Studies On The Differences Of Yield And Quality And Their Physiological Mechanism For Different Plant-type Varieties At Different Altitudes Locations In Maize (Zea Mays L.)

Three different plant-type maize, compact type maize (Zhengdan958), semi-compact type maize (Dongdan60) and flat type maize (Changyu13) were planted at three different altitudes locations, which were Motan-Beibei(Low-altitude, 220m), Zuojiawan-Shapingba (Middle-altitude, 530m) and Changtian-Fengdu (High-altitude, 1300m). From the Tasselling stage, every 10-days, picked the materials which were leaf,vagina,stem,ear and bracteole, then researched the dynamic accumulation of their dry-weight, and detected the sucrose content in functional leaf and grain, also detected the metabolic activity of sucrose enzyme in functional leaf, finally, combined the yield difference and quality difference, to prove the yield and quality formative mechanism of different plant-type maize at different altitudes locations in Chongqing. The results were as follows:(1) Effect by altitude for the biological dry-weight of maize is significant, the biological dry-weight of different materials are increased following the boost of altitude, and the trend is: high-altitude's (Fengdu) >middle-altitude's (Shapingba) >low-altitude's (Beibei). Furthermore, the biological dry-weight at high-altitude location is significant higher than that at middle-altitude location and low-altitude location.(2) Yield variance of different plant-type varieties is very significant. The yield of semi-compact type maize (Dongdan60) is significant higher than that flat type maize (Changyu13) and compact type maize (Zhengdan958). For different materials, the yield from high to low were as follow: semi-compact type maize (Dongdan60) >flat type maize (Changyu13) >compact type maize (Zhengdan958). (3) Altitude influence for content of protein and starch is very significant; the protein content of three plant-type varieties is consistent at different altitudes locations, which is: low-altitude's (Beibei)>middle-altitude's (Shapingba) >high-altitude's (Fengdu); On the contrary, altitude influence for contents of starch is: high-altitude's (Fengdu)>middle-altitude's (Shapingba)>low-altitude's (Beibei); While effect by the interaction of variety and altitude for the oil content is very significant, for example: oil content of compact type maize (Zhengdan958) at low-altitude location is significant higher than that at middle-altitude location and high-altitude location, however, flat type maize at high-altitude location is very significant better than that at middle-altitude location and low-altitude location.(4) At low-altitude location, from tasselling stage to maturity end, the trend of sucrose metabolic enzymes was a single peak curve; sucrose content in functional leaves was influenced by sucrose synthetase (SS) and sucrose phosphate synthetase (SPS). The trend of sucrose content also was single peak curve, but there were differences among different types. After the grain filling stage, compact type maize (Zhengdan958), the activities of sucrose synthetase (SS) and sucrose phosphate synthetase (SPS) reduced faster, correspondingly, sucrose content in functional leaves was reduced, lead to the supply of sucrose in leaves was inadequate, so it's the source-restrict type. While flat type maize (Changyu13), sucrose content in grain was increased continuingly, it means, in its grain, the transformative and synthesis efficiency from sucrose to starch was lower, so that, the dry matter accumulation of grain was obstructed, and then it is the sink-restrict type.(5) Yield is influenced significantly by genotype, on this basis, yield formative rule is: Strong source is the necessary precondition for high-yield, also is the dominant factor, sink changes with the source varies, but the sink has a certain feedback to the source. So, imbalance is absolute between source and sink, while balance is relative. However, the formation of quality was influenced by genotype,environmental factors and interaction between them.