Effects of Tree Age on Pollen, Seed, and Seedling Characteristics in Great Basin Bristlecone Pine

Seed and pollen were collected from Great Basin bristlecone pine trees (Pinus longaeva D. K. Bailey) at Mammoth Creek (Utah) and the Methuselah Grove (California). Analyses determined whether seed and pollen viability, seed weight and germinability, and seedling biomass decreased with increasing age of the parent tree and whether putative mutations increased with increasing parent tree age. There were significant differences in seed weight and seedling biomass between the two locations. Seed from the Methuselah Grove was lighter and Methuselah seedling biomass was lower at all four harvest dates. However, regression analyses did not identify any relationship between tree age and any variable.