Abstract
Drought is the most important factor limiting rice productivity in the rainfed areas of Asia. In this study, 48 pyramiding lines (PLs) and their recurrent parent, IR64, were evaluated over two years for their yield performances and related traits under severe drought stress at the reproductive stage (RS), the vegetative stage (VS) and irrigated control in order to understand the relationship between drought tolerance (DT) and yield potential (YP) in rice and their underlying mechanisms. When compared with IR64, all PLs had significantly improved DT to RS and 36 PLs also had significantly improved DT to VS. In addition, 17 PLs had higher YP than IR64 and the remaining 31 PLs had a similar YP IR64 under irrigated conditions. Detailed characterization of the PLs revealed three possible mechanisms that functioned together to contribute to their improved DT. The most important mechanism was dehydration avoidance (DA), characterized by significantly higher growth rate and biomass of all PLs than IR64 under stress and no reduction in biomass under control conditions. The second mechanism was efficient partitioning, characterized by improved harvest index in all PLs compared with IR64, resulting primarily from heavier grain weight and/or higher spikelet fertility under control conditions, which was the major constituent of the improved YP in the 17 best performing PLs. Drought escape (DE) by accelerated heading under drought was the third mechanism that contributed to DT of the PLs to RS. The considerable variation in the measured traits among the PLs with similar levels of DT and YP implies the complex genetic control of the mechanisms for DT/YP and offers opportunities to improve DT and YP further by fine-tuning of a small number of QTLs segregating among the PLs using MAS. Finally, our results indicate that selection for yield plus some secondary traits under appropriate type(s) of stress and non-stress conditions similar to the target environments are critically important for improving both DT and YP in rice.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 11
Claim · model-written summary
All pyramiding lines had significantly improved drought tolerance to the reproductive stage compared with IR64
- Taxon
- rice (Oryza sativa L.)
Oryza sativat0 - Material
- 48 pyramiding lines (PLs)e0
- Treatment
- severe drought stress at the reproductive stage (RS)e0
- Outcome
- DT to RSe1
- Direction
- significantly improvede1
- Comparator
- IR64e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e0“48 pyramiding lines (PLs) and their recurrent parent, IR64, were evaluated over two years for their yield performances and related traits under severe drought stress at the reproductive stage (RS)”
e1“When compared with IR64, all PLs had significantly improved DT to RS and 36 PLs also had significantly improved DT to VS”
Claim · model-written summary
Thirty-six pyramiding lines had significantly improved drought tolerance to the vegetative stage compared with IR64
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Material
- 36 PLse1
- Treatment
- the vegetative stage (VS)e2
- Outcome
- DT to VSe1
- Direction
- significantly improvede1
- Comparator
- IR64e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e1“When compared with IR64, all PLs had significantly improved DT to RS and 36 PLs also had significantly improved DT to VS”
e2“under severe drought stress at the reproductive stage (RS), the vegetative stage (VS) and irrigated control”
Claim · model-written summary
Seventeen pyramiding lines had higher yield potential than IR64 under irrigated conditions
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Material
- 17 PLse3
- Outcome
- YPe3
- Direction
- highere3
- Comparator
- IR64e3
- Setting
- irrigated conditionse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e3“In addition, 17 PLs had higher YP than IR64 and the remaining 31 PLs had a similar YP IR64 under irrigated conditions”
Claim · model-written summary
The remaining 31 pyramiding lines had yield potential similar to IR64 under irrigated conditions
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Material
- 31 PLse3
- Outcome
- YPe3
- Direction
- similare3
- Comparator
- IR64e3
- Setting
- irrigated conditionse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e3“In addition, 17 PLs had higher YP than IR64 and the remaining 31 PLs had a similar YP IR64 under irrigated conditions”
Claim · model-written summary
Under stress, all pyramiding lines had significantly higher growth rate and biomass than IR64
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Material
- all PLse4
- Treatment
- under stresse4
- Outcome
- growth rate and biomasse4
- Direction
- significantly highere4
- Comparator
- IR64e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e4“The most important mechanism was dehydration avoidance (DA), characterized by significantly higher growth rate and biomass of all PLs than IR64 under stress and no reduction in biomass under control conditions”
Claim · model-written summary
Under control conditions, pyramiding lines showed no reduction in biomass
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Outcome
- biomass under control conditionse4
- Direction
- no reductione4
- Setting
- control conditionse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e4“The most important mechanism was dehydration avoidance (DA), characterized by significantly higher growth rate and biomass of all PLs than IR64 under stress and no reduction in biomass under control conditions”
Claim · model-written summary
All pyramiding lines had improved harvest index compared with IR64
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Material
- all PLse5
- Outcome
- harvest indexe5
- Direction
- improvede5
- Comparator
- IR64e5
- Setting
- control conditionse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e5“The second mechanism was efficient partitioning, characterized by improved harvest index in all PLs compared with IR64, resulting primarily from heavier grain weight and/or higher spikelet fertility under control conditions, which was the major constituent of the improved YP in the 17 best performing PLs”
Claim · model-written summary
Improved harvest index was primarily due to heavier grain weight and/or higher spikelet fertility
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Outcome
- harvest indexe5
- Qualifier
- heavier grain weight and/or higher spikelet fertilitye5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e5“The second mechanism was efficient partitioning, characterized by improved harvest index in all PLs compared with IR64, resulting primarily from heavier grain weight and/or higher spikelet fertility under control conditions, which was the major constituent of the improved YP in the 17 best performing PLs”
Claim · model-written summary
Under drought, accelerated heading contributed to drought tolerance of the pyramiding lines to the reproductive stage
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Treatment
- under droughte6
- Outcome
- headinge6
- Direction
- acceleratede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e6“Drought escape (DE) by accelerated heading under drought was the third mechanism that contributed to DT of the PLs to RS”
Claim · model-written summary
Variation among pyramiding lines implies complex genetic control of drought tolerance and yield potential mechanisms
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Outcome
- genetic control of the mechanisms for DT/YPe7
- Qualifier
- considerable variation in the measured traitse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e7“The considerable variation in the measured traits among the PLs with similar levels of DT and YP implies the complex genetic control of the mechanisms for DT/YP”
Claim · model-written summary
Selection for yield plus secondary traits under appropriate stress and non-stress conditions is critically important for improving drought tolerance and yield potential
- Taxon
- rice (Oryza sativa L.)Oryza sativat0
- Outcome
- selection for yield plus some secondary traitse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“rice (Oryza sativa L.)”
e0“selection for yield plus some secondary traits under appropriate type(s) of stress and non-stress conditions similar to the target environments are critically important for improving both DT and YP”
The same questions in other papers
drought · phenology · Oryza sativa (rice)Results differ
1 paper in the same direction as this paper · 16 in the opposite direction
- negative
- negative
- no effect
14 papers more in this group
See all 18 papers →drought · tolerance: abiotic · Oryza sativa (rice)Positive and negative results
13 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
12 papers more in this group
See all 16 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.