Studies On The Sucrose Metabolism And Starch Synthesis Of Wheat With Different Quality Type On The Different Soil Condition

Wheat is one of the important cereal crops all over the world. About 35～40 percent people look at the wheat as the main crop in the world. At the same time, protein and starch content in wheat kernel are higher, so it can be used as the important material of food processing industries. The accumulation, distribution and transportation of photosynthetic production in wheat plant are the key factors deciding the wheat yield, economic coefficient and economic yield. Starch and sucrose are the main terminal productions of wheat photosynthesis. Sucrose is the main form of carbohydrate transportation and storage in higher plants, and it also is signal molecule coordinating source-sink relationship of plants. So sucrose has the special position during plants sugar metabolism. In the C－N metabolism of wheat plant, sucrose metabolism and starch synthesis are two processes, which are both dependant and restricted by each other. Consequently, it is more important to study and control the distribution of photosynthetic production between starch and sucrose.Starch is the main content of both the seeds of cereal crops such as wheat, rice , maize and the storage products such as root tuber and stem tuber. Starch is also an important source of carbon and energy in human food and animal fodder. Only the starch in cereal kernel may provide about 80 percent energy to human being, and many food and drink are relative to starch. In general, the starch in wheat grain comprises about 70% of endosperm weight and 57% of kernel weight (65% of dry weight). Starch synthesis and accumulation takes place during grain filling in wheat. The wheat yield and quality are affected directly by starch biosynthesis and accumulation in the kernel during grain filling. However, studies on wheat quality are mainly concentrated on the protein and its composition for a long time, and overlooked the effects of starch and its composition on the wheat quality and food quality. In recent years, starch uses become to be more and more extensive, more and more researchers including agriculture, grain-oil and food fields attach importance to the study and use of wheat starch. Therefore, it has more important theoretical value and actual significance to improve the yield of wheat and the processing quality studying sucrose metabolism, starch accumulation in the kernel and the changes of enzyme activities involved in them of wheat.For this reason, the accumulating developments of sucrose and starch and the changes in the activities of the enzymes involved in the sucrose metabolism and starch accumulation were studied on the condition of pond culture, using three kind of winter wheat cultivars with strong,medium and weak gluten force as experimental materials, and depending on three kind of representative soil texture (medium clay, light loam and sandy loam soil) and four different soil type (gray damp soil, rice soil, shajiang black soil and loess soil) in Henan province. Analytical methods of overseas experts were consulted. The samples were taken at the regular time and frozen in liquid nitrogen for 30min, and then placed in a freezer at ultralow temperature. The main results were as the follows:1 The regulation of sucrose metabolism of wheat cultivars with different quality type In the three wheat cultivars with different gluten force, the activities of SPS and SS in the flag leaf, 2nd leaf, flag leaf sheath and kernel of Yumai 49 (medium gluten force cultivars) were higher than that of Gaomai 8901 (strong gluten force cultivars) and Luomai 1 (weak gluten force cultivars), but the activities of SPS and SS in the upmost stem or 2nd stem of Luomai 1 were higher than that of the other two cultivars. It showed that the sucrose synthesis and degradation metabolism in the nutritive organs and kernel was active, which could lead to starch accumulation and get high yield. The changing trend of SPS and SS activities was almost the same as that of sucrose content of corresponding position. It concluded that SPS was the key enzyme to control sucrose synthesi...