海洋生态与环境科学重点实验室知识库

海草是唯一一类能够适应海洋沉水生活的单子叶被子植物。近年来，海草床生态系统的急剧衰退引起了人们对海草保护和恢复的关注。鳗草（Zostera marina L.）是我国温带海域多数海草床的优势种，广泛分布于山东省、河北省和辽宁省沿海水域。有性繁殖是鳗草重要的繁殖策略之一，基于鳗草的有性繁殖特征开展生态修复工作尚存在诸多技术难点，包括种子产量评估、种子利用效率等方面。本研究针对鳗草有性繁殖过程中的3个关键阶段即生殖枝、种子和种苗，首先探究了鳗草端枝克隆生长和生殖枝转变能力，并利用网箱法评估了威海天鹅湖鳗草种群生殖枝供种能力；然后，比较研究了我国温带海域4个典型鳗草种群的种子特征；最后，开展了鳗草种苗培育与移植修复实验。主要研究内容及结果如下：

1. 鳗草生殖枝有性繁殖力研究

通过单株移植标记实验，跟踪观察了鳗草生殖枝的转变过程，探究了鳗草端枝克隆生长和生殖枝转变能力。结果发现，鳗草端枝具有较高的生殖枝转变比例（66.7%），且在移植7个月后，茎枝的克隆数量高于自然种群约2倍，生殖枝的潜在种子产量高于自然种群约4倍，表明单株移植修复效果良好，且可能会提高鳗草端枝的克隆生长能力和转变为生殖枝后的潜在种子产量，该结果为鳗草移植修复提供了参考。

利用网箱暂养离体生殖枝的方法评估了威海天鹅湖鳗草种群生殖枝的供种能力。结果表明，威海天鹅湖鳗草种群平均每个生殖枝可产生约50个种子，约占潜在种子产量的24.39%，并据此提出了生殖枝绑石播种法，该方法省去了播种修复过程中生殖枝与种子的保存环节，且不会对环境产生污染，值得进一步通过野外实验验证方法的可行性。

2. 不同地理种群鳗草种子特征比较研究

比较了我国温带海域大连、唐山、威海和青岛4个鳗草种群的种子形态和萌发活性，并进一步比较了唐山和大连种群种子中的总糖、蛋白质、脂肪、灰分、水解氨基酸和脂肪酸含量。结果发现，不同地理种群鳗草种子形态和萌发活性具有显著的不同。威海种群的种子最小，大连种群的种子最大，唐山和青岛种群种子大小相近，介于威海和大连种群之间。青岛种群的种子萌发活性最高，推测与该种群种子休眠期较短有关。唐山和大连种群鳗草种子中蛋白质和灰分的相对含量显著不同。糖类是鳗草种子最主要的供能物质，鳗草种子中精氨酸、谷氨酸和天冬氨酸3种氨基酸，亚油酸、棕榈酸和油酸3种脂肪酸的含量相对较高。研究为指导不同地理种群鳗草播种修复提供了理论基础。

3. 鳗草种苗培育与移植修复研究

探究了种子低温保存预处理、淡水浸种预处理以及不同播种方法对鳗草种子萌发和建苗效果的影响，并将室内培育的种苗进行了移植，比较了两种不同规格的种苗的移植效果。结果表明，低温保存（0°C，1-2个月）和淡水浸种（48 h）预处理可以显著促进唐山鳗草种群种子萌发和建苗。首次尝试了将线绳播种技术应用到鳗草修复之中。研究表明，相比于表面播撒，浅埋播种（1 cm）和线绳播种均可以显著提高种子萌发率和建苗率，其中建苗率可分别提高约6和4倍。室内育苗结合种苗移植也可以显著提高鳗草种子利用效率，种子室内育苗建苗率可达69.2%，种苗移植成活率可达86.7%，两种规格的种苗移植成活率无显著差异， 但高度大于15 cm的大规格种苗具有较强的克隆生长能力。

本研究通过对鳗草生殖枝、种子和种苗3个有性繁殖关键阶段的研究，进一步加深了对鳗草有性繁殖特征的理解，提高了鳗草种子利用效率和修复成功率，为我国鳗草资源的保护与恢复提供了理论基础和技术支持。

Seagrass is the only monocotyledonous angiosperm that can adapt to submerged life in the ocean. The rapid decline of seagrass bed ecosystem in recent years has drawn attention to the conservation and restoration of seagrass. Eelgrass (Zostera marina L.) is one of the dominant species of seagrasses in temperate areas in China. It is widely distributed in coastal waters of Shandong, Hebei and Liaoning Provinces. Sexual reproduction is one of the important reproductive strategies of eelgrass. There are still many technical difficulties in ecological restoration based on sexual reproduction characteristics of eelgrass, including seed yield assessment and seed use efficiency. In this study, three key stages in the process of sexual reproduction of eelgrass, namely, reproductive shoot, seed and seedling, were studied. Firstly, the clonal ability and reproductive shoot transition ability of terminal shoot of eelgrass were investigated, and the seed provision efficacy of detached reproductive shoots of eelgrass population in Swan Lake in Weihai was evaluated by using net cages. Then, the seed quality of four key eelgrass populations in temperate areas was comprehensively compared. Finally, studies on the cultivation and transplantation of eelgrass seedlings were carried out. The main research contents and results were as follows:

1. Sexual reproduction effort of eelgrass reproductive shoots

The transmutation process of eelgrass reproductive shoots was tracked by single shoot transplantation experiment, and the clonal ability and reproductive shoot transition ability of terminal shoot of eelgrass were investigated. The results showed that the terminal shoots of eelgrass had a high percentage of reproductive shoot transformation (66.7%), and the number of clones was about 2 times higher than that of the natural population, and the potential seed yield per reproductive shoot was about 4 times higher than that of the natural population after 7 months of transplantation. The results indicated that single plant transplantation had good repair effect, and it may improve the clonal ability of terminal shoots of eelgrass and potential seed yield after conversion to reproductive shoots. The results provide a reference for transplantation of eelgrass.

The detached reproductive shoots of eelgrass population in Swan Lake in Weihai were raised in net cages to evaluate their seed supply capacity. The results showed that each reproductive shoot of eelgrass population in Swan Lake could produce about 50 seeds on average, accounting for 24.39% of the potential seed yield. Based on this, the stone-anchored seeding method using detached eelgrass reproductive shoots was proposed. The method eliminates the preservation of the reproductive shoots and seeds in the process of seeding restoration, and does not pollute the environment, so it is worth further verifying the feasibility of the method through field experiments.

2. Seed characteristics of eelgrass in different geographical populations

The seed morphology and germination activity of eelgrass populations in Dalian, Tangshan, Weihai and Qingdao were evaluated. The contents of total sugar, protein, fat, ash, hydrolysis amino acid, and fatty acid in seeds between Tangshan and Dalian populations were compared. The results showed that seed morphology and germination activity of eelgrass were significantly different among different geographical populations. The seeds of Weihai population were the smallest, and the seeds of Dalian population were the largest. The seed sizes of Tangshan and Qingdao populations were similar, between Weihai and Dalian populations.The germination activity of seeds in Qingdao population was the highest, which was speculated to be related to the short dormant period of seeds in Qingdao population. The relative contents of protein and ash in eelgrass seeds of Tangshan and Dalian populations were significantly different. Carbohydrates were the main energy supply substances of eelgrass seeds, and the contents of arginine, glutamic acid and aspartic acid, linoleic acid, palmitic acid, and oleic acid were relatively high in eelgrass seeds. The study provided a theoretical basis for guiding the restoration of eelgrass seeding in different geographical populations.

3. Cultivation and transplantation of eelgrass seedlings

The effects of seed cryopreservation pretreatment, fresh water immersion pretreatment and different sowing methods on seed germination and seedling establishment of eelgrass were investigated, and the indoor cultivated seedlings were transplanted, and the transplantation effects of two different specifications of seedlings were compared. The results showed that low temperature preservation (0°C, 1-2 months) and fresh water immersion (48 h) pretreatment could significantly promote seed germination and seedling establishment of Tangshan eelgrass population. This study is the first attempt to apply the seed tape sowing technique to the restoration of eelgrass. The results showed that compared with surface sowing, both seed burial sowing (1 cm) and seed tape sowing could significantly improve the seed germination rate and seedling establishment rate, and the seedling establishment rate could be increased by about 6 and 4 times, respectively. Indoor seedling cultivation combined with seedling transplantation could significantly improve the utilization efficiency of eelgrass seeds. The rate of indoor seedling cultivation could reach 69.2%, and the survival rate of seedling transplantation could reach 86.7%. There was no significant difference in the survival rate between the two sizes of seedlings, but the large size of seedlings with a height greater than 15 cm had a stronger ability to clone.

This study improved the understanding of the eelgrass sexual reproduction characteristics, which was help for field eelgrass restoration, and provided the theoretical basis and technical support for the conservation and recovery of eelgrass resources.

目 录

第1章 绪论 1

1.1 研究背景 1

1.1.1 海草     1

1.1.2 鳗草     2

1.1.3 鳗草有性繁殖     3

1.1.4 鳗草生态修复技术     6

1.2 研究内容及意义    9

1.2.1 科学问题     9

1.2.2 研究内容     9

1.2.3 技术路线     10

1.2.4 研究意义     10

1.3 本章小结 10

第2章 鳗草生殖枝有性繁殖力研究 11

2.1 引言 11

2.2 鳗草端枝克隆生长和生殖枝转变能力研究 13

2.2.1 实验方法     13

2.2.2 实验结果     14

2.2.3 讨论     16

2.2.4 小结     16

2.3 鳗草生殖枝供种能力评估——网箱法 17

2.3.1 实验方法     17

2.3.2 实验结果     20

2.3.3 讨论     23

2.3.4 小结     25

2.4 本章小结 25

第3章 不同地理种群鳗草种子特征比较研究 27

3.1 引言 27

3.2 实验方法 28

3.2.1 种子获取     28

3.2.2 种子形态学指标测定 29

3.2.3 种子萌发活力检测     29

3.2.4 种子营养成分测定     29

3.2.5 数据分析     29

3.3 实验结果 30

3.3.1 环境条件     30

3.3.2 种子形态学特征 30

3.3.3 种子萌发活力     30

3.3.4 种子营养成分     33

3.4 讨论 35

3.5 本章小结 36

第4章 鳗草种苗培育与移植修复研究     37

4.1 引言 37

4.2 低温保存预处理对鳗草种子萌发和建苗的影响 38

4.2.1 实验方法     38

4.2.2 实验结果     39

4.2.3 讨论     42

4.2.4 小结     43

4.3 淡水浸种预处理对鳗草种子萌发和建苗的影响 44

4.3.1 实验方法     44

4.3.2 实验结果     45

4.3.3 讨论     48

4.3.4 小结     48

4.4 不同播种方法对鳗草种子萌发和建苗的影响    49

4.4.1 实验方法     49

4.4.2 实验结果     50

4.4.3 讨论     53

4.4.4 小结     54

4.5 人工种苗培育与移植研究    55

4.5.1 实验方法     55

4.5.2 实验结果     56

4.5.3 讨论     58

4.5.4 小结     59

4.6 本章小结 59

第5章 结论与展望     61

5.1 研究总结 61

5.2 创新点    62

5.3 存在问题 62

5.4 研究展望 62

参考文献       63

致 谢     79

作者简历及攻读学位期间发表的学术论文与研究成果   81