盐渍胁迫对柳杉苗木生长及生理生化指标的影响毕业论文_林学毕业论文

盐渍胁迫对柳杉苗木生长及生理生化指标的影响毕业论文

2021-04-20更新

摘 要

本文以柳杉(Cryptomera fortunei)3年生容器苗为材料,采用NaCl溶液浇灌的方法对柳杉苗木进行盐渍胁迫实验。盐处理浓度分别为0.3%、0.4%和0.5%,以0.1%盐处理浓度作为对照(CK),分别观测苗木的盐害症状、苗高、地径、叶片叶绿素总含量、相对电导率、脯氨酸含量、丙二醛含量、SOD酶活性以及植株不同部位的Na 、K 、Ca2 含量等指标。试验结果表明:

  1. 盐浓度为0.3%和0.4%时,对柳杉苗高和地径的生长表现出较小的促进作用,但促进效果不显著。在为期90d的盐胁迫试验中,处理组苗木小枝叶片均出现枯萎现象,各处理组均有植株死亡,0.5%处理组苗木死亡率为93.33%,0.4%处理组苗木死亡率为43.33%,0.3%处理组苗木死亡率为30%。
  2. 在盐胁迫过程中,超氧化物歧化酶(SOD)含量、丙二醛含量和相对电导率在试验前期就大幅度上升,说明盐渍胁迫对柳杉叶片细胞组织造成破坏,对柳杉苗木的生长产生了严重影响。柳杉叶片的脯氨酸含量在试验后期的大幅度增加,表明盐渍胁迫对柳杉叶片细胞的伤害很大,细胞结构破坏,使其无法正常代谢。
  3. 盐胁迫对柳杉苗木内离子含量及分布产生极显著影响,地上部分明显大于地下部分,过多的Na 、K 转移到叶片,导致离子平衡被破坏,植株首先出现叶片失活和枯梢现象,而后逐渐表现为枝干死亡和整株苗木死亡。由此可见,柳杉苗木可以在盐浓度低于0.3%的环境中生长,但生长状况不良。

关键词:盐渍胁迫;柳杉;形态指标;生理指标;盐离子

Effects of Salinity Stress on Physiological and Biochemical Characteristics of Cryptomeria fortunei Seedlings

Abstract

In this paper, the salt tolerance of Cryptomera fortunei seedlings was studied by watering with NaCl solution. Salt treatment concentrations were 0.3%, 0.4% and 0.5% respectively, and 0.1% salt treatment concentration was used as control (CK). Salt damage symptoms, seedling height, ground diameter, total chlorophyll content, relative conductivity, proline content, malondialdehyde content, SOD enzyme activity and Na , K , Ca2 content in different parts of the plant were observed respectively. The test results showed that:

(1) Salt stress with concentration of 0.3% and 0.4% had little effect on the growth of height and ground diameter of Cryptomeria fortunei seedlings, but the effect was not significant. In a 90-day salt stress test, the seedlings of the treatment group showed withered leaves on twigs and twigs, and the seedlings of each treatment group died. The seedling mortality rate of the 0.5% treatment group was 93.33%, that of the 0.4% treatment group was 43.33%, and that of the 0.3% treatment group was 30%.

(2) In the process of salt stress, the content of superoxide dismutase (SOD), malondialdehyde and relative conductivity increased greatly in the early stage of the experiment, which indicated that salt stress caused damage to the cell tissue of Cryptomeria fortunei leaves and had a serious impact on the growth of Cryptomeria fortunei seedlings. Proline content in leaves of Cryptomeria fortunei increased greatly in the later stage of the experiment, which indicated that saline stress caused great damage to cells in leaves of Cryptomeria fortunei and destroyed the cell structure, making it unable to metabolize normally.

(3) Salt stress has a very significant effect on the ion content and distribution in Cryptomeria fortunei seedlings. The above-ground part is obviously larger than the underground part. Excessive Na and K are transferred to the leaves, which leads to the destruction of ion balance. The plant first shows leaf inactivation and withered tip, and then gradually shows the death of branches and the death of the whole seedling. It can be seen that Cryptomeria fortunei seedlings can grow in the environment with salt concentration lower than 0.3%, but the growth condition is poor.

Key words: Saline stress: Cryptomeria fortunei: Morphological index: Physiological index; Salt ion

目 录

前 言 1

1 综 述 2

1.1盐渍土壤国内外研究概况 2

1.2盐渍土壤改良的主要方法 2

1.3盐碱胁迫对植物的危害 3

1.3.1渗透胁迫 3

1.3.2离子失调 3

1.4柳杉盐渍胁迫国内外研究概况 3

2 材料与方法 4

2.1柳杉苗木 4

2.2试验方法 4

2.3盐害调查及形态指标测定 4

2.4生理指标测定 5

2.4.1叶绿素总含量测定 5

2.4.2相对电导率测定 5

2.4.3丙二醛(MDA)含量测定 5

2.4.4脯氨酸含量测定 6

2.4.5超氧化物歧化酶(SOD)活性测定 6

2.5离子测定 7

2.5.1样品处理 7

2.5.2待测液制备 7

2.6数据统计与分析 7

3 结果与分析 8

3.1盐渍胁迫对柳杉苗木生长的影响 8

3.2盐渍胁迫对苗高生长量的影响 9

3.3盐渍胁迫对地径生长量的影响 10

3.4盐渍胁迫对柳杉苗木生理生化指标的影响 11

3.4.1盐渍胁迫对柳杉苗木叶片叶绿素总含量的影响 11

3.4.2盐渍胁迫对柳杉苗木叶片相对电导率的影响 11

3.4.3盐渍胁迫对柳杉苗木叶片丙二醛含量的影响 12

3.4.4盐渍胁迫对柳杉苗木叶片脯氨酸含量的影响 13

3.4.5盐渍胁迫对柳杉苗木叶片SOD酶含量的影响 14

3.5盐渍胁迫对柳杉苗木离子含量及分布的影响 15

4 讨论 19

4.1盐渍胁迫对苗木形态及苗木生长的影响 19

4.2盐渍胁迫对苗木生理指标的影响 19

4.3盐渍胁迫对离子的影响 20

5 结论与展望 21

5.1主要结论 21

5.2展望 21

致 谢 22

参考文献 23

前 言

随着全球气候变暖和人口不断增长,人地矛盾日益严重,土壤盐渍化面积日趋增大,土壤盐碱化成为影响植物生长最大的非生物胁迫因素之一。我国盐碱土地总面积约9900万hm2,主要分布在东北平原,西北干旱、半干旱地区,黄淮海平原及东部沿海地区[3];其中,西北干旱区盐碱土总面积约1300万hm2,是我国盐碱土面积最大的地区,主要包括青海、新疆、内蒙古西部和甘肃河西走廊等地区;其次为滨海地区,盐碱土面积约800万hm2,主要包括黄海、渤海和东海的海岸沿线[4]

柳杉(Cryptomera fortunei)为亚热带常绿乔木树种,横向分布于长江流城以南至西南等地区,垂直分布在海拔400-1400m之间[5],降水量达1000mm以上,年平均气温14-19℃,常与甜楮、栲类等混生,略耐阴、耐寒[6]。中等喜光,浅根系无明显主根,侧根发达,在土层深厚肥沃、疏松湿润、排水良好的酸性土壤上生长良好。对二氧化硫、氯气、氟化氢等有害气体有较好的吸抗性;柳杉边材黄白色,心材淡红褐色,材质较轻软,耐腐力强,易加工,可供电杆、器具、家具等用材;树皮入药,可解毒、杀虫、止痒,有主治癣疮、烫伤之功效[7]

柳杉具有很高的经济价值,而且目前国内外对柳杉盐胁迫研究不多,因此选择柳杉进行盐胁迫试验,研究柳杉苗木在不同盐浓度条件下的生长状况、苗木形态变化、生理指标及Na 、Ca2 和K 离子含量变化,为柳杉苗木在盐渍化区域栽培应用提供科学依据。

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