本文選題：黑麥草幼苗　切入點：凍融　出處：《吉林大學》2017年碩士論文　論文類型：學位論文

【摘要】：凍融現(xiàn)象是指由于季節(jié)性或晝夜溫度的變化使土壤反復出現(xiàn)凍結-融化的過程。凍融過程所引起的環(huán)境改變對植物生長發(fā)育產(chǎn)生一系列直接或間接影響,使得植物形態(tài)特征和生理功能等方面形成了特殊的適應性。酸沉降現(xiàn)象是指大氣中的酸性物質通過降水的方式遷移到地表的過程,酸沉降脅迫對植物的生長發(fā)育產(chǎn)生嚴重不利影響,這已成為全球性環(huán)境污染問題之一。本論文以冬牧70黑麥草(Secale Cereale Lolium)為研究對象,采用模擬凍融、模擬酸沉降、模擬凍融和酸沉降復合脅迫3種脅迫試驗,研究了黑麥草幼苗葉片的生理生化指標變化,揭示了黑麥草幼苗對凍融和酸沉降脅迫的生理響應特征,為進一步研究牧草和草坪草對凍融和酸沉降逆境脅迫條件下的適應性提供理論依據(jù)。主要研究結果如下:1、模擬凍融試驗:隨著溫度變化,黑麥草幼苗葉片中滲透調節(jié)物質含量和抗氧化酶活性均呈顯著性變化(P0.05)。在融-凍階段(10~-2℃),當溫度降低至-2℃時,可溶性蛋白、可溶性糖和丙二醛(MDA)含量均出現(xiàn)峰值;超氧化物歧化酶(SOD)、過氧化物酶(POD)活性隨溫度降低,呈上升趨勢。在凍-融階段(-2~10℃),當溫度升高至10℃時,可溶性蛋白、可溶性糖和MDA含量均呈下降趨勢;SOD、POD活性隨溫度降低顯著升高;溫度升高顯著降低(P0.05)。2、模擬酸沉降試驗:隨著酸性增強,黑麥草幼苗葉片中可溶性蛋白、可溶性糖含量呈上升趨勢;MDA含量呈下降趨勢;SOD、POD活性隨酸性增強,不斷上升,不同處理組間存在顯著性差異(P0.05)。在pH2.5酸沉降處理下,可溶性蛋白、可溶性糖含量出現(xiàn)最小值;MDA含量出現(xiàn)峰值。在pH4.5酸沉降處理下,可溶性蛋白和可溶性糖含量均出現(xiàn)峰值;MDA含量出現(xiàn)最小值。在pH2.5酸沉降處理下,SOD、POD活性均出現(xiàn)最小值。在pH4.5酸沉降處理下,SOD、POD活性出現(xiàn)峰值。3、復合脅迫試驗:復合脅迫下的黑麥草幼苗葉片中可溶性蛋白含量大于單一凍融組;可溶性糖、MDA含量均小于單一凍融組。當溫度降至-2℃時,可溶性蛋白、MDA含量出現(xiàn)峰值,當溫度回升至10℃時,均出現(xiàn)最小值�？扇苄蕴呛孔兓�(guī)律不明顯。SOD、POD活性均大于單一凍融組。當溫度降至-2℃時,SOD、POD活性均出現(xiàn)峰值;溫度回升至4℃時,SOD活性出現(xiàn)最小值;當溫度上升至10℃時,POD活性出現(xiàn)最小值。凍融和酸沉降脅迫對黑麥草幼苗葉片有較敏感的反應,其生理生化指標間存在顯著性差異。黑麥草幼苗具有一定的抗寒性和抗酸能力,在逆境脅迫下,黑麥草幼苗葉片可通過激活體內抗氧化酶系統(tǒng)及累積滲透調節(jié)物質兩種途徑進行適應調解,達到抑制膜脂過氧化。
[Abstract]:Freezing and thawing is the repeated freezing and thawing process of soil due to seasonal or diurnal temperature changes. The environmental changes caused by the freezing and thawing process have a series of direct or indirect effects on plant growth and development. This makes the plant form a special adaptability in terms of its morphological characteristics and physiological functions. Acid deposition is a process in which acidic substances in the atmosphere migrate to the earth's surface by precipitation. Acid deposition stress has a serious adverse effect on the growth and development of plants, which has become one of the global environmental pollution problems. The physiological and biochemical changes of the leaves of ryegrass seedlings were studied in order to reveal the physiological response of ryegrass seedlings to freeze-thaw and acid deposition stress. In order to provide theoretical basis for further study on the adaptability of forage and lawn to freezing and thawing and acid deposition stress, the main results are as follows: 1, simulated freeze-thaw experiment: with the change of temperature, The content of osmotic regulators and the activity of antioxidant enzymes in the leaves of ryegrass seedlings showed significant changes. In the thawing and freezing stage, the contents of soluble protein, soluble sugar and malondialdehyde (MDAs) were all peak when the temperature was reduced to 2 鈩，

本文編號：1632541