黑龙江和图们江流域菱属(Trapa L.)植物分布格局及形态多样性

菱属(Trapa L.)的系统分类一直存在较大分歧,至今还没有一个比较公认的分类系统。黑龙江和图们江流域是菱属物种多样性的重要分布区之一,为了揭示该流域菱属植物的地理分布格局和形态多样性,我们进行了大量实地调查和研究。结果显示,从该地区28个湖中共采集到菱属11个种及8个种内变异类型,表明它们具有丰富的形态多样性;结合查阅菱属354份标本资料,共获得92个分布地点数据;采集到的11个物种的地理分布格局呈不均衡性,其中细果野菱(Trapa maximowiczii Korsch.)分布最广,野菱(Trapa incisa Siebold et Zucc.)、兴凯菱(Trapa khankensis Pshennikova)和科热夫尼科夫菱(Trapa kozhevnikovirum Pshennikova)为狭域分布种;东部乌苏里江和图们江流域是菱属物种多样性的分布中心,可能是第四纪冰期避难所;菱属植物多数种间形态特性相对稳定,东北菱(Trapa manshurica Fler.)、耳菱(Trapa potaninii V.Vassil)、丘角菱(Trapa japonica Fler.)、西伯利亚菱(Trapa sibirica Fler.)和细果野菱共有8个种内形态变异类型;种群内多数分类性状稳定,种群间形态变异较明显;菱属植物分布格局不均衡和种内形态变异的形成可能与基因流的扩散限制有关。本研究结果为进一步澄清菱属分类混乱问题奠定了基础,进一步结合分子标记技术研究系统演化关系将对揭示菱属的进化历史具有重要意义。

Distribution Pattern and Morphological Diversity of Trapa L. in the Heilong and Tumen River Basin

Considerable disagreements about the classification system of Trapa L. still exist, with no current unified view. The Amur River and Tumen River basin is an important species distribution and diversity center of Trapa. To reveal the geographical distribution pattern and morphological diversity of Trapa plants in this basin, we conducted field surveys and research. We found 11 species and 8 types of intraspecific variability from 28 lakes in the area, indicating that Trapa exhibited rich morphological diversity. In addition, 354 Trapa specimens were also consulted and a total of 92 distribution data locations were obtained. The geographical distribution pattern of the 11 species was not balanced. The distribution of Trapa maximowiczii Korsch.was the widest, while Trapa incisa Siebold et Zucc., Trapa khankensis Pshennikova, and Trapa kozhevnikovirum Pshennikova showed narrow domain distribution. The Eastern Ussuri River and Tumen River basin was found to be the diversity distribution center of Trapa, and might be a Quaternary glacial refuge. Interspecific morphological features of Trapa were relatively stable. Trapa manshurica Fler., Trapa potaninii V.Vassil., Trapa japonica Fler., Trapa sibirica Fler., and Trapa maximowiczii Korsch.exhibited eight intraspecific variabilities. Most morphological characters were stable within the population, whereas variabilities were obvious between populations. The diffusion limit of gene flow was an important factor resulting in the imbalanced distribution patterns and intraspecific variability of Trapa. This research lays the foundation for clarifying Trapa classification. Based on the results, combined with molecular marker technology, studying the phylogenetic relationships could have significant impact in revealing the evolutionary history of the Trapa genus.