【作者】 李亚军；

【导师】 高亚军；

【作者基本信息】 西北农林科技大学 ， 肥料学， 2010， 硕士

【摘要】 查明氮高效基因型与氮低效基因型油菜之间的差异及其对氮肥的响应规律,有助于揭示油菜高效吸收利用氮素的机理,从而为培育氮高效新品种和不同氮效率油菜的氮肥管理提供依据。本文基于课题组前期的工作基础,采用盆栽试验对氮吸收效率差异显著的两个甘蓝型油菜(13号和4号)在不同供氮水平下(0、0.05、0.1、0.15、0.2gN/kg)氮效率、营养特性、农学性状及其他生理特性的差异作了较全面的分析比较,结果表明:1.在供氮水平0~0.2gN/kg范围内,油菜氮效率和吸收效率随氮水平增加呈降低趋势,氮利用效率则随氮水平增加呈先增加后降低趋势;氮高效基因型的氮效率和吸收效率比氮低效基因型对氮肥响应更敏感。氮高效与低效基因型的氮效率、氮吸收效率的差异在氮水平较低时更显著。2.油菜氮素吸收对供氮水平的反应没有明显的基因型差异,但在不同生育阶段有不同的特点:在苗期和薹期,氮高效与氮低效基因型地上部氮素累积量均随施氮量增加呈先增后减的趋势;从花期到角果期,地上部分氮素累积量则呈持续增加趋势;至成熟期时,总吸氮量、不同器官氮素累积量均随施氮量提高而增加。从苗期到角果期,氮高效与氮低效基因型地上部含氮量随施氮量增加均呈增高趋势,但在苗期增幅较小,随后增幅则逐渐提高;至成熟期时,各器官含氮量随施氮量增加有先降后升趋势。油菜氮素的分配对供氮水平的反应也没有明显的基因型差异:氮高效与氮低效油菜的氮收获指数均由于施用氮肥而增加。随着施氮量提高,氮高效与氮低效基因型根、茎秆中的氮素比例均有逐渐降低趋势,籽粒中氮素比例则有增大趋势。不同氮效率基因型氮素累积量的差异表现出明显的阶段性:从苗期到角果期,氮高效与氮低效基因型之间地上部氮素累积量始终没有显著差异,而成熟期氮高效基因型的总吸氮量、不同器官氮累积量均有高于氮低效基因型的趋势。从苗期到花期,不同供氮水平下,氮高效基因型地上部含氮量均呈高于氮低效基因型的趋势;从角果期至成熟期,氮高效与氮低效基因型植株含氮量的差异则因供氮水平而不同。不同氮效率基因型的氮素分配有差异:氮高效基因型的氮收获指数略高于氮低效基因型。成熟期氮高效基因型根中的氮素比例均高于氮低效基因型;而茎秆中氮素的比例则呈低于氮低效基因型趋势。3.氮水平对不同氮效率油菜的生长具有相似的影响:氮高效基因型的单株产量、根系生物量、地上部分生物量、总生物量、各器官生物量占总生物量的比例、单株角果数、千粒质量、株高、第一分枝高度和一级分枝数等随氮水平的变化规律均与氮低效基因型的基本一致。然而,氮水平影响不同氮效率油菜之间差异的大小:氮高效基因型的单株产量、根系生物量、地上部分生物量、总生物量、根系、茎叶和籽粒占总生物量的比例、根冠比、收获指数、单株角果数、角果粒数、株高、一级分枝数和茎粗均高于氮低效基因型,角果皮占总生物量的比例、千粒质量和第一分枝高度低于氮低效基因型,但其差异其显著性均随氮水平高低而不同。4.在苗期和薹期,油菜叶片SPAD值随供氮水平增加没有显著的变化,在花期,SPAD值随氮水平提高显著增大。从苗期到花期,不同氮水平下氮高效基因型的SPAD值均显著高于氮低效基因型。5.成熟期单株磷、钾累积量随氮水平提高有显著增加的趋势,而磷、钾含量没有显著变化。氮高效基因型的单株磷、钾累积量和含钾量显著高于氮低效基因型;而含磷量只有在较低氮水平下显著高于氮低效基因型。更多还原

【Abstract】 It will be helpful for revealing the mechanism of N uptake and utilization by canola and support N-efficient-cultivar breeding and N management of canola to investigate the differences between canola genotypes differing in nitrogen efficiency and its responses to N fertilizer. Based on the prophase screening by our research team, two canola genotypes(No. 13 and 4) significantly differing in N uptake efficiency were grown in pots under different N rates(0、0.05、0.1、0.15、0.2gN/kg). The N efficiency,nutrition characteristics, agronomic traits and other physiological characteristics were compared. The results show as following:1. Range from 0 to 0.2gN/kg, N efficiency and N uptake efficiency of two canola genotypes decreased with N rate increasing while N utilization efficiency increased in the lower N rate range and then decreased in the higher N rate. N efficiency and N uptake efficiency of N-efficient genotype was more sensitive to N rate than that of N-inefficient genotype. The difference of N efficiency and N uptake efficiency between different genotypes was greater when less N fertilizer was applied.2. The results indicated that no significant genotypic difference in N uptake responses to N rate was found. However, they were different in various growth stages. In seedling stage and bud stage, N accumulation in aboveground part of both N-efficient and N-inefficient genotypes increased and then decreased with the increasing of N rate while they increased steadily from flowing stage to pod developing stage. At maturity stage, N accumulation in whole plant and in various sections increased when N fertilizer rate increased. For both genotypes, N concentration of aboveground part had increase trend with the rising of N rate from seedling stage to pod developing stage. However, there was small increase in seedling stage and it tended to expand in the following stage. At maturity stage, N concentration of various parts decreased slightly and then increased slightly with the rising of N rate. No significant genotypic difference in N distribution in plant responses to N rate was found, either. For both genotypes, N harvest index was enhanced due to the application of N fertilizer. Ratio of N in root, stem to N in whole plant tended to reduce with the rising of N rate while ratio of N in seed to N in whole plant was opposite. Genotypic differences in N uptake were different in various growth stages. There was no significant difference in N accumulation in aboveground part between two genotypes from seedling stage to pod developing stage while N-efficient genotype had greater N accumulation in whole plant and various sections than N-inefficient genotype at maturity stage. N-efficient genotype had higher N concentration of aboveground part than N-inefficient genotype from seedling stage to flowing stage while N concentration differences between them depended on N rate. N distribution in different parts of canola varied between two genotypes. N harvest index of N-efficient genotype was slight higher than N-inefficient genotype. Ratio of N in root to N in whole plant of N-efficient genotype was higher than N-inefficient genotype while Ratio of N in stem was lower.3. N-efficient genotype and N-inefficient genotype showed similar trend that grain yield, roots biomass, shoot biomass, total biomass, percentage of different parts biomass in whole plant biomass, silique number per plant, 1000-seed weight, height, the fist valid branch height and primary branches number fluctuated with the increase of N rate. N-efficient genotype had higher grain yield, roots biomass, shoot biomass, total biomass, percentage of root biomass in whole plant biomass, percentage of stem and leaves biomass in whole plant biomass, percentage of grain biomass in whole plant biomass, root to shoot ratio, harvest index, silique number per plant, seeds per silique, height, primary branches number and stem diameter than N-inefficient genotype, while it had lower percentage of silique wall biomass in whole plant biomass, 1000-seed weight and the fist valid branch height than N-inefficient genotype. However, the differences varied according to N rate.4. There was no response of the SPAD value to N rates from seedling stage to bolting stage. It was increased as N rates increased at florescence stage. The SPAD value of N efficient genotype was significantly higher than N inefficient genotype under different N rates from seedling stage to florescence stage.5. The P and K accumulation per plant was increased as N rate increased. There was no response of P and K content to N rates at harvest time. The P and K accumulation, K content per plant of N efficient genotype was significantly higher than N inefficient genotype, but P content was only showed under lower N rates.更多还原