Study On Nutrition Content And Quality Evaluation Of Different Chinese Yam (Dioscorea Opposite Thunb.) Cultivars

China is one of the centers of Chineses Yam (Dioscorea opposite). There was resourceful Chinese Yam in China. There is much special adaptability and variety and characteristic various of in different region in long history process of domestic cultivation. The content and compose of Chinese Yam nutrient substance was different from variety to genotype and was affected by environment conditions in process of growth.1,Agronomic traits and nutrient content of Chinese Yam tuber in growth period:This experiment investigated 4 Chinese Yam materials including 1 local cultivar and 3 introduction cultivars for studying the investigation of economical character and determination of main nutrient contents in the growth period. It was different in economical character and main nutrient contents in these materials. The results would provide a theoretical basis for planting different Chinese Yam in Hohhot.The results showed:(1) JP1 was the prior cultivar with stubby tuber shape and high tuber yield and easy to harvest, transport and processing compare to other varieties.(2) Nutriment change is differences of 4 materials during plants growth period. There was big different in contents of starch and polysaccharide respectively and similar change trend of the contents of soluble sugar, soluble protein and amino acid.(3) B1, the local cultivar had an early nutriment accumulation from the tuber inflation stage. It finished nutriment accumulation faster than other materials. Fertilization and watering should be begun in the early planting stage.JP1, the introduction cultivar had a little late nutriment accumulation from the peak tuber inflation stage. Fertilization and watering should be begun in the middle inflation stage.2,Agronomic traits and nutrient content of Chinese Yam tuber during storage period: This experiment investigated 21 Chinese Yam materials for studying the nutrient contents in tuber storage period. The results indicated:(1) B1 had a high soluble sugar and polysaccharide content. SFJ19 had a high dry matter and soluble protein content. JSPX26 had a high polysaccharide and soluble protein content. And JP1 had a high starch and amino acid content. These materials should be recommended with a comprehensive nutritive value.(2) SFJ19 was the best materials for dried yam. In the earlier storage stage, TQ4 could be process yam powder JSPX26 in the later storage stage, JP2 in the middle storage stage and JP2 in the later storage stage, could be process preserved yam , yam drink, canned yam and yam jam so on. ZS14 had very important medical value because of its polysaccharide in the former storage stage.