干旱区研究

干旱区研究 ›› 2022, Vol. 39 ›› Issue (6): 1875-1884.doi: 10.13866/j.azr.2022.06.18

• 植物生态 • 上一篇    下一篇

柠条种子萌发对不同温度和土壤含水量的响应

杨慧(),张泽,张兰,闫兴富()   

  1. 北方民族大学生物科学与工程学院/国家民委黄河流域农牧交错区生态保护重点实验室，宁夏 银川 750021
  • 收稿日期:2022-06-09 修回日期:2022-09-02 出版日期:2022-11-15 发布日期:2023-01-17
  • 通讯作者: 闫兴富
  • 作者简介:杨慧（1997-），女，硕士研究生，从事植物生态学研究. E-mail: 2786707811@qq.com
  • 基金资助:
    国家自然科学基金(31660195);宁夏回族自治区重点研发计划项目(2018BEG02001)

Responses of seed germination of Caragana korshinskii to different temperatures and soil water content

YANG Hui(),ZHANG Ze,ZHANG Lan,YAN Xingfu()   

  1. College of Biological Science and Engineering, North Minzu University/Laboratory of Ecological Protection of Agro-pastoral Ecotones in the Yellow River Basin, Yinchuan 750021, Ningxia, China
  • Received:2022-06-09 Revised:2022-09-02 Online:2022-11-15 Published:2023-01-17
  • Contact: Xingfu YAN

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摘要：

柠条（Caragana korshinskii）是我国西北荒漠和半荒漠地区沙地草场的豆科旱生灌木，也是该区水土保持和防风固沙实践中广泛应用的主要灌木树种之一。本文在人工气候箱控制的6个恒温（5 ℃、10 ℃、15 ℃、20 ℃、25 ℃和30 ℃）条件下，设置不同梯度的土壤含水量处理（4%、8%、12%、16%、20%和30%），研究了柠条种子萌发对温度和土壤含水量的响应。结果表明：（1） 温度和土壤含水量及二者的交互作用对柠条种子萌发率、萌发速率、萌发指数和活力指数均具有极显著影响。在10 ℃下萌发率最高达87.5%，在15 ℃、20 ℃和25 ℃下也较高，当温度增至30 ℃时萌发率大幅降低；萌发速率、萌发指数和活力指数均在5 ℃下最小，且均随温度升高先增大后减小，在25 ℃或15 ℃最大。（2） 随着土壤含水量增加，萌发率、萌发指数和活力指数在不同温度下均呈先升高后降低的趋势，在5 ℃下的30%土壤含水量处理最大，其他温度下均在20%或16%时最大；萌发速率在5 ℃下随土壤含水量增加逐渐升高，在其他温度下随土壤含水量增加先升高后降低，其中10 ℃、15 ℃和20 ℃下的20%处理最大，而25 ℃和30 ℃下的16%处理最大。夏秋季节较高的温度和土壤含水量对柠条种子萌发的抑制可能是保证部分种子进入土壤种子库并降低幼苗死亡风险的保护性策略，而种子在早春的较低温度和土壤含水量条件下萌发可能是对这种抑制作用的一种补偿。

关键词: 柠条, 温度, 土壤含水量, 种子萌发, 实生苗更新

Abstract:

Caragana korshinskii is a xeromorphic shrub of Fabaceae distributed in the sandy grasslands of the desert or semi-arid areas in Northwest China, and one of the main shrub species applied widely in the practice of water, soil conservation, wind-break, and sand-fixation. In this paper, different soil water contents (4%, 8%, 12%, 16%, 20%, and 30%) were conducted to investigate the responses of the seed germination of C. korshinskii to different temperatures and soil water content under six constant temperatures (5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, and 30 ℃) controlled using artificial climate incubators. The results showed that: Temperature, soil water content, and their interaction all significantly impacted the germination percentage (GP), germination rate (GR), germination index (GI), and vigor index (VI) of C. korshinskii seeds. Seeds exposed to 10 ℃ had the highest GP of 87.5%, and those to temperatures of 15 ℃, 20 ℃, and 25 ℃ had high GP as well. Then, it substantially declined when the cultivation temperature elevated to 30 ℃. GR, GI, and VI were all minimized at 5 ℃, and they all increased first and declined with elevated temperature, and maximized at 25 ℃ or 15 ℃. With the soil water content elevating, trends of increasing and decreasing were all detected in GP, GI, and VI at all temperatures. The maxima of the above three parameters were observed at 30% soil water content under 5 ℃ while they were detected at 20% or 16% soil water content under other temperatures. With increased soil water content, the GR of seeds cultivated at 5 ℃ increased gradually. However, those of seeds cultivated at other temperatures increased first and then declined. It maximized in 20% soil water content at the temperatures of 10 ℃, 15 ℃, and 20 ℃, while in 16% soil water content at the temperatures of 25 ℃ and 30 ℃. The inhibition effects of higher temperature and soil water content on the germination of C. korshinskii seeds during the summer and autumn may be a protective strategy to ensure some seeds enter soil seed bank and reduce the risk of seedling mortality. Also, the C. korshinskii seeds could germinate at relatively lower temperatures and soil water content during early spring, which may compensate for the above inhibition effects of higher temperature and soil water content on seed germination.

Key words: Caragana korshinskii, temperature, soil water content, seed germination, seedling regeneration