Figure 1.
Enhanced growth phenotype of MSH1 lines in sorghum.
The transgene and crossing procedure used to derive sorghum populations is indicated. (A) The phenotype of the F1 progeny derived from crossing Tx430×MSH1-dr. (B) Field grown F2, F3 and F4 sorghum lines show variation in plant architecture and height. (C) Panicles from Tx430 (on left, 66 g, 8 mm stem) versus a larger F2 individual (on right, 112 g, 11 mm stem), and (D) seed yield after threshing. (E) The MSH1-dr sorghum phenotype under field conditions. (F) Sorghum MSH1 F2, F3 and F4 populations grown in progeny rows in a 2011 field experiment. Wild type inbred Tx430 is indicated. Variation in plant height, flowering time and plant architecture is apparent; all plants shown are non-transgenic and Tx430 genotype.
Figure 2.
Increased phenotypic variation in MSH1 F2 lines.
(A) Boxplots of within-row field variance for indicated traits, with values normalized as a proportion of the maximum observed row variance for that trait. Differences in variances between the F2 and wild type populations were significant for plant height (Brown-Forsythe test, p<0.001) and grain yield (p<0.01). (B) Histograms for yield per panicle in the F2 population compared to wild type, from the two field plantings. (C) Percentile values for yield per panicle in the F2 population compared to wild type, estimated from bootstrapping; error bars represent standard deviation.
Figure 3.
Phenotypic changes over MSH1 F2, F3 and F4 generations.
(A) Selection had varying results, with response for yield into the F3 generation, but not into the F4 generation. For each lineage, the mean generation performance is represented as a point. (B) Boxplots of F2, F3, and F4 line means for various traits, giving a population-wide view of line performance. Dashed lines indicate the 95% confidence interval for wild type Tx430 mean.
Figure 4.
Line performance shows environmental interactions.
Joint regression (with Wright modification) indicates differential response between lines to location.