| 土埋深度影响物种水平的种子质量-种子出苗关系 |
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| 引用本文： | 王祖幸,何维明. 土埋深度影响物种水平的种子质量-种子出苗关系[J]. 植物生态学报, 2019, 43(10): 899-908. DOI: 10.17521/cjpe.2019.0154 |
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| 作者姓名： | 王祖幸 何维明 |
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| 作者单位： | 中国科学院大学资源与环境学院, 北京 101408 |
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| 基金项目： | 国家重点研发计划(2017YFC1200102) |
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| 摘 要： | 种子出苗对种间关系和群落组成具有重要影响。种内研究表明种子质量与种子出苗之间存在正相关关系, 但这种关系很少在物种水平进行检验, 尤其是在不同土壤埋藏深度条件下。为此, 该文开展了一个因子实验(10种植物和5种土埋深度(0、1、2、4和8 cm))以检验是否在不同土层中“种子质量-种子出苗之间的正相关关系”始终存在。该文在不同土埋深度播种50粒种子(重复5次), 连续30天观测种子出苗, 并提出了一个耐土埋性指标。结果表明: (1) 10种植物的最适出苗深度为0-2 cm土层; 6种植物的最大出苗率发生在1 cm土埋深度。(2)种子质量与耐土埋性之间存在显著的正相关关系, 种子质量越大耐土埋性越强, 适宜出苗的土层越深。(3)当土层较深(4或8 cm)时, 种子出苗率和持续出苗时间随种子质量增加而增大, 种子出苗率与持续出苗时间之间存在正相关关系; 这些关系在较浅土层(0、1或2 cm)并不存在。这些结果有助于进一步理解种子大小与出苗之间的关系, 以及种子出苗过程中的策略。
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| 关 键 词： | 土壤埋藏深度 种子质量 出苗率 出苗速率 耐土埋性 |
| 收稿时间： | 2019-06-24 |
Effects of soil-burial depths on the relationship between seed mass and seed emergence |
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| WANG Zu-Xing,HE Wei-Ming. Effects of soil-burial depths on the relationship between seed mass and seed emergence[J]. Acta Phytoecologica Sinica, 2019, 43(10): 899-908. DOI: 10.17521/cjpe.2019.0154 |
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| Authors: | WANG Zu-Xing HE Wei-Ming |
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| Affiliation: | College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China |
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| Abstract: | Aims Seed emergence is a key stage of plant life history and thus of important impacts on interspecific relationships and community composition. Increasing evidence has shown that seed mass determines (or strongly affects) seed emergence within a species, but it has seldom been tested across species at different depths of soil burial. Accordingly, the purpose of this study was to examine the influence of soil burial depths on the relationship between seed mass and seed emergence. Methods We performed a full-factorial experiment. Two factors included plant species (i.e. Achillea millefolium, Achnatherum sibiricum, Chenopodium glaucum, Centaurea maculosa, Medicago falcata, Poa pratensis, P. secunda, Solidago canadensis, Stipa bungeana and Vulpia octoflora) and soil burial depth (i.e. 0, 1, 2, 4 and 8 cm). Each combination was replicated five times, totaling 250 pots (10 species × 5 burial depths × 5 replicates). For each species, seed mass was determined prior to sowing at a given soil burial depth. We watered the pots and recorded seed emergence every day for 30 days. We determined the first date of seed emergence, and calculated the overall seed emergence, the tolerance to soil burial, and T50 (i.e. the number of days in the presence of 50% emergence). Seed mass and seed emergence were analyzed using an analysis of variance, and the relationships between two variables were tested using correlation analyses. Important findings We found that: (1) The optimum soil burial depth for seed emergence varied among the species, and for most of tested species this optimum depth ranged from 0 to 2 cm (i.e. shallow soil); six species had the maximum seed emergence at 1 cm soil burial depth, and no species had the maximum seed emergence at 4 or 8 cm. (2) There was a positive correlation between seed mass and the tolerance to soil burial across the 10 tested species, specifically, the tolerance to soil burial and the optimum depths increased with seed mass. (3) At deeper soil burial depths (i.e. 4 or 8 cm), there were significantly positive correlations among seed mass, seed emergence, and T50; in contrast, such correlations did not occur at shallower burial depths (i.e. 0, 1 or 2 cm). |
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| Keywords: | soil burial depth, seed mass, seed emergence rate, emergence speed, tolerance to soil burial |
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