不同阴离子形态锌化合物胁迫下玉米的生理生态特征研究

【作者】 王玉芳；

【导师】 王仁卿；

【作者基本信息】 山东大学 ， 生态学， 2008， 硕士

【摘要】 随着经济的发展,因污水灌溉、农用化肥等带来的农田土壤污染越来越严重,农田土壤质量日趋下降,而土壤质量与食品安全密切相关,因此土壤污染的研究与治理成为大家广泛关注的焦点。伴随着土壤重金属污染和盐分积累的加重,进行不同阴离子形态重金属化合物胁迫下作物的生理生态特征研究,有助于了解重金属与阴离子之间的关系以及它们与植物之间的关系,可为更好地了解重金属与阴离子的相互作用提供理论依据,为食品安全策略提供参考资料,有重要的理论和现实意义。本研究设计三种锌化合物ZnSO₄、zn（NO₃）₂和ZnCl₂的三种浓度梯度—低浓度(0.1gkg^-1)、中浓度(0.3gkg^-1)和高浓度(0.5gkg^-1)以及空白对照,选择北方重要农作物玉米（Zea Mays L.）为研究对象,进行人工模拟重金属胁迫实验,通过测定形态学特征,拔节期、开花期和蜡熟期三个生长期的光合生理特征和叶绿素荧光特征以及各器官的锌含量,探讨不同阴离子形态锌化合物胁迫下玉米的生理生态特征。结果如下:（1）形态学特征锌对玉米的作用效果明显。浓度梯度间差异显著,低浓度锌促进生长,高浓度抑制生长,中浓度处于过渡态,不同化合物对玉米作用不同。不同浓度锌对玉米各器官的影响也不同。同浓度条件下,不同阴离子化合物对玉米生长的作用存在差异性。低浓度时,ZnSO₄处理长势最好:中浓度时,Zn（NO₃）₂长势最好;高浓度时,Zn（NO₃）₂对玉米的毒害作用最弱,而ZnCl₂对玉米的毒害作用最强。另外,各浓度处理的株高和叶面积的变化呈现生长期的波动性。（2）光合生理特征各处理的光合速率和蒸腾速率的日变化曲线均为单峰型,光合速率因生长期的不同呈现不同的变化趋势。同浓度水平的不同化合物间呈现光合能力的差异性,S1、N1和N2光合速率高于对照,表现促进生长的作用。拔节期时,气孔因素可能是光合速率下降的主要原因;开花期和蜡熟期,非气孔因素可能是光合速率下降的主要原因,也并不排除气孔因素的影响,但与叶绿素含量变化无明显关系。（3）叶绿素荧光特征各处理的光系统Ⅱ的有效量子产量（ΦPSⅡ）和电子传递速率（ETR）的日变化趋势均为单峰型,原初光能转化效率F_v/F_m均在0.8左右,光系统Ⅱ都具有较高的光合活性,ΦPSⅡ和ETR因生长期的不同呈现不同的变化趋势。同浓度水平不同化合物处理呈现光能利用的差异性。S1、N1、N2和N3的ΦPSⅡ和ETR始终高于对照,利于玉米高效利用光能。（4）对锌的吸收特性玉米植株各部位的Zn含量随着Zn投放浓度的增加呈递增趋势,各器官对Zn的积累量存在差异性,根和茎在减轻Zn毒害效应方面发挥了重要作用。Zn转移能力随胁迫浓度的变化而变化,不同化合物的变化趋势有所不同。中、低浓度时,SO₄^2-更利于锌的吸收,高浓度时,Cl^-对锌吸收的促进作用最强。在一定范围内,三种阴离子对锌转移的促进作用顺序:SO₄^2-＞NO₃^-＞Cl^-。更多还原

【Abstract】 With the development of economy, soil pollution has been increasingly serious as a result of sewage irrigation, agricultural fertilizers and so on. Soil quality is getting worse. Soil quality and food safety are closely related, so the study of soil pollution and disposal become the focus of widespread attention.Because the heavy metal contamination and the accumulation of salt are more and more serious, the eco-physiological study of crop has important theoretical and practical meaning, which is helpful to know about the relationship between the heavy metal and anions and that between them and plants, is theoretical basis to understand the interaction of heavy metal and anions better and provides reference for the food security strategy.We used 0.1 g kg^-1,0.3 g kg^-1 and 0.5 g kg^-1 of zinc concentration with three zinc compounds which are ZnSO₄、Zn（NO₃）₂ and ZnCl₂, marked as low concentration, middle concentration and high concentration respectively, and the control, chose maize, the important crop in the north, as the object of study to simulate the heavy metal stress artificially. Morphological features, photosynthesis and chlorophyll fluorescence at the jointing , flowering and dough stage, and the zinc content in various organs were measured in order to examine the eco-physiological characteristics of maize under stress of zinc compounds with different anions. The results are as follows:（1） Morphological characteristicsZinc had obvious effects on maize. There was significant difference among different concentration treatments. The growth of maize was promoted under low level and was inhibited under high level. The maize under middle level was in the excessive stage, and grew differently due to the compounds. The organs of maize grew differently under zinc stress. Under the same concentration condition, there are differences among the effect on maize of zinc compounds with different anions. Under the condition of low concentration the maize under ZnSO₄ stress grew best, and under the condition of middle concentration the maize under Zn（NO₃）₂ stress grew best. Under the condition of high concentration ZnCl₂ poisoned the maize strongest, and Zn（NO₃）₂ weakest. The plant height and leaf area of all treatments fluctuated with the growing period.（2） PhotosynthesisThe diurnal change of photosynthetic rate （Pn） and transpiration rate （Tr） presented a single-peak curve. The trends of Pn varied with the growing period. Under the same concentration condition, photosynthetic capacity was different according to the zinc compounds with different anions. The Pn of maize under the S1, N1 and N2 was larger than the control, so S1, N1 and N2 were helpful to the growth of maize. The stomatal limitation might cause the decliner of Pn at jointing stage and the non-stomatal limitation might be the main reason of low Pn at flowering and dough stage. The low Pn might be due to the stomatal limitation also but had nothing to do with the change of chlorophyll content significantly.（3） Chlorophyll fluorescenceThe diurnal change of PSⅡquantum efficiency （ΦPSⅡ） and electron transport rate （ETR） presented a single-peak curve. The maximal quantum yield of PSⅡ（F_v/F_m） was around 0.8, which meant that the maize of all treatments had high photosynthetic activity. The trends ofΦPSⅡand ETR varied with the growing period. Under the same concentration condition, the capacity of using solar energy was difference according to the compounds with different anions. S1, N1, N2 and N3, whoseΦPSⅡand ETR were higher than the control, were beneficial to use solar energy efficiently for maize.（4） The absorption of zincZinc content in different position of maize increased with stress level, and was different between organs. Root and stem played an important role in lightening the poison of zinc. Zinc transfer capacity of maize varied with stress level, and different compounds were in different trends. Under the low and middle concentration condition, SO₄^2- was more helpful to the absorption of zinc than others, but under the high concentration condition Cl^- was the best one to simulate zinc absorption. The order of anions in promoting zinc transferring was SO₄^2-, NO₃^- and Cl^-.更多还原