Journal of Systematics and Evolution ›› 2018, Vol. 56 ›› Issue (3): 231-242.DOI: 10.1111/jse.12306

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Towards a better understanding of the Chenopodium album aggregate (Amaranthaceae) in the Middle East: A karyological, cytometric and morphometric investigation

Farzaneh Habibi1,2, Petr Vít1,3, Mohammadreza Rahiminejad2, and Bohumil Mandák1,3*   

  1. 1The Czech Academy of Sciences, Institute of Botany, Zámek 1, CZ-252 43, Průhonice, Czech Republic 2Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran 3Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6 – Suchdol, CZ-165 21, Czech Republic
  • 收稿日期:2017-12-11 接受日期:2018-01-31 出版日期:2018-05-10 发布日期:2018-07-11

Towards a better understanding of the Chenopodium album aggregate (Amaranthaceae) in the Middle East: A karyological, cytometric and morphometric investigation

Farzaneh Habibi1,2, Petr Vít1,3, Mohammadreza Rahiminejad2, and Bohumil Mandák1,3*   

  1. 1The Czech Academy of Sciences, Institute of Botany, Zámek 1, CZ-252 43, Průhonice, Czech Republic 2Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran 3Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6 – Suchdol, CZ-165 21, Czech Republic
  • Received:2017-12-11 Accepted:2018-01-31 Online:2018-05-10 Published:2018-07-11

摘要:

The study of variation in nuclear genome size, especially when combined with common garden experiments, significantly contributes to disentangling interspecies relationships within taxonomically complicated plant groups. The Chenopodium album aggregate is among the morphologically most variable groups and consists of many weakly differentiated cosmopolitan entities. We analysed nuclear genome size variation in diploid and polyploid species of the aggregate from Iran using flow cytometry of 282 accessions from 88 populations of 7 species. To this end, we also determined chromosome numbers and performed a morphometric study to reveal the extent of intraspecific morphological variation. We found that Iranian species are exclusively diploid (C. vulvaria), tetraploid (C. novopokrovskyanum, C. strictum, C. sosnowskyi and C. chaldoranicum) or hexaploid (C. album subsp. album, C. album subsp. iranicum and C. opulifolium). Six homogeneous relative genome size groups were distinguished among the species studied. Our morphometric study surprisingly revealed that under similar ecological conditions Chenopodium species are morphologically stable and well distinguishable, exhibited very little morphological variation. Hence, immense variation in leaf shapes, branching and inflorescence organization seen in the field has not been repeated under greenhouse conditions. The only exception was C. album s. str. which exhibited numerous morphotypes, covering the variation of remaining species.

Abstract:

The study of variation in nuclear genome size, especially when combined with common garden experiments, significantly contributes to disentangling interspecies relationships within taxonomically complicated plant groups. The Chenopodium album aggregate is among the morphologically most variable groups and consists of many weakly differentiated cosmopolitan entities. We analysed nuclear genome size variation in diploid and polyploid species of the aggregate from Iran using flow cytometry of 282 accessions from 88 populations of 7 species. To this end, we also determined chromosome numbers and performed a morphometric study to reveal the extent of intraspecific morphological variation. We found that Iranian species are exclusively diploid (C. vulvaria), tetraploid (C. novopokrovskyanum, C. strictum, C. sosnowskyi and C. chaldoranicum) or hexaploid (C. album subsp. album, C. album subsp. iranicum and C. opulifolium). Six homogeneous relative genome size groups were distinguished among the species studied. Our morphometric study surprisingly revealed that under similar ecological conditions Chenopodium species are morphologically stable and well distinguishable, exhibited very little morphological variation. Hence, immense variation in leaf shapes, branching and inflorescence organization seen in the field has not been repeated under greenhouse conditions. The only exception was C. album s. str. which exhibited numerous morphotypes, covering the variation of remaining species.

Key words: Chenopodium, chromosome numbers, flow cytometry, multivariate morphometrics, taxonomy.