【作者】 刘娣；

【导师】 王衍安；

【作者基本信息】 山东农业大学 ， 果树学， 2010， 硕士

【摘要】 锌是植物必需的微量元素之一,在许多生化过程中起重要作用,苹果是世界四大水果之一,且是对缺锌敏感的作物之一,缺锌和高锌胁迫均可引起苹果树体碳素代谢的失调,进而影响苹果的产量和品质,有机酸作为碳代谢的中间产物,可以以能源物质、结构物质和配体结合物质的形式参与矿质元素的吸收运转和分配。然而果树具有多年生且连年贮藏营养的特性,因其碳素代谢机制复杂,目前关于锌胁迫下有机酸如何影响苹果锌的吸收运转分配的问题还不清楚。本文以大田盛果期富士、砂培两年生富士和水培平邑甜茶为试验材料,研究了锌胁迫对苹果有机酸及锌吸收运转分配的影响,探讨了锌胁迫下苹果锌吸收运转分配与有机酸的关系。主要结果如下:1.大田富士根中锌浓度和有机酸浓度萌芽期病树高于正常树,盛花期正常树高于病树。生理落果期病树根中锌浓度显著高于正常树,有机酸的浓度细根中正常树高于病树,而粗根中则病树高于正常树。各物候期根系锌浓度与有机酸浓度有显著相关性。2.盆栽试验进一步验证,缺锌显著提高了两年生富士吸收根中酒石酸、苹果酸、草酸和延长根中酒石酸的含量,而高锌则增加了苹果吸收根和延长根中酒石酸与苹果酸的含量,降低了延长根中草酸的含量。说明缺锌和高锌导致了苹果根系有机酸含量的变化。3.短时间缺锌胁迫减少了平邑甜茶根中的锌含量,提高了根和茎中酒石酸,苹果酸和草酸的浓度,锌在根原生质体中的浓度保持不变,相关性分析表明此时根系锌浓度与有机酸浓度呈显著负相关。同时缺锌促进了有机酸向地下部的分配,随着时间的延长,根长和根面积增加,根冠比提高,根系分泌的酒石酸和苹果酸含量增加,锌吸收速率提高。4.长时间缺锌胁迫,平邑甜茶根、茎、叶中锌浓度显著下降,净光合速率下降,体内的有机酸含量减少,根长、根面积、根直径和根尖数显著下降。5.短时间高锌胁迫增加了平邑甜茶根、茎、叶的锌含量,提高了根、茎、叶中酒石酸、苹果酸和根中草酸的浓度,锌向液泡和细胞壁的分配增加,相关性分析表明此时根系锌浓度与有机酸浓度呈显著正相关,而锌转运系数与有机酸浓度呈显著负相关。与此同时高锌促进了有机酸向地下部的分配,随着时间的延长,根长和根面积增加,根冠比提高,根系分泌的苹果酸含量增多,锌吸收速率提高,但锌转运系数降低。6.长时间高锌胁迫,平邑甜茶植株锌含量显著升高,根和叶中酒石酸、苹果酸和草酸的浓度下降,根直径和根尖数显著下降,锌转运系数降低。7.外源有机酸促进了缺锌胁迫下平邑甜茶植株对锌的吸收运转,降低了高锌胁迫下根系对锌的吸收。更多还原

【Abstract】 Zinc (Zn) is an essential microelement in plants, playing an important role in many biochemical processes. Apple is one of the four major fruits in the world and is sensitive to Zn deficency. Zinc deficiency and Zn toxicity could disorder carbon metabolism of apple tree, which affected the yield and quality of apple. Organic acids are not only intermediate products of carbon metabolism, but also can participate in the absorption and distribution of mineral elements in the form of energy, structure and ligands substance. However, apple tree is characteristic of perennial growth and successive nutritional storage. As the carbon metabolism mechanism is complicated, the problem of how organic acids influence Zn uptake, translocation and distribution in apple tree under Zn stress is unclear currently.‘Fuji’of full fruiting period in the field, two-year-old sand cultivar‘Fuji’and water cultivar Malus hupehensis (Pamp.) were selected as materials to explore the influence and relationship among Zn uptake, translocation, distribution and organic acids under Zn stress in apple tree. The main results were as follows:1. Zn and organic acids concentrations were mostly higher in root of rosette tree than that of normal tree at budding stage. However, at florescence stage, Zn and organic acids concentrations were mostly higher in root of normal tree than that of rosette tree. At physiological fruit dropping stage, Zn concentration of root was higher in rosette tree than that in normal tree. Organic acids concentrations in thin roots decreased in rosette tree while increased in normal tree, but in thick roots increased in rosette tree while decreased in normal tree. Zn concentrations were significantly correlated with organic acid concentrations at the three stages.2. According to further verification of pot experiment, Zn deficiency significantly increased the contents of oxalic acid, malic acid and tartaric acid in absorbing roots and tartaric acid in extensive roots in two-year-old‘Fuji’. High Zn stress increased the tartaric acid content in absorbing roots and decresed the tartaric acid and malic acid content in extensive roots. It illustrated that Zn deficiency and toxicity resulted in root organic acids contents changed in apple tree.3. Short-term Zn deficiency decreased the hydroponical Malus hupehensis (Pamp.) Zn contents of roots and increased tartaric acid, malic acid and oxalic acid concentrations in roots and stems. Zinc concentration in protoplasts of root was not changed. Correlation analysis showed that zinc and organic acid concentrations were significantly negatively related at this time. Zinc deficiency also resulted in organic acids distribution in root increase. With the prolong of growth time, root length and root area increased, root to shoot ratio, root secretion of tartaric acid and malic acid concentrations increased, Zn uptake rate elevated.4. Long-term Zn deficiency stress reduced Zn concentrations in roots, stems and leaves of hydroponical Malus hupehensis (Pamp.), net photosynthetic rate, and internal organic acids decreased. Root length, root area, root diameter and number of tips decreased significantly.5. Under the condition of short-term Zn toxicity stress, the hydroponical Malus hupehensis (Pamp.) roots, stems and leaves of Zn concentrations were significantly increased, tartaric acid and malic acid concentrations in roots, stems and leaves and oxalic acid concentration in roots increased, Zn concentrations in the vacuole and cell wall increased. Correlation analysis showed that organic acid levels were significantly positively correlated with Zn levels, while significantly negatively correlated with Zn transfer factor at this time. At the same time Zn toxicity promoted the organic acids allocation in root, with the prolong of growth time, root length, root area, root to shoot ratio increased, root secretion of malic acid content increased, Zn uptake rate increased, but Zn transfer factor decreased.6. Long-term Zn toxicity stress increased Zn concentrations of each organ in the hydroponical Malus hupehensis (Pamp.), tartaric acid, malic acid and oxalic acid concentrations of roots and leaves decreased, root diameter and number of tips significantly reduced, Zn transfer factor decreased.7. Exogenous organic acids promote the hydroponical Malus hupehensis (Pamp.) Zn absorption and translocation under Zn deficiency and reduced the root accumulation under Zn toxicity.更多还原