植物生态学报 ›› 2020, Vol. 44 ›› Issue (9): 895-904.DOI: 10.17521/cjpe.2020.0197

• 研究论文 •    下一篇

交配距离与父本数量对野慈姑有性繁殖的影响

周盼盼1, 陈全1, 张宇杰2, 汪正祥1,3, 戴璨1,3,*()   

  1. 1 湖北大学资源环境学院, 武汉 430062
    2 湖北大学生命科学学院, 武汉 430062
    3 区域开发与环境响应湖北省重点实验室, 武汉 430062
  • 收稿日期:2020-06-18 修回日期:2020-07-20 出版日期:2020-09-20 发布日期:2020-07-27
  • 通讯作者: * 戴璨(daican@hubu.edu.cn). ORCID: 周盼盼: 0000-0002-8326-3062
  • 基金资助:
    国家自然科学基金(31670232);湖北省自然科学基金(2019CFA066)

Effects of mating distance and number of pollen donors on sexual reproduction of Sagittaria trifolia

ZHOU Pan-Pan1, CHEN Quan1, ZHANG Yu-Jie2, WANG Zheng-Xiang1,3, DAI Can1,3,*()   

  1. 1 School of Resources and Environmental Science, Hubei University, Wuhan 430062, China
    2 School of Life Sciences, Hubei University, Wuhan 430062, China
    3 Hubei Key Laboratory of Regional Development and Environmental Response (Hubei University), Wuhan 430062, China;
  • Received:2020-06-18 Revised:2020-07-20 Online:2020-09-20 Published:2020-07-27
  • Contact: DAI Can
  • Supported by:
    Supported by the National Natural Science Foundation of China(31670232);the Natural Science Foundation of Hubei(2019CFA066)

摘要:

植物的有性繁殖是生活史和进化的核心, 母本及环境对繁殖的影响固然重要, 父本的贡献亦不容忽视。父本来源与多样性对坐果结籽和后代质量的影响明显, 但由于不同物种或种群的繁殖特点和进化历程, 往往也会呈现其独特性。该研究旨在探究挺水植物野慈姑(Sagittaria trifolia)是否存在自交或远交衰退, 以及父本数量对其繁殖和后代表现的影响。通过人工控制授粉, 设置自交、近距离异交(<50 km)、远距离异交(>200 km) 3种交配距离以及单、双两类父本数量, 共计5种授粉处理, 观测野慈姑坐果概率、单果种子数量、种子面积、萌发率(2018和2019年)、幼苗芽长(2018和2019年)共7项指标。结果显示: 不同距离的交配对野慈姑的坐果概率、单果种子数量、种子面积、萌发率、幼苗芽长没有显著影响, 野慈姑未出现明显的自交衰退或远交衰退现象。父本数量的增加对野慈姑的结实数量(坐果概率、单果种子数量、种子面积)无影响, 但结实质量方面, 双父本处理的种子萌发率略高于单父本处理。综上所述, 交配距离与父本数量对野慈姑的繁殖表现影响较小, 这可能与其频繁的自交历史、远距离的基因扩散以及高度相似的水生环境有关; 同时, 该研究基于20余个自然种群的基因型, 研究结果也表明了野慈姑物种水平有性繁殖的优异和稳定性。

关键词: 交配距离, 父本数量, 自交衰退, 远交衰退, 野慈姑

Abstract:

Aims Sexual reproduction is the core of plant life history and evolution. Besides the influence of maternal genotype and environment, the contribution of paternal parts on reproduction should not be ignored. In particular, the distance and diversity of pollen donor have significant impacts on fruit setting and offspring quality, which often show distinctive patterns due to specific reproductive characteristics and evolutionary processes of different species or populations. Our objective was to study the effects of mating distance and number of pollen donors on reproductive performance of Sagittaria trifolia.
Methods Three mating distances including selfing, outcrossing of short distance (<50 km), and outcrossing of long distance (>200 km) and two types of pollen donors (single- and double-donor) were investigated in S. trifolia using hand-pollination. Besides selfing, the remaining factors formed a factorial design, resulting in a total of five pollination treatments. We analyzed the differences in fruiting probability, seed number per fruit, seed size, germination rate of F1 seed (year 2018 and 2019) and their seedling length (year 2018 and 2019).
Important findings Different mating distances had no significant effects on fruiting probability, seed number per fruit, seed size, germination rate or seedling length of S. trifolia, implying that there was no inbreeding or outbreeding depression in this species. The increase from single to double pollen donors had no effect on seed production of S. trifolia, but seed germination rate in double-donor treatment was slightly higher than that of single- donor. All together, mating distance and number of donors had little influence on reproductive performance of S. trifolia, which might be related to frequent selfing history, long-distance gene dispersal and high similarity in aquatic habitats of this species. Meanwhile, this study was based on mutual mating designs between genotypes from over 20 natural populations. Such results also imply high and stable reproductive output of S. trifolia at species level.

Key words: mating distance, number of donors, inbreeding depression, outbreeding depression, Sagittaria trifolia