Effects Of BR And GA On Wheat Grain Starch Granule Distribution,Accumulation And Processing Quality

Starch content and the proportion of amylose and amylopectin in wheat grain affect the processing quality. The differences among different spike-position and grain-position affect the yield and quality of wheat homogeneity. This study was conducted with four wheat cultivars, two large-spike wheat varieties which were WM8 and 4072, two multi-spike wheat varieties which were LM21 and YN15. BR and GA were sprayed for three times, in the flowering day, after flowering5d, after flowering 10d. Dynamic change of different part's grain weight, starch particle size distribution, starch accumulation, the change of sugar and the starch processing quality of grain were measured for exploring the effect of BR and GA to starch particle size distribution, the content and composition of starch, and the starch processing quality. In order to provide for the quality and high yielding theoretical basis and technical approach. The main findings are as follows.1 The control of BR and GA to grain weight and grain yield of different spike positionWM8, 4072, LM21 and YN15 were used to analyse the yield of different spike position and the grain weight of five spike grain position. It was found that different wheat cultivars all showed mesial-advantage, midst was the strongest, inferior part was second, top was the weakest. The regulating effect of spraying BR, GA was different in different wheat cultivars. multi-spike wheat varieties increase ear yield mainly by increasing grain number, but large-spike wheat varieties mainly by increasing grain weight and grain number. The effect on different spike position and different spike grain position was different by spraying BR and GA. The regulating effect on the weak spike-position was greater than on the strong spike-position, the regulating effect on the weak grain-position was greater than on the strong grain-position. But the regulating effect of BR was greater than GA.2 The control of BR and GA to starch particle size distribution of different spike positionMature wheat seed has two types of starch granules, particle size≥10μm called A-type large starch particle and size <10μm called B-type large starch particle. the distribution trend of all varieties of starch granules is similar. The surface area of B-type starch particle was more than 85% of the total. The distribution of the number of wheat starch granule showed single distribution, While the number of B-type starch particles accounted for 99.9% .The study showed that most starch particles of wheat seed were small starch particles.Through the analysis of the four species, five grain-positions'starch granularity, the results showed that, The volume, surface area and number distribution all exist significant differences in wheat different grain-positions. The strong grain-position existes high volume, surface area and number distribution of B-type starch grains, but the content of A-type starch grains were lower than the weak grain-positions. The weak grain-positions were contrary to the strong grain-positions. The difference in multi-spike wheat cultivars were greater than the large-spike wheat cultivars.The results showed that the two hormones can effectively control both of wheat starch grain volume and surface area distribution, the regulating effect on different wheat cultivars existes genotypic differences. BR and GA can effectively control the number distribution of B-type starch grain which lower than 0.6μm and between 0.6 and 10μm. but can't change the number of A-type starch grain which greater than or equal to 10μm.Through the study on the distribution of grain starch granularity in five grain-positions, the resultsshowed that, spraying BR and GA can effectively control the number percent of grain starch grainwhich were lower than 10μm in different grain-positions. The effect on the number of A-type and B-type starch grains was not significant. But can effectively control the grains'surface area and volume in different grain-positions. The general trend was that it can reduce the starch grains'surface area and volume percent which were lower than 10μm in strong grain-positions grains, it can significantly increase B-type starch grains'surface area and volume percent in weak grain-positions grains, it can relatively increase A-type starch grains'surface area and volume percent in strong grain-positions grains, it can reduce A-type starch grains'surface area and volume percent in weak grain-positions grains. It lessened the difference in different grain-positions, and beneficial to homogeneous regulation. The regulating effect of BR and GA on different wheat cultivars existed genotypic differences.3 Effects of BR and GA on starch accumulation and sugar content in wheat's different spike-position and grain-positionThe test showed that the amylose, amylopectin and starch accumulation in different grain-position were significantly different. Different spike type all showed a common trend. In prophase, the amylose, amylopectin and total starch of strong grain-position accumulated faster than the weak grain-positions, but slower than the weak grain-positions in anaphase. In Maturity, the amylose and total starch content in weak grain-positions was more than the strong grain-positions.The trend of sucrose and total sugar content in different grain-positions was consistent, The multi-spike cultivars of LM21 and YN15 showed that first increased to peak point and then rapidly decreased, on 10d reached the maximum, from 10 to 15d decreased rapidly. The large-spike wheat gradually decreased after flowering 5d, the four cultivars all become the lowest in mature. Among different grain-position, the sucrose and total sugar content of weak grain-position were higher than the strong grain-position. In the stage of starch rapid synthesis, sucrose and total soluble sugar decreased rapidly, which indicating that the starch transformation and synthesis were active at this period, the starch synthesis ability in strong grain-positions was better than in weak grain-positions.The regulatory of BR and GA on the varieties wheat starch accumulation was different .The influence of the content of amylase and amylopectin in varieties wheat was not significant during the pior period. Later the content have increased. GA improved the content of amylose in lm21 and 4072 significantly. BR and GA could increase the content of amylopectin in lm21 and 4072 significantly during the latter period .But the effect on WM8 and YN15 was not significant. BR. GA to the influence of the whole starch is in accord with the amylase and amylopectin . Different varieties had difference in the genotype.BR and GA to the influence of the wheat sucrose and total sugar had the significant difference in different grain-position. Different varieties had difference in the genotype.The content of the wheat sucrose and total sugar in weak wheat grain position is larger than strong grain position. The differences in bike spike grain position were more than multi-spike.The differences in treatment and the control were in 5-10 days and 15-30 days .The differences in the 10-15 days stage that the starch rapid synthesis were non-significant. BR processed was to reduce the content of the wheat sucrose and total sugar.But GA raise. It showed that BR increase yield by promoting the transformation ability ,and GA by promoting accumulating time. 4 The regulation of BR and GA on sugar at filling stage in wheat flag leaf, stem and sheathThis experiment showed that spraying BR and GA can improve the chlorophyll content in the flag leaf, in particular increased the chlorophyll content at midanaphase in the flag leaf, thereby enhancing the photosynthetic capacity of leaves and anti-aging; The regulating effect of BR and GA on sucrose and total sugar content in the stem, leaf and sheath exist genotypes differences. In general, GA has decreased trend, significantly reduce the sucrose and total sugar content at filling stage in the three organs of WM8, YN15 and 4072, but less impact on the LM21; BR has the increased trend, especially in the stem, sheath.Through the correlation analysis of the sucrose, total sugar and starch accumulation rate of wheat grain in the stem, flag leaf and sheath showed that the starch accumulation rate and the sucrose and total sugar content in the three organs hava positive correlation, the correlation with the sucrose and total sugar content in the flag leaf was the least. But the correlation with the sheath and stems was significant. The correlation with the total sugar was more significant than the sucrose.5 Effect of BR and GA on the wheat processing qualityBR and GA can effectively control wheat pasting parameters and farinograph parameters. In gelatinization parameters, BR has the greatest impact on peak viscosity, GA has the greatest impact on the gelatinization temperature. The effect of BR on RVA parameters was greater than GA; in farinograph parameters, BR has the greatest impact on the water absorption and time of stability, the effect of GA on water absorption, development time, stability time and falling numberwas significant, the effect of GA on farinograms was greater than BR, but the effect on the falling number, GA was greater than BR.BR and GA can improve the grain amylopectin and total starch content, decrease amylose content in grains and improve the proportion of amylopectin and amylose. The effect on large-spike cultivars WM8 and 4072 significantly greater than the multi-spike cultivars Lumai 21 and YN15. BR and GA can significantly increase the grain protein content of 4072. The effect of BR on the amylopectin / amylose is less than GA. Overall, the effect of BR on the starch content is greater than the effect of GA on the starch content.Through correlation analysis showed that the extraction rate, amylopectin and starch content has a significant positive correlation; water absorption, amylopectin / amylose and protein content has a significant positive correlation, but has a significant negative correlation with amylose content. Name unremitting value has a significant negative correlation with amylose content, but has a significant negative correlation with protein content. Low viscosity, peak viscosity, setback and final viscosity has a significant negative correlation with protein content and amylopectin content, but has a significant positive correlation with the amylose content.Through this research showed that the midst spike was the strongest, the inferior spike was second, the top spike was the weakest in wheat different spike-positions. The midst 1 and 2 can represent the strongest grain-position, the top 1 and 2 can represent the weakest grain-position. Spraying BR and GA can increase yield, the regulating effect on the weak grain-position was greater than on the strong grain-position. The volume, surface area and number distribution all exist significant differences in wheat different grain-positions. The strong grain-position existes high volume, surface area and number distribution of B-type starch grains, but the content of A-type starch grains were lower than the weak grain-positions. The weak grain-positions were contrary to the strong grain-positions. Spraying BR and GA can effectively control the grains'surface area and volume in different grain-positions. It can significantly increase B-type starch grains'surface area and volume percent in weak grain-positions grains. It lessened the difference in different grain-positions, and beneficial to homogeneous regulation. The amylose and total starch content in weak grain-positions was more than the strong grain-positions. Spraying BR and GA can effectively control the proportion of amylose and amylopectin, it can increase the amylopectin content in weak grain-positions, and beneficial to homogeneous regulation. Spraying BR and GA can effectively control wheat pasting parameters and farinograph parameters, therefore improve the wheat quality.