油菜素内酯对盐和高温胁迫下羊草生理特性的影响

发布时间：2018-04-20 05:33

  本文选题：羊草 + 盐胁迫　； 参考：《西南大学》2017年硕士论文

【摘要】：羊草(Lemymus chinensis(Trin.))是一种禾本科多年生的重要牧草,不仅具有草质可口、蛋白含量高、草量多等特点,还对防止水土流失,改善草原生态环境等有重要的作用。而各种胁迫因素的加剧、生态环境的破坏使羊草的生长受到严重的威胁。油菜素内酯(Brassinolide,BR)是一种新型的植物生长调节剂,可有效促进植物的生长发育,缓解胁迫对植株造成的伤害。本文通过外源喷BR,研究其对羊草生长的影响,以及缓解羊草在盐胁迫和高温胁迫下的伤害,并探讨其作用机理,为调控羊草的抗逆性提供理论依据和技术参考。主要研究结果如下:1.不同浓度油菜素内酯对盐胁迫下羊草生长发育的作用通过外源喷施不同浓度(0.01mg/L、0.1mg/L、1mg/L)的BR处理盐胁迫(NaCl浓度为150 nmol/L)的羊草幼苗,探寻其对羊草生长发育的影响。试验表明:适当浓度的BR有助于缓解盐胁迫对羊草生长造成的伤害,其中0.1mg/L的BR处理增加羊草株高、叶面积、根冠比、叶绿素b、类胡萝卜素、可溶性蛋白、干鲜重效果最好以及MDA的含量最低,叶面积与干鲜重与对照相比,差异显著;而0.01mg/L的BR浓度增加叶绿素总量、叶绿素a、根系活力和脯氨酸的含量最多,效果最好。就五种抗氧化酶的活性来讲,超氧化物歧化酶(SOD)和谷胱甘肽还原酶(GR)活性最高的处理是BR浓度为0.01mg/L,抗坏血酸过氧化物酶(APX)和过氧化物酶(POD)活性最高的处理是BR浓度为1mg/L,而过氧化氢酶(CAT)活性最高的处理在BR浓度为0.1mg/L。综合分析可知,在本试验中的盐胁迫下喷施BR的适宜浓度为0.01-0.1mg/L。2.不同浓度油菜素内酯对高温胁迫下羊草生长发育的作用通过在常温下用不同浓度(0.01mg/L、0.1mg/L、1mg/L)的BR处理高温(光照10h/38℃,黑暗14h/25℃)胁迫的羊草幼苗,探讨其对羊草生长发育的影响。试验表明,在常温下:适宜浓度的BR有助于增加羊草的株高、叶面积、叶长、叶宽、干鲜重、光合色素、脯氨酸、可溶性物质和抗氧化酶的活性,减少MDA的含量;其中从羊草的株高、干鲜重来看,1mg/L的BR浓度处理显著地增加了羊草干物质的积累;从根系活力来看,BR浓度为0.1mg/L时,根系活力最大,有助于羊草的生长。在高温下,适宜浓度的BR处理,可缓解高温胁迫对羊草的伤害:1mg/L的BR处理时,叶绿素a、类胡萝卜素、叶绿素总量、叶绿素a/b值,脯氨酸含量以及GR的活性最大;0.1mg/L的BR浓度处理时,羊草的叶宽、干鲜重、叶绿素b、可溶性糖和蛋白、根系活力和SOD、CAT、APX的活性最大,MDA的含量最小;BR浓度为0.01mg/L时,株高、叶面积、叶长以及POD的活性最大。综合来说,在本试验的条件下,在常温时:BR浓度为0.1mg/L和1mg/L时,促进羊草生长和提高生物量的效果显著;在高温时:BR浓度为0.1mg/L处理缓解高温胁迫对羊草带来的伤害较为适宜。
[Abstract]:Lemymus chinensis Trina (Lemymus chinensis) It is a kind of gramineous perennial forage, which not only has the characteristics of delicious grass quality, high protein content and much grass quantity, but also plays an important role in preventing soil erosion and improving grassland ecological environment. However, the growth of Leymus chinensis was seriously threatened by the aggravation of various stress factors and the destruction of ecological environment. Brassinolide Brassinolide (Brassinolide) is a new plant growth regulator which can effectively promote plant growth and development and alleviate the damage caused by stress. In this paper, the effects of exogenous BRR on the growth of Leymus chinensis were studied, and the injury of Leymus chinensis under salt and high temperature stress was alleviated, and its mechanism was discussed, which provided theoretical basis and technical reference for regulating the resistance of Leymus chinensis to stress. The main results are as follows: 1. Effects of different concentrations of Brassinolide on the growth and Development of Leymus chinensis under Salt stress the effects of Br on the growth and Development of Leymus chinensis with NaCl concentration of 150 nmol / L) were investigated by spraying different concentrations of 0.01 mg / L (0.1 mg / L) Br. The results showed that the appropriate concentration of Br could alleviate the harm caused by salt stress on the growth of Leymus chinensis, and the Br treatment of 0.1mg/L increased the plant height, leaf area, root / shoot ratio, chlorophyll b, carotenoid, soluble protein. The effect of dry fresh weight was the best and the content of MDA was the lowest, the difference between leaf area and dry fresh weight was significant, while Br concentration of 0.01mg/L increased the content of total chlorophyll, chlorophyll a, root activity and proline, and the effect was the best. As far as the activity of five kinds of antioxidase is concerned, The highest activity of superoxide dismutase (SOD) and glutathione reductase (Glutathione reductase) was 0.01 mg / L, the highest activity of ascorbic acid peroxidase (APX) and peroxidase (POD) was 1 mg / L, while the activity of catalase was the highest. The higher concentration of Br was 0.1 mg / L ~ (-1) 路L ~ (-1) 路L ~ (-1). The optimum concentration of Br sprayed under salt stress was 0.01-0.1 mg / L ~ (-2). Effects of different concentrations of Brassinolide on the growth and Development of Leymus chinensis under High temperature stress the effects of Br on the growth and Development of Leymus chinensis under High temperature (10h/38 鈩，

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