Modeling branching effects on source-sink relationships of the cotton plant

TL;DR

This study uses a functional-structural model to analyze how branching affects source-sink relationships in cotton plants, revealing that branches increase leaf area and influence biomass distribution without significantly altering organ sink strengths.

Contribution

It introduces a modeling approach to quantify the effects of branching on source-sink dynamics in cotton, highlighting structural impacts on biomass allocation.

Findings

Branched cotton has more organs but smaller on the trunk.

Branch phytomer production is delayed by 4-5 growth cycles.

Presence of branches increases leaf area and slightly alters biomass parameters.

Abstract

Compared with classical process-based models, the functional-structural plant models provide more efficient tools to explore the impact of changes in plant structures on plant functioning. In this paper we investigated the effects of branches on the sourcesink interaction for the cotton plant (Gossypium hirsutum L.) based on a two-treatment experiment conducted on cotton grown in the field: the singlestem plants and the plants with only two vegetative branches. It was observed that the branched cotton had more organs for the whole plant but the organs on the trunk were smaller than those on the single-stem cotton. The phytomer production of the branches was four or five growth cycles delayed compared with the main stem. The organs on the trunk had similar dynamics of expansion for both treatments. Effects of branches were evaluated by using the functionalstructural model GREENLAB. It allowed estimating the coefficients of sink strength to differentiate the biomass acquisition abilities of organs between different physiological ages. We found that the presence of the two vegetative branches increased the ground projection area of plant leaves and had led to slight changes on the directly measured parameters; the potential relative sink strengths of organs were found similar for the two treatments.