Page 83 - 《广西植物》2025年第5期
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5 期 朱莹等: 鸢尾属 31 个分类群的花粉形态及其分类学意义 8 8 7
critical point drying methodꎬ followed by scanning electron microscopy ( SEM) observation and systematic cluster
analysis of pollen morphology. The results were as follows: (1) All the pollen grains of the 31 taxa were monad and
heteropolarꎬ oblateꎬ suboblate or spheroidal in shapeꎬ with medium or large size. The sulcus membrane was smooth or
ornamented. The pollen grains were semitectate or atectateꎬ with different types of heterobrochate (rarely gemmate ̄
clavate) exine ornamentation. (2) The pollen grains of Iris tigridia were inaperturateꎬ while those of the remaining taxa
were sulcate. Zonasulcate pollen grains were found in I. bungeiꎬ I. kobayashii and I. ventricosa. For the first time the
disulcate pollen grains were found in I. hookeri in genus Iris. (3) Cluster analysis showed that at a squared Euclidean
distance of 10ꎬ 31 taxa could be clustered into seven typesꎬ i. e.ꎬ Sibirica typeꎬ Germanica typeꎬ Pumila typeꎬ
Ruthenica typeꎬ Laevigata typeꎬ Spuria type and Tigridia type. The taxa studied cluster basically in accordance with the
subgeneraꎬ sections and series of the morphotaxonomy. Of the seven typesꎬ the Germanica type had the largest pollen
grains and a heterobrochate reticulate exine with the largest luminaꎬ while the Ruthenica type had the smallest pollen
grains and a microreticulate or nanoreticulate exine. The Pumila type was characterized by atectate pollen grains with a
gemmate ̄clavate exine ornamentation and the Spuria type was characterized by suboblate shape pollen grains with an
ornamented sulcus membrane. (4) The possible evolutionary trends of the pollen morphology of three subgenera were
proposed: the subgenus Limniris was more primitive than the subgenus Irisꎬ series Ruthenicae was the most primitive
taxon among the species studiedꎬ and subgenus Pardanthopsis and section Lophiris could be the intermediate types in the
transition of the subgenus Limniris to the subgenus Iris. (5) The critical ̄point drying method and 2ꎬ2 ̄dimethoxypropane
(DMP) direct method were suitable methods for the preparation of pollen micromorphology of the genus Iris. The results
of this study indicate that the pollen morphology of 31 Iris taxa reflects both consistency and differences. The morphology
data of pollen can be used as supplementary characteristics to identify the subgeneraꎬ sections and seriesꎬ providing
reliable palynological evidence.
Key words: Irisꎬ critical ̄point drying methodꎬ pollen morphologyꎬ taxonomic implicationsꎬ SEM
鸢尾属(Iris L.)植物是世界著名的观赏植物ꎬ 强的遗传保守性ꎬ其大小、形状、外壁纹饰及萌发
全世界约 260 种ꎬ分布在北半球温带地区ꎬ主要分 器官作为重要的孢粉学分析指标比其他性状更稳
布在 欧 亚 大 陆 和 北 美ꎬ 约 有 4 种 分 布 在 北 非 定( 武 海 霞 等ꎬ2012)ꎮ 在 最 低 的 分 类 水 平 ( 属、
(Wilsonꎬ 2011)ꎮ 中国是鸢尾属分布中心之一ꎬ约 种)上ꎬ花粉独特的形态和结构性状的组合通常指
产 58 种ꎬ其中 21 种为特有种(Zhao et al.ꎬ 2000)ꎮ 向某一特定的属或种ꎬ因此即使非常不明显的性
鸢尾属植物目前的属下分类主要基于形态学ꎬ但 状也具有系统学价值( 海德玛莉哈布里特等ꎬ
其种类众多ꎬ表型变异和遗传多样性丰富ꎬ导致其 2021)ꎬ特别是在分类群界定方面ꎬ当多基因树研
分类有诸多困难ꎬ因此相关研究者建立了很多分 究的结果相互矛盾时ꎬ花粉数据结合其他形态学
类系 统ꎬ其 中 以 Dykes( 1913)、Lawrence( 1953)、 证据就成为评判最具代表性基因树的一个重要指
Rodionenko(1987)、赵毓棠(1985)和 Mathew(1989) 标(Ulrich et al.ꎬ 2013)ꎮ 孢粉学早在 20 世纪 90
分类系统的影响最大(程琳等ꎬ2021)ꎮ 这些系统各 年代便用于鸢尾属的系统发育研究ꎬ一些学者对
有侧重ꎬ对冠饰鸢尾类群、琴瓣鸢尾类群、野鸢尾类 特定亚属或特定地区的类群进行了详细研究ꎬ并
群和球根鸢尾类群的分类地位意见并不一致ꎮ 近 指出鸢尾属属下花粉特征的进化趋势和分类价值
年来ꎬ一些学者通过分子研究对属下分类系统进行 ( Colasantem et al.ꎬ 1989ꎻ Goldbatt & Thomasꎬ
了调整和修订(王玲和卓丽环ꎬ2006ꎻWilsonꎬ 2009ꎻ 1992ꎻ Pinar & Dönmezꎬ 2000ꎻ Dönmez & Pinarꎬ
牟少华等ꎬ2011ꎻKang et al.ꎬ 2020)ꎬWilson(2011) 2001)ꎮ 国内学者对 34 种国产鸢尾属植物进行了
在前人的基础上结合多种学科证据提出了修订的 花粉形态结构研究ꎬ为鸢尾属的系统分类与进化
分类系统ꎬ但此系统还未被广泛认同ꎬ目前国际上 提供 了 初 步 的 孢 粉 学 资 料 ( 齐 耀 斌 和 赵 毓 棠ꎬ
比较通用的为 Mathew(1989)系统ꎮ 1987ꎻ杨瑞 林ꎬ2002ꎻ 余 小 芳 等ꎬ2010ꎻ 马 玉 梅 等ꎬ
花粉是高度退化的雄配子体ꎬ其形态特征受 2017)ꎮ 但是ꎬ在这些研究中采用自然干燥法或乙
植物基因型控制而不受外界环境的影响ꎬ具有极 酰分解法处理样品时ꎬ因花粉收缩变形比较严重

