Drought stress tolerance of two wheat genotypes

Abstract

Biotic and abiotic stress effects can limit the productivity of plants to great extent. In Hungary, drought is one of the most important constrains of biomass production, even at the present climatic conditions. The climate change scenarios, developed for the Carpathian basin for the nearest future predict further decrease in surface water resources. Consequently, it is essential to develop drought stress tolerant wheat genotypes to ensure sustainable and productive wheat production under changed climate conditions. The aim of the present study was to compare the stress tolerance of two winter wheat genotypes at two different scales. Soil water regime and development of plants, grown in a pot experiment and in large undisturbed soil columns were evaluated. The pot experiments were carried out in a climatic room in three replicates. GK Élet wheat genotype was planted in six, and Mv Emese in other six pots. Two pots were left without plant for evaporation studies. Based on the mass of the soil columns without plant the evaporation from the bare soil surface was calculated in order to distinguish the evaporation and the transpiration with appropriate precision. A complex stress diagnosis system was developed to monitor the water balance elements. ECH<sub>2</sub>O type capacitive soil moisture probes were installed in each of the pots to perform soil water content measurements four times a day. The irrigation demand was determined according to the hydrolimits, derived from soil hydrophysical properties. In case of both genotypes three plants were provided with the optimum water supply, while the other three ones were drought-stressed. In the undisturbed soil columns, the same wheat genotypes were sawn in one replicate. Similar watering strategy was applied. TDR soil moisture probes were installed in the soil at various depths to monitor changes in soil water content. In order to study the drought stress reaction of the wheat plants, microsensors of 1.6 mm diameter were implanted into the stems and connected to a quadrupole mass spectrometer for gas analysis. The stress status was indicated in the plants grown on partly non-irrigated soil columns by the lower CO<sub>2</sub> level at both genotypes. It was concluded that the developed stress diagnosis system could be used for soil water balance elements calculations. This enables more precise estimation of plant water consumption in order to evaluate the drought sensitivity of different wheat genotypes.

Phenology, Growth and Yield of Three Wheat (Triticum aestivum L.) Varieties as Affected by High Temperature Stress

“…Wheat, barley and a triticale cultivar were evaluated in three season under three thermal condition: control and two timing of heating before anthesis and found stem elongation stage is most sensitive to high temperature stress (yield reduction 46%) Ugarte et al (2007) Hungary Wheat 'GK-Elet' and 'Mv-Emese' Pot culture experiment in growth chamber indicated that 'MvEmese'was good drought stress tolerance than GK-Elet Lukacs et al (2008) Bulgaria Two drought tolerant wheat ('Katya' 'Zlatitza') and two sensitive 'Sadovo' and 'Miziya')…”

Modelling soil water content variations under drought stress on soil column cropped with winter wheat

“…Potential evapotranspiration was determined by the pan evaporation method (Szász, 1997): a pan with a large surface was filled with water and placed next to the soil columns, and its weight loss was regularly monitored. The potential evapotranspiration rate was found to be constant and equal to 0.254 10 -3 m 3 day -1 (Lukács et al, 2008).…”

“…For mathematical modelling of the soil water balance elements under non-regular conditions we used data, obtained from the stress diagnosis set up introduced by Lukács et al (2008). The system consisted of eight soil columns with winter wheat, placed in identical plexiglass boxes with an area of 0.15x0.15 m 2 (Fig.…”

“…Further, the volumetric soil water content was determined by multiplying the gravimetric soil water content by the soil bulk density (1.18x10 3 kg m -3 ). Data on temporal changes in the water content of the pots with bare soil were used to calculate the evaporation from the soil surface for NS and S columns as described in Lukács et al (2008). Development of the winter wheat plants was also monitored.…”

“…In this study, we used data obtained from a detailed soil water balance study carried out in a climate room (Lukács et al, 2008) to assess the applicability of the SWAP (Soil, Water, Atmosphere and Plant) mathematical model (van Dam, 2000;van Dam et al, 2008) to climatic conditions that significantly differ from those that the model has been developed and tested for. The hypothesis of this study was that if we successfully apply a model for meteorological conditions, for which the built-in physical relationships are still valid (e.g.…”