关键词: 聚类分析, 聚类分析

Abstract: Physiological and pathogenic mechanism of iron toxicity in plants is the excessive accumulation of iron and iron compounds that induce a variety of active free radicals which attack membrane lipids, leading to lipid peroxidation and membrane damage. In excess under Fe²⁺ stress, the superoxide dismutase (SOD), peroxidase (POD) activity and malondialdehyde (MDA) of plants content increased with the anti iron toxicity are closely related. In order to study the response mechanism of rice by ferrous iron toxicity, a field experiment on the different types of cold water paddy field carry different concentrations Fe²⁺ on rice physiological activity, growth and yield. The results showed that: different types of cold water paddy field added Fe²⁺, the POD, SOD activity and the MDA content of the rice leaves and roots increased with the increase of Fe²⁺ concentration, the cold water paddy field (cold- water fields, muddy fields) environmental factors such as low temperature increased activity of POD and MDA content, decreased the activity of SOD in rice, the leaves and roots of rice in the cold water paddy field (cold- water fields, muddy fields) were damaged degree higher than the yellow clayey soil by ferrous; effect of Fe²⁺ on rice physiological activity is mainly manifested in the tillering stage and heading stage, especially the rice leaves and roots in the tillering stage are damaged more susceptible by ferrous; suitable Fe²⁺ concentration is conducive to improve rice yields.