本文選題：蔗糖 + 高溫��； 參考：《蘭州理工大學》2017年碩士論文

【摘要】：近年來,隨著全球變暖的加劇,低溫和高溫等極端天氣的發(fā)生愈加頻繁。溫度的異常變化嚴重影響農(nóng)業(yè)生產(chǎn)和發(fā)展。馬鈴薯是我國四大主糧之一,高溫和低溫逆境是影響馬鈴薯生長發(fā)育的主要因素。蔗糖是光合作用的主要產(chǎn)物,在植物的生長發(fā)育中具有重要的作用。脅迫條件下,較高濃度的蔗糖可以直接作為保護物質(zhì),低濃度的蔗糖可以作為代謝底物或信號起作用。為了研究蔗糖對馬鈴薯低溫和高溫逆境的緩解作用,本實驗以馬鈴薯幼苗為材料,經(jīng)外源蔗糖預處理1天之后分別用于低溫和高溫脅迫處理,測定相關(guān)生理生化指標,分析蔗糖提高馬鈴薯低溫和高溫耐受性的機制。主要結(jié)果如下:(1)經(jīng)42℃高溫脅迫11個小時后,蒸餾水處理的對照組和山梨醇處理組出現(xiàn)葉片萎蔫,莖桿失水倒伏,而蔗糖處理的幼苗依然莖桿挺直,葉片也未出現(xiàn)失水的現(xiàn)象;(2)經(jīng)4個小時-2℃低溫處理后,山梨醇處理組和對照組出現(xiàn)嚴重凍傷,莖桿呈水漬狀,葉片顏色加深,蔗糖處理過的幼苗依然保持葉片鮮綠,柔軟有彈性;(3)在高溫和低溫脅迫下,蔗糖預處理能降低葉片丙二醛含量和相對電導率從而降低膜的損傷;(4)蔗糖預處理能夠降低高溫和低溫脅迫下馬鈴薯葉片H_2O_2的含量,降低馬鈴薯葉片O_2~(.-)的產(chǎn)生速率,從而減輕了葉片的氧化損傷;蔗糖預處理增加了高溫和低溫下馬鈴薯葉片SOD、POD、CAT和APX酶的活性,緩解了溫度脅迫造成的氧化損傷;(5)蔗糖預處理增加了高溫和低溫脅迫下葉片蔗糖含量和總糖含量;蔗糖預處理增加了高溫脅迫下葉片脯氨酸和可溶性蛋白的含量;綜上所述,蔗糖預處理馬鈴薯幼苗可降低其體內(nèi)ROS和MDA的水平,提高抗氧化酶活性,并能增加脯氨酸、可溶性糖以及可溶性蛋白的含量,從而提高了馬鈴薯幼苗對低溫和高溫的耐受性。
[Abstract]:In recent years, as global warming intensifies, extreme weather such as low temperature and high temperature occur more and more frequently.Abnormal temperature changes seriously affect agricultural production and development.Potato is one of the four main grains in China. High temperature and low temperature stress are the main factors affecting the growth and development of potato.Sucrose is the main product of photosynthesis and plays an important role in plant growth and development.Under stress, sucrose at higher concentration can be used as protective substance directly, and sucrose at low concentration can act as metabolic substrate or signal.In order to study the mitigation effect of sucrose on potato seedlings under low temperature and high temperature stress, potato seedlings were pretreated with exogenous sucrose for 1 day, respectively, and the physiological and biochemical indexes were measured.The mechanism of sucrose increasing tolerance to low temperature and high temperature in potato was analyzed.The main results were as follows: (1) after high temperature stress at 42 鈩，

本文編號：1733490