Abstract
Canola is an extremely important commodity to the western Canadian economy. Annual or geographic fluctuations in yield due to heat stress can have a significant influence on total production. To increase the stability of canola yield, breeders need to select for increased heat tolerance in a reliable, repeatable, cost effective manner that represents commercial production conditions. Field experiments with 10 (5 maintainer and 5 restorer) inbreds and the 25 corresponding hybrids were conducted across 2 years with 2 locations per year. Each experiment had two planting dates (normal planting date and a late planting date). The experiments were designed to determine if: 1) planting date can be used as a proxy for heat stress; 2) heterosis can minimize the impact of heat stress; and 3) direct selection within a heat-stress environment improves genetic gain for heat-stress tolerance. Principal component analysis of the Tmax, Tmin, Tmean, soil moisture, daily light integral and yield were conducted. The resulting biplot analyses demonstrate that the temperature variables had a greater impact on yield than soil moisture or daily light integral and therefore planting date was identified as a successful proxy for heat stress. The heat-stress treatment caused a 23% mean reduction in seed yield (20% reduction within the hybrids and 25% reduction within the inbreds) indicating that heterosis can reduce the impact of higher temperatures on canola yield. The mean heat susceptibility index was 0.94 and 1.20 for the hybrids and inbreds respectively; further demonstrating that the hybrids were more heat tolerant than the inbreds. Analyses of the GCA for the inbreds shows 4 cross-over interactions between the two temperature treatments indicating that direct selection for heat tolerance will be necessary to increase the response to selection for this trait. Overall canola breeders interested in increasing heat tolerance need to consider utilizing planting date as a high-temperature treatment and cannot rely on indirect selection from experiments under optimal conditions.
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Claims 11
Claim · model-written summary
The heat-stress treatment reduced mean seed yield of canola by 23% relative to normal planting.
- Taxon
- canola
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Brassica napus var. napust0 - Treatment
- heat-stress treatmente1
- Outcome
- seed yielde1
- Direction
- reductione1
- Value
- 23%e1
- Comparator
- normal planting datee2
- Setting
- Field experimentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“spring canola (Brassica napus L.)”
e0“Field experiments with 10 (5 maintainer and 5 restorer) inbreds and the 25 corresponding hybrids were conducted across 2 years with 2 locations per year”
e1“The heat-stress treatment caused a 23% mean reduction in seed yield (20% reduction within the hybrids and 25% reduction within the inbreds)”
e2“Each experiment had two planting dates (normal planting date and a late planting date)”
Claim · model-written summary
In hybrids, the heat-stress treatment reduced seed yield by 20% relative to normal planting.
- Taxon
- canolaBrassica napus var. napust0
- Material
- hybridse1
- Treatment
- heat-stress treatmente1
- Outcome
- seed yielde1
- Direction
- reductione1
- Value
- 20%e1
- Comparator
- normal planting datee2
- Setting
- Field experimentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e0“Field experiments with 10 (5 maintainer and 5 restorer) inbreds and the 25 corresponding hybrids were conducted across 2 years with 2 locations per year”
e1“The heat-stress treatment caused a 23% mean reduction in seed yield (20% reduction within the hybrids and 25% reduction within the inbreds)”
e2“Each experiment had two planting dates (normal planting date and a late planting date)”
Claim · model-written summary
In inbreds, the heat-stress treatment reduced seed yield by 25% relative to normal planting.
- Taxon
- canolaBrassica napus var. napust0
- Material
- inbredse1
- Treatment
- heat-stress treatmente1
- Outcome
- seed yielde1
- Direction
- reductione1
- Value
- 25%e1
- Comparator
- normal planting datee2
- Setting
- Field experimentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e0“Field experiments with 10 (5 maintainer and 5 restorer) inbreds and the 25 corresponding hybrids were conducted across 2 years with 2 locations per year”
e1“The heat-stress treatment caused a 23% mean reduction in seed yield (20% reduction within the hybrids and 25% reduction within the inbreds)”
e2“Each experiment had two planting dates (normal planting date and a late planting date)”
Claim · model-written summary
The mean heat susceptibility index of hybrids was 0.94.
- Taxon
- canolaBrassica napus var. napust0
- Material
- hybridse3
- Outcome
- mean heat susceptibility indexe3
- Value
- 0.94e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e3“The mean heat susceptibility index was 0.94 and 1.20 for the hybrids and inbreds respectively”
Claim · model-written summary
The mean heat susceptibility index of inbreds was 1.20.
- Taxon
- canolaBrassica napus var. napust0
- Material
- inbredse3
- Outcome
- mean heat susceptibility indexe3
- Value
- 1.20e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e3“The mean heat susceptibility index was 0.94 and 1.20 for the hybrids and inbreds respectively”
Claim · model-written summary
Hybrids were more heat tolerant than inbreds.
- Taxon
- canolaBrassica napus var. napust0
- Material
- hybridse4
- Outcome
- heat tolerante4
- Direction
- more heat tolerante4
- Comparator
- inbredse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e4“the hybrids were more heat tolerant than the inbreds”
Claim · model-written summary
The GCA analysis of inbreds showed 4 cross-over interactions between the two temperature treatments.
- Taxon
- canolaBrassica napus var. napust0
- Material
- inbredse5
- Treatment
- two temperature treatmentse5
- Outcome
- cross-over interactionse5
- Value
- 4e5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e5“Analyses of the GCA for the inbreds shows 4 cross-over interactions between the two temperature treatments indicating that direct selection for heat tolerance will be necessary to increase the response to selection for this trait”
Claim · model-written summary
The authors conclude that direct selection for heat tolerance will be necessary to increase the response to selection.
- Taxon
- canolaBrassica napus var. napust0
- Outcome
- direct selection for heat tolerance will be necessarye5
- Qualifier
- to increase the response to selection for this traite5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e5“Analyses of the GCA for the inbreds shows 4 cross-over interactions between the two temperature treatments indicating that direct selection for heat tolerance will be necessary to increase the response to selection for this trait”
Claim · model-written summary
The authors recommend that canola breeders use planting date as a high-temperature treatment and not rely on indirect selection under optimal conditions.
- Taxon
- canolaBrassica napus var. napuse7
- Outcome
- utilizing planting date as a high-temperature treatmente7
- Qualifier
- cannot rely on indirect selection from experiments under optimal conditionse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“canola breeders interested in increasing heat tolerance need to consider utilizing planting date as a high-temperature treatment and cannot rely on indirect selection from experiments under optimal conditions”
Claim · model-written summary
Planting date was identified as a successful proxy for heat stress in canola.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- planting datee6
- Outcome
- successful proxy for heat stresse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e6“the temperature variables had a greater impact on yield than soil moisture or daily light integral and therefore planting date was identified as a successful proxy for heat stress”
Claim · model-written summary
Temperature variables had a greater impact on canola yield than soil moisture or daily light integral.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- temperature variablese6
- Outcome
- impact on yielde6
- Direction
- greater impacte6
- Comparator
- soil moisture or daily light integrale6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spring canola (Brassica napus L.)”
e6“the temperature variables had a greater impact on yield than soil moisture or daily light integral and therefore planting date was identified as a successful proxy for heat stress”
The same questions in other papers
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See all 22 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.