[Mapping quantitative trait loci for meat quality trait in a Large White x Meishan cross]

To search for the chromosome regions for quantitative trait loci (QTL) affecting meat quality in pigs, a three-generation resource family was developed in China using three Large White grand sires and seven Meishan grand dams. A total of 147 F2 progenies derived from two populations in 1998 (n = 81) and 2000 (n = 66) were phenotyped for meat quality. All animals were typed for 48 microsatellite markers covering six chromosomes: 1, 2, 3, 4, 6 and 7. Linear model and least square analyses were used for interval mapping meat quality in jointed population and single population, permutation for empirical threshold. The strongest linkage at chromosome-wide level (P < 0.01) and genome-wide level (P < 0.05) on chromosome 4 affecting intramuscular fat (IMF) QTL from the population in 2000 was detected with explained phenotypic variance of 5.24%, and Meishan's QTL increased the intramuscular fat content. There was a suggestive QTL for IMF near the threshold of chromosome-wide in the same region in jointly population. The QTL for pH value in m. Semispinalis Capitis and m. Biceps Femoris were located on chromosomes 1 and 3, respectively. One and three QTL affecting WHC reached the thresholds of chromosome-wide level in the populations of 1998 and 2000, respectively. In the population of 1998, QTL for moisture content at chromosome-wide level was on SSC6 and in jointed populations were on SSC2, 6 and 7. There were imprinting effects in moisture content QTL, and Meishan and Large White pigs all had favorable effects influencing moisture on different chromosomes.