【作者】 杨慧；

【导师】 潘远智；

【作者基本信息】 四川农业大学 ， 园林植物与观赏园艺， 2011， 硕士

【摘要】 酸雨是当代国际性的重大生态环境问题之一。中国已经成为继欧洲、北美的第三大酸雨污染区,我国国土近40%的面积受到酸雨的危害；特别是我国西南地区四川盆地、重庆、贵州受到严重的酸雨危害。本研究以四川省地被植物葱兰(Zephyranthes Candida Herb.)为材料,研究其在不同浓度模拟酸雨(pH2.0、2.5、3.0、4.0、5.6)条件下的生长及生理生化变化,同时以外施Ca(NO3)2的方式,初步研究外源Ca2+对葱兰的抗酸雨能力的影响。研究结果表明：(1)在模拟酸雨胁迫下,葱兰有机物代谢受阻：叶片可溶性蛋白和可溶性糖含量显著降低,但pH4.0处理的葱兰叶片中可溶性糖含量高于CK,反应了一定浓度酸雨的肥效作用；(2)膜系统稳定性降低,透性增强：相对电导率(EC)和丙二醛(MDA)值随模拟酸雨酸度的增强及时间的延长而增加,但MDA随着胁迫时间的增加各处理与CK的差距越来越小；(3)自由基积累,抗氧化酶活性增强：过氧化氢酶(POD)和超氧化物歧化酶(SOD)含量均随模拟酸雨浓度的增加而增加；且SOD含量与模酸雨的酸度在整个试验期间呈显著负相关；(4)降低叶绿素(Chl)含量：高浓度(pH≤3.0)的酸雨能显著降低葱兰叶片Chla和Chlb的含量,且随着酸雨胁迫时间的延长和酸度的增强,Chla和Chlb含量的下降幅度增大；试验末期,Chla/b随pH值的降低而增加；(5)降低葱兰光和能力：在试验第30d葱兰叶片净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)随着模拟酸雨pH值的下降呈先升后降的趋势,蒸腾速率(Tr)则随胁迫时间的延长和酸度的增强呈下降趋势；(6)增加叶片中Ca2+的流失：葱兰叶片中Ca2+的含量随模拟酸雨酸度的增强而减少,且pH2.0的模拟酸雨处理后的叶片中Ca2+含量显著低于其他处理。外施10mmolCa(NO3)2降低了葱兰根际土壤的酸度,增加了土壤中Ca2+的向上运输,使葱兰叶片细胞质中Ca2+浓度适宜；增加了葱兰叶片可溶性蛋白和可溶性糖含量,提高了其有机物代谢活动；增强保护酶SOD、POD的活性,减少自由基积聚,减低MDA和细胞质膜透性,从而减轻酸雨对葱兰膜系统的攻击与破坏,维持质膜的正常生理功能；缓解Chl的降解,增力(?)Chla和Chlb含量,使Chla/b相对比较稳定,增强葱兰Pn、Gs、Ci,缓解呼吸速率的增加,增加葱兰光合速率,缓解酸雨对其危害。且Ca2+对葱兰模拟酸雨胁迫下的各项生理功能的缓解作用在强酸度(pH≤3.0)作用下效果越明显。经过30d的试验,综合考虑得出酸雨对葱兰的伤害阈值为pH≤2.5,葱兰较一般植物耐酸雨能力强,可以作为强酸雨地区的园林地被植物大面积推广；而外施10mmolCa(NO3)2可以显著增强葱兰各项生理功能,一定程度上抵御了酸雨对葱兰的伤害,在酸雨高发期可以对地被植物进行喷施外源Ca(NO3)2以增加地被植物的抗酸雨能力。更多还原

【Abstract】 Acid rain was one of the major international ecological environment problems. China has become the third acid rain pollution area after European and north American.The area of our country nearly 40% by acid rain hazards; Especially China’s southwest sichuan basin, chongqing, guizhou coniferous suffered serious damage of acid rain.The objective of this experiment was to study the effect of simulated acid rain at different Ph levels on physiological of Zephyranthes candida Herb. and the regulation function of Ca2+. With pot experiments, this paper studies the effect of simulated acid rain that included 5 different pH levels (pH 2.0,2.5,3.0,4.0,5.6) and the regulation function of Ca2+ on the organic matter metabolism,and membrane damage, and antioxidant enzyme activity, Chi content, and gas exchange parameters of Zephyranthes candida leaves.Under simulated acid rain stress,(1)Organics metabolism of Zephyranthes candida leaves were suffocated, the content of leaf soluble protein and soluble sugar were reduced.But the content of soluble sugar exceeded the CK when ph4.0,which reflect the fertilizer efficiency of certain concentration of acid rain;(2)Stability of the system was reduced, the membrane permeability was increased. the EC and MDA value increased with simulation of acid rain concentration and time increased, however the MDA increased slowly with the gap between each deal and CK by more and more small.(3)Free radicals accumulation, antioxidant enzymes active strengthening. POD and SOD content increased with acid concentration; and there was a significant negative correlation in SOD content and concetrtion of simulated acid rain.(4)The content of chlorophyll was reduced. High concentration (pH) of acid rain in 3.0 acuities can significantly decrease Chla and Chlb onion orchid blade. with the incereaes of acidity and lengthen of time, the Chla and Chlb content decreaced with the greater declines. The end of the trial period, the Chla/b increased with the lower pH.(5)Photosynthetic capacity was reduced either. Reduce LanGuang and ability:at 30d of the test,the Pn, Gs, Ci first increased and then decreased with simulation acid rain dropped,Tr was declining with time increases and acidity enhancement.(6)The loss of leaf Ca2+ was increased.Tt was reduced constantly with the incereasing of acidity of simulated acid rain.while the content of the leaf Ca2+ which was dealed with pH2.0 acid rain was significantly below other processingThe outside 10nimol Ca (NO3)2,reduced the acidity of root soil, enhanced the upward transportation of Ca2+ in soil;and improved its organic metabolization activity through Increasing the content of soluble sugar and soluble protein;and lighted the attack and damage to membrane system from acid rain,keeped a normal physiology function through enhanceing protection of SOD and POD activity of enzyme, reduceing the radicals accumulation, reduceing the MDA and cytoplasmic membrane permeability;eased the degradation of Chi, Chla and Chlb content, increased Chla/b to make them relatively steady, strengthened Pn, Gs, Ci, eased respiratory rate increases, eased the mitochondrial damage of acid rain, thus increaseing photosynthetic rate and ease the damage of acid rain.however, the soothing effects from Ca2+ to simulate acid rain stress was more obviously under pH<3.0After 30d experiment, it was comprehensive consided that the damage threshold for acid rain to Zephyranthes candida was pH<2.5, which showed that the Zephyranthes candida was more generally antacid plant,and could be used as a strong antacid plant,for the acid rain area widely. Outside 10mmol Ca (NO3)2 could significantly enhance all physiological function,and certainly defended the damage of acid rain,and could possibly exogenous Ca (NO3)2 to increase cover plant’s resistance to acid rain ability in acid rain in frequency.更多还原