Essential resources for plant growth are usually patchily distributed. During the process of propagation, interconnected ramet pairs of stoloniferous plant buffalograss (Buchloe dactyloides) may therefore experience contrasting resource supply such as light. Under heterogeneous light supply, anatomical structure of newly developed leaves is regulated by the light condition of mature leaves. However, little is known about whether leaf anatomical structure of clonal ramets is affected by the light environment of interconnected ramets in clonal plants under heterogeneous light supply.Methods
Two light levels were set, with high light (natural sunlight) and low light (shade, 10% natural sunlight). Interconnected ramet pairs of buffalograss were exposed to homogeneous or heterogeneous light conditions.
Important findings Main vein diameter, bundle sheath cell number, leaf thickness and adaxial/abaxial mesophyll thickness of shaded ramets were remarkably decreased in spatially heterogeneous light environment; while no signifiacnt difference of these parameters was observed between ramets developed under homogeneous high light and low light conditions. Under heterogeneous light supply, adaxial/abaxial mesophyll thickness and abaxial stomatal size in unshaded elder daughter ramets (EDR) were remarkably increased, while adaxial/abaxial mesophyll thickness, stomatal density and size, leaf thickness, and bundle sheath cell number in unshaded younger daughter ramets (YDR) were reduced. Ramets under homogeneous high light conditions had higher stomatal density and larger stomata than those under homogeneous low light conditions. Adaxial/abaxial mesophyll thickness, stomatal density and size in buffalograss ramets were significantly affected by the light conditions of interconnected ramets.Conclusions
Unshaded EDR benefit from their connection to shaded YDR, while unshaded YDR experience marked cost due to its connection to shaded EDR. The plastic decrease of shaded ramets under heterogeneous light may be associated with its reduced survival cost, and elevated survival rate under shading.