硫肥对春油菜幼苗生理指标和土壤酶活性的影响

该研究以春油菜幼苗为材料,采用土壤盆栽试验,设7个不同施硫(0、35、70、105、140、175、210mg·kg^-1)处理,通过测定春油菜幼苗的株高、植株鲜重、叶绿素含量、MDA含量、SOD、POD、CAT活性、土壤全氮含量、pH、蔗糖酶、过氧化氢酶和脲酶活性指标,分析不同施硫量对春油菜幼苗生理生化指标和土壤相关酶活性的影响。结果表明:在春油菜苗期施用硫肥对幼苗的农艺性状、生理生化指标和土壤酶活性均产生了一定影响。施硫量在35~105mg·kg^-1范围时,对植株鲜重有明显的促进作用;施硫量在70~105mg·kg^-1范围时,类胡萝卜素含量达到最高;施硫量在70~105mg·kg^-1范围时,叶片中POD和CAT的活性明显升高,而MDA含量明显下降;经相关分析,MDA含量与POD活性呈极显著负相关(r=-0.92,P<0.01),与CAT活性呈显著负相关(r=-0.72,P<0.05),说明叶片MDA含量受POD和CAT活性变化的影响;施硫量高于105mg·kg^-1时,土壤脲酶和蔗糖酶活性受到抑制;施硫量高于140mg·kg^-1时,土壤过氧化氢酶活性受到抑制;随着施硫量的增加,土壤pH值和叶片SOD活性逐渐下降;经相关性分析,土壤脲酶活性和全氮含量间呈极显著正相关(r=1,P<0.01),表明土壤全氮含量受土壤脲酶活性变化的影响。由此可知,在低硫(35~105mg·kg^-1)条件下对春油菜幼苗生理生化指标及土壤酶活性具有一定的促进作用,而在高硫(>105mg·kg^-1)条件下则产生抑制。

Effects of sulfur fertilizer on physiological indexes and soil enzyme activity of spring rape seedlings

Sulfur element is a medium trace element needed for plant growth. In order to clarify the physiological and biochemical indexes and soil enzyme activity of spring rape seedlings under different sulfur applications, based on the spring rape seedlings, the seven sulfur fertilizer 0, 35, 70, 105, 140, 175, 210 mg·kg^-1] were set up by pot experiment, and the plant height, plant fresh weight, the content of chlorophyll and MDA, the activities of SOD, POD and CAT of leaves, the content of soil total nitrogen, pH and the activity of invertas and catalase were measured respectively. The results were as follows: Sulfur application had certain influence on the agronomic characters, physiological and biochemical indexes of spring rape seedlings and soil enzyme activity. In a range of sulfur application(35-105 mg·kg^-1)the plant fresh weight was significantly promoted, carotenoid content was the highest when sulfure fertilization was 70-105 mg·kg^-1; In a range of sulfur application(75-105 mg·kg^-1), the activities of POD and CAT in leaves were significantly increased, but the content of MDA in leaves was significantly decreased; According to correlation analysis, an extremely negative correlation was observed with MDA content and POD activity(r=-0.92, P<0.01), and a significant negative correlation was observed with MDA content and CAT activity(r=-0.72, P<0.05), indicating that MDA content is affected by the POD and CAT activities; The activities of invertase and urease in soil were inhibited with sulfur application higher than 105 mg·kg^-1, the activity of catalase in soil was inhibited with sulfur application higher than 140 mg·kg^-1; with the increase of sulfur fertilizer, the activity of SOD in leaves and soil pH showed decreasing trends; according to correlation analysis, an extremely positive correlation was observed between the content of total nitrogen and the activity of urease(r=1, P<0.01), indicating that soil total nitrogen content is affected by the soil urease activity. Therefore, physiological and biochemical indexes of spring rape seedlings and soil enzyme activity were promoted with low sulfur application(35-105 mg·kg^-1), while these indexes were inhibited with high sulfur application(>105 mg·kg^-1). This study can provide some theory reference for sulfur fertilization of spring rape.