论文标题:两种化感物质对茄子幼苗生理特性的影响
Effects of Two Kinds of Allelochemicals on Physiological Characteristics in Eggplant Seedlings(Solanum Melongena L.)
论文作者
论文导师 郁继华,论文学位 硕士,论文专业 蔬菜学
论文单位 甘肃农业大学,点击次数 115,论文页数 66页File Size11685K
2006-06-02论文网 http://www.lw23.com/lunwen_331608012/
Allelopathy; Eggplant; Seed germination; Seedling growth; Photosynthetic Characteristics; Chorophyll Flourescence Parameters; Absorbed light allocation; Ultrastructure of Chloroplast; Active oxygen scavenging system
本试验采用外源施用2,6-二叔丁基苯酚和邻苯二甲酸二甲酯两种化感物质,处理浓度分别为50、100、200、300μmol/L以及100、200、300、500μmol/L。以甘肃地方茄子品种兰杂一号为试材,以基质栽培方式对其种子萌发及幼苗生长过程中的各项生理生化指标进行了测定与分析。结果表明: 2,6-二叔丁基苯酚(>50μmol/L)与邻苯二甲酸二甲酯(>100μmol/L)处理后,茄子种子的发芽势、发芽率、发芽指数和活力指数以及胚根长、鲜重以及胚根根系活力均降低,同时茄子幼苗的生长受抑,表现在株高、茎粗、全株干、鲜重等的降低。叶面积先增加后降低。根系新根发生量较少,且根色发黄,同时根系活力降低。但根冠比的分析结果表现为根系的生长大于地上部生长。利用综合影响因子来衡量两种化感物质的化感作用强度,邻苯二甲酸二甲酯的化感作用较强。 两种化感物质使茄子叶片叶绿素含量、蒸腾速率、光合速率、气孔导度下降,细胞间隙CO2浓度先降低后升高;说明2,6-二叔丁基苯酚与邻苯二甲酸二甲酯对茄子叶片光合速率的抑制在处理前期表现为气孔因素,在处理后期表现为非气孔因素。茄子叶片Fo升高。Fv/Fm、φPSⅡ、Fv’/Fm’、qP降低。说明茄子受到了光抑制,叶片PSⅡ反应中心不可逆破坏或可逆失活。2,6-二叔丁基苯酚使茄子叶片NPQ先升高后降低,邻苯二甲酸二甲酯使NPQ低于对照。说明在2,6-二叔丁基苯酚处理前期,PSⅡ的原初光化学反应通过下调光合电子传递来匹配碳代谢对ATP和NADPH的需求减少;而2,6-二叔丁基苯酚处理后期以及邻苯二甲酸二甲酯处理下有可能是由于该物质使还原型电子受体积累增加自由基的产生,使反应中心部分失活和天线系统受到伤害,造成过剩激发能积累,不能通过叶黄素循环耗散,光合能力受抑。此外,光化学反应速率的降低以及天线热耗散和反应中心过剩能量的增加。叶绿体结构也遭到严重破坏,基粒数目减少,淀粉粒数目增加,体积增大。碳水化合物在叶肉细胞内大量积累,不利于光合作用的进行。低浓度处理条件下,脂滴数量逐渐减少,这说明叶绿体中所固定的能量可用于转化为脂肪的能量越来越少。而较高浓度处理条件下,脂滴数目有所增加,是由于类囊体降解,降解产物脂质发生集结。 随着化感物质处理浓度的提高,茄子根系膜脂过氧化产物MDA的含量呈明显的上升趋势。SOD活性降低,不能及时有效地清除O2.-,造成茄子根系中超氧自由基的大量积累,加速根系的衰老,进而影响地上部生长。CAT活性明显下降,可能不是清除过氧化氢的主要途径。同时,根系抗坏血酸-谷胱甘肽(AsA-GSH)循环中关键酶和抗氧化剂谷胱甘肽还原酶(GR)、抗坏血酸过氧化物酶(APX)活性以及谷胱甘肽(GSH)虽然均低于对照,但随处理时间的延长有增加的趋势,有可能是H2O2的产生
Treated with exogenous Phenol, 2,6-bis (1,1-dimethylethyl) and 1,2-Benzenedicarboxylic acid, dimethyl ester, two kinds of allelochemiacals, whose concentrations were 50、100、200、300μmol/L and 100、200、300、500μmol/L separately. Lanza NO.1 , which was one of the local varieties was selected as the material in this study. The effects of two kinds of allelochemicals on seed germination, seedling growth and physiological characteristics in eggplant were studied in substrate culture. The results showed that: Under the treatments of phenol, 2,6-bis (1,1-dimethylethyl) (>50μmol/L) and 1,2-Benzenedicarboxylic acid, dimethyl ester (>100μmol/L) , germination energy, germination rate, germination index and vigor index of eggplant seeds decreased. Meanwhile, the substances were the barrier of the length , fresh weight and activities of roots. Moreover, The seedling height, stem diameter, fresh weight, dry weight of eggplant seedlings were also decreased under these two kinds of allelochemicals. The number of newly-grown-out roots were small and the color was yellow, the activities of roots decreased as well. But the results of root and top ratio showed that the growth of root was more rapid than top. The integrated effect factor was used as a method to measure the allelopathy intensity of those two kinds of allelochemicals, whose results were that 1,2-Benzenedicarboxylic acid, dimethyl ester had larger allelopathy intensity. Phenol, 2,6-bis (1,1-dimethylethyl) and 1,2-Benzenedicarboxylic acid, dimethyl ester at different concentrations were the barrier of the content of chlorophyll, transpiratory rate, net photosynthetic rate and stomatal conductance. The intracellular CO2 concentration decreased in the former period and then increased. It indicated that the cause of reduction of net photosynthetic rate in eggplant in former period might be mainly stomata limitation and non-stomata limitation in later period. The two kinds of allelochemicals decreased Fv/Fm,φPSⅡ, Fv’/Fm’, qp while increased Fo. The eggplant was under photoinhibition, the reaction center of PSⅡwas damaged. Phenol, 2,6-bis (1,1-dimethylethyl) made NPQ increase then decrease. 1,2-Benzenedicarboxylic acid, dimethyl ester decreased NPQ. In the earlier period when treated with phenol, 2,6-bis (1,1-dimethylethyl), the primary reaction of PSⅡreduced the requirement of ATP and NADPH by making the
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