Dissertation > Agricultural Sciences > Crop > Cereal crops > Rice

Study on the Mechanism of Night Temperature to Grain Filling of Inferior in Rice

Author SongXingNian
Tutor ZhaoQuanZhi
School Henan Agricultural University
Course Crop Cultivation and Farming System
Keywords Plumpness Grain filling Night-time temperatures Soluble sugar Starch Key enzyme of starch synthesis
CLC S511
Type Master's thesis
Year 2011
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In recent years, with the acceleration of industrialization and the intensification of human activities to global climate warming, the yield and quality of food crops had a significant impact. In this study, consecutive two years in 2009-2010 in Henan Agricultural University of Science Garden, conducted an experimental plot of rice. A field experiment approach to the Huang-Huai River Valley to Promotion the conventional rice varieties Fangxin 4 for the test material. For inferior grains of rice the problem of poor plumpness, respectively from material production and operation,grain storage capacity and other aspects, in-depth study of the system caused by differences in inferior grain plumpness of the physiological mechanism. The results are as follows:1. Night temperature on rice yield and its component factors, the results show: the actual production performance of high temperature heat for the night <control, and their difference reached a significant level.The night temperature on yield reduction is mainly manifested in the setting rate, Grains and grain weight reduction on grain plumpness.Night temperature on rice quality in milling quality, high temperature treatment of the roughness of the night, milled rice rate was significantly lower than the control, imperfect grains were significantly higher than the control. Quality in appearance, strong weak chalky grain rate, significantly increased ,as compared with the control chalkiness.2. Night temperature on grain weight and grain positions of different degrees of enrichment. The results showed that: The grain weight and grain plumpness of super grains were larger than those of inferior grains in mature period; grain position, the maturity of the grain kernel weight and grain plumpness has basically maintained with the flowering time of filling the order consistenly, that is a branch, the two treatments showed a strong grain 6> 5> 4> 3> 1> 2, inferior grains showed a> 6> 5> 4> 3> 2; Second branch, the branch 1> 2 branches> 3 branches> 4 branches, the seed on the each second branch showed (1)> 4> 3> 2, one branch, the average grain weight Grain and grain plumpness of grain is greater than the second branch, The kernel weight and plumpness at control treatment is greater than those under nighttime temperature. Second branch, the first grain has bigger different with the rest, and the night temperature is greater than the control treatment. Second branch, the first grain has a bigger different with the rest, and the night temperature is greater than the control treatment. It can be seen, night temperature can promote the grain weight (especially the rest seeds except first one on the second branch of inferior grains) the differences between grain weight and grain filling on treatments mainly lie on second branches of inferior grains) ( Except one particular bit outside the rest of grain), the second is a branch on the first 2,3 Ranked Grains.3. The impact of night temperature on rice on the clover leaf SPAD value the results show that:the clover leaf SPAD value of the growth period both showed a downward trend with the prolongation of filling time in filling stage, leaf senescence continuously with the process of grain filling. Night temperatures, Chlorophyll values of flag leaf, the top two leaves and the top three leaves were lower than those of the natural (control) temperature), variance analysis showed that Night temperature lower the average chlorophyll values of three functional leaves of rice significantly (the average value of 6 times chlorophyll values). Treatments on the clover leaf SPAD values of the performance of the control> night temperature, that is the average chlorophyll value of three functional leaves of rice significantly lower at night temperature, that is, high temperature treatment at night play a catalytic role of leaf senescence.4. Night temperature on leaf senescence. The results show that filling,the night temperature lower chlorophyll content significantly leading to aging in advance to shorten the grain filling stage; night temperature to SOD activity in post-5d peak, significantly reduced the SOD activity of the 10d and 25d; the CAT activity of ahead of 5d to peak, significantly improved the CAT activity of 20d, significantly reduced the CAT activity of 25d; on the POD activity was not significant; increased the MDA content significantly.5. Research on night temperature on rice stems and sheaths of non-structural carbohydrate accumulation and output. The results showed that, both stem and sheath, sugar and starch content between the treatments had the same trend at the growth period. After high temperature treatment at night, whether sugar or starch content was lower than that of the same period of control. Sugar content in stem and sheath was higher than the starch content; sugar and starch content in stem was higher than that in sheath.At the output rate of non-structural carbohydrates of filling stage in stem and sheath, sugar and starch had higher output than that of the control after high temperature treatment and it indicated that high temperature treatment at night could promote the operation of assimilation, which was conducive to enrich rice grain filling.6. Night temperature on the soluble sugar content in grain. The results showed that as to different grain position changes of soluble sugar content of mature grains in the grain filling stage, the strong grain soluble sugar content in grain is basically less than inferior grains. Before and at the middle of the grain filling stage , after night high temperature treatment sugar content in strong and inferior grains were higher than that of the control , indicating that the ability of night high temperature synthesis of starch was inferior to that of the control . At filling stage, the control grains and high temperature strength tablets at nightdeveloped into rapid decline in sugar content.7. Night high temperature on starch content of capsules. The results showed that t the whole grain starch accumulation inhe grain filling period had the same increasing trend of total dry weight with the "S"-type change. Starch accumulation of control in mature was more than that of night high temperature . Similarly , amylose, amylose accumulation had the same rule as the total of starch accumulation .8. Night temperature on the activity of filling capsules. The results revealed that, activity changes of AGPP and SSS enzymes showed a single peak curve, the performance began to lower activity during filling; with the filling process, the activity increased, reached peak on the twentieth day after flowering and then declined rapidly. GBSS activity was gradually increased with the growth period. GBSS enzyme activity of weak grain at the filling stage was higher than AGPP and the SSS activity. High temperature treatment on activity at night had some inhibition activity of the control treatment was always higher than that of night temperature treatment.

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