Abstract
Wheat is essential to global food security however climate change threatens its yield. While the impacts of gradual temperature increases are known, the effects of heat waves (HW), which are becoming more frequent and severe, are less understood particularly under field conditions. This study explores the impact of pre- and post-anthesis (AN) HW on grain yield (GY), grain number (GN), average grain weight (AGW), and physiological determinants of GN. To quantify the pre- and post-AN HW effects on GY, GN and AGW of two cultivars with constitutive contrasting levels of GN and AGW; to determine whether a higher or lower sensitivity to a HW would be related to genotypic inherent characteristic; and to ascertain whether penalties in GN due to pre-AN HW are direct on reproductive output or indirect by affecting crop growth. Most details on AGW determination are offered in the companion paper. Experiments were irrigated and carried out in two locations of NE Spain. Main treatments consisted in the factorial combination of two contrasting genotypes (Pistolo of high AGW and Sublim of high GN), and three HW that were imposed in the field using portable tents covered with transparent polyethylene films, but with the base opened to favour air circulation, during 9–11 continuous days, increasing temperatures during the day only, which resulted in average daily temperature 3–4 ºC warmer. The HW started either at booting (pre-AN HW) or 15 days after anthesis (post-AN HW). An additional HW (combination of pre- and post-AN HW) was imposed in one location while thinning treatment at the onset of stem elongation in the other. Under unheated conditions, both cultivars had similarly high yields. The increment of yield potential with thinning was lower in Pistolo (33 %) than Sublim (79 %). Both cultivars had similar spike number plasticity, but only Sublim showed spike fertility plasticity to added resources as well. HW significantly reduced GY: Pistolo was more sensitive to pre-AN HW, but not to post-AN HW. Yield losses were mainly due to reduced GN with pre-AN HW, and reduced AGW with post-AN HW. Pre-AN HW increased floret mortality mostly in central spikelets, while thinning boosted floret survival, especially in distal spikelets, restoring fertility even in typically sterile basal spikelets. Thinning reduced HW damage in Pistolo from 18 % to 1 %, but not in Sublim (c. 14 % in both conditions). This implies that HW effects could be mainly indirect, through affecting growth, or mainly direct, affecting floret developmental process (and not reversed when more assimilates become available), depending on the genotype. Post-AN HW caused greater GY penalties (24.8 %) than pre-AN HW (15.1 %), but this seemed related to environmental variation during treatments than a true greater sensitivity. More in depth analyses regarding AGW is provided in the companion paper. The HW treatment consistently reduced yield, with GN mainly affected when applied pre-anthesis and AGW when imposed during grain filling. However, the magnitude of these penalties differed between genotypes and seemed to be resource driven in one but not in the other genotype. This indicates that a pre-AN HW can impair spike fertility and consequently grain yield, and that genotype-specific responses may reflect direct effects on reproduction or indirect effects via reduced source strength. Responses to HW seemed not to be a genotypic constitutive characteristic, as the response changes between cultivars depending on the timing of the HW and the GY strategies, making breeding for HW resilience less straightforward. Breeding programs should not solely consider the particular yield component strategies when selecting for yield stability under stress. The plasticity to resource availability seemed unrelated to that for HW. • GY sensitivity to heat wave (HW) did not clearly depend on the genotypic GY components strategy and availability of resources. • Sensitivity of GN spike −1 to pre-anthesis HW was partially driven by increased floret mortality, mainly through grain abortion. • The response of a yield component to heat stress seemed to be inversely related to the relevance of that component. • Effects of HW varies with timing and GY strategies, not solely due to fixed genotypic traits.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. 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 20
Claim · model-written summary
Under unheated conditions, Pistolo and Sublim had similarly high yields.
- Taxon
- wheat
Triticum aestivumt0 - Outcome
- similarly high yieldse0
- Qualifier
- Under unheated conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under unheated conditions, both cultivars had similarly high yields”
t0“wheat cultivars”
Claim · model-written summary
Thinning increased Pistolo yield potential by 33%.
- Taxon
- wheatTriticum aestivumt0
- Material
- Pistoloe0
- Treatment
- thinninge0
- Outcome
- yield potentiale0
- Direction
- incremente0
- Value
- 33 %e0
- Comparator
- Sublime0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increment of yield potential with thinning was lower in Pistolo (33 %) than Sublim (79 %)”
t0“wheat”
Claim · model-written summary
Thinning increased Sublim yield potential by 79%.
- Taxon
- wheatTriticum aestivumt0
- Material
- Sublime0
- Treatment
- thinninge0
- Outcome
- yield potentiale0
- Direction
- incremente0
- Value
- 79 %e0
- Comparator
- Pistoloe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increment of yield potential with thinning was lower in Pistolo (33 %) than Sublim (79 %)”
t0“wheat”
Claim · model-written summary
Both cultivars showed similar spike-number plasticity.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- similar spike number plasticitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both cultivars had similar spike number plasticity”
t0“wheat”
Claim · model-written summary
Only Sublim showed spike-fertility plasticity to added resources.
- Taxon
- wheatTriticum aestivumt0
- Material
- Sublime0
- Outcome
- spike fertility plasticity to added resourcese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“only Sublim showed spike fertility plasticity to added resources as well”
t0“wheat”
Claim · model-written summary
Heat waves significantly reduced grain yield.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- HWe0
- Outcome
- GYe0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“HW significantly reduced GY”
t0“wheat”
Claim · model-written summary
Pistolo was more sensitive to pre-anthesis heat waves.
- Taxon
- wheatTriticum aestivumt0
- Material
- Pistoloe0
- Outcome
- sensitive to pre-AN HWe0
- Direction
- more sensitivee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pistolo was more sensitive to pre-AN HW, but not to post-AN HW”
t0“wheat”
Claim · model-written summary
Pistolo was not more sensitive to post-anthesis heat waves.
- Taxon
- wheatTriticum aestivumt0
- Material
- Pistoloe0
- Outcome
- post-AN HWe0
- Direction
- note0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pistolo was more sensitive to pre-AN HW, but not to post-AN HW”
t0“wheat”
Claim · model-written summary
Pre-anthesis heat waves reduced grain number.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- pre-AN HWe0
- Outcome
- GNe0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“reduced GN with pre-AN HW”
t0“wheat”
Claim · model-written summary
Post-anthesis heat waves reduced average grain weight.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- post-AN HWe0
- Outcome
- AGWe0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“reduced AGW with post-AN HW”
t0“wheat”
Claim · model-written summary
Pre-anthesis heat waves increased floret mortality, chiefly in central spikelets.
- Taxon
- wheatTriticum aestivumt0
- Organ / stage
- central spikeletse0
- Treatment
- Pre-AN HWe0
- Outcome
- floret mortalitye0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pre-AN HW increased floret mortality mostly in central spikelets”
t0“wheat”
Claim · model-written summary
Thinning increased floret survival, especially in distal spikelets.
- Taxon
- wheatTriticum aestivumt0
- Organ / stage
- distal spikeletse0
- Treatment
- thinninge0
- Outcome
- floret survivale0
- Direction
- boostede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“thinning boosted floret survival, especially in distal spikelets”
t0“wheat”
Claim · model-written summary
Thinning restored fertility in usually sterile basal spikelets.
- Taxon
- wheatTriticum aestivumt0
- Organ / stage
- basal spikeletse0
- Treatment
- thinninge0
- Outcome
- fertilitye0
- Direction
- restoringe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“while thinning boosted floret survival, especially in distal spikelets, restoring fertility even in typically sterile basal spikelets”
t0“wheat cultivars”
Claim · model-written summary
Thinning reduced heat-wave damage in Pistolo from 18% to 1%.
- Taxon
- wheatTriticum aestivumt0
- Material
- Pistoloe0
- Treatment
- Thinninge0
- Outcome
- HW damagee0
- Direction
- reducede0
- Value
- 1 %e0
- Qualifier
- 18 %e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thinning reduced HW damage in Pistolo from 18 % to 1 %”
t0“wheat”
Claim · model-written summary
Thinning did not reduce heat-wave damage in Sublim, around 14% in both conditions.
- Taxon
- wheatTriticum aestivumt0
- Material
- Sublime0
- Treatment
- Thinninge0
- Outcome
- 14 % in both conditionse0
- Value
- 14 %e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thinning reduced HW damage in Pistolo from 18 % to 1 %, but not in Sublim (c. 14 % in both conditions)”
t0“wheat”
Claim · model-written summary
Post-anthesis heat waves caused a 24.8% grain-yield penalty.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Post-AN HWe0
- Outcome
- GY penaltiese0
- Direction
- greatere0
- Value
- 24.8 %e0
- Comparator
- pre-AN HWe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Post-AN HW caused greater GY penalties (24.8 %) than pre-AN HW (15.1 %)”
t0“wheat”
Claim · model-written summary
Pre-anthesis heat waves caused a 15.1% grain-yield penalty.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- pre-AN HWe0
- Outcome
- GY penaltiese0
- Direction
- greatere0
- Value
- 15.1 %e0
- Comparator
- Post-AN HWe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Post-AN HW caused greater GY penalties (24.8 %) than pre-AN HW (15.1 %)”
t0“wheat”
Claim · model-written summary
The apparent timing difference in yield penalties may reflect environmental variation during treatment.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- greater sensitivitye0
- Qualifier
- environmental variation during treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this seemed related to environmental variation during treatments than a true greater sensitivity”
t0“wheat”
Claim · model-written summary
Heat-wave responses varied with timing and yield strategies rather than fixed cultivar traits.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- Effects of HW varies with timing and GY strategiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Effects of HW varies with timing and GY strategies, not solely due to fixed genotypic traits”
t0“wheat”
Claim · model-written summary
Breeding programs should consider more than yield-component strategy when selecting heat-stable wheat.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- should not solely consider the particular yield component strategies when selecting for yield stability under stresse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Breeding programs should not solely consider the particular yield component strategies when selecting for yield stability under stress”
t0“wheat”
The same questions in other papers
pruning · survival · Triticum aestivum (wheat)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
pruning · pest · Triticum aestivum (wheat)Positive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
pruning · yield · Triticum aestivum (wheat)Positive and negative results
32 papers in the same direction as this paper · 60 in the opposite direction
- no effect
- no effect
- negative
89 papers more in this group
See all 93 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.