BayCEER Workshop 2023
12 October 2023
Amazing maize (Zea mays L.): Insights into soil resource acquisition strategies and drought adaptation of landraces and modern cultivars
2 Soil Science, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
3 Animal Ecology I, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95447 Bayreuth, Germany
4 Ecological Microbiology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95447 Bayreuth, Germany
5 Institute for Agroecology and Organic Farming, Bavarian State Research Center for Agriculture, 85354 Freising, Germany
6 Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95447 Bayreuth, Germany
7 Physics of Soils and Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland
8 Institute for Crop Science and Plant Breeding, Bavarian State Research Center for Agriculture (LfL), Lange Point 12, 85354 Freising, Germany
9 Chair of Soil Science, Institute of Ecology, Technische Universitaet Berlin, 10587 Berlin, Germany
10 Soil Biology Group, Wageningen University, 6708 PB Wageningen, the Netherlands
P 4.5 in Thinking sharp: Insights from inbetween
A holistic understanding of the strategies crops use to acquire soil resources is pivotal in achieving sustainable food security. However, little is known about variety-specific root and rhizosphere traits for resource acquisition, their plasticity and adaptation to drought.
We conducted a greenhouse experiment to phenotype root and rhizosphere traits (mean root diameter, specific root length, root tissue density, root nitrogen content, specific rhizosheath mass, arbuscular mycorrhizal fungi abundance) of 16 landraces and 22 modern cultivars of maize (Zea mays L.) under well-watered and drought-stressed conditions.
Our results demonstrate that landraces and modern cultivars diverge in their root and rhizosphere traits. While landraces follow a 'do-it-yourself' strategy with high specific root length, modern cultivars exhibit an 'outsourcing' strategy with increased mean root diameters. Furthermore, we identified specific rhizosheath mass that integrates various rhizosphere processes as indicative of an 'outsourcing' strategy. Drought similarly affects root and rhizosphere traits of landraces and modern cultivars. Landraces, however, exhibit significantly higher plasticity and drought-adaptive responses.
We suggest that selection through breeding leads to distinct resource acquisition strategies between maize landraces and modern cultivars. In future breeding, greater consideration should be given to specific effects of drought on resource acquisition and to variety-specific differences between landraces and modern cultivars.
Keywords: arbuscular mycorrhizal fungi, crop breeding, Index for Adaptive Responses, phenotypic plasticity, rhizosheath, root diameter, root economics space, specific root length