【作者】 刘展鹏；

【导师】 郭相平；

【作者基本信息】 河海大学 ， 农业水土工程， 2007， 硕士

【摘要】 以玉米农大108为试验对象，采用PEG模拟干旱和小区试验，研究了水分胁迫及复水条件下，玉米农艺指标、生理指标、生化指标和产量等补偿效应产生的规律、条件及其生理机制。结果表明：农艺指标、生理指标的补偿效应主要表现是旱后复水效应，胁迫期间则表现为抑制效应。复水后，玉米根系活力、植株生长速率、叶片光合速率、PSII系统生理活性等方面均可表现出补偿和超越补偿效应。补偿效应与胁迫时期、胁迫历时、胁迫程度和器官形成时期有关。胁迫前形成的叶片，遭受胁迫后光合能力受到抑制，且随胁迫程度和历时的增加而加重，复水后仍然低于对照，且随胁迫程度增加而降低。胁迫后新生叶片则表现为超越补偿效应。胁迫前形成的根系，其TTC还原强度降低，复水后亦低于对照；胁迫后新生根系的TTC还原强度在复水后高于对照，出现超越补偿效应。上述结果表明，水分胁迫的生理活性的补偿效应，主要通过后继新生器官和组织实现，水分胁迫应当尽量在营养生长结束之前实施。旱后复水玉米生长补偿与光合补偿存在某种相互促进的正反馈机制，库源关系的改变是上述产生机制的基础。最后以PPC模型为基础，选取不同的根系活力、叶绿素浓度等生理指标，对复水后玉米生理补偿效应进行了定量评价，避免了评价主观性。更多还原

【Abstract】 Compensatory effects of agronomic, physiological, biochemical properties and mechanism under water stress and rewatering were investigated by simulated water stress experiment by PEG and field experiments on Maize Nongda-108. The results indicated that compensatory or over-compensatory effects of agronomic and ecological characters behaved primary on improvements of root activity, root form, growth rate, photosynthesis rate, photosynthesis potential after rewatering while restrain effects appeared during stress period. Leaf photosynthetic rate, root activity, growth rate and activity of photosynthetic system II could be higher than controlled treatment (CK) and resulted in over compensatory effects. Compensatory effects related to stress periods of growth stage, stress duration, stress severity and forming periods of leaves and root. Leaves formed before water stress had lower net photosynthetic rate(Pn) after rewatering than CK and the intendancy was enhanced with severity of stress. The leaves formed after stress had higher Pn than Ck. Roots formed before water stress had lower TTC reduced capacity both during stress time and after rewatering than CK while for the roots formed after stress were higher in TTC induced capacity, suggesting the newborn organs are the basis for over compensatory effects under water stress and stress should be exposed before the end of vegetative growth. Soluble sugar concentration increased both in root and shoot during stress time and decreased after rewatering compared to CK. A positive feedback mechanism was suggested to explain the relation between growth compensation and photosynthetic compensation depended on the synchronization of over compensatory effects of growth rate and Pn of leaves and variety in soluble sugar concentration. Finally, PPC-RAGA model was used to evaluate comprehensive effective quantificationally based on the data of simulated water stress experiments. The model could avoided subjective ingredient influences of investigator on conclusion and the results of the model fitted well with those by using traditional comprehensive evaluation, suggesting the model was reasonable if the physiological properties were chosen correctly.更多还原