Effects Of Temperature Stress During Grain Filling Stage On Rice Grain Productivity And Quality

In the year of 2007 to 2008,we use Wujing 15,Nanjing 44 and Xudao 3 for the material through the solid phase for the five days each time in the artificial climate box temperature treatment, to study the time period of strong temperature stress on rice yield and quality the impact and related physiological effects. The main result is as follows:1.The solid phase temperature 40℃and 14℃low temperature creates the paddy rice underproduction in various time intervals, three variety various time intervals 40℃processing average underproduction 12.63%,14℃processing average reduces production 9.78%, in which the medium-term seed production before the larger, and strong reduction in the latter half of the gradual trend of small, 35℃and 18℃processing underproduction because of variety, but different, 18℃even has the production increase function in certain time intervals, the temperature coercion underproduction is mainly because the fertility large scale drop result, 40℃high temperature coercive effect than the effect of low temperature 14℃, and this effect in grouting earlier period (1-10d) especially prominent, explained that compares high or low temperature is not to favor the grain to be substantial. The temperature coercion is 4quite small to the paddy rice weight of a thousand seeds' influence, slightly has the enhancement, average increased range between 0.15-0.65g, various varieties performance basic consistent.2. Solid time temperature coercion influence paddy rice quality:①With regard to quality of the processing, the different time interval and the different temperature process to the paddy rice rate of husked rise, the polished rice rate, the entire polished rice rate influence are small, and 40℃processing cuts the rate of husked rise, the polished rice rate, the entire polished rice rate.②In aspect of appearance, with the rising of the temperature, the rate of chalky rice, chalky whiteness increased significantly ,it shows it is conducive to the formation of chalky rice on 40℃.The two varieties performance at the same trends .③With regard to the nutritional quality, it is closely related between the temperature of the Solid phase on the impact of grain protein content and its corresponding processing time. At different temperatures and different processing time , the protein content is inconsistent. At filling stage , high temperature is conducive to the accumulation of grain protein.④At the respect of cooking and eating quality, the low temperature increased the amylose accumulation, but the high temperature reduced the amylose accumulation. The RVA characteristic value two variety 40℃high-temperature treatment has the lowest disintegration value and the final viscosity as well as the highest dextrinize temperature, the peak time increases along with the temperature postpones.3.Solid period temperature coercion to paddy rice related physiology target influence. The Pro content in the different time interval, 40℃processing is higher than 35℃processing throughout, but 14℃the low-temperature treatment accumulates to the Pro content also has certain influence, 40℃processing >35℃processing >14℃processing >18℃processing. MDA temperature coercion, its content is higher than the normal temperature comparison obviously, the high temperature 40℃processing performance is most obvious; 18℃processes the Q enzyme activeness to be highest, starts along with the grouting advancement, the Q enzyme activity rises gradually, and after Guangzhou 15-20d achieves high, hereafter gradually drops.