摘要： 为研究酸化土壤对晚稻根系活力、吸收面积、POD与SOD活性等根系生理特性指标以及植株氮素利用效率指标的影响,探讨酸化土壤影响晚稻氮素利用效率的途径,以前期试验筛选出的7个具有不同氮素敏感性的酸性敏感型晚稻品种为材料,在湖南长沙县不同酸度大田开展了试验.结果表明:酸化土壤使各品种根系活力、总吸收面积、活跃吸收面积与POD活性降低,但下降的程度与品种氮素敏感类型有关,一般氮素敏感型品种极显著下降,氮素中间型品种显著下降,而氮素迟钝型品种下降不显著;酸化土壤使各品种孕穗期和齐穗期根系SOD活性极显著下降,但对灌浆期根系SOD活性影响不明显;各品种在酸化稻田上的氮素积累量、氮素利用效率、氮肥效率和氮生理效率多呈下降趋势,其中,前三者的下降程度与品种氮素敏感性有关,一般氮素敏感型品种下降极显著,氮素中间型品种下降显著,而氮素迟钝型品种下降趋势不显著;而各品种氮生理效率一般均呈极显著下降趋势,与品种氮素敏感性无关.根系生理特性与氮素利用效率指标的相关性分析表明,根系POD活性和根系活力与晚稻品种氮素利用效率指标相关性较明显,因此,初步确定酸化土壤对晚稻氮素利用效率的影响主要是通过影响根系POD活性和根系活力实现的.

关键词: 晚稻, 酸化土壤, 根系生理特性, 氮素利用效率

Abstract: In order to study the effects of acidified soil on indexes of roots physiological properties,roots activity,absorption area,activity of POD and SOD and indexes of nitrogen utilization efficiency of late rice to discuss the influence approach of acidified soil on nitrogen utilization efficiency of late rice,experiments were conducted in fields with different pH in Changsha,Hunan Province,with 7 acid-sensitive late rice varieties with different nitrogen sensibility screened from former tests as materials.The results showed that activity,total absorption area,active absorption area and POD activity of roots of all varieties decreased in acidified paddy soil,while the decreasing significance was related to types of nitrogen sensibility of varieties.In common,the decrease of nitrogen-sensitive varieties was very significant,that of nitrogen-intermedia varieties was significant,while that of nitrogen-obtuse varieties was not significant.The roots SOD activity at booting and full heading stage of all varieties was significantly decreased by acidified soil,while that at filling stage was affected unclearly.The nitrogen accumulation,nitrogen utilization efficiency in common,nitrogen fertilizer efficiency and nitrogen physiological efficiency of all varieties were decreased in acidified field in common,in which the decreasing significance of the former three indexes was related to types of nitrogen sensibility of varieties,that is to say,the decrease of nitrogen-sensitive varieties was very significant,that of nitrogen-intermedia varieties was significant,while that of nitrogen-obtuse varieties was not significant.The decrease of nitrogen physiological efficiency of all varieties was very significant,which was not related to types of nitrogen sensibility of varieties.Correlation analysis between roots physiological indexes and nitrogen utilization efficiency indexes showed that the correlation between roots POD activity,roots activity and nitrogen utilization efficiency indexes was more evident,so we could preliminarily confirm that effect of acidified soil on nitrogen utilization efficiency of late rice was mainly realized by affecting roots POD activity and roots activity.

Key words: Late rice, Acidified soil, Root physiological property, Nitrogen utilization efficiency

中图分类号: 

• S511.01

• S143.1