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

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