摘 要

本文以培忠杉（Taxodium‘peizhongii’）3年生容器苗为材料，采用NaCl溶液浇灌的方法对苗木进行盐渍胁迫实验，盐处理浓度分别设置为CK（0.1%）、0.3%、0.4%和0.5%，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）在不同盐浓度胁迫下，培忠杉苗木均出现叶片变黄枯萎的现象，但在90d试验期内并未出现植株死亡现象，但苗木的苗高和地径生长量受到抑制。

（2）培忠杉处理组苗木叶片的叶绿素含量均低于对照组，叶绿素含量随着盐浓度的增高而降低；盐渍胁迫后，苗木叶片相对电导率呈现先升高后降低的趋势，表明苗木对盐胁迫有一定的适应性；不同处理组苗木的脯氨酸含量总体呈上升趋势，有利于缓解盐胁迫带来的危害；丙二醛含量的多少与苗木受伤害的程度成正相关，不同盐浓度处理组苗木丙二醛含量均呈现先上升后下降的趋势；SOD酶活性随着盐浓度的升高变化趋势较小，一直维持在较高水平，这有利于清除活性氧，维持膜透性的稳定。

（3）随着盐处理浓度的增高，培忠杉苗木体内的Na 含量逐渐升高，但是K /Na 和Ca² /Na 比值变化较小，表明培忠杉苗木具有较强的维持体内离子平衡的能力，耐盐性较强。

关键词：盐渍胁迫；培忠杉；生长指标；生理指标；盐离子

Effects of Salt Stress on Growth and Physiological and Biochemical Indexes of Taxodium‘peizhongii’Seedlings

Abstract

In this experiment, the robust and consistent 3-year growing Taxodium‘peizhongii’ was used as the experimental material, and the changes in seedling height, ground diameter, chlorophyll content, malondialdehyde content, relative electrical conductivity and superoxide dismutase activity of Taxodium‘peizhongii’were analyzed through the salt stress treatment at different concentrations, so as to study the salt tolerance level of Taxodium‘peizhongii’ and its growth physiological changes under different degrees of salt stress. The results showed that：

（1）Under different salt concentration stresses, Taxodium‘peizhongii’seedlings were exposed to yellowing and wilting of leaves, but no death occurred during the 90d test period, but the growth of seedling height and ground diameter was inhibited.

（2）The chlorophyll content of the experimental group was lower than that of the control group, and the chlorophyll content decreased with the increase of salt concentration. The decrease of relative conductivity of seedlings after salt stress indicates that the seedlings have certain adaptability to salt stress; and the relative conductivity increases with the increase of salt concentration. The proline content of seedlings under different treatments generally showed an upward trend to reduce the damage caused by salt stress. The content of malondialdehyde was positively correlated with the degree of damage of seedlings. The content of malondialdehyde in seedlings of different treatment groups increased first and then decreased. Taxodium‘peizhongii’ adapted quickly to salt stress. The activity of SOD enzyme changed little with the increase of salt concentration, and Taxodium‘peizhongii’ had stronger salt tolerance.

（3）With the increase of salt treatment concentration, the Na content in Taxodium‘peizhongii’seedlings gradually increased, but the K /Na and Ca² /Na ratios changed little, indicating that Taxodium‘peizhongii’ seedlings have strong ability to maintain ion balance in vivo and strong salt tolerance.

Key words：Salinity stress；Taxodium ‘peizhongii’；Growth indicators；The biochemical indicators；Salt ion

目 录

前 言 - 1 -

1 文献综述 - 2 -

1.1盐渍对植物生长的影响及研究情况 - 2 -

1.2 盐胁迫的危害 - 2 -

1.2.1 对植物生长的影响 - 2 -

1.2.2 对植物生理指标的影响 - 3 -

1.2.3 离子失调 - 3 -

1.2.4 生理代谢紊乱 - 3 -

2 材料与方法 - 4 -

2.1 试验材料 - 4 -

2.2 试验方法 - 4 -

2.3 苗高与地径测定 - 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 盐渍胁迫对培忠杉苗木生长的影响 - 8 -

3.1.1 盐渍胁迫对培忠杉苗木苗高生长量的影响 - 9 -

3.1.2 盐渍胁迫对培忠杉苗木地径生长量的影响 - 10 -

3.2 盐渍胁迫对培忠杉苗木生理指标的影响 - 11 -

3.2.1 盐渍胁迫对培忠杉苗木叶片叶绿素总含量的影响 - 11 -

3.2.2 盐渍胁迫对培忠杉苗木叶片相对电导率的影响 - 12 -

3.2.3 盐渍胁迫对培忠杉苗木叶片丙二醛含量的影响 - 14 -

3.2.4 盐渍胁迫对培忠杉苗木叶片脯氨酸含量的影响 - 15 -

3.2.5 盐渍胁迫对培忠杉苗木叶片超氧化物歧化酶（SOD）活性的影响分析 - 16 -

3.3 盐渍胁迫对培忠杉苗木不同部位不同离子含量的影响 - 17 -

4 讨论 - 21 -

4.1 盐渍胁迫对培忠杉苗木生长的影响 - 21 -

4.2 盐渍胁迫对培忠杉苗木生理指标的影响 - 21 -

4.3 盐渍胁迫对培忠杉苗木不同部位离子含量的影响 - 22 -

5 结论与展望 - 24 -

5.1 结论 - 24 -

5.2 展望 - 24 -

致 谢 - 26 -

参考文献 - 27 -

前 言

培忠杉（Taxodiomeria‘peizhongii’）是20世纪60年代林木育种专家叶培忠教授将墨西哥落羽杉（Taxodium mucronatum）与柳杉（Cryptomeria fortunei）远缘杂交培育出的杉科新品种，为中国特有，培忠杉具有“父本”和 “母本”双方多种优良生物性状和不同寻常的种质优势。培忠杉树形优美，适应性十分广泛，其具有生长迅速、耐盐碱和耐水湿能力强等特点，且具有较强的抗风能力^[1]。1972年通过连年无性繁殖共得种苗6000余株，此后该杂交种开始被陆续引种至上海、浙江、湖北等地进行试种。2004年国家林业局给培忠杉颁发了林木良种证书，2007年，培忠杉成功获得了美国专利局授予的植物专利。

培忠杉，半常绿的高大乔木，外形与母本墨西哥落羽杉相似。培忠杉叶的侧生小枝为螺旋状散生；叶呈条形，扁平，长度约1cm，排列紧密，列成二列，呈羽状，通常在一个平面上。分析表明培忠杉与母本墨西哥落羽杉的遗传距离远小于与父本柳杉的遗传距离^[2]。