Effects of defoliation and shading on the physiological cost of reproduction in silky locoweed Oxytropis sericea

摘要: Background The production of flowers, fruits and seeds demands considerable energy nutrients, which can limit the allocation these resources to other plant functions and, thereby, influence survival future reproduction. magnitude physiological costs reproduction depends on both factors limiting seed (pollen, ovules or resources) capacity plants compensate for high resource demand. Methods To assess consequences reproductive costs, we used shading defoliation reduce photosynthate by fully pollinated a perennial legume, Oxytropis sericea (Fabaceae), examined resulting impact allocation, nectar, fruit production. Key results Although leaf manipulations reduced photosynthesis nectar production, they did not alter as revealed (13)C tracing, That organs increased >190 % taproot mass declined 29 between flowering fruiting indicates that was physiologically costly. Conclusions insensitivity manipulation is consistent with either compensatory mobilization stored ovule limitation. Seed differed considerably two years study in association contrasting precipitation prior flowering, perhaps reflecting limits performance.