Mapping Consistent Rice (Oryza sativa L.) Yield QTLs under Drought Stress in Target Rainfed Environments

Abstract

BackgroundDrought stress is a major limitation to rainfed rice production and yield stability. Identifying yield-associated quantitative trait loci (QTLs) that are consistent under drought stress predominant in target production environments, as well as across different genetic backgrounds, will help to develop high-yielding rice cultivars suitable for water-limited environments through marker-assisted breeding (MAB). Considerable progress has been made in mapping QTLs for drought resistance traits in rice; however, few have been successfully used in MAB.ResultsRecombinant inbred lines of IR20 × Nootripathu, two indica cultivars adapted to rainfed target populations of environments (TPEs), were evaluated in one and two seasons under managed stress and in a rainfed target drought stress environment, respectively. In the managed stress environment, the severity of the stress meant that measurements could be made only on secondary traits and biomass. In the target environment, the lines experienced varying timings, durations, and intensities of drought stress. The rice recombinant inbred lines exhibited significant genotypic variation for physio-morphological, phenological, and plant production traits under drought. Nine and 24 QTLs for physio-morphological and plant production traits were identified in managed and natural drought stress conditions in the TPEs, respectively. Yield QTLs that were consistent in the target environment over seasons were identified on chromosomes 1, 4, and 6, which could stabilize the productivity in high-yielding rice lines in a water-limited rainfed ecosystem. These yield QTLs also govern highly heritable key secondary traits, such as leaf drying, canopy temperature, panicle harvest index and harvest index.ConclusionThree QTL regions on chromosome 1 (RM8085), chromosome 4 (I12S), and chromosome 6 (RM6836) harbor significant additive QTLs for various physiological and yield traits under drought stress. The similar chromosomal region on 4 and 6 were found to harbor QTLs for canopy temperature and leaf drying under drought stress conditions. Thus, the identified large effect yield QTLs could be introgressed to develop rice lines with stable yields under varying natural drought stress predominant in TPEs.Electronic supplementary materialThe online version of this article (doi:10.1186/s12284-015-0053-6) contains supplementary material, which is available to authorized users.

QTL mapping for heading date, leaf area and chlorophyll content under cold and drought stress in two related recombinant inbred line populations (Japonica rice) and meta‐analysis

“…Under normal irrigation, water remains 2 to 10 cm above the soil surface. Since the water distribution of north-east of China is uneven, so we set drought-stressed treatments as natural rain-fed conditions to simulate natural drought stress in the actual production process (Gu, Yin, Zhang, Wang, & Struik, 2014;Prince, Beena, Gomez, Senthivel, & Babu, 2015). We stopped irrigation after the tillering stage until harvest and replenished the water when the soil water potential was below À50 kPa to save the plants from being exposed to very severe stress that leads to death in reproductive stage (Kumar, Venuprasad, & Atlin, 2007).…”

Association mapping for photosynthesis and yield traits under two moisture conditions and their drought indices in winter bread wheat (Triticum aestivum L.) using SSR markers

“…However, further investigations are needed to verify the potential of these QTLs in a broad range of contrasting water conditions. Identifying QTLs related to plant-development with consistency across different environments as well as different genetic backgrounds will help in developing high-yielding crop varieties (Prince et al, 2015). Maccaferri et al (2008) also emphasized the consistency of a QTL across a broad range of environmental conditions, and that the coincidence of QTLs across environments is critical to breed crops for wide adaptation and yield stability (Cattivelliet al, 2008).…”

Genetic Mapping Of Morpho-Physiological Traits Involved During Reproductive Stage Drought Tolerance In Rice

“…As per findings of [21], 5 QTLs were detected for leaf rolling trait out of which one QTL was in chromosome 9 at a distance of 65.6cM. Also in another experiment conducted under drought stress condition, phenotypic variation of 24.8% detected for the leaf rolling QTL on chromosome 6 [27]. Under drought stress situation, chromosome 12 contains another QTL for leaf rolling trait near RM101.…”

“…The responses to drought in the vegetative stage and reproductive stage are much different [15]. Several experiments have been reported previously for morpho-physiological responses under reproductive stage drought stress [16–27].…”