Fruit production of shrub, Caragana korshinskii, following above-ground partial shoot removal: mechanisms underlying compensation

A number of studies have showed that under some conditions plant may partially, fully or overcompensate for tissue loss, however, the mechanisms underlying compensation are not well understood and still need to be researched. We examined the ability of Caragana korshinskii to compensate for fruit production after above-ground partial shoot removal. Fruit production of 30% main shoot length removal (30% RSL) and 25 and 50% main shoot number removal (25% RSN, 50% RSN) resulted in overcompensation and the response of 60% main shoot length removal (60% RSL) was full compensation. Plants’ responses associated with compensation included (1) greater reproduction efficiency (RA); (2) increased fruit set; (3) decreased fruit abortion; (4) increased seed number per pod; and (5) higher individual seed biomass. These responses may have resulted from more nectar production per flower, more sucrose flux per pod and more sucrose flux per seed of clipped plants, which may in turn have resulted from (1) drawing upon more non-structural carbohydrate (TNC) from roots to supply flower bud development and the flush of new foliage; (2) supplying more photosynthetic assimilation to fruit development owing to increases in leaf-level photosynthetic rates. Increases in leaf-level photosynthetic rates may be caused by more nutrient (nitrogen) and water availability per unit area of resource leaves after clipping.