| Three kinds of parent pig (Meishan, Landrace and Larger White) and four crossbred pigs (Landrace×Larger White (L×W) , Larger White×Landrace (W ×L), Me ishan×Larger White (M×W), larger White×Meishan (W×M) ), which in total number was 350, were raised under similar conditions. They were slaughtered when they reached 90 kg. The M. Longissimus dorsi(LD) and M. Biceps feraoris(BF) were sampled and the morphology of muscle fiber, the number and distribution of connective tissue, the content of total reducing sugar and mineral element and the correlation between these parameters and meat quality were examined in different species.1. Correlation between the muscle fiber character and meat quality(1) The area and diameter of muscle fiber of Meishan with supreme fat were significantly lower than those of the Landrace and Large White with supreme Lean(p<0. 01). The heteromorphism index of Meishan was also lower than that of Landrace and Larger White, which signified the high homogeneity of muscle fiber. The muscle fiber diameter of (crossbreeding combination) W XM pigs and M×W pigs are overdominance genetic and mediate genetic, respectively. The heterosis percentage of WXM pigs was high, which was 24.71%. The muscle fiber diameter of Landrane and Larger White were overdominance genetic, respectively.(2)The characters of muscle fiber could be classified into two principal component. The morphological quantity parameters were area, diameter, Long diameter and short diameter and density, to which the function of density was negative. The morphological qualitative parameters were roundness degree, heteromorphism index and ratio of long diameter and short diameter, to which the function of roundness degree was negative. The two principal component contribute to 89.0309%.(3). The area of muscle fiber, diameter, long diameter, short diameter increased, there was a trend of increase of moisture and water loss percentagein the muscle, decrease of water holding capacity (WHO and intramuscular fat (IMF) , color of muscle and pH. The increase of density signified the improvement of meat quality. Roundness degree signified improvement of meat color, function of IMF, the function of heteromorphism index and ratio of long diameter and short diameter are just in contrast with roundness degree. 2. Correlation between connecting tissue character and meat quality Connecting tissue was shown clearly in the sections with Van Gieson staining. It could be classified into five kind (1-5) according to quantity and distribution. It could be classified into substantial vs loose, continuous vs disconnected, which make up to 8 phenotypes.1) There was great heterogeneity in individuals of lean type pigs, while in Meishan pig there is homogeneity. The number of connective tissue were in BF higher than that of LD (P<0. 01) . There is positive correlation between number of connective tissue and pH1 value(r=0. 2902, P<0. 05).2) There was a majority of substantial or disconnected connective tissue type in Lean pigs .while there is loose and continuous connective tissue in Meishan pigs. There was decrease on water holding capacity, meat color and IMF in disconnected connective tissue type. There was more fat cells in loose tissues, which could improve IMF and WHC. So pigs of loose and continuous connecting tissue were more favorable in order to improve meat quality.3) Content of total reducing sugarThe content of total reducing sugar in the meat decreased significantly after storage at -20℃, while there was no much change after storage at (14 ±2)℃. The big decrease in content of reducing sugar may be the main course of decrease of meat flavor.4. The correlation between mineral element and meat quality.1) There was a low content of K and Mg in Meishan pigs with high IMF.2) Mineral element could weaken the meat color, pH value, IMF and WHC.
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