Effects Of Manganese Stress On The Growth Of Selenium-enriched Rice And The Contents Of Selenium And Manganese In Plants

Rice(Oryza sativa L.)is one of the most widely eaten food crops in the world.Selenium-enriched rice is more and more common in daily life.The special variety of selenium-enriched rice is rich in various nutrients beneficial to the human body.For example,vitamins,γ-oryzanol,tocopherols,and anthocyanins.Selenium is an important element in the body and is beneficial to the organism,depending on its morphology,intake and bioavailability.Selenium,a specific chemical used to treat cancer,enhances the body’s resistance to stress and protects the body.Manganese is one of the essential micronutrients for the normal operation of plants.One of the most important physiological functions of manganese in plants is reflected in the process of photosynthesis.In this study,selenium-enriched red rice was selected as the research material.The pot experiment was conducted to study the selenium-manganese content of different rice varieties under different levels of manganese stress at different growth stages,and the physiological and biochemical study of selenium-enriched red rice was systematically studied by hydroponic experiment.Its characteristics and its antioxidant activity are intended to provide a scientific basis for the safe application of selenium in agricultural production.The following results were obtained through experiments: The fluctuation of SPAD value in non-selenium-enriched rice under tillering,booting stage,heading stage and milky stage was more severe than that of selenium-enriched rice,which could reflect the resistance of selenium-enriched rice to manganese stress to some extent.The results showed that the SPAD value of selenium-enriched rice under high concentration of Mn(100mg/kg)was higher than that of non-selenium-enriched rice,which proved that the presence of selenium could effectively improve the adverse effects of manganese toxicity on plant photosynthesis.The determination of selenium and manganese in stems and leaves during the important growth stages of four rice stages at the tillering stage,booting stage,heading stage and milk stage of multi-level manganese stress showed that the leaf part manganese concentration was higher than that of the stem at the tillering stage and the booting stage.The concentration of the part indicates that most of the manganese elements in the early stage of rice growth are concentrated in the leaves.Compared with the ordinary low-selenium white rice 725,the three selenium-enriched varieties show low absorption effects on manganese toxicity to varying degrees.Among them,selenium-enriched glutinous rice has the best performance.It can be seen from the heading stage that Z5097 B has higher enrichment of manganese than other selenium-enriched varieties.The milk ripening period is close to the end of the rice,and the selenium content in the stem of the leaves has also decreased to varying degrees.725 shows a very low level of selenium,even in the 25mg/kg Mn treatment group,100mg/kg Mn treatment group almost zero.Compared with the selenium content of the other three groups of selenium-enriched rice,the stress of manganese toxicity on non-selenium-enriched rice is very obvious.The glutinous selenium-rich glutinous rice Z5097A/R2035 showed relatively stable performance,and the manganese concentration of stems and leaves was lower than that of other experimental materials,and the change was not large.Excessive manganese toxicity did not cause excessive effects on it.The following results were obtained by analyzing the selenium and manganese contents in the selenium-enriched rice and non-selenium-enriched rice.The percentage of rice bran manganese content in the selenium-enriched rice varieties accounted for 52%-60% of the total grain manganese content.For selenium-enriched rice,the manganese enrichment in rice bran is higher.The content of manganese in the polished rice was extremely low after treatment with manganese poisoning,and the proportion of manganese in the polished rice and endosperm decreased gradually with the increase of manganese concentration.The hydroponic experiment was conducted to determine the antioxidant activity-related enzymes in the leaves and roots of rice seedlings.The results showed that the total antioxidant capacity(T-AOC)of non-selenium-enriched rice 725 was observed in both rice leaves and roots.Compared with selenium-enriched rice varieties,it can be determined that selenium-enriched rice is superior to non-selenium-enriched rice in antioxidant capacity,and the superoxidase dismutase(SOD)of leaves and roots show a trend of increasing first and then decreasing with the concentration of manganese treatment.The SOD values in the leaves and roots of selenium-enriched rice were higher than those in non-selenium-enriched rice.The content of catalase(CAT)in leaves and roots of three selenium-rich varieties was higher than that in non-selenium-enriched rice.In summary,the selenium-enriched hybrid rice and selenium-enriched glutinous rice used in this study can be used as natural antioxidants and health foods,and can be used in the commodity market to balance the supplement of trace elements in human body,and can also effectively improve farmland to some extent.The current situation of soil pollution manganese exceeding the standard is an excellent rice variety that is beneficial to production,has market potential,and is easy to increase the value of by-products.