This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.
Protecting cotton crops under elevated CO2 from waterlogging by managing ethylene
Soil waterlogging and subsequent ethylene release from cotton tissues has been linked with abscission of developing cotton fruits. This glasshouse study investigates the effect of a nine-day waterlogging event and carbon dioxide enrichment (eCO2, 700 ppm) on a fully linted cultivar Empire and a lintless cotton mutant (5B). We hypothesised that cotton performance in extreme environments such as waterlogging can be improved through mitigating ethylene action. Plants were grown at 28/20oC day/night temperature, 50-70% relative humidity, 14/10 light/dark photoperiod under natural light and were exposed to waterlogging and eCO2 at early reproductive growth. Ethylene synthesis was inhibited by spraying aminoethoxyvinylglycine (AVG, 830 ppm) one day prior to waterlogging. Waterlogging significantly increased ethylene release from both cotton genotypes, although fruit production was significantly inhibited only in Empire. AVG consistently reduced waterlogging-induced abscission of fruits, mainly in Empire. Limited damage to fruits in 5B, despite increased ethylene production during waterlogging suggested that fruit abscission in 5B was inhibited by disrupting ethylene metabolism genetically. Elevated CO2 promoted fruit production in both genotypes and was more effective in 5B than in Empire plants. Hence 5B produced more fruits than Empire, providing additional sinks (existing and new fruit) that enhanced the response to CO2 enrichment.
FP17184 Accepted 13 September 2017
© CSIRO 2017