Wheat Crop under Waterlogging: Potential Soil and Plant Effects

Abstract

Inundation, excessive precipitation, or inadequate field drainage can cause waterlogging of cultivated land. It is anticipated that climate change will increase the frequency, intensity, and unpredictability of flooding events. This stress affects 10–15 million hectares of wheat every year, resulting in 20–50% yield losses. Since this crop greatly sustains a population’s food demands, providing ca. 20% of the world’s energy and protein diets requirements, it is crucial to understand changes in soil and plant physiology under excess water conditions. Variations in redox potential, pH, nutrient availability, and electrical conductivity of waterlogged soil will be addressed, as well as their impacts in major plant responses, such as root system and plant development. Waterlogging effects at the leaf level will also be addressed, with a particular focus on gas exchanges, photosynthetic pigments, soluble sugars, membrane integrity, lipids, and oxidative stress.

Waterlogging Effects in Adventitious Roots, Tillering and Yield of Bread Wheat Germplasm

“…Root features determine plants ability to absorb water and nutrients for their growth, development and grain production [8,32,33,34]. Adventitious roots play a crucial role to overcome nutrient deficiency, providing an increased capacity to adapt to different environments [35,36].…”

“…Waterlogged soil undergoes significant changes in its displays a decrease in its Eh. According to [11], a soil with an Eh close to 0 mV will have an oxygen concentration of approximately 1%, leading plant roots to switch from aerobic to anaerobic metabolism [8][9][10][11]. Thus, roots are the first plant organs to be affected by hypoxia and anoxia due to waterlogging; resulting in impaired root functioning and detrimental effects in shoots [12].…”

“…The formation of adventitious roots in response to waterlogging may be a strategy to reduce oxygen deficiency, as these roots facilitate gas transport between submerged tissues and the aerial portion of the plant. In addition, these morphological adaptations play a decisive role in nutrient and water uptake during waterlogging, significantly contributing to survival [8,23] and to maintain productivity. The selection of potential progenitors in breeding programs largely depends on the evaluation and understanding of the existing genetic variability [24,25].…”

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chemical properties [6][7][8]. As the soil pores fill with water rather than the gas phase, oxygen concentration is reduced which is exacerbated by the drastic reduction of gas exchange between the soil and the atmosphere [8,9].

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chemical properties [6][7][8]. As the soil pores fill with water rather than the gas phase, oxygen concentration is reduced which is exacerbated by the drastic reduction of gas exchange between the soil and the atmosphere [8,9]. The remaining oxygen trapped in the soil is rapidly consumed by root respiration and by microbial activity in rhizosphere, resulting in hypoxia or even environmental anoxia.

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