Tiller dynamics and assimilate partitioning in Lolium perenne with particular reference to flowering

摘要: SUMMARY The fate of 100 seedling plants Lolium perenne L. was studied over a period 2 years in field plot. The birth and death tillers the production inflorescences followed, components seed yield were recorded detail first year. pattern distribution 14CO2 assimilated by main shoot examined at monthly intervals during flowering season 14C-assimilate from individual leaves inflorescence also studied. capacity to assimilate prior re-distribution previously accumulated growth assessed. Plants died more or less constant rate with time only 54 survived end 2–yr period. First year mortality associated severe grazing cutting but second ungrazed observed. There great variability surviving plants. In both number live per plant increased July April particularly rapid tillering March establishing maximum value for each similar phase after July. declined 50% stem elongation emergence majority dead young secondary (in year) tertiary mean age 40 days. Such had poor assimilatory onset not supplied shoot. Most experiment flowered one quarter produced inflorescences. earlier tiller greater its chance seed. weight development seed-bearing florets spikelet. relatively little export “C-assimilate shoot, lower internodes formed major sink post-anthesis assimilate. seeds appeared be independent current some evidence that remobilised utilised new tillers. Overall, results confirm view grass is dynamic population short-lived indicate increasing competition exerts influence on survival tillers.