The roots of drought resistance
Abstract
Future strategies of crop production must increasingly focus on an efficient resource use. Water is yet a limiting factor for plant growth in many regions of the world and global change raises additional concern of more frequent drought situations. The root system is considered a key trait for better drought resistance via efficient water uptake. Root systems are expected to have high natural diversity which is still largely unexploited for crop improvement. Furthermore, dehydration avoidance via efficient root water uptake is considered to be compatible with high yields, which is not the case for many aboveground water stress response mechanisms. Until now there is no comprehensive understanding which root system types and particular root parameters are most suitable under a determined hydrological situation to efficiently supply the plant with water. However, an informed choice of promising plant material would be crucial when targeting the root system for crop improvement, because still there is no screening method to phenotype large unknown populations for root traits. We suggest that adequate plant genetic resources for root mediated superior drought resistance can be readily found when understanding the ecohydrological background that shaped the evolution of root system diversity. This hypothesis builds on the assumption that root system evolution is an optimization process of the plant to the hydrological regime at its site of origin. The main objective of our project therefore is to establish the relation between the diversity of plant root systems and the ecohydrological conditions at their sites of origin. This relation will be studied for a set of durum wheat landraces from origins along an aridity gradient, selected wild relatives (einkorn and emmer) and modern cultivars. We expect that particularly landraces are efficient uptake types (“water spenders”), while wild relatives conserve growth limiting traits of “water savers” that reduce their aboveground losses. Initially the project will characterize the root system architecture of the genotypes with a new type of hyperspectral imaging system for rhizoboxes. Distinct rooting strategies and their relation to environmental characteristic will be established by cluster and principal component analysis. Building on the empirical findings, an innovative coupling of ecohydrological and root architecture modeling will provide a tool to properly analyze the hypothesis of root systems being an optimization to site hydrology. The significance of different root system types to convey improved drought resistance will be validated in a field experiment. We will particularly study if there is a clear distinction among genotypes using a strategy of water spending with efficient root water uptake, and others relying on water saving with a conservative water use. From the outcome of the project we expect to enable breeders to make a targeted choice of genetic resources, e.g. in genebank search, that provide them plant material with adequate root characteristics to improve the water uptake capacity of agricultural crops.
keywords Root system Drought resistance Biodiversity Ecohydrology Modeling Plant breeding
Publikationen
Project staff
Gernot Bodner
Priv.-Doz. Dr. Gernot Bodner
gernot.bodner@boku.ac.at
Tel: +43 1 47654-95115
Project Leader
02.01.2013 - 01.01.2016
Peter Hietz
Univ.Prof. Mag.rer.nat. Dr.rer.nat. Peter Hietz
peter.hietz@boku.ac.at
Tel: +43 1 47654-83110
Project Staff
02.01.2013 - 01.01.2016
BOKU partners
External partners
Institute of Plant Sociology
Monika Sobotik
partner
Department of Water Engineering, Politecnic of Turin
Francesco Laio
partner
University of Vienna, Computational Science Center
Daniel Leitner
partner