Regulation of tillering in sorghum: genotypic effects
Open Access
- 29 April 2010
- journal article
- research article
- Published by Oxford University Press (OUP) in Annals of Botany
- Vol. 106 (1), 69-78
- https://doi.org/10.1093/aob/mcq080
Abstract
Genotypic variation in tillering can be caused by differences in the carbon supply–demand balance within a plant. The aim of this study was to understand and quantify the effects of genotype on tillering as a consequence of the underlying internal competition for carbohydrates. Five sorghum hybrids, derived from inbred lines with a common genetic background and with similar phenology and plant height but contrasting tillering, were grown in five experiments. The experiments covered a wide range in radiation and temperature conditions, so that number of tillers produced varied significantly. Data on leaf area, tiller number, and biomass accumulation and partitioning were collected at regular intervals. To quantify internal plant competition for carbohydrates, a carbohydrate supply–demand index (S/Dindex) was developed and related to variation in tillering. The appearance of main shoot leaves and tillers was highly co-ordinated across genotypes. High-tillering hybrids had a greater appearance frequency of early tiller ranks than low-tillering hybrids, and this was associated with narrower and hence smaller main shoot leaves. A generalized S/Dindex of internal plant competition accounted for most of the observed variation in maximum tiller number (Ntiller,max) across genotypes. However, genotypic differences in the relationship between the S/Dindex and Ntiller,max suggested that high-tillering hybrids also had a lower S/D threshold at which tillers appeared, possibly associated with hormonal effects. The results support the hypothesis that genotypic differences in tillering were associated with differences in plant carbon S/D balance, associated with differences in leaf size and in the threshold at which tillers grow out. The results provide avenues for phenotyping of mapping populations to identify genomic regions regulating tillering. Incorporating the results in crop growth simulation models could provide insight into the complex genotype-by-management-by-environment interactions associated with drought adaptation.Keywords
This publication has 42 references indexed in Scilit:
- Regulation of tillering in sorghum: environmental effectsAnnals of Botany, 2010
- Simulating the Yield Impacts of Organ-Level Quantitative Trait Loci Associated With Drought Response in Maize: A “Gene-to-Phenotype” Modeling ApproachGenetics, 2009
- Architectural Evolution and its Implications for Domestication in GrassesAnnals of Botany, 2007
- Models for navigating biological complexity in breeding improved crop plantsTrends in Plant Science, 2006
- EcoMeristem, a model of morphogenesis and competition among sinks in rice. 1. Concept, validation and sensitivity analysisFunctional Plant Biology, 2006
- Trait physiology and crop modelling as a framework to link phenotypic complexity to underlying genetic systemsAustralian Journal of Agricultural Research, 2005
- An overview of APSIM, a model designed for farming systems simulationEuropean Journal of Agronomy, 2002
- Developing Guidelines for Replanting Grain Sorghum: I. Validation and Sensitivity Analysis of the SORKAM Sorghum Growth ModelAgronomy Journal, 1997
- Photoassimilate Partitioning of Main Shoot Leaves in Field‐Grown Spring Barley1Crop Science, 1985
- TILLERING AND LEAF PRODUCTION IN WHEAT AS AFFECTED BY TEMPERATURE AND LIGHT INTENSITYCanadian Journal of Botany, 1965