Figure 1.
Germination rate of Jagger and 2714.
The experiment was performed in 2011. Seed collected from a greenhouse was tested 1, 2, 3, 4, 5, and 6 weeks after harvesting in an incubator where constant temperature at 24°C was set up. The germination rate was an average of three replicates, and no standard error was calculated.
Figure 2.
Chromosomal location and genetic effects of QTsg.osu-3A for seed germination.
The QTLs were characterized at high temperature (HT) and normal temperature (NT) in years 2008, 2009, and 2010, when seed was harvested 15, 30, or 45 days. Germination rate was tested in the recombinant inbred lines (RILs) of the Jagger×2174 population. Molecular markers along the chromosome are placed as centimorgans on the horizontal axis. The horizontal dotted line represents a common threshold value of 2.5 LOD.
Table 1.
A summary of genetic effects of QTsg.osu-3A on seed germination under various temperatures.
Figure 3.
Specific amplification of TaMFT-A1.
Primer MFT-F1M and MFT-A1R1 were used to amplify the complete TaMFT-A1 from three nullisomic-tetrasomic (NT) Chinese Spring (CS) lines, N3AT3B (1), N3BT3A (2), N3DT3A (3), as well as Jagger (4) and 2174 (5).
Figure 4.
Diagram for mutated sites at the Jagger TaMFT-A1 haplotype.
Star symbol indicates positions of two reported polymorphisms in the CS allele for weak dormancy compared with the Zen allele for strong dormancy. Triangle star indicates the position of polymorphic site in intron 2 due to the presence of the poly ‘G’. Dot symbol indicates mutation sites throughout the Jagger TaMFT-A1 gene compared with the other three alleles.
Figure 5.
Primer MFT-A1F2 and MFT-A1R2 were used to amplify TaMFT-A1 from Jagger (331 bp) and 2174 (319 bp). PCR products were directly run on a 1% agarose gel.
Figure 6.
Genetic effect of TaMFT-A1 on germination rate.
The germination rate was averaged from each of the Jagger allele (A) or the 2174 allele (B) in the population (n = 96) that were characterized at high temperature (HT) and normal temperature (NT) in 2009 (Fig. 6A) and 2010 (Fig. 6B), when seed was harvested 15, 30, 45, or 70 days. Bar indicates standard error.
Figure 7.
Expression profiles of TaMFT-A1.
A) Transcript levels of TaMFT-A1a (the Jagger allele) and TaMFT-A1b (the 2174 allele) in the after-ripened seeds. RNA samples were collected from embryos of seeds, when the seeds were tested at 2 weeks (2 wks), 4 weeks (4 wks), and 7 weeks (7 wks) after harvest. B) Regulation of TaMFT-A1 transcript levels by temperature. The RNA samples were collected from 2174 seeds that were treated with normal temperature (NT, 25°C), low temperature (LT, 4°C) for overnight, and high temperature (HT, 37°C) for 5 days. Transcript levels are shown using the values calculated by the 2(−ΔΔCT) method, where CT is the threshold cycle, and actin was used as an endogenous control. The values represent mean expression levels (n = 12), and the bar indicates standard error.