Abstract
Leaf rust ( Puccinia recondita Rob. ex Desm. f. sp. tritici ) resistant near isogenic lines (NIL) of wheat ( Triticum aestivum L.) have generally lower yields than the susceptible recurrent parent under disease free conditions. Analysis of growth and yield should increase our understanding of the reduced yielding ability of NIL. In a 3‐yr field study, the yield components of the leaf rust susceptible cultivar Arina were compared with six resistant NIL carrying the resistance gene Lr9 introduced from Aegilops umbellulata . The NIL were derived from two independently developed backcross populations with Arina as the recurrent parent. The NIL were phenotypicaily very similar to Arina. At anthesis and at mediumilk stage, the total aboveground dry matter was similar for the NIL and Arina. Differences in the dry matter accumulation appeared only after the medium milk stage. At maturity, the NIL had a 12% lower grain yield than Arina (5.88 ha −1 ) with a range from 5 to 14%. The lower grain yield resulted from a 3 to 11% reduction in grain number per square meter and a 2 to 7% reduction in mean grain weight. The smaller grain number per square meter was the result of a 6% smaller tiller number per plant and a 2% smaller grain number per ear. Artificially reducing grain number per ear suggested that both a reduced supply of assimilates and a diminished capacity to incorporate assimilates in the grain caused the reduced grain yield of the NIL. Deleterious effects of alien genes linked with the Lr9 gene from Aegilops umbellulata cannot be ruled out. However, the small differences within and between the NIL of the two Lr9 populations for the parameters tested suggest a direct relation between the yield depression and the leaf rust resistance conferred by the Lr9 gene.
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Claims 11
Claim · model-written summary
The Lr9 near isogenic lines were phenotypically very similar to Arina.
- Taxon
- wheat
Triticum aestivumt0 - Material
- NILe0
- Outcome
- phenotypicaily very similare0
- Comparator
- Arinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The NIL were phenotypicaily very similar to Arina.”
t0“Winter Wheat”
Claim · model-written summary
Aboveground dry matter was similar for the near isogenic lines and Arina at anthesis and medium milk stage.
- Taxon
- wheatTriticum aestivumt0
- Material
- NILe0
- Organ / stage
- anthesis and at mediumilk stagee0
- Outcome
- total aboveground dry mattere0
- Direction
- similare0
- Comparator
- Arinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At anthesis and at mediumilk stage, the total aboveground dry matter was similar for the NIL and Arina.”
t0“Winter Wheat”
Claim · model-written summary
Dry matter accumulation diverged only after the medium milk stage.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- dry matter accumulatione0
- Direction
- Differencese0
- Qualifier
- only after the medium milk stagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Differences in the dry matter accumulation appeared only after the medium milk stage.”
t0“Winter Wheat”
Claim · model-written summary
At maturity, the near isogenic lines yielded 12% less grain than Arina, with a 5 to 14% range.
- Taxon
- wheatTriticum aestivumt0
- Material
- NILe0
- Outcome
- grain yielde0
- Direction
- lowere0
- Value
- 12%e0
- Qualifier
- range from 5 to 14%e0
- Comparator
- Arinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At maturity, the NIL had a 12% lower grain yield than Arina (5.88 ha −1 ) with a range from 5 to 14%.”
t0“Winter Wheat”
Claim · model-written summary
The near isogenic lines had 3 to 11% fewer grains per square meter.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- grain number per square metere0
- Direction
- reductione0
- Value
- 3 to 11%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The lower grain yield resulted from a 3 to 11% reduction in grain number per square meter and a 2 to 7% reduction in mean grain weight.”
t0“Winter Wheat”
Claim · model-written summary
The near isogenic lines had 2 to 7% lower mean grain weight.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- mean grain weighte0
- Direction
- reductione0
- Value
- 2 to 7%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The lower grain yield resulted from a 3 to 11% reduction in grain number per square meter and a 2 to 7% reduction in mean grain weight.”
t0“Winter Wheat”
Claim · model-written summary
The smaller grain number was associated with 6% fewer tillers per plant.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- tiller number per plante0
- Direction
- smallere0
- Value
- 6%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The smaller grain number per square meter was the result of a 6% smaller tiller number per plant and a 2% smaller grain number per ear.”
t0“Winter Wheat”
Claim · model-written summary
The smaller grain number was associated with 2% fewer grains per ear.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- grain number per eare0
- Direction
- smallere0
- Value
- 2%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The smaller grain number per square meter was the result of a 6% smaller tiller number per plant and a 2% smaller grain number per ear.”
t0“Winter Wheat”
Claim · model-written summary
Reducing grains per ear suggested that reduced assimilate supply contributes to lower yield in the near isogenic lines.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Artificially reducing grain number per eare0
- Outcome
- reduced grain yielde0
- Qualifier
- reduced supply of assimilatese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Artificially reducing grain number per ear suggested that both a reduced supply of assimilates and a diminished capacity to incorporate assimilates in the grain caused the reduced grain yield of the NIL.”
t0“Winter Wheat”
Claim · model-written summary
Reducing grains per ear suggested that diminished capacity to incorporate assimilates in grain contributes to lower yield.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Artificially reducing grain number per eare0
- Outcome
- reduced grain yielde0
- Qualifier
- diminished capacity to incorporate assimilates in the graine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Artificially reducing grain number per ear suggested that both a reduced supply of assimilates and a diminished capacity to incorporate assimilates in the grain caused the reduced grain yield of the NIL.”
t0“Winter Wheat”
Claim · model-written summary
Small differences among Lr9 lines suggested a direct relationship between yield depression and Lr9 resistance.
- Taxon
- wheatTriticum aestivumt0
- Material
- NILe0
- Gene
- Lr9 genee0
- Outcome
- yield depressione0
- Qualifier
- suggest a direct relatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the small differences within and between the NIL of the two Lr9 populations for the parameters tested suggest a direct relation between the yield depression and the leaf rust resistance conferred by the Lr9 gene.”
t0“Winter Wheat”