Linkage among genes controlling monoterpene constituent levels in loblolly pine

Linkages among four loci controlling cortical monoterpene composition were studied. Results suggested that three (myrcene, limonene, and β-phellandrene) are closely linked, while the fourth (β-pinene) is less closely linked to the others. Data from both full-sib and half-sib families were utilized. The latter required knowledge of recessive gene frequencies in the male parents, and efficiencies varied greatly with the magnitude of these frequencies. Although no bias is expected when half-sib families are used to detect linkage, estimates of recombination rates may be biased if linkage disequilibrium is present. However, recombination rates obtained from half-sib families were usually not greatly different from those obtained from full-sibs. Some new generalized methods are presented for detecting linkage and for estimating rates of recombination. Forest Sci. 32:97-112.