【作者】 曾青松；

【导师】 刘军；

【作者基本信息】 四川农业大学 ， 园林植物与观赏园艺， 2009， 硕士

【摘要】 本研究以生长状况相近、冠幅60cm、基茎1.5cm左右的年生日香桂（‘Rixianggui’）、速生金桂（‘Sushengjingui’）、早银桂（’Zaoyingui’）、早红桂（’Zaohonggui’）扦插苗为研究对象,采用简易静态熏气室法对四个桂花品种进壬SO₂（2.5mg/m³、5mg/m³、7.5mg/m³）和NO₂（1.2mg/m³、2.4mg/m³、3.6mg/m³）熏气和人工扬尘处理,以比较四个品种间抗污染能力。调查、分析经SO₂和NO₂处理后植株受害程度、症状类型、敏感性和显症时间等,再通过测定与植物抗性密切相关的叶绿素含量、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、过氧化氧酶（CAT）活性、丙二醛（MDA）含量、脯氨酸含量等动态变化,分析这些生理生化反应与污染气体浓度、处理时间和植物抗性的相互关系。结果表明:1.四个桂花品种在粉尘处理试验中叶片无明显伤害症状,各项抗性指标在对照水平波动,差异不显著,表明本试验中扬尘处理对几种参试桂花品种无明显影响。2.四个桂花品种SO₂处理的整体伤害症状最先出现在中上部:NO₂处理的整体伤害症状最先出现在中下部:SO₂处理和NO₂处理的单片叶伤害伤害症状有一定的相似性,典型症状表现为叶脉间出现界限分明的不规则;黑褐色坏死斑,而日香桂在NO₂处理中呈褐色坏死斑;四个桂花品种对SO₂和NO₂敏感性差异较大,高浓度处理出现症状时间差异显著。早红桂为高抗品种,第12 d出现伤害症状:日香桂为中抗品种,第9 d出现伤害症状;速生金桂和早银桂最敏感,第6 d即可见伤害症状。3.四个桂花品种在SO₂试验过程中以及日香桂和速生金桂在NO₂处理过程中叶绿素总量均先上升再下降。在NO₂处理过程中,早红桂和早银桂叶绿素含量先降低,然后回升。四个品种在SO₂处理过程中和NO₂低浓度处理过程中叶绿素a/b值均下降,早红和日香桂在NO₂处理中叶绿素a/b大于对照,速生金桂和早银桂在NO₂高浓度处理时a/b值大于对照。4.四个桂花品种SOD和POD活性随着处理时间的增加均先上升后下降,相同处理不同品种SOD和POD活性下降的时间和幅度均有不同。早红桂比对照的活性增加比率幅度明显高于速生金桂和早银桂。CAT活性在两种气体处理下都下降,且随处理浓度增加和时间延长而活性下降的幅度加大,不同品种间降幅明显不同,早红桂降幅始终没超过20%,而早银桂和速生金桂在高浓度处理下降幅超过50%,品种间差异显著,降幅与抗性呈负相关。5.四个品种经SO₂和NO₂胁迫处理后,MDA含量都有上升。四个品种在处理前6 d MDA含量增加比较缓慢。随着熏气时间的延长和处理浓度的增大,MDA的含量逐渐增加,膜脂过氧化程度逐渐增大。抗性品种MDA含量上升幅度显著小于敏感品种。6.四个桂花品种体内脯氨酸含量均有增加,随处理浓度的增大和处理时间的延长,积累量也增多。抗性品种早红桂含量上升持续时间长,上升幅度大,在超过伤害值域后降幅小,与之相反,抗性较弱的早银桂含量上升幅度较小,后期出现含量下降的现象,且与叶片伤害症状形成对应。7.由四个桂花品种对SO₂和NO₂对两种气体抗性隶属度平均值得到的综合抗污染能力排序:早红桂＞日香桂＞速生金桂＞早银桂。将隶属度值与各指标作相关分析结果表明,POD活性、MDA含量和Pro含量三项指标与综合评定结果之间极显著相关（P＜0.01）,这三个指标可作为测定桂花品种抗性的关键指标。SOD活性和CAT与综合评定结果之间存在显著相关关系（P＜0.05）,这三个指标可作为测定四个桂花品种抗性的可靠指标。8.症状观察记录综合分析所得四个桂花品种的抗性排序与抗性生理指标综合分析所得抗性排序完全吻合,表明采用高浓度污染气体处理植物,通过观察其伤害症状及症状出现的早晚来评价植物抗性,操作简单、省时省力、结果准确可靠,是一种简单而行之有效的抗性植物筛选方法。9.早红桂和日香桂在两种气体不同浓度处理下均表现出极强的抗性,能在污染较为严重区域正常生长。速生金桂和早银桂在高浓度处理下表现欠佳,但在中的浓度下仍能表出较强抗性,能在一般污染环境中正常生长。试验所选四个桂花品种在现代城市环境中具有极高的抗大气污染能力;是十分值得推广应用的优良的园林香化、绿化和美化树种。更多还原

【Abstract】 Potted cuttings of four cultivars of four years of Osmanthus fragrans of ’Rixianggui’, ’Susheng jingui’,’Zaoyingui’ and’Zaohonggui’ with similar growth conditions,canopy diameter about 60cm,base diameter about 1.5cm were treated by dust and fumigated by sulfur dioxide（2.5mg/m³、5mg/m³、7.5mg/m³） and nitrogen dioxide（1.2mg/m³、2.4mg/m³、3.6mg/m³） in a special designed fumigation equipment to compare the anti-pollution capacity of the four cultivars.The damage,injured symptom,sensitivity and time of injured symptom came out were investigated and analysed.The dynamic changes of content of chlorophyll,activities of SOD,POD and CAT,content of MDA and proline which closely related to plant resistance were tested.The relationships of physiological and biochemical response between pollutan concentrations,processing time and plant resistance were analysed.The main results are as the followings.1.The four cultivars of Osmanthus fragrans’s leaves had no obvious injury symptom by dust,the physiological resistance indicators were waved at the level of check and had no significant difference.It shown that the four cultivars treated by dust had no significant effect.2.The four cultivars of Osmanthus fragrans’s overall injury symptom first to appear in the upper part of the cuttings fumigated by sulfur dioxide and first to appear in the lower part fumigated by nitrogen dioxide.The injury symptom of single leaf had a certain similarity fumigated by SO₂ and NO₂.Irregular dark brown necrotic spot with clear boundaries between the nerves was the typical injury symptom.But the necrotic spots color of ’Rixianggui’ was brown when fumigated by NO₂.The four cultivars had a comparatively different sensitivity to SO₂ and NO₂,the time of injured symptom came out in high concentrations had significant difference.’Zaohonggui’ has high resistance;injured symptom came out at 12^th day.’Rixianggui’ has middling resistance;injured symptom came out at 9^th day.’Susheng jingui’and ’Zaoyingui’wre most sensitive,injured symptom came out at 6^th day.3.The content of chlorophyll first increasing then decreasing when the four cultivars fumigated by SO₂ and ’Rixianggui’and’Sushengjingui’ fumigated by NO₂.The content of chlorophyll first decreasing then came back when ’Zaohonggui’and’Zaoyingui’ fumigated by NO₂.When the four cultivars fumigated by SO₂ and low concentration of NO₂ the chlorophyll a/b ratio all decreased,’Zaohonggui’and ’Rixianggui" fumigated by NO₂ the chlorophyll a/b ratio higher than CK,"Sushengjingui’ and’Zaoyingui" fumigated by high concentration of NO₂ the chlorophyll a/b ratio also higher than CK.4.The four cultivars’ SOD and POD activity with the increase in processing time were first increased and then decreased,the decline of SOD and POD activity with different cultivars of the same treat have different time and amplitude.The increase rate amplitude of ’Zaohonggui’ to CK was significantly higher than that of ’Sushengjingui’ and’Zaoyingui’.CAT activity under the two gases fumigate was fallen,and with the increasing of concentration and time the extension of the decrease in activity increased, decrease amplitude between the cultivars were obviously different,’Zaohonggui’ never drop more than 20%,’Zaoyingui’and ’Sushengjingui’ decrease more than 50%when fumigated by high concentration,between cultivars had decrease amplitude significant differences,decline was negative correlated with the resistance.5.Fumigated by SO₂ and NO₂,the four cultivars’ MDA content were increased,the MDA content increased slowly in the fist six days.With the extension of fumigation time and concentration,MDA content increased gradually,the degree of membrane lipid peroxidation increases.’ The increase MDA content of resistant cultivars were significantly less than the sensitive cultivars.6.The proline content of four cultivars increased,with the increasing of concentration and fumigates time,the accumulation also increased.The proline content of resistant varietiy of ’Zaohonggui’ keepd a long increase time and large increase amplitude,and in a small decline beyond the injuries range.In contrast,weak resistant varietiy ’Zaoyingui’ increases smaller and the content was decreased at later period.When the content was decreased,the injury symptom appeared.7.Comprehensive evaluation of the resistance of the four cultivars to SO₂ and NO₂ made by subordination value,The resistance of the four cultivars from strong to weak is as the followings:’Zaohonggui’＞’Rixianggui’＞’Susheng jingui’＞’Zaoyingui’.Correlation analysis result of subordination value and indexes shows that POD activity,MDA content and the Pro content very significantly correlation with comprehensivee assessment（P＜0.01）,These three indicators can be used as key determination indicators of resistance of Osmanthus fragrans cultivars.CAT and SOD activity between the comprehensive evaluation of the results,there was a significant correlation（P＜0.05）,these three indicators can be measured as four cultivars of Osmanthus fragrans reliable indicator of resistance.8.The resistance order made by comprehensive analysis of observed symptom from four cultivars of Osmanthus fragrans and comprehensive analysis of physiological resistance indexes were exactly the same.It shown that by using high concentrations of polluted gas to fumigate plants and observing their injury symptom and injury symptom appeared time to evaluate their resistance which simple operation,save time and manpower,resulting in accurate and reliable,is a simple and effective method for screening of resistant plants.9.’Zaohonggui’ and ’Rixianggui’ fumigated by different concentrations of SO₂ and NO₂ both have shown strong resistance,they can growth normally in severe pollution regions.Even ’Sushengjingui’and’Zaoyingui’ fumigated by high concentration pollution gases had not growth as well as medium and low concentrations,but also shown strong resistance,they can growth normally in slight pollution regions.The selected four cultivars of Osmanthus fragrans in this test have very high capacity of anti-air pollution in modern urban environment,they were extremely worthy of promotion and application as excellent trees to make landscape fragrant,green and beauty.更多还原