| In order to search for morphological and physiological mechanism of super-high yield in rice, the characteristics of plant type , photosynthetic traits, sencence properties, grain filling rate, and export rate of culm-sheath substance in ripening phase of rice were comparatively studied between super-high yield combination Liangyoupeijiu and controls of Shanyou63 and 9311. The results were as follows:1. The main morphological characters of super-high yield hybrid riceThe length of first, second and third leaves from top of high yield hybrid Liangyoupeijiu was 49. 45 cm, 62. 95cm, and 74. 65cm respectively. Their leaf width was 2.49cm, 2.07cm, and 1. 83cm . Their leaf area was 100. 99cm2,107. 80 cm2, and 113. 06 cm2. Their specific leaf weight was 4.82 mg cm-2,4 24 mg cm2 ,and 4 20 mg. cm-2 . Their leaf original angle was 7.1, 10. 2, and 14. 1. Their leaf rolling index was 56.1%, 32.3%, and 24.2%.Their leaf erecting index was 97. 8%, 95. 0%, and 86. 4%. ?The diameter of internode of the first, second and third internode from root of Liangyoupeijiu was 6. 82mm, 5. 78mm, and 5. 08mm respectively. As compared to Shanyou63 and 9311, the leaf angle of Liangyoupeijiu was smaller than that of controls. The specific leaf weight, leaf rolling index and leaf erecting index of Liangyoupeijiu were higher than those of controls. The area of the uppermost three pieces of Leaves of Liangypupei jiu was 6. 6% and 13.7% greater than Shanyou63 and 9311 respectively. The results indicated that configuration of leaf angle of Liangyoupeijiu made its plant type measure up to perfection. Itmaintained larger photosynthesis area in its ripening phase. Meanwhile, the plant type of Liangyoupeijiu was better than that of the controls. All these traits enabled it to enhance its efficience for solar energy utilization and lodging resistance.2. The photosynthetic traits and sencence properties of super-high yield hybridAs compared to Shanyou63 and 9311, the photosynthetic rate of Liangyoupeijiu in flag leaf was 13.5% and 14.6% higher respectively in heading stage, while 16.6% and 16.1% higher respectively at mature grain stage. The content of chlorophyll and soluble protein as well as the activity of superoxide dismutase(SOD) of Liangyoupeijiu decreased more slowly than those of the controls 25 and 30 days after heading stage. At the same stages, the contents of soluble sugar and the activity of peroxide (POD) of Liangyoupeijiu were higher than those of controls, and the content of malonaldehydic acid(MDA) was lower than that of the controls. So in flag leaf Liangyoupeijiu exhibited more strongly activity of inner active oxygen eliminating enzyme, slower aging , higher photosynthetic rate, and more strongly physiological activity and photosynthetic capability than those of the controls. All these were useful to accumulate more photosynthetic substance in ripening phase of Liangyoupeijiu.3. The grain filling rate and export rate of culm-sheath substance of super-high yield hybrid riceGrain dry substance of Shanyou63 accumulated quickly during the early stage, but it stopped early. The weight of thegrains started to decrease on 21st day after heading for Shanyou63, but it started to decrease on 25th day after heading stage for Liangyoupeijiu. It showed the time of grain dry substance accumulating for Liangyoupeijiu was longer than that of Shanyou63.From heading stage to 35th day after heading , the export rate of culm-sheath dry substance was 9. 4%, 30. 0% , and 34. 5% respectively for Liangyoupeijiu, Shanyou 63, and 9311.The reason for lower dry substance translocation of Liangyoupeijiu compared with the controls was that the culm-sheath dry substance weight decreased from heading stage, but it started to rise again 21st day after heading stage. The grains of Liangyoupeijiu had plumpness, while function leaves aged more slowly and maintained stronger photosynthetic capability. Meanwhile, culm-sheath dry substance of Shanyou63 and 9311 kept exporting all the time so that the export rate of Liangyoupeijiu was lowest.4. Th...
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