CALCIUM PARTIALLY RELIEVES THE DELETERIUS EFFECTS OF HYPOXIA ON A MAIZE CULTIVAR SELECTED FOR WATERLOGGING TOLERANCE

Abstract

Low soil oxygen concentrations due to waterlogging or transient floodingseverely reduce maize production. However, genotypes with tolerance or even resistanceto hypoxia develop morphological and biochemical adaptation mechanisms which mayprove to be useful criteria for the selection and breeding of new improved genotypes.The objective of this work was to evaluate the effect of levels and modes of applicationof calcium sources on biomass yield, the contents of total soluble sugars and reducedsugars and on the activities of invertase isoforms and phosphoenolpyruvate carboxylase,in a maize variety (BRS 4154) derived from the 14th selection cycle for tolerance totransient soil flooding conditions, when cultivated under waterlogging conditions. Thestudy was carried out in a greenhouse, utilizing 20 kg pots, filled with a lowland soil.The effects of two sources of calcium (CaCl2, 300 kg ha-1 and CaSO4, 500 and 1.500 kgha-1) and three modes of application (applied 8 cm below surface, mixed with the wholesoil volume and surface application) were tested in soils kept at field capacity andwaterlogged after plants reached growth stage V6. Above ground biomass yield, thecontents of total soluble sugars and reducing sugars and the activities of the neutralcitosol (INC), acid vacuolar (IAV), acid cell wall invertases and phosphoenolpyruvatecarboxylase were determined at the onset of flowering. Calcium application partiallyrelieved the deleterious effect of waterlogging on biomass yield and the activities ofINC, IAPC and PEPcase.

Keywords

• BRS 4154
• transient waterlogging
• invertase
• PEPcase