有机肥对桃幼树铬胁迫缓解效果的研究

摘要

Using two -year -old ‘Luxing/wild peach’(Amygdalus persica Linn.)as the research ob-ject,the pot experiment was conducted to study the effects of organic manure on plant growth,soil enzyme ac-tivities and Cr concentration in each part of peach trees under different levels of Cr stress (0,100,200 mg/kg).The results showed that with the increase of Cr stress level,the peach trees showed a decreasing trend on the chlorophyll content,photosynthesis,growth rate of trunk girth and accumulation amount of dry mass.The application of organic manure could mitigate the impact of Cr stress on the growth of young peach trees to some extent and increase the plant biomass.Under the Cr stress,the activities of soil enzymes were in-hibited.Applying organic manure could alleviate the inhibitory effects of Cr on soil enzyme activities.The ac-tivities of urease,phosphatase,catalase and protease except for invertase were significantly enhanced by ap-plying organic manure than those of no organic manure treatment.The Cr concentration in plant samples were studied by ICP -Ms using microwave digestion.It showed that the concentration of Cr in various organs signif-icantly increased under Cr stress.Organic manure could remarkably reduce the accumulation of Cr in plants under exogenous Cr stress.Under the high Cr dosage stress,the Cr concentration in each part of peach trees decreased by 39.2% ~85.3% after organic manure application than those of no organic manure application. Above all,the application of organic manure could obviously mitigate the injury of peach trees by Cr stress and enhance the resistance of plants to Cr pollution.%以2年生‘鲁星／毛桃’（Amygdalus persica Linn．）为试材，通过盆栽模拟试验，研究不同浓度铬（0、100、200 mg／kg）胁迫下有机肥对桃幼树生长状况、土壤酶活性及桃幼树各部位对 Cr 吸收分配的影响。结果表明，随着外源 Cr 胁迫程度的加剧，桃幼树表现出叶绿素含量下降、光合作用减弱、干周增长速率减小、干物质积累量降低的趋势。施加有机肥可以不同程度地缓解 Cr 胁迫对桃幼树生长的影响，增大植株生物量。Cr 胁迫下，土壤酶活性受到抑制，有机肥能缓解 Cr 对土壤酶活性的抑制作用，除蔗糖酶外，脲酶、磷酸酶、过氧化氢酶和蛋白酶活性较未施有机肥处理显著提高。通过测定植株内 Cr 含量可知，Cr 胁迫下桃幼树各部位Cr 含量显著增加；施用有机肥对降低植株各部位 Cr 积累效果显著，重度 Cr 胁迫下，施加有机肥处理比未施有机肥处理桃幼树各部位 Cr 含量降低了39．2％～85．3％。可见，通过增施有机肥能够明显减缓 Cr 胁迫对桃幼树的伤害，增强植株对 Cr 的抵抗力。