磷高效基因型大麦磷吸收及利用的生理生化特征

发布时间：2019-06-12 05:59

【摘要】：磷是限制作物增产的大量营养元素之一,在磷矿资源有限和磷肥当季利用率低的双重背景下,提高作物对磷素资源的高效利用已成为当今农业发展亟需解决的重要课题。从植物磷营养性状入手,开展作物根际土壤磷素动态转化、根系适应低磷胁迫的塑性变化以及体内磷素转移和再利用的高效机理的系统研究,对于充分挖掘土壤磷库资源和作物自身磷素利用潜力,提高磷肥利用率具有重要的现实意义。本研究通过土培试验,以不同磷效率基因型大麦为材料,对其在不同供磷条件下的根际土壤无机磷组分、根系形态与生理特性、叶片磷组分及酸性磷酸酶活性特征展开了对比研究,阐明了磷高效基因型大麦磷高效吸收和利用的部分生理生化特性。主要研究结果如下：(1)在极低磷(25mgkg-1)、低磷(50mgkg-1)和正常磷(75mgkg-1)水平下,不同基因型大麦根际土壤有效磷含量均显著低于非根际土壤,其中磷高效基因型大麦DH110+、DH147的亏缺程度(32.2%-44.5%)大于低效基因型DH49(17.4%-28.1%)。从不同形态无机磷在土壤中的含量变化来看,正常施磷水平下,各无机磷组分在根际土壤中的亏缺量均无显著的基因型差异；但在极低磷和低磷水平下,高效基因型大麦根际土壤Ca2-P、Ca8-P和Al-P的亏缺量显著高于低效基因型,Fe-P在极低磷水平下的高效基因型中显著亏缺,其含量分别较非根际土壤降低了6.2%-6.3%,Ca10-P、O-P的亏缺量无显著的基因型差异。表明,高效基因型大麦利用土壤Ca2-P、Ca8-P和A1-P能力强于低效基因型,且对活性较低的Fe-P有一定利用能力。(2)不同施磷水平下,磷高效基因型大麦总根长、总根表面积、比根长、侧根长及侧根表面积均显著高于磷低效基因型,分别为低效基因型的1.46-2.06倍、1.12-1.51倍、1.35-1.72倍、1.69-2.42和1.40-1.78倍,而平均根系直径为低效基因型的70.6%-90.2%,不定根长、不定根表面积仅在正常供磷条件下差异显著。其中,总根长、总根表面积各施磷水平下对大麦植株磷素吸收的贡献较高。随施磷水平降低侧根长、侧根表面积对大麦植株磷素吸收的贡献增加,不定根长、不定根表面积对大麦植株磷素吸收的贡献降低,表明,高基因型大麦在侧根伸展上的优势有利于发挥其对土壤磷素的探索和吸收。低磷胁迫下,磷高效基因型大麦根系活力显著高于低效基因型,而其根系酸性磷酸酶活性则显著低于低效基因型,表明其对低磷胁迫程度的适应性更强。(3)低磷胁迫显著降低了不同基因型大麦下部叶和上部叶中的无机磷含量,但对难溶态磷含量影响较小。低磷胁迫下,上部叶核酸态磷含量表现为高效基因型显著高于低效基因型,而其在下部叶的含量则表现为高效基因型显著低于低效基因型。低磷胁迫下,下部叶酯磷含量和分配比例表现为高效基因型低于低效基因型,且极低磷水平下,高效基因型下部叶酯磷分配比例(13.4%-17.0%)低于上部叶(19.6%-21.3%),低效基因型不同部位叶片酯磷分配比例差异较小。大麦上部叶酯磷含量受低磷胁迫时仅在低效基因型中有显著降低,并显著低于高效基因型。核酸态磷和酯磷在高效基因型大麦叶片中的含量及分配特征表明其上部叶的磷素营养状况较优,同时其下部叶易溶性有机磷的分解转化作用更强。此外,低磷胁迫下,大麦下部叶酸性磷酸酶的活性显著增加,且高效基因型显著高于低效基因型,亦表明高效基因型大麦对下部叶酯磷的活化利用能力更强。
[Abstract]:Phosphorus is one of the most important nutrient elements to limit crop yield, and in the dual context of the limited resource of phosphate rock and the low utilization rate of phosphate fertilizer, the efficient utilization of the phosphorus resource of the crops has become an important subject to be solved in the present agricultural development. Based on the nutrient characters of the plant phosphorus, the dynamic transformation of the phosphorus in the rhizosphere of the crop, the plastic change of the root system to the low-phosphorus stress and the high-efficiency mechanism of the transfer and re-utilization of the phosphorus in the plant are studied, And the utilization rate of the phosphate fertilizer is of great practical significance. In this study, a comparative study was conducted on the characteristics of inorganic phosphorus, root morphology and physiological characteristics, phosphorus component and acid phosphatase activity of the rhizosphere soil under different phosphorus supply conditions by soil-culture test with different phosphorus-efficiency genotype barley as the material. Some physiological and biochemical characteristics of high-efficiency absorption and utilization of phosphorus-efficient and high-efficiency genotypes of barley were set forth. The main results are as follows: (1) The effective phosphorus content of the rhizosphere soil of different genotypes of barley is lower than that of non-rhizosphere soil at the level of very low phosphorus (25 mg kg-1), low phosphorus (50 mg kg-1) and normal phosphorus (75 mg kg-1), of which the phosphorus high-efficiency genotype barley DH110 +, The deficiency of DH147 (32.2%-44.5%) was greater than that of the low-efficiency genotype DH49 (17.4%-28.1%). According to the change of the content of the inorganic phosphorus in different forms in the soil, there was no significant difference in the amount of the inorganic phosphorus component in the rhizosphere soil under the normal phosphorus application level, but at the low phosphorus and low phosphorus level, the high-efficiency genotype barley rhizosphere soil Ca 2-P, The loss of Ca8-P and Al-P was significantly higher than that of the low-efficiency genotype. Fe-P was a significant deficit in the high-efficiency genotype at very low phosphorus level. The content of Ca8-P and Al-P decreased by 6.2%-6.3%, Ca10-P and O-P in the non-rhizosphere soil. It is shown that the ability of high-efficient genotype barley to utilize the Ca 2-P, Ca8-P and A1-P in the soil is stronger than that of the low-efficiency genotype, and the Fe-P with lower activity has a certain utilization ability. (2) The total root length, total root surface area, specific root length, lateral root length and lateral root surface area of the high-efficiency genotype of the phosphorus were significantly higher than that of the phosphorus inefficient genotype at different phosphorus application levels, and were 1.46-2.06-fold, 1.12-1.51-fold, 1.35-1.72-fold, 1.69-2.42 and 1.40-1.78-fold, respectively, of the low-efficiency genotypes. The average root diameter was 70.6%-90.2% and the root surface area of the adventitious root was only significant under normal phosphorus supply. The total root surface area and the total root surface area have high contribution to the phosphorus absorption of the barley plant at different phosphorus application levels. the contribution of the lateral root length and the lateral root surface area to the phosphorus absorption of the barley plant is increased with the application of the phosphorus level, the adventitious root length and the adventitious root surface area are reduced to the contribution of the phosphorus absorption of the barley plant, The advantage of high-genotype barley on lateral root extension is to play its role in the exploration and absorption of soil phosphorus. Under the low-phosphorus stress, the root activity of the high-efficient genotype of the barley was significantly higher than that of the low-efficiency genotype, while the activity of the acid phosphatase of the root system was significantly lower than that of the low-efficiency genotype, indicating that it was more adaptive to the degree of low-phosphorus stress. (3) The low-phosphorus stress significantly reduced the content of the inorganic phosphorus in the lower and upper leaves of the barley with different genotypes, but the effect on the content of the insoluble phosphorus was small. Under the low-phosphorus stress, the content of the high-efficiency genotype of the upper leaf was significantly higher than that of the low-efficiency genotype, while the content of the lower leaf was significantly lower than that of the low-efficiency genotype. in that low-phosphorus stress, the phosphorus content and the distribution ratio of the lower leaf ester show that the high-efficiency genotype is lower than the low-efficiency genotype, and the high-efficiency genotype lower leaf ester phosphorus distribution proportion (13.4%-17.0%) is lower than the upper leaf (19.6%-21.3%) at the low phosphorus level, The difference of phosphate-phosphorus distribution in different parts of the low-efficiency genotype was small. When the content of the upper leaf ester of the barley is lower than that of the low-phosphorus stress, only the low-efficiency genotype has a significant reduction, and is obviously lower than the high-efficiency genotype. The content and distribution of the nucleic acid and the phosphate in the high-efficient genotype of the barley leaves indicate that the phosphorus content of the upper leaves is better, and the decomposition and conversion of the soluble organic phosphorus in the lower leaves of the high-efficiency genotype barley leaves is stronger. In addition, under low phosphorus stress, the activity of the acid phosphatase of the lower leaf of the barley was significantly increased, and the high-efficiency genotype was significantly higher than that of the low-efficiency genotype.
【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S512.3

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