Limits...
QTL analysis of root morphology, flowering time, and yield reveals trade-offs in response to drought in Brassica napus.

Fletcher RS, Mullen JL, Heiliger A, McKay JK - J. Exp. Bot. (2014)

Bottom Line: We found strong genetic correlations among all traits, suggesting a trade-off among traits may exist.Summing across traits and treatments we found 20 QTLs, but many of these co-localized to two major QTLs, providing evidence that the trade-off is genetically constrained.Our results suggest a causal model where such QTLs affect root mass directly as well as through their impacts on flowering time.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA Cargill Specialty Seeds and Oils, Fort Collins, CO 80525, USA richard_fletcher@cargill.com.

No MeSH data available.


Related in: MedlinePlus

Localization and relative effect sizes of QTLs for the six traits analysed. Box widths indicate LOD 1.5 confidence intervals for the QTLs. The box height represents the percentage variance explained. Colour indicates the directional effect of the Wichita allele (blue, positive; grey, negative). The pleiotropic QTLs on chromosomes A10 and C02 are bracketed in red. Numbers next to boxes indicate the QTL naming scheme.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4265167&req=5

Figure 3: Localization and relative effect sizes of QTLs for the six traits analysed. Box widths indicate LOD 1.5 confidence intervals for the QTLs. The box height represents the percentage variance explained. Colour indicates the directional effect of the Wichita allele (blue, positive; grey, negative). The pleiotropic QTLs on chromosomes A10 and C02 are bracketed in red. Numbers next to boxes indicate the QTL naming scheme.

Mentions: We scanned for QTLs associated with DTF, RPF, and yield along with the sensitivity of yield to drought. Seven QTLs for DTF were mapped; four in the wet and three in the dry treatments. For RPF, three QTLs were identified in the wet environment and two in the dry. Analyses of yield found three QTLs for each environment. Summing across all four traits, a total of 20 additive QTLs were discovered (Fig. 3). QTLs co-localized to regions on linkage groups A03, A10, and C02 (Fig. 3), thus implicating tight linkage or pleiotropy as the cause of the strong genetic correlations observed among traits. In particular, two regions on A10 and C02 (bracketed in red in Fig. 3) explained a large proportion of the variation for each trait and their estimated effects were always larger than other QTLs discovered for any particular trait. All of the QTLs discovered for yield co-localized with QTLs for DTF, further supporting the strong relationship between these traits where a flowering time of ~68 days increases the probability of higher yield (Fig. 2). These results also show that, unlike yield, the genetics underlying DTF and RPF did not overlap entirely. For example, DTF.wet1 and DTF.wet2 had no relationship to RPF where RPF.wet3, located on C07, had no relationship to DTF. This also suggests that the QTLs on A10 and C02 may be responsible for most, or all, of the genetic correlation (r = 0.45) of RPF measured in the wet and dry treatment (Supplementary Table S2).


QTL analysis of root morphology, flowering time, and yield reveals trade-offs in response to drought in Brassica napus.

Fletcher RS, Mullen JL, Heiliger A, McKay JK - J. Exp. Bot. (2014)

Localization and relative effect sizes of QTLs for the six traits analysed. Box widths indicate LOD 1.5 confidence intervals for the QTLs. The box height represents the percentage variance explained. Colour indicates the directional effect of the Wichita allele (blue, positive; grey, negative). The pleiotropic QTLs on chromosomes A10 and C02 are bracketed in red. Numbers next to boxes indicate the QTL naming scheme.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4265167&req=5

Figure 3: Localization and relative effect sizes of QTLs for the six traits analysed. Box widths indicate LOD 1.5 confidence intervals for the QTLs. The box height represents the percentage variance explained. Colour indicates the directional effect of the Wichita allele (blue, positive; grey, negative). The pleiotropic QTLs on chromosomes A10 and C02 are bracketed in red. Numbers next to boxes indicate the QTL naming scheme.
Mentions: We scanned for QTLs associated with DTF, RPF, and yield along with the sensitivity of yield to drought. Seven QTLs for DTF were mapped; four in the wet and three in the dry treatments. For RPF, three QTLs were identified in the wet environment and two in the dry. Analyses of yield found three QTLs for each environment. Summing across all four traits, a total of 20 additive QTLs were discovered (Fig. 3). QTLs co-localized to regions on linkage groups A03, A10, and C02 (Fig. 3), thus implicating tight linkage or pleiotropy as the cause of the strong genetic correlations observed among traits. In particular, two regions on A10 and C02 (bracketed in red in Fig. 3) explained a large proportion of the variation for each trait and their estimated effects were always larger than other QTLs discovered for any particular trait. All of the QTLs discovered for yield co-localized with QTLs for DTF, further supporting the strong relationship between these traits where a flowering time of ~68 days increases the probability of higher yield (Fig. 2). These results also show that, unlike yield, the genetics underlying DTF and RPF did not overlap entirely. For example, DTF.wet1 and DTF.wet2 had no relationship to RPF where RPF.wet3, located on C07, had no relationship to DTF. This also suggests that the QTLs on A10 and C02 may be responsible for most, or all, of the genetic correlation (r = 0.45) of RPF measured in the wet and dry treatment (Supplementary Table S2).

Bottom Line: We found strong genetic correlations among all traits, suggesting a trade-off among traits may exist.Summing across traits and treatments we found 20 QTLs, but many of these co-localized to two major QTLs, providing evidence that the trade-off is genetically constrained.Our results suggest a causal model where such QTLs affect root mass directly as well as through their impacts on flowering time.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA Cargill Specialty Seeds and Oils, Fort Collins, CO 80525, USA richard_fletcher@cargill.com.

No MeSH data available.


Related in: MedlinePlus