VOC emissions as drought stress indicators in old and modern maize varieties

Maike Rieger1, Julia David1, Finja Löher1, Asegid Akale, Tina Köhler2, Wolfgang Babel3, Johanna Pausch4, Anke Nölscher1
1 Atmospheric Chemistry
2 Soil Physics
3 Micrometeorology
4 Agroecology

P 1.1 in Soil-vegetation-atmosphere interactions in a changing climate

Climate change confronts humanity with an increasing frequency of extreme conditions such as droughts. To feed our growing world-population and to minimize losses in crops, it is crucial to rapidly recognize stress since only optimally supplied plants can achieve the best yields. Plant emissions of volatile organic compounds (VOCs) haven been shown to vary in composition and emission strength under (drought) stress. Despite a high demand of maize – due to population growth – research about drought-related VOC emissions is sparse, although there is the potential of airborne VOC-markers to indicate drought stress of entire maize fields.

Therefore, we investigated VOC-emissions from 12 different maize-varieties under drought and natural conditions. The chosen modern and old genotypes, which cover landraces, population varieties and hybrids, represent a broad range of different water use efficiencies and above ground biomass. Emission rates were determined from leaf level flow-through chambers during the growing season from July to September 2021. Samples were taken in the field on thermo-desorption tubes which were subsequently analysed by a gas chromatograph with a flame ionisation detector (GC-FID) in the laboratory.

The field measurement campaigns were conducted with the aim to (1) determine the variability of VOC emission rates within one variety, (2) screen all varieties under natural conditions, and (3) directly compare drought and natural conditions within one variety.

Keywords: VOC, Emission rates, Maize, Drought stress