【作者】 宿飞飞；

【导师】 陈伊里；

【作者基本信息】 东北农业大学 ， 作物遗传育种， 2014， 博士

【摘要】 分根交替灌溉是基于节水灌溉技术原理与作物感知早生信号的理论而提出的。它是在部分根区干旱(PRD)技术的基础上发展而来。它是采取对作物一部分根区进行正常灌溉,对另一部分根区给予适度干旱胁迫,正常灌溉及适度干旱胁迫交替作用于作物根区,通过虚假旱生信号刺激诱导相关基因活化与表达,进而增强植株生理活性,保证植株健康生长,提升作物水分利用效率。本论文以马铃薯为研究对象,采取室内盆栽试验,在生育前期通过正常灌溉(CK)、分根交替灌溉(PRD)和干旱处理(DW)三种控水处理之后再复水的试验设计,系统研究分根交替灌溉(PRD)对马铃薯植株生长特性、光合特性、渗透调节特性、抗氧化酶等生理特性的影响,分析各项指标变化特点及基本规律,揭示分根交替灌溉处理对马铃薯影响的生理机理。并运用分子生物技术,研究马铃薯植株相关基因系统对早生信号刺激的感知和传导所引起的分子反应。主要结论如下：(1)分根交替灌溉能有效促进马铃薯植株整体生长势。控水灌溉复水后,马铃薯株高和叶面积的整体变化、植株干物质累积量和累积速率高于CK和DW处理。(2)分根交替灌溉处理的马铃薯植株光合作用适应性强。PRD处理马铃薯净光合速率(PN)高,维持最大光合能力、光能转化效率高,为植株保持良好的生长创造基本条件。(3)分根交替灌溉提高了马铃薯植株防失水能力。PRD处理共质体溶质浓度增加和渗透势降低,增加了细胞膨压。叶片保水持续时间长,植株抗旱性更强。(4)分根交替灌溉能够增强细胞抗氧化酶生理活性。PRD处理的SOD、POD、CAT活性均高于CK和DW处理,而且随着含水量的降低导致植株抗氧化能力更强；PRD处理的MDA活性、活性氧含量和产生速率水平较其它两个处理低,受氧化胁迫轻。(5)分根交替灌溉有利于马铃薯渗透调节物质的积累。PRD处理的马铃薯叶片脯氨酸、可溶性糖、可溶性蛋白等渗透调节物质累积量呈上升趋势,在PRD处理中渗透调节物质累积量在各个时期均高于CK和DW处理。局部、虚假的灌溉方式利于促进渗透调节物质积累,增强植株渗透保水能力,降低干旱胁迫的伤害。(6)分根交替灌溉技术可有效提高灌溉水分利用效率,增加马铃薯产量。分根交替灌溉在减少叶片水分蒸发量的同时,刺激了植株再生长和吸收功能的补偿效应,使马铃薯产量比常规灌溉提高4.06%,灌溉水分利用效率比常规灌溉提高31.6%。(7)分根交替灌溉可诱导增强水通道蛋白RD28基因表达能力。采用实时荧光定量PCR技术获得PRD处理的马铃薯叶片中RD28基因的相对表达量高,说明PRD处理诱导抗旱基因的表达能力强于其它处理,有利于增强植株的抗旱能力。研究结果表明,应用根系分根交替灌溉技术可以有效提升马铃薯植株抗旱性能,提高植株生长品质,为实现节水增产的生产目的提供有效保障,可以通过进一步探索实践将该技术推广应用于田间模式。更多还原

【Abstract】 Partial root-zone alternate irrigation belongs to deficit irrigation. It is proposed on the principle of water-saving irrigation and applications of signal transduction and xerophytophysiology. In partial root-zone alternate irrigation, half the roots are allowed to dehydrate and meanwhile the irrigated roots on the other side continue to provide sufficient amounts of water. The theory of xerophytophysiology proposes that giving a false drought stimulus, the plant grows healthier with higher physiological activities through activating drought responsive genes. There is no decrease in yield, but increase in water use efficiency. Partial root-zone alternate irrigation, as one application of xerophytophysiology, is considered as an important technique for improving crop quality, increasing water use efficiency and solving the shortage of agricultural water resource for sustainable agriculture.In the present research, pot experiment was designed using potato plant as material with three irrigation treatments at early growth stage. The three treatments were as follows,1) control-full irrigation,2) PRD-partial root-zone alternate irrigation and 3) drought. Some physiological responses such as plant growth, leaf photosynthesis, osmotic adjustment and antioxidant activity were analyzed to elucidate the physiological mechanisms for growth and yield improvement by partial root-zone alternate irrigation. The expression of some activated genes was also analyzed to investigate the molecular biological reaction caused by xeric signal stimulus perception and transduction. Conclusions were as follows.(1) Partial root-zone alternate irrigation improved potato plant growth.No significance was found in plant growth rate and leaf area under partial root-zone alternate irrigation compared with full irrigation control and drought treatment. After release from partial root-zone alternate irrigation, plant growth was improved by the high physiological activities. Plant height and leaf area were higher in partial root-zone alternate irrigation than those in full irrigation and drought. Plant dry biomass accumulation and accumulation rate from 50 to 70 days after germination were higher in partial root-zone alternate irrigation than those in full irrigation and drought. The whole plant growth was partial root-zone alternate irrigation> full irrigation> drought.(2) Leaf photosynthetic ability was improved by partial root-zone alternate irrigation.Leaf photosynthetic light-response curve showed that the net photosynthetic rate under the same light density was high in partial root-zone alternate irrigation followed by full irrigation and that in drought treatment was the lowest. Leaf photosynthetic capacity in partial root-zone alternate irrigation was significantly higher than those in full irrigation and drought. Dark respiration was lower in partial root-zone alternate irrigation and drought than in full irrigation. Partial root-zone alternate irrigation increased photosynthetic capacity and quantum use efficiency. The increase in ability of using weak light and decrease in dark respiration contributed to the accumulation of photosynthetic products leading to improved growth.(3) Partial root-zone alternate irrigation increased leaf water retention ability.P-V curve showed that osmotic potential at full turgid status (pFT) in partial root-zone alternate irrigation was lower than those in full irrigation and drought, which indicated that the leaf ability to maintain turgor under partial root-zone alternate irrigation was higher than the other treatments. Cell water was recompartmented by partial root-zone alternate irrigation with higher symplastic water fraction and lower apoplastic water fraction due to the active increase in cell solutes and decrease on osmotic potential. The high symplastic water fraction contributed to cell biochemical and physiological metabolisms.Leaf water retention ability was analyzed using excised leaf transpiration declining curve. It was found that the time used to dry the excised leaf to a relative water content of 0.10 was longer in partial root-zone alternate irrigation than in full irrigation and drought. Water lose in excised leaf was decreased by partial root-zone alternate irrigation. This result showed that the short period treatment by partial root-zone alternate irrigation stimulated to active physiological responses with thicken cell epicuticular layer or more wax depositing onto the leaf surface, which indicated high drought resistance.(4) High antioxidant activities were induced by partial root-zone alternate irrigation.SOD, POD and CAT activities were higher in partial root-zone alternate irrigation than those in full irrigation and drought treatments. MDA produced high during the treatment period of partial root-zone alternate irrigation, but showed lower level than in the other two irrigation treatments after rewatering, indicating the low cell membrane injury. The same result was found in the production of super anion radicals (O2). All these results indicated that partial root-zone alternate irrigation did not induce a real stress but a transient drought stimulation to potato plant.(5) Partial root-zone alternate irrigation increased the accumulation of osmoregulation substances.As the soil water decrease during the treatments of both partial root-zone alternate irrigation and drought, some osmoregulation substances like poline, soluble sugars and soluble proteins in leaves accumulated actively and showed high concentration in partial root-zone alternate irrigation compared with full irrigation and drought. Therefore, the active accumulation of osmotic solutes would increase leaf water retention ability to avoid the damage caused by water stress.(6) Partial root-zone alternate irrigation increased water use efficiency and the final potato tuber yield. The decrease of leaf excessive water transpiration could stimulate the compensation effects of plant growth and water absorption, which increased yield by 4.06% and water use efficiency increased by 31.6%. Therefore, partial root-zone alternate irrigation has the potential in attain water saving and yield increasing.(7) Partial root-zone alternate irrigation induced the high level of RD28 gene expression.The high expression level of RD28 gene in partial root-zone alternate irrigation showed that some drought resistant genes were activated, and the plant might have high resistance to water stress.In conclusion, partial root-zone alternate irrigation increased plant resistance to drought and improved plant growth and tuber quality. It could provide the effective guarantee to realize the aim of saving water and increasing yield production and could be applied to the field production.更多还原