【作者】 许耀照；

【导师】 郁继华；

【作者基本信息】 甘肃农业大学 ， 蔬菜学， 2005， 硕士

【摘要】 温度是限制蔬菜植物分布的主要因素之一。随着温室效应的加强,夏秋设施内气温常可达40℃以上,露地也常达35℃以上(杜永臣,1996)。水杨酸(Salicylic acid,SA),被认为是一种新的植物激素(Malamy.1990)。研究表明:SA 影响植物的光合、种子萌发(原永兵,1994);抗热性(Dat etal.,1998)。Dat etal., 1998 年首次报道了在芥末(Sinapis alba L.)幼苗上喷施SA 可提高耐热性,葡萄幼苗(王利军等,2001)上也有报道,但对黄瓜幼苗外施SA 提高耐高温的研究较少。因此,本文以黄瓜(Cucumis sativus L.)为试材,研究了在不同温度下,用不同浓度SA 处理对黄瓜种子萌发及幼苗的影响,所得实验结果如下: 1 黄瓜种子萌发能力的最适温度是30℃,在30℃以上,随温度升高而降低。2 黄瓜萌发种子胚根胚芽的鲜重、简明活力指数、幼苗生长势(S),均随温度的升高而降低,在30℃时,其均有最大值。3 黄瓜种子的胚根胚芽中的POD酶活性随温度的升高而降低,在30℃时有较大值。4 黄瓜幼苗叶片Fo、NPQ 均随温度升高而升高;不同处理时期,在温室条件下,随处理时期延长,黄瓜幼苗叶片Fo、NPQ 均在逐渐升高;在40℃/30℃时,黄瓜幼苗叶片Fo、NPQ 变化趋势均和对照一致,嫁接苗的增幅小于自根苗。5 黄瓜幼苗叶片Fv/Fm、FPSⅡ、qP、Fv’/Fm’均随温度升高而降低;不同处理时期,在温室条件下,随处理时期延长,黄瓜幼苗叶片Fv/Fm、FPSⅡ、qP、Fv’/Fm’均在逐渐降低;在40℃/30℃胁迫下,黄瓜幼苗叶片Fv/Fm、FPSⅡ、qP、Fv’/Fm’变化趋势均和对照一致;嫁接苗的降幅小于自根苗。6 黄瓜幼苗叶片Pn、CE、AQY 均随温度升高而降低,在30℃/20℃时均有最大值。7 黄瓜幼苗叶片的Chla、Chlb、Chla+Chlb、Chla/Chlb 和Caro 含量、POD 酶活性均随温度升高而降低,嫁接苗的降幅小于自根苗。8 黄瓜幼苗叶片MDA、Pro 含量均随温度升高而升高,嫁接苗的增幅小于自根苗。9 黄瓜幼苗的株高、壮苗指数、地上部干物质含量(%)、根冠比均随温度升高而降低,嫁接苗的降幅小于自根苗。10 在高温时,喷施不同浓度SA 后,对黄瓜种子萌发和幼苗影响的变化趋势均与对照一致,但变化趋势明显弱于对照,低浓度SA(0.05 mmolL-1)对黄瓜种子萌发和幼苗影响不明显,高浓度SA(0.5 mmolL-1)有不同程度的抑制作用,最佳浓度是0.1 mmolL-1。11 黄瓜嫁接苗的耐高温性高于自根苗,且0.1 mmolL-1 的SA 对黄瓜幼苗抗高温性显著。更多还原

【Abstract】 The temperature was one of the main factors to limit the distribution of vegetable plant. Enhance along with the world green-house, Protected horticulture for producing air temperature could been often reached above 40℃, the air temperature of open field also often reached above 35℃in summer and autumn(Du Yun-chen,1996). Salicylic acid(SA),was regarded as a new plant hormone.(Malamy.1990)The researches had showed: Salicylic acid(SA)had effect on plant photosynthesis, the seed germination(Yuan Yongbing,1994), anti-heat(Dat etal.,1998). Anti-heat of plant could been increased by spraying SA on the muster seedlings at the first(Dat etal.,1998), grape seedlings(Wang Li-jun,2001). But the reports that SA could been increased the ability to anti-heat on cucumber seedlings were very rare. Therefore, Cucumber seed and seedlings were used as research material in this paper. The effects of seed germination and seedlings growth were studied by spraying different concentration SA under the different temperature. There were some results; 1 Germination rate of cucumber seeds went down successively along with the temperature up. 30 ℃was the most suitable temperature of cucumber seed germination. 2 Some indexes successively went down with the temperature up , such as the root of embryo, the fresh weigh of embryo bud, vigor indexes ,they reached the maximum at 30℃. 3 The POD activity of root and bud successively went down with the temperature up. The POD activity reached the maximum at 30℃. 4 The Fo and NPQ of grafted and own-rooted seedlings successively went up with the stress temperature up. At the different treatment periods and under the condition of green-house, The Fo and NPQ went up with treatment going on. At the differ treatment periods and at 40℃/30℃, The Fo and NPQ of grafted and own-rooted seedlings were in accordance with CK. the enhance extent of grafted seedlings was lower than own-rooted seedlings. 5 The Fv/Fm, ?PSⅡ, qP and Fv,/Fm, of grafted and own-rooted seedlings went down with the stress temperature up .At the different periods and under the condition of green-house;the Fv/Fm, ?PSⅡ, qP and Fv,/Fm, went down with the treatment period going on;At the different period and at stress-temperature of 40℃/30℃, the change tendency was in accordance with CK ; the lowering extent of grafted seedlings was lower than own-rooted seedlings. 6 The Pn, CE, AQY of grafted and own-rooted seedlings successively went down with the temperature up, and they had the maximum30℃/20℃. 7 The contents of Chla, Chlb, Chla+Chlb, Chla/Chlb and Caro, the activity of POD grafted seedlings and own-rooted seedlings went down with stress temperature up. The lowering extent of grafted seedlings was lower than own-rooted seedlings. 8 The contents of MDA and Pro in grafted and own-rooted seedlings went up with stress temperature up. The enhance extent of grafted seedlings was lower than own-rooted seedlings. 9 The plant height, vigor index ,dry material contents of ground, the ratio of root-top went down with the stress temperature up. The lowering extent of grafted seedlings was smaller than own-rooted seedlings. 10 Under the stress temperature, the change tendency of seed germination and seedlings were in accordance with CK, after spraying SA. But the change extent was obviously poorer than CK. The low concentration SA(0.05mmolL-1)had small effect on seed germination and seedlings ,but the high concentration SA(0.5mmolL-1)had different restrain on seed germination and seedlings. The best concentration of SA was 0.1 mmolL-1 11 The ability to anti-high temperature of grafted seedlings was superior to own-rooted seedlings. The most suitable concentration of SA to cucumber seedlings was 0.1 mmolL-1更多还原