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

Abstract

Drought is one of the major limitations to rice productivity worldwide. The present study compared variation in seventeen rice genotypes of Egyptian origin for morpho-physiological traits to identify the best genotypes with combination of adaptive traits under water-limited condition (DS). The DS reduced days to heading (DTH), plant height (PH), flag leaf angle (FLA), flag leaf area (FLAR), chlorophyll content (CHC), relative water content (RWC), grain yield (GY), and its components. Among genotypes, Hybrid 2 expressed the highest GY, panicle length (PL), number of tillers (NT), panicles per plant (NPP), and harvest index (HI) with maximum spikelet sterility (SS) under non-stress condition (NS), while the same genotype expressed ≈ 41% yield reduction under DS. The genotype Giza 179 had earlier DTH, higher and stable GY, FLAR, and yield component traits such as NPP, PW, and HI across the water regimes with least yield reduction (30.5%) under DS. The GY and FLAR, RWC, PL, NT, NPP, PW, and HI were positively correlated under DS. The cluster analysis showed a similarity index of 25% among genotypes. The high yielding genotypes Giza 179, IET 1444, and IRAT 170 had also increased yield components (PL, NT, NPP, PW, TGW and HI) under DS that were attributed to highest FLAR, RWC, and PH, while having reduced LR, FLA, TR, and SS; therefore, these genotypes were categorized as drought-tolerant. The Hybrid 2 and Giza 179 genotypes can perform well under NS; however, the cultivation of Giza 179, Sakha 107, IET 1444, and IRAT 170 would give an advantage in DS-prone areas, hence, these can be used as a donor parental line in future rice breeding programs.

Identification of Drought Tolerant Rice (Oryza Sativa L.) Genotypes with Asian and African Backgrounds

“…Three levels of drought stress corresponding to 5% (m 3 /m 3 ), 10.6% (m 3 /m 3 ), and 16% (m 3 /m 3 ) soil moisture content, representing severe, moderate, and low drought, respectively, were used by Singh et al [ 14 ] to assess the response of rice cultivars to early-season drought stress. Different methods of screening rice genotypes for drought tolerance have been used by researchers through classical markers or DNA/molecular markers [ 15 , 16 ]. Depending on the specific objective, each type of marker may present advantages and/or disadvantages.…”

Morpho-physiological characterization of multi-canopy rice cultivation systems in various genotype combinations

“…Plants with an appropriate canopy shape can capture light resources optimally and have a high value of solar radiation use efficiency [28]. Plants with these characteristics can produce higher biomass and daily grain yields following the results of previous studies, which stated that the high production capacity of biomass before or after the heading stage is a characteristic of high-yielding rice [25,26,31]. The rate of photosynthesis and SPAD value can be vital selection characteristics in the MCRC system.…”

Prospects Of Developing Drought Resilience In Crop Plants Through Strategic Modifications In Root System Architecture

“…For example, exposure of wheat plants to drought during post-anthesis stage, it either repressed grain maturation or left the grain completely unfilled (Dhanda & Sethi, 2002;Thakur et al, 2010) while when exposed during pre-anthesis stage cultivars showed increased drought tolerance at seed filling stage (Wang et al, 2014(Wang et al, , 2015. The drought stress during panicle initiation and flowering stages in rice leads to drastic reduction in spikelet and grain number per panicle (Ghoneim 2018(Ghoneim , 2020Gaballah et al, 2022;Ishimaru et al, 2022). Some plants employ drought escape strategies by favoring early flowering, increased growth rate, higher photosynthesis capacity and preservation of reserves for seed development (Gaballah et al, 2022).…”

“…The drought stress during panicle initiation and flowering stages in rice leads to drastic reduction in spikelet and grain number per panicle (Ghoneim 2018(Ghoneim , 2020Gaballah et al, 2022;Ishimaru et al, 2022). Some plants employ drought escape strategies by favoring early flowering, increased growth rate, higher photosynthesis capacity and preservation of reserves for seed development (Gaballah et al, 2022). Flowering, vegetative and seed maturation stages of maize are most vulnerable to water scarcity, causing yield loss up to 50, 25 and 21% respectively (Sah et al, 2020).…”