Effect Of Macronutrient On Chromium Absorption And Physiological Characteristics Of Maize Seedlings

Chromium is known as a widely distributed element in the crust and most important environmental pollutant. Compared with other pollutants, heavy metals will cause serious environmental pollution and ecological damage as it can be existed for a long time in environment. Cr (VI)will not only induce toxicity, mutagenicity and carcinogenicity, but also seriously affected crop yield and quality. It can be accumulated and progressively enlarged through food chain such as plant-animal-man, and eventually threat to the survival of humanity.Nutrients are chemical elements which is necessary in maintaining normal metabolism and completing life cycle of the plants.Nitrogen, phosphorus, potassium are essential macro elements to plant growth, and also commonly used fertilizer in agriculture.Nitrogen is one of the most important nutrients, known as the life element, it has the close relationship with crop yield and quality. Phosphorus is essential for plant growth. It is a vital component in many important compounds of plants, and also participating in a large number of physiological processes.Potassium is the most widely distributed metal in plants,and it has a variety of important physiological functions in plants.There is interaction between heavy metals and plant nutrients in the plant growth environment.Heavy metal stress can reduce the absorption of nutrients, such as phosphorus, potassium and other nutrients.So does the transport efficiency. The result is it made loss of plant mineral nutrition, and csused disorder of physiological metabolism and chemical composition process.Plant has its own defense system against heavy metals.The rational use of large amounts of nutrients,such as nitrogen, phosphorus,potassium and other elements, may improve a series of physiological and biochemical reactions to enhance the defense system, thereby mitigating the role of the heavy metal stress.In this study, solution culture method was used to study the effects on chromium absorption and physiological characteristics of maize seedlings under the control of nutrient(nitrogen, phosphorus and potassium).The study will be helpful to understand the toxicity of chromium(VI) on Maize seeding. It provides methods of thinking for the reduction of chromium toxicity in the plants.It has great practical significance in improving maize yield and quality and to preventing chromium harm.The results are summarized as follows:(1)Solution culture method was used to study the effects of different levels of nitrogen and chromium on maize seedlings corn absorption, transport and physiological characteristics.The results show that the growth of maize seedlings was inhibited as they are subjected to a certain degree of the hexavalent chromium. And with the chromium concentration increased, the effect became more significant. Nitrogen can alleviate heavy metal Cr toxicity on the corn seedlings, and with the potassium concentration increased, the relief effect became more notable.(2) Solution culture method was used to study the effects of different levels of phosphorus and chromium on maize seedlings corn absorption, transport and physiological characteristics.The results show that the growth of maize seedlings was inhibited as they are subjected to a certain degree of the hexavalent chromium. And with the chromium concentration increased, the effect became more significant.Phosphorus can alleviate heavy metal Cr toxicity on the corn seedlings, and with the potassium concentration increased, the relief effect became more notable.(3)Solution culture method was used to study the effects of different levels of potassium and chromium on maize seedlings corn absorption, transport and physiological characteristics.The results showed that the growth of maize seedlings was inhibited as they are subjected to a certain degree of the hexavalent chromium. And with the chromium concentration increased, the effect became more significant. Potassium can alleviate heavy metal Cr toxicity on the corn seedlings, and with the potassium concentration increased, the relief effect became more obvious.