TABLE 3

Enzyme activity QTL

EnzymeMarkerLocationF-ratioDifference (%)
PGMM435V:11222.6616.2
GPDG3845IV:5622.0715.0
PGIM488I:612.153.6
G3845IV:5610.773.3
G6PG3845IV:5626.198.4
G4715BV:6011.40−5.9
MI291BV:7442.3312.5
HXKG3088IV:804.93−5.9
MYRG3786I:1929.7921.1
MI358III:5021.5221.8
SDHG4026I:8518.5238.3
G4532II:2010.97−13.7
  • For each trait, this table shows the most significant molecular markers, their locations, the F-ratios attributable to each marker, and the percentage difference in enzyme activity between QTL homozygotes carrying Columbia or Landsberg alleles. Positive difference values indicate higher activity for the Columbia allele. QTL for HXK and PGI activity are significant based on a priori planned tests at the known enzyme-encoding loci using sequential Bonferroni significance thresholds (AtHXKl near marker G3088, P = 0.029; PGI-b near marker G3845, P = 0.0015). F-ratios shown in boldface exceed the genome-wide 5% significance threshold determined by Monte Carlo simulation. Remaining markers exceed the approximate threshold of Lander and Botstein (1989) and should be regarded as marginally significant. Two potential G6P QTLs at V:60 and V:74 are reported because, even though they are in close proximity, they have effects of opposite sign. No statistically significant QTL were found for FBP, PER, or CHI. All d.f. > 1, 73. Total R2 attributable to molecular markers for enzymes with significant QTL:PGM, 0.23; GPD, 0.23; PGI, 0.24; G6P, 0.48; HXK, 0.06; MYR, 0.39; SDH, 0.32. Individual QTL explained up to 26% of the genetic variation.