Reference: 
Fracheboud Y, Jompuk C, Ribaut J-M, Stamp P, Leipner J. Genetic analysis of cold-tolerance of photosynthesis in maize. Plant Molecular Biology, 56,241-253 (2004)

Segregation data: 119 SSRs analyzed in 254 F2 individuals
Phenotypic observations: 9 traits analyzed in seedlings of 226 F2:3 families grown in controlled environment (growth chamber) at 25 (.25) or 15 (.15) C, e.g CER.25 = CER in plants grown at 25 C.

Fo: Ground fluorescence of dark adapted leaves (chlorophyll fluorescence parameter, arbitrary units)
Fv/Fm:  Maximum quantum efficiency of photosystem II primary photochemistry (chlorophyll fluorescence parameter, relative units)
SPAD: Leaf greenness (arbitrary units)
PhiPSII: Operating quantum efficiency of photosystem II photochemistry (chlorophyll fluorescence parameter, relative units)
Fv’/Fm’: Trapping efficiency of photosystem II (chlorophyll fluorescence parameter, relative units)
qP: photochemical quenching factor (chlorophyll fluorescence parameter, relative units)
CER: CO2 Exchange Rate (micromol m-2 s-1)
ShootDW: Shoot dry weight (mg)
N: Shoot nitrogen content (% of shoot dry weight)

fracheb1map.inp is an Rmap input file constructed according to the instructions in chapter 6.1.2 of the QTL cartographer manual. It contains the map information for the population. Run Rmap using this file as input to generate a QTL cartographer map file.
fracheb1cross.inp is an Rcross input file constructed according to the instructions in chapter 6.3.2 of the QTL cartographer manual. It contains the marker scores and traits data. Run Rcross using this file as input to generate a QTL cartographer cro file.