Photoassimilate Distribution in Spartina alterniflora Loisel. II. Autumn and Winter Storage and Spring Regrowth1
- R. W. Lytle and
- R. J. Hull2
Vegetative regeneration of natural Spartina alterniflora Loisel. stands is critical to the stability and sustained productivity of Atlantic tidal salt marshes. Environmental conditions and human activity may limit the seasonal regeneration of energy reserves in perennial vegetative organs. Therefore, the use of energy stored in overwintering organs for vegetative growth in the spring was investigated. Leaf blades of mature flowering culms were exposed to 14CO2 during October. Entire plants were harvested during the ensuing winter and growing season. Distribution of 14C-photosynthate in plants was measured by radioassay and radioautographic techniques. Approximately 50% of the late-season photosynthate recovered from the plants had been translocated to basal organs, with rhizomes and tillers serving as major accumulation sites. During spring growth, almost half of the remaining stored 14C was translocated into tillers and plants emerging from rhizome buds. Shoots drew heavily upon stored energy sources through the fourth to fifth leaf stages of development. In mid-summer, new rhizomes were regenerated largely by using energy stored in overwintered rhizomes. In S. alterniflora, energy transferred from one season to the next was utilized in suppport of early shoot growth and to produce organs which would serve as current season storage.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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