机构地区:[1]浙江大学环境与资源学院教育部环境修复与生态健康重点实验室,浙江杭州310058
出 处:《浙江大学学报(农业与生命科学版)》2012年第5期599-607,共9页Journal of Zhejiang University:Agriculture and Life Sciences
基 金:土壤与农业可持续发展国家重点实验室开放基金;国家自然科学基金资助项目(30971859);浙江省科技厅重大专项重点项目(2010E70002);浙江省大学生创新创业孵化项目(2009R401246);国际植物营养研究所(IPNI)资助项目
摘 要:以30个菠菜基因型为材料,采用水培方法评价其在低氮(2mmol/L)和高氮(10mmol/L)水平下对氮素吸收与利用效率的差异。结果表明,供试菠菜基因型在2个氮水平下氮素吸收和利用效率的相关指标均存在显著差异。在高氮水平下,菠菜地上部干质量、含氮量、氮累积量和氮素吸收效率显著高于低氮水平;而氮素利用效率和氮素利用效率指数明显低于低氮水平。其中地上部干质量在低氮和高氮条件下均具有较大的变异系数,可以作为同一供氮水平下氮效率(NUE)的重要评价指标,而地上部氮累积量、氮素吸收效率和氮素利用效率指数的变异系数也较高,且与地上部干质量具有极显著的正相关,故可作为菠菜氮效率的辅助评价指标。根据不同菠菜基因型在低氮和高氮条件下低于或高于供试基因型地上部干质量的平均值作为氮低效基因型和氮高效基因型,所筛选出的氮高效基因型在低氮和高氮水平下均具有较高的地上部干质量、地上部氮累积量、氮素吸收效率、氮素利用效率和氮素利用效率指数。通径分析表明,氮素吸收效率在2个氮水平下对菠菜氮效率的贡献明显高于氮素利用效率,但氮素利用效率对氮效率也有一定的贡献。由此可见,在菠菜氮高效品种的选育工作中应协同提高低氮和高氮条件下氮素的吸收和利用效率。Nitrogen (N) is an essential element for both crop development and yield, however, excessive application of N fertilizer not only increases the production cost but also causes environmental pollution. Therefore, there is an urgent need to improve nitrogen use efficiency (NUE) and minimize N losses for the development of sustainable agricultural systems. Numerous studies showed that NUE may be improved by N management strategies hut this approach needed a lot of input. It is therefore critical to select and cultivate crops with enhanced NUE. Previous studies on NUE were mainly focused on crops, such as rice, wheat, barley, canola, however researches on vegetables were rather limited, even though over-fertilization was prevalent nowadays in vegetable production in China. The aim of this study was to investigate genotypic differences in growth traits and NUE in spinach (Spinach oleracea L. ) grown under N-deficient and N-sufficient conditions in hydroponic cultivation. Dry matter, N accumulation, N usage index, N uptake and utilization efficiency were measured and compared for 30 spinach genotypes grown under N-deficient (2 mmol/L) and N-sufficient (10 retool/L) conditions by hydroponic experiment. The results showed significant differences in all parameters of NUE among the spinach genotypes under N- deficient and N-sufficient conditions. At the higher N level, plants produced higher shoot dry masses, N concentrations, N accumulation and N uptake efficiency, but lower N utilization efficiency and N utilization ratios. The shoot dry mass may be used as a critical index for evaluating the difference in NUE in spinach genotypes at the same N level because of high co-efficiency of variation at low and high N levels. In addition, shoot N accumulation, N uptake efficiency and N utilization ratio also showed high co-efficiency of variation, and exhibited a significant positive correlation with shoot dry mass. Efficient and inefficient genotypes were selected based on the criterion of producing more o
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