关键词: 低蛋白质日粮, 低蛋白质日粮, 优质肉鸡, 河田鸡, 屠宰性能, 肌肉成分

Abstract: Based on the investigation of growth condition, fruit quality, endangered degree, and cultivation methods as well as management status of three kinds of crab-apple grown in natural conditions in Liucun town in Changping district were investigated in the present work. Results showed that great differences existed in the content of soluble sugar and fruit weigh which changed with rate of 10.81%～15.13%,22.3g～40.27g, and performed with mid-thick skin and slightly crisp or flexible flesh in Malus asiatica. The fruits index of other two crabapple species had no differences in fruit quality. The content of soluble sugar and fruit weigh of Malus Micaromalus which changed with rate of 17.00%～18.21%,8.25g～10.66g, and flesh firmness performed with thin brittle compaction, And the data were 14.23%～16.55% and 6.47～9.03g in fruit of Malus prunifolia with thin crisp flesh. Analysis of fruit quality indicated that there may be considerable Variation in the individual trees, very likely screening excellent strains from Malus asiatica. The ratio of sugar to acid was in the moderate range of taste, which means all of them were good breeding material to develop fresh varieties. Suggestions on ancient tree qualification, strengthening management, cultural connotations development, scientific research for protection and development about ancient crabapple trees were given based on the investigation.