apex (node 3). Nodes were incubated in controlled conditions after dissection and the outgrowth of axillary buds and roots was recorded every day for a week. The study demonstrated a seasonal influence on the potential activity of axillary buds and root primordia, particulary for buds at node 3. The data indicated a genetic variation in potential for outgrowth during winter : AberHerald had a higher percentage of potentially active buds than Huia during winter, irrespective of the node position. Moreover AberHerald buds had faster rates of outgrowth than Huia buds. We conclude than the fate of the buds is certainly a key point in relation both to cultivar differences in winter tolerance and to their growth potential when temperatures increase