Root Traits Responses to Irrigation Intervals in Rice (Oryza sativa)

Abstract

Drought is one of major abiotic stresses that effect rice production. Roots play vital role in absorption of water and nutrients from soil contributing for drought tolerance. The present study quantified the effects of different irrigation intervals on root development and agronomical traits of three Egyptian rice cultivars, Giza177, Giza178, Sakha107, IET1444 as a popular drought tolerant and Moroberekan as control genotype. Irrigation treatments were imposed 15 days after transplanting and applied for every 4, 8 and 12 days during 2018 and 2019 rice growing seasons. The results showed the reduction in root architecture traits with prolonged irrigation intervals. A significant decrease in plant height, number of panicles plant-1, grain yield (t ha-1) and relative water content, while sterility (%) and water use efficiency significantly increased over irrigation intervals. The highly significant and positive correlation was found among grain yield and root:shoot ratio, relative water content and number of panicles plant-1, while the negative correlation was with root xylem vessel number and sterility. It was concluded that, the drought reduced the grain yield and its components due to poor developed root system. Moroberekan and IET1444 genotypes can be used as a donor parent for rice breeding program. Further studies are also required to identify factors that contribute to the high yield potential of both Giza178 and Sakha107 under different water stress condition. © 2021 Friends Science Publishers

Evaluation of Morpho-Physiological Traits in Rice Genotypes for Adaptation under Irrigated and Water-Limited Environments

“…The FLAR, leaf area index (LAI), leaf relative water contents (LRWC), and chlorophyll pigments are putative traits used as evaluation criteria for drought tolerance [8,41,42]. Decrease in leaf area under DS might be attributed to less leaf growth owing to decrease in cell division and expansion concomitantly with decreases in turgor potential and water potential, as evident from decrease in RWC in the present study [17,42,43].…”

“…Growing world population and decline of water resources for crop production prioritize the development of high-yielding drought-tolerant cultivars with better adaptability to water-limited condition [7]. Drought is one of the major limitations to rice production, causing huge economic losses and having large effects on rice yield and its components, particularly during the reproductive stage [8]. If drought period matches with panicles initiation stage in rice, the number of spikelets and grains per panicle, including grain yield, are reduced [9,10].…”

Molecular Genetic Diversity and Combining Ability for Some Physiological and Agronomic Traits in Rice under Well-Watered and Water-Deficit Conditions

“…Strong positive relationships were identified between grain yield and each of relative water content, chlorophyll content, number of panicles/plant, number of filled grains/panicle, and 1000-grain weight. This indicates their importance as valuable characteristics for indirect selection, particularly in segregated early generations, under drought stress [ 7 , 8 , 94 ]. In addition, grain yield was adversely associated with sterility percentage and leaf rolling [ 11 , 94 , 95 ].…”

“…Moreover, this production should be increased to cope with continuing population growth and the threat of environmental pressures [ 5 ]. Drought stress is a harsh environmental factor with devastating impacts on global rice production [ 6 , 7 ]. Nearly half the cultivated area of rice worldwide is predicted to suffer from water shortages, causing a substantial reduction in rice yield [ 8 ].…”

Drought Impacts and the Tolerance Mechanisms in Rice (Oryza sativa L.): A Review

“…These mechanisms improve the uptake of water and delay the impact of drought stress on the shoot (Barnábas et al, 2008). Furthermore, the hydraulic conductivity of the root is also influenced by the size of xylem vessels, which ultimately determines plant productivity under water stress (Gaballah et al, 2021). An increase in the amount of ABA present in the root may restrict ethylene's activities, which may prevent plant growth (Tátrai et al, 2016).…”