The Interdependence of Tillers inLolium multiflorumLam.—a Quantitative Assessment

Abstract

Experiments were made to determine the extent of reciprocal transfer of products (derived from the assimilation of ¹⁴CO₂) between various parts of the young vegetative grass plant (Lolium multiflorum Lam.). When individual laminae on different tillers were supplied with ¹⁴CO₂, 47–64 per cent of the fixed carbon was exported after 24 h. The principal sinks were the root system and the shoot or tiller to which the fed leaf was attached. Other tillers also received significant quantities of radiocarbon. When whole tillers were supplied with ¹⁴CO₂ the percentage of fixed radiocarbon exported within 24 h ranged from 14–31 per cent. Of this, 50–74 per cent was recovered from the root system (except in the case of export from the youngest tiller) but exchange of material between tillers also occurred.A reciprocity diagram is presented and it is concluded that despite the magnitude of the exchange no tiller showed an over-all net gain or loss. The main shoot and the tillers differed in the extent of their carbon exchange and in their degree of independence. The oldest daughter tiller of the main shoot was the most independent and the main shoot most interdependent.