【摘要】 盆栽试验研究了土壤-水稻-铅-微生物相互作用的体系中,外源铅不同处理水平(CK、100、300、500、700、900mg·kg-1)对两种水稻土壤微生物生物量碳、氮,微生物活性,水稻生理指标及生物量的影响。结果表明:水稻土壤中微生物量碳、氮,微生物活性及水稻叶绿素与生物量都随铅处理水平的增大而增加,多数指标在300~500mg·kg-1铅处理时出现峰值,然后随铅水平的增加而降低,它们的转折点受土壤性质(如颗粒组成,有机质含量等)影响。试验范围内,水稻脯氨酸含量和过氧化物酶活性都随铅处理水平的增大而缓慢增加。体系中土壤微生物指标和水稻生理指标的变化存在一定的相关性,其大小也受土壤类型的制约。试验还表明,土壤微生物量氮、脱氢酶活性及水稻过氧化物酶活性是铅处理后更为敏感的生物学指标。更多还原

【Abstract】 The effect of lead (Pb) treatment on the soil microbial biomass carbon (Cmic), microbial biomass nitrogen (Nmic), micro-bial activities, rice physiological indices and rice biomass in the interactive system of soil-rice-lead and microbe, were studied by a greenhouse pot experiment. Lead was applied at six different levels in two different paddy soils, namely 0 (CK), 100, 300, 500, 700 and 900 mg·kg-1 soil. The results showed that Pb treatment had a stimulating effect on soil Cmic, Nmic, microbial activities, rice chlorophyll content and rice biomass at low Pb treatment levels and an inhibitory influence at high Pb levels. Most indices appeared peak values at the levels from 300 mg·kg-1 to 500 mg·kg-1 Pb treatments. However, the degree of influence on Cmic, Nmic, microbial activities and rice biomass by Pb was related to the clay and organic matter contents of the soils. Meanwhile, Lead was effective in inducing proline accumulation and its toxicity caused oxidative stress in rice plants at the tested Pb levels. Correlations between soil microbial indices and rice physiological indices were also affected by soil properties. The results also indicated that soil Nmic, soil dehydrogenase and rice peroxidase were more sensitive biological indicators reflecting Pb contamination.更多还原