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Favorable alleles for stem water-soluble carbohydrates identified by association analysis contribute to grain weight under drought stress conditions in wheat.

Li W, Zhang B, Li R, Chang X, Jing R - PLoS ONE (2015)

Bottom Line: Sixteen novel WSC-favorable alleles were identified, and five of them contributed to significantly higher TGW.In addition, pyramiding WSC favorable alleles was not only effective for obtaining accessions with higher WSC, but also for enhancing TGW under different water regimes.The results indicate a high potential for using marker-assisted selection to pyramid WSC favorable alleles in improving WSC and TGW in wheat.

View Article: PubMed Central - PubMed

Affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement / Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Agronomy College, Shanxi Agricultural University, Taigu 030801, China.

ABSTRACT
Drought is a major environmental constraint to crop distribution and productivity. Stem water-soluble carbohydrates (WSC) buffer wheat grain yield against conditions unfavorable for photosynthesis during the grain filling stage. In this study, 262 winter wheat accessions and 209 genome-wide SSR markers were collected and used to undertake association analysis based on a mixed linear model (MLM). The WSC in different internodes at three growth stages and 1000-grain weight (TGW) were investigated under four environmental regimes (well-watered, drought stress during the whole growth period, and two levels of terminal drought stress imposed by chemical desiccation under the well-watered and drought stress during the whole growth period conditions). Under diverse drought stress conditions, WSC in lower internodes showed significant positive correlations with TGW, especially at the flowering stage under well-watered conditions and at grain filling under drought stress. Sixteen novel WSC-favorable alleles were identified, and five of them contributed to significantly higher TGW. In addition, pyramiding WSC favorable alleles was not only effective for obtaining accessions with higher WSC, but also for enhancing TGW under different water regimes. During the past fifty years of wheat breeding, WSC was selected incidentally. The average number of favorable WSC alleles increased from 1.13 in the pre-1960 period to 4.41 in the post-2000 period. The results indicate a high potential for using marker-assisted selection to pyramid WSC favorable alleles in improving WSC and TGW in wheat.

Show MeSH
Accumulation (A) and frequency distribution (B) of 16 favorable alleles in modern varieties from different decades.Bars indicate 2×SE.
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pone.0119438.g007: Accumulation (A) and frequency distribution (B) of 16 favorable alleles in modern varieties from different decades.Bars indicate 2×SE.

Mentions: Breeding leaves a strong footprint at the genome level [42]. A number of important genes (alleles) were positively selected, as implicated by changes in numbers and frequency [43]. We estimated the accumulation and frequency distribution of 16 favorable alleles identified in our research in modern varieties from different decades. The average number of favorable WSC alleles increased from 1.13 in the pre-1960 period to 4.41 in the post-2000 period (Fig. 7A). Most modern varieties carried one or two favorable alleles before 1970, whereas modern varieties after 1990 have as many as eight favorable alleles (Fig. 7B). The obvious positive selection of the 16 favorable alleles identified here proves their value in breeding programs over past decades. However, compared with the 16 favorable alleles, the average number (4.41) in post-2000 varieties is relatively lower and indicates considerable potential for further improvement.


Favorable alleles for stem water-soluble carbohydrates identified by association analysis contribute to grain weight under drought stress conditions in wheat.

Li W, Zhang B, Li R, Chang X, Jing R - PLoS ONE (2015)

Accumulation (A) and frequency distribution (B) of 16 favorable alleles in modern varieties from different decades.Bars indicate 2×SE.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4358973&req=5

pone.0119438.g007: Accumulation (A) and frequency distribution (B) of 16 favorable alleles in modern varieties from different decades.Bars indicate 2×SE.
Mentions: Breeding leaves a strong footprint at the genome level [42]. A number of important genes (alleles) were positively selected, as implicated by changes in numbers and frequency [43]. We estimated the accumulation and frequency distribution of 16 favorable alleles identified in our research in modern varieties from different decades. The average number of favorable WSC alleles increased from 1.13 in the pre-1960 period to 4.41 in the post-2000 period (Fig. 7A). Most modern varieties carried one or two favorable alleles before 1970, whereas modern varieties after 1990 have as many as eight favorable alleles (Fig. 7B). The obvious positive selection of the 16 favorable alleles identified here proves their value in breeding programs over past decades. However, compared with the 16 favorable alleles, the average number (4.41) in post-2000 varieties is relatively lower and indicates considerable potential for further improvement.

Bottom Line: Sixteen novel WSC-favorable alleles were identified, and five of them contributed to significantly higher TGW.In addition, pyramiding WSC favorable alleles was not only effective for obtaining accessions with higher WSC, but also for enhancing TGW under different water regimes.The results indicate a high potential for using marker-assisted selection to pyramid WSC favorable alleles in improving WSC and TGW in wheat.

View Article: PubMed Central - PubMed

Affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement / Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Agronomy College, Shanxi Agricultural University, Taigu 030801, China.

ABSTRACT
Drought is a major environmental constraint to crop distribution and productivity. Stem water-soluble carbohydrates (WSC) buffer wheat grain yield against conditions unfavorable for photosynthesis during the grain filling stage. In this study, 262 winter wheat accessions and 209 genome-wide SSR markers were collected and used to undertake association analysis based on a mixed linear model (MLM). The WSC in different internodes at three growth stages and 1000-grain weight (TGW) were investigated under four environmental regimes (well-watered, drought stress during the whole growth period, and two levels of terminal drought stress imposed by chemical desiccation under the well-watered and drought stress during the whole growth period conditions). Under diverse drought stress conditions, WSC in lower internodes showed significant positive correlations with TGW, especially at the flowering stage under well-watered conditions and at grain filling under drought stress. Sixteen novel WSC-favorable alleles were identified, and five of them contributed to significantly higher TGW. In addition, pyramiding WSC favorable alleles was not only effective for obtaining accessions with higher WSC, but also for enhancing TGW under different water regimes. During the past fifty years of wheat breeding, WSC was selected incidentally. The average number of favorable WSC alleles increased from 1.13 in the pre-1960 period to 4.41 in the post-2000 period. The results indicate a high potential for using marker-assisted selection to pyramid WSC favorable alleles in improving WSC and TGW in wheat.

Show MeSH