The Roles of Sink Size and Location in the Partitioning of Assimilates in Wheat Ears
- 1 January 1983
- journal article
- research article
- Published by CSIRO Publishing in Functional Plant Biology
- Vol. 10 (3), 313-327
- https://doi.org/10.1071/pp9830313
Abstract
Geometric factors influencing the partitioning of 14C-labelled photosynthate between two sinks were examined in wheat ears. An awn on one spikelet was the only source of current assimilate while grains in two other spikelets were the competing sinks. The number of grains in these and their distance and vascular connection to the source were varied, while access to stem reserves could be cut off by heat ringing. Even this apparently simple experimental system presented a number of complications, such as a bias in favour of 14C movement to the upper spikelets within an ear and to the upper grains within a spikelet. These are considered before results on the effect of relative size, distance and vascular connection are described. The larger sink obtained more than its pro-rata share of 14C, usually more than the square of its size relative to the smaller sink. Partitioning between sinks of differing distance was in proportion to 1/d², where d is the relative distance of the two sinks from the source. A sink on the opposite side of the ear received only one-tenth to one-thirtieth as much as a comparable sink on the same side as the source and the competing sink.Keywords
This publication has 6 references indexed in Scilit:
- The Growth and Development of the Wheat Apex: The Effects of Photoperiod on Spikelet Production and Sucrose Concentration in the ApexAnnals of Botany, 1982
- The Wheat Spikelet—Growth Response to Light and Temperature—Experiment and HypothesisAnnals of Botany, 1981
- Accumulation and Conversion of Sugars by Developing Wheat Grains. I. Liquid Culture of Kernels Over Several DaysFunctional Plant Biology, 1981
- Distribution of carbon‐14 assimilated by wheat awnsAnnals of Applied Biology, 1978
- The Weights of Individual Grains of the Wheat Ear in Relation to Their Growth Potential, the Supply of Assimilate and Interaction Between GrainsFunctional Plant Biology, 1978
- Effect of Relative Size and Distance of Competing Sinks on the Distribution of Photosynthetic Assimilates in WheatFunctional Plant Biology, 1978