生物多样性 ›› 2016, Vol. 24 ›› Issue (6): 665-700.DOI: 10.17520/biods.2015254

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雌雄异熟植物露蕊乌头开花时间对雌雄功能期及表型性别的影响

李琳1, 路宁娜2, 樊宝丽3, 赵志刚1,,A;*()   

  1. 1 兰州大学生命科学学院, 草地农业生态系统国家重点实验室, 兰州 730000
    2 西北师范大学生命科学学院, 兰州 730000
    3 甘肃省治沙研究所, 兰州 730000
  • 收稿日期:2015-09-18 接受日期:2016-03-10 出版日期:2016-06-20 发布日期:2016-06-20
  • 通讯作者: 赵志刚
  • 基金资助:
    国家自然科学基金(31370402)、中央高校基本科研自由探索项目(lzujbky-2015-95)、甘肃省自然科学基金(145RJZA166)及草地农业生态系统国家重点实验室开放基金资助(SKLGAE201504)

Effect of flowering time on floral sexual durations and phenotypic gender in dichogamous Aconitum gymnandrum

Lin Li1, Ningna Lu2, Baoli Fan3, Zhigang Zhao1,*()   

  1. 1 School of Life Sciences, Lanzhou University, State Key Laboratory of Grassland Agro-Ecosystem, Lanzhou 730000
    2 College of Life Sciences of Northwest Normal University, Lanzhou 730000
    3 Gansu Desert Control Research Institute, Lanzhou 730000
  • Received:2015-09-18 Accepted:2016-03-10 Online:2016-06-20 Published:2016-06-20
  • Contact: Zhao Zhigang

摘要:

开花时间决定了植物雌雄功能的交配机会, 最终影响繁殖成功。交配环境假说认为雌雄异熟植物开花时间的差异能引起植物表型性别的变异, 改变种群内的交配环境, 影响植物对雌雄功能的最佳性分配。为了研究开花时间对雌雄异熟植物的雌雄性别时期及表型性别的影响, 本文以毛茛科雄性先熟植物露蕊乌头(Aconitum gymnandrum)为实验材料, 记录了雄性和雌性功能期, 分析了植株开花时间、花的雌雄功能期和表型性别的关系。结果表明: 在植物同一花序内, 较晚开放的花有更长的雄性期和更短的雌性期, 性分配在时间上偏雄。雌雄功能期在时间上的相对分配随植物开花时间的变化表现出相似的趋势: 较晚开的花或较晚开花的个体, 花的雄性功能期相对于雌性功能期更长, 在时间上更偏向雄性功能。而且, 开花时间的差异影响种群内花的性比和植物个体的表型性别动态。随着开花时间由早到晚的变化, 种群内早期以雄花为主,末期以雌花为主, 种群内性别环境由偏雄向偏雌变化, 因此植株个体的平均表型性别则从偏雌转向偏雄。本文结果支持交配环境假说, 雄性先熟的露蕊乌头开花早期, 种群内花的性别比偏雄, 种群表型性别环境偏雄, 因而植物个体平均表型性别偏雌, 性别分配(即时间分配)偏向雌性功能, 而晚开花个体的平均性别偏雄, 更偏向雄性功能的分配。

关键词: 露蕊乌头, 开花时间, 表型性别, 雄性先熟, 性别功能期

Abstract

The flowering time plays an important role in the mating opportunities of male and female functions and final reproductive success in plants. The mating environment hypothesis predicts that the differences of flowering time in protandrous species can change individual’s phenotypic gender and the mating environment within a population, finally affect the optimal allocation of resources to sexual functions. To determine the effect of flowering time on sexual durations and phenotypic gender in protandrous plants, we recorded the male and female phase durations of all flowers in protandrous Aconitum gymnandrum (Ranunculaceae), and examined the relationships of flowering phenology and floral sexual durations and phenotypic gender. The results showed that the late flowers (top) had longer male duration versus female duration compared to early those (basal) within a inflorescence, showing temporally male-biased allocation. The relatively temporal allocations to both sexual durations also presented a similar trend among plants with different flowering time. Relatively longer male duration vs. female duration in the later flowers or late-flowering individuals, showed temporally male-biased allocation. Furthermore, individual’s variation in flowering time affected floral sex ratio within population and the dynamics of phenotypic gender of individuals. It showed a shift from male-biased to female-biased gender during flowering season in A. gymnandrum population, because most of the individuals had only male-phase flowers at the beginning of flowering stage and only female-phase flowers at the end. Therefore, mean phenotypic gender of individuals shifted from femaleness to maleness with flowering time. Our results support the mating environment hypothesis, i.e. male-biased floral sexual ratio (mating environment) early in protandrous A. gymnandrum population leads to female-biased phenotypic gender of individuals flowered early and thus female-biased temporal sex allocation in early-flowering individuals and early flowers within inflorescences in comparison with the late-flowering individuals and late flowers.

Key words: Aconitum gymnandrum, flowering time, phenotypic gender, dichogamous, sexual durations