THE INTERRELATIONSHIP BETWEEN TILLERS AND RHIZOMES OF POA PRATENSIS L.—AN AUTORADIOGRAPHIC STUDY

Summary. The main shoot or selected tillers of seedling plants of Poa pratensis L. were supplied with 14 CO 2 and the distribution of 14 C‐assimilates was followed by autoradiography. The primary tillers were initially supplied with 14 C‐assimilates from the main shoot but, once established, became independent of the parental shoot for carbohydrates. Similarly, developing rhizome‐tillers were supported by the main shoot and established primary tillers but soon became self‐supporting, Defoliation of all the tillers of the plant but one led to the defoliated primary and rhizome tillers being supplied with radiocarbon from the remaining intact shoot. Thus, although the primary tillers and rhizome‐tillers in the intact plant appear to be physiologically independent, the entire tiller‐rhizome system may be re‐integrated after defoliation, allowing assimilate redistribution. P. pratensis may be regarded as a convenient link between the non‐weedy herbage grasses which generally lack rhizomes and the weedy rhizomatous grasses typified by Agropyron repens (L.) Beauv. Etat des relations entre les talles et les rhizomes de Poa pratensis L. Etude autoradiographique