Regrowth Of White Clover After Chilling: Assimilate Partitioning And Vegetative Storage Proteins

Under temperate climates, grassland species are subjected to over-wintering which may significantly influence their early spring growth capacity, In white clover (Trifolium repens L.), it is known that overwintering capacity can differ among cultivars. Ability of this forage legume to recover from winter damage mill, therefore, have a great influence on its persistence in grass-clover associations. Experiments were undertaken with two different white clover cultivars (Huia and AberHerald). Leaf appearance rate, dry matter distribution, C-14 assimilate partitioning, and vegetative storage protein accumulation were determined in plants subjected to a 4-wk chilling period (5/0 degrees C, day/night) and subsequent warmer temperatures (15/10 degrees C), and compared with control plants (20/15 degrees C), Chilling treatment decreased leaf appearance rate, with AberHerald producing more leaves than Huia, This can be considered as a major aspect of cold adaptation strategy because leaf appearance rate controlled carbon acquisition. Low temperature increased dry matter partitioning to below-ground tissues. AberHerald allocated more assimilates to stolons than Huia, Accumulation of a 17.3-kDa protein, believed to act as a,vegetative storage protein, also increased after the chilling treatment, Regrowth was characterized by rapid mobilization of the 17.3-kDa protein in stolons and by preferential carbon allocation to stolen apices, AberHerald showed a higher regrowth potential than Huia in view of its morphological and physiological characters which include carbon acquisition and assimilate partitioning patterns, favoring shoot regrowth and acquisition of stolen reserves.