Effect Of Foliar Application Of Selenium On The Yield And Quality Of Ratooning Rice

Ratooning rice not only have the advantage of short growing period and high daily output,but also saving time and water,adjusting labor force,lower production cost and higher economic benefit,and etc.Since the rapid development of Chinese agriculture,ratooning rice have been increasingly taking vital role in ensuring food security in China with the highly efficient and multi cropping system.However,ratooning rice still exist a lot of disadvantage,such as,low grain yield and head rice rate fragile and easy to break during the processing and so on,when be compared with main crop.Thus,ascertain what effects were caused on the yield and quality of ratooning rice after applying selenium and explore the physiological mechanism of ratooning rice caused by selenium.Attempting to provide basis for high quality and high yield cultivation techniques for ratooning rice.In our study,the effects of selenium on the yield and quality of ratooning rice were investigated by setting different selenium dates and selenium amount by foliar application,aim to reveal the grain yield of ratooning rice,the relationship between yield and yield components,relative quality change,and selenium content and glutamine synthetase（GS）activity of ratooning rice during grain filling stage.The effects of selenium on yield and quality of ratooning rice were analyzed,and the physiological mechanism of selenium during the growing and development period of regenerated rice was surveyed.The following results were obtained:（1）The rate of brown rice,polished rice and chalkiness grain rate of ratooning rice were the main quality indexes affecting the whole polished rice rate of ratooning rice.The whole polished rice rate of ratooning rice increased with the growth of rice brown rice rate and fine rice rate,and decreased with the increase of chalkiness grain rate.（2）The selenium content of ratooning rice was positively correlated with the whole polished rice rate and negatively correlated with the chalkiness grain rate.The results showed that the increase of selenium content in regenerated rice contributed to the increase of whole head rice rate and the decrease of chalkiness grain rate.Application of 11.25 g·hm^-2 Na₂SeO₃ at the initial heading date and the full heading stage significantly increased the whole head rice rate of the ratooning rice,and the whole head rice rate of the ratooning rice with 1%urea and selenium at the full heading stage was the highest,with an increase of 5.77%.（3）There was a significant positive correlation between the protein content of the ratooning rice and the selenium content of rice.The results showed that selenium application on leaf surface could promote protein synthesis in rice grain.The protein content of ratooning rice combined application of 1%urea and selenium was better than that of single application of 1%urea or selenium,and the protein yield of ratooning rice increased by 12.56%.（4）There was a significant positive correlation between the protein content of ratooning rice and the activity peak of glutamine synthetase（GS）during grain filling stage to maturity stage.The protein content of rice increased with the increase of GS enzyme activity.The results showed that foliar application of selenium could increase the activity of glutamine synthetase（GS）,promote protein synthesis and increase the content of rice protein in ratooning rice.（5）The grain number,solid grain number and seeding set rate of the ratooning rice were the main yield components that affected the yield of ratooning rice.The yield of ratooning rice increased with the increase of grain number,real grain number and seed setting rate.（6）The grain number,solid grain number and seeding set rate were positively correlated with selenium content in ratooning rice.The results showed that foliar selenium increased the yield of ratooning rice,mainly by raising the content of rice selenium,and improving the grain number,solid grain number and seeding set rate,and the yield was improved.Foliar application of selenium can increase the yield of ratooning rice.The yield of 1%urea and selenium is better than that of single application of selenium,and the yield of combined application increased by 8.17%.