Study On Difference Of Zinc Content In Grain And Zinc-rich Technology In Different Cultivars Of Japonica Rice

Zinc is an essential element of the human body,and zinc deficiency can induce a variety of diseases.Rice is the main food crop of human beings.It is of great significance to study the zinc-rich technology of rice and increase the zinc content of rice to improve human health.In this experiment,the difference of zinc content was clarified andthe optimal zinc-rich fertilization method was determined by analyzing the difference of rice zinc content and the accumulation and distribution of zinc in nine high-quality japonica rice in Jilin Province.The main findings are as follows:1.The yield difference of different cultivars is significant.The yield increasing rate of each variety after application of zinc fertilizer was between 2.3%and 7.2%,the yield of Jiyang No.1 was the highest,and that of Jinong 899 was the lowest.Among different zinc application methods,the increasing yield with zinc fertilizer at the flowering stage（SF）is the highest.2.The difference in zinc content between rice varieties was extremely significant.The zinc contentof each rice variety is between 18.1and 29.3 mg·kg^-1,and Jiyang No.1,Ji Nongda 809,Jizhen 302,Jihong No.6,Changchun 717 and Daohuaxiang 2 are High-zinc cultivars,Ji Nongda899 is a medium-zinc cultivar,Pingyi No.8 and Jijing 515 are low-zinc cultivars.The zinc content of different varieties of rice increased by 18.0%after application of zinc fertilizer;the zinc content of rice by four kinds of zinc fertilizer application methods such as S,SB,SF and SBF increased by8.3%,17.4%and 19.5,respectively.%and 27.0%,but there was no significant difference in the average zinc content between the three spray treatments.3.In the application without zinc fertilizer andonly soil application of zinc fertilizer,zinc in rice at booting stage and flowering stage mainly accumulates in stem and sheath.The main accumulation sites of zinc in mature stage are stem sheath and rice;after spraying on the surface of zinc fertilizer leaves,the blade becomes a zinc-donating carrier.When zinc is surplus,in addition to accumulating in the stem sheath,zinc accumulates in the leaves.4.In this test,the zinc content of the husk is 1.2 to 5.4 times that of rice.After the zinc content in the rice reaches a certain level,it is no longer elevated,but accumulates in the husk.The transfer of zinc from the husk to the rice is a key step affecting the increase in zinc content in rice.5.The application with zinc spraying can significantly increase the zinc content in rice.The application with zinc spraying at the booting stage and the flowering stage can maximize the zinc content of each variety of rice;The effect of increasing yield is best with zinc fertilizer both soil and foliar spray application at flowering stage.