Research Paper

Morphology and micro-morphology of achenes and their taxonomic implications to Lactuca species (Cichorieae; Asteraceae)

Zhen Wei, Ran Chu, Mengjie Luan, Zhenwei Lu, Yonggui Ma, Xinrui Luo, Yang Lu, Xuemin Xu, Shixin Zhu

Published on: 24 February 2022

Page: 171 - 180

DOI: 10.6165/tai.2022.67.171


Lactuca L. is the central genus of Lactucinae (Cichorieae; Asteraceae), containing cultivated lettuce and its wild relatives. In this study, we used Scanning Electron Microscope, Plain Stereo Microscope and Automated Digital Microscope to observe, record and discuss the achene characters and surface micro-features of Lactuca (including taxa of ex-Pterocypsela Shih) and Notoseris Shih species. The taxon sampling consisted of fifteen globally distributed Lactuca species and Chinese originated Notoseris species. The results indicated that the morphological and micro-morphological features of achenes were of great importance to identify Lactuca species at the genus and species level. We conclude that two key features, the presence or absence of beak and the arrangement and shape of epidermal cells, can be used to distinguish Lactuca from Notoseris. The shape and margin of the achene body, the beak length and the number of ribs on either side of achene are key features to classify Lactuca species. The ornamentation of epidermal cells can also provide extra evidence to determine closely related Lactuca species. The interspecific relationships among the Lactuca species based on achene features are consistent with the results of previously molecular systematics of these species.

Keyword: Achene micro-morphology, achene morphology, Lactucinae, Lactuca, Notoseris, Pterocypsela, SEM

Literature Cited

Abid, R. and M. Qaiser. 2015. Cypsela morphology of Lactuca L. and its allied genera (Cichoreae-Asteraceae) from Pakistan and kashmir. Pak. J. Bot. 47(5): 1937–1955.

Ayaz, S., M. Ahmad, M. Zafar, M.I. Ali, S. Sultana, M.R.U. Mustafa, O. Kilic, D.N. ?obano?lu, A. Demirpolat, A. Ghani, R. Afza, K. Ahmad, M. Munir, N. Kalsoom and J. Raza. 2020. Taxonomic significance of cypsela morphology in tribe Cichoreae (Asteraceae) using light microscopy and scanning electron microscopy. Microsc. Res. Tech. 83(3): 239–248.
DOI: 10.1002/jemt.23407View Article Google Scholar

Barthlott, W. 1981. Epidermal and seed surface characters of plants: systematic applicability and some evolutionary aspects. Nord. J. Bot. 1(3): 345–355.
DOI: 10.1111/j.1756-1051.1981.tb00704.xView Article Google Scholar

Bona, M. 2020. Systematic importance of achene macro-micromorphological characteristics in selected species of the genera Crupina, Jurinea, and Klasea (Asteraceae) from Turkey. Microsc. Res. Tech. 83(11): 1345–1353.
DOI: 10.1002/jemt.23526View Article Google Scholar

G?zel, M.E., K. Co?kun?elebi, N. Kilian, S. Makbul and M. G?ltepe. 2021. Phylogeny and systematics of the Lactucinae (Asteraceae) focusing on their SW Asian centre of diversity. Plant Syst. Evol. 307(1): 7.
DOI: 10.1007/s00606-020-01719-yView Article Google Scholar

Jeffrey, C. 1966. Notes on Compositae: I. Kew Bull. 18(3):427–486.
DOI: 10.2307/4115797View Article Google Scholar

Jeffrey, C. and H.J. Beentje. 2000. Cichorieae. In: Beentje HJS, S. A. L (ed) Flora of Tropical East Africa, Compositae 1. Rotterdam, pp. 63–108.

Jones, K.E., E.E. Schilling, E.F. Dias and N. Kilian. 2018. Northern Hemisphere disjunctions in Lactuca (Cichorieae, Asteraceae): independent Eurasia to North America migrations and allopolyploidization. Willdenowia. 48(2): 259–284.
DOI: 10.3372/wi.48.48206View Article Google Scholar

Kilian, N., B. Gemeinholzer and H.W. Lack. 2009a. Tribe Cichorieae. In: Funk VA SA, Stuessy T and Bayer R (ed) Systematics, evolution and biogeography of the Compositae. Vienna: IAPT. pp. 343–383.

Kilian, N., R. Hand, G.N. Hadjikyriakou, C.S. Christodoulou and M.B. Dagher-Kharrat. 2017a. Astartoseris (Cichorieae, Asteraceae), a new, systematically isolated monospecific genus accommodating Lactuca triquetra endemic to Lebanon and Cyprus. Willdenowia. 47(2): 115–125.
DOI: 10.3372/wi.47.47203View Article Google Scholar

Kilian, N., R. Hand and E. von Raab-Straube. (general editors). 2009b. (Continuously updated): Cichorieae Systematics Portal. Published at; accessed [28 October 2021].

Kilian, N., A. Sennikov, Z.H. Wang, B. Gemeinholzer and J.W. Zhang. 2017b. Sub-Paratethyan origin and Middle to Late Miocene principal diversification of the Lactucinae (Compositae: Cichorieae) inferred from molecular phylogenetics, divergence-dating and biogeographic analysis. Taxon. 66(3): 675–703.
DOI: 10.12705/663.9View Article Google Scholar

Lebeda, A., I. Dole?alov? and D. Astley. 2004a. Representation of wild Lactuca spp. (Asteraceae, Lactuceae) in world genebank collections. Genet. Resour. Crop Ev. 51(2): 167–174.
DOI: 10.1023/B:GRES.0000020860.66075.f7View Article Google Scholar

Lebeda, A., I. Dole?alov?, V. Fer?kov? and D. Astley. 2004b. Geographical distribution of wild Lactuca species (Asteraceae, Lactuceae). Bot. Rev. 70(3):328–356.
DOI: 10.1663/0006-8101(2004)070[0328:GDOWLS]2.0.CO;2View Article Google Scholar

Lebeda, A., E. K??stkov?, I. Dole?alov?, M. Kitner and M.P. Widrlechner. 2019a. Wild Lactuca species in North America. In: North American Crop Wild Relatives. Vol 2. pp. 131–194.
DOI: 10.1007/978-3-319-97121-6_5View Article Google Scholar

Lebeda, A., E. K??stkov?, M. Kitner, ?. Majesk?, I. Dole?alov?, C.K. Khoury, M.P. Widrlechner, J. Hu, D. Carver, H.A. Achicanoy and C.C. Sosa. 2019b. Research gaps and challenges in the conservation and use of North American wild lettuce germplasm. Crop Sci. 59(6): 2337–2356.
DOI: 10.2135/cropsci2019.05.0350View Article Google Scholar

Liu, L., L. Guan, X. Liu, X.M. Xu and S.X. Zhu. 2015. Achene morphology and achene Wall' anatomy characteristics of Notoseris and its related genera. Guizhou Agric. Sci. 43(10): 11–15.

Ozcan, M. and K. Demir. 2021. Pappus and fruit micromorphology and fruit anatomy in some members of the tribe Cardueae (Asteraceae) from Turkey with their contributions to systematics. Microsc. Res. and Tech. 85(2): 641–666.
DOI: 10.1002/jemt.23938View Article Google Scholar

Shih, C. 1987. On the circumscription of the genus Prenanthes L. and Notoseris Shih: a new genus of Compositae from China. Acta Phytotaxon. Sin. 25(3): 189–203.

Shih, C. 1988a. Revision of Lactuca L. and two new genera of tribe Lactuceae (Compositae) on the mainland of Asia. Acta Phytotaxon. Sin. 26(5): 382–393.

Shih, C. 1988b. Revision of Lactuca L. and two new genera of tribe Lactuceae(Compositae) on the mainland of Asia. Acta Phytotaxon. Sin. 26(6): 418–428.

Shih C. 1991. On circumscription of the genus Cicerbita Wall., and two new genera of Compositae from Sino-Himalayan region. Acta Phytotaxon. Sin. 29(5): 394–417.

Shih, C. 1997. Flora Reipublicae Popularis Sinnicae, Vol 80. Beijing: Science Press.

Shih, C. and Y.L. Chen. 1996. Faberiopsis Shih et Y. L. Chen, genus novum familiae Compositarum Sinensium. Acta Phytotaxon. Sin. 34(4): 438–439.

Shih, C. and N. Kilian. 2011. Cichorieae [excl.Tragopogon, Taraxacum, Hieracium and Pilosella]. Science Press & St Louis: Missouri Botanical Garden, Beijing.

Sikder, A. and S. Moktan. 2021. Cypsela diversity in some members of Compositae through LM study and its taxonomic significance. Microsc. Res. and Tech. 84(9): 2046–2057.
DOI: 10.1002/jemt.23760View Article Google Scholar

Stebbins, G.L. 1953. A new classification of the tribe Cichorieae, family Compositae. Madro?o. 12(3):65–81.

Thiers, B. 2016. Index Herbariorum: A global directory of public herbaria and associated staff.

Uwimana, B., M.J. Smulders, D.A. Hooftman, Y. Hartman, P.H. van Tienderen, J Jansen., L.K. McHale, R.W. Michelmore, R.G.Visser and C.C. van de Wiel. 2012. Crop to wild introgression in lettuce: following the fate of crop genome segments in backcross populations. BMC Plant Biol. 12(1): 43.
DOI: 10.1186/1471-2229-12-43View Article Google Scholar

Wang, Z.H., H. Peng and N. Kilian. 2013. Molecular phylogeny of the Lactuca alliance (Cichorieae subtribe Lactucinae, Asteraceae) with focus on their Chinese centre of diversity detects potential events of reticulation and chloroplast capture. PLoS One. 8(12): e82692.
DOI: 10.1371/journal.pone.0082692View Article Google Scholar

Wei, T., R. van Treuren, X. Liu, Z. Zhang, J. Chen, Y. Liu, S. Dong, P. Sun, T. Yang, T. Lan, X. Wang, Z. Xiong, Y. Liu, J. Wei, H. Lu, S. Han, J.C. Chen, X. Ni, J. Wang, H. Yang, X. Xu, H. Kuang, T. van Hintum, X. Liu and H. Liu. 2021. Whole-genome resequencing of 445 Lactuca accessions reveals the domestication history of cultivated lettuce. Nat. Genet. 53(5): 752–760.
DOI: 10.1038/s41588-021-00831-0View Article Google Scholar

Wei, Z., M.M. Julkowska, J.O. Lalo?, Y. Hartman, G.J. de Boer, R.W. Michelmore, P.H. van Tienderen, C. Testerink and M.E. Schranz. 2014. A mixed-model QTL analysis for salt tolerance in seedlings of crop-wild hybrids of lettuce. Mol. Breeding. 34(3): 1389–1400.
DOI: 10.1007/s11032-014-0123-2View Article Google Scholar

Wei, Z., S.X. Zhu, R.G. Van den Berg, F.T. Bakker and M.E. Schranz. 2017. Phylogenetic relationships within Lactuca L. (Asteraceae), including African species, based on chloroplast DNA sequence comparisons. Genet. Resour. Crop Ev. 64(1):55–71.
DOI: 10.1007/s10722-015-0332-5View Article Google Scholar

Xu, X.M., Z. Wei, T. Zhang and S.X. Zhu. 2021. Achene micro-morphology of Anaphalis DC. (Gnaphalieae-Asteraceae) from China. Pak. J. Bot. 53(5): 1883–1892.
DOI: 10.30848/PJB2021-5(10)View Article Google Scholar

Zhang, J.W., D.E. Boufford and H. Sun. 2013. Systematic significance of achene morphology in Soroseris, Syncalathium and Parasyncalathium (Asteraceae: Cichorieae). Bot. J. Linn. Soc. 173(3): 476–486.
DOI: 10.1111/boj.12046View Article Google Scholar

Zhu, S.X., H.N. Qin and C. Shih. 2006. Achene wall anatomy and surface sculpturing of Lactuca L. and related genera (Compositae: Lactuceae) with notes on their systematic significance. J. Integr. Plant. Biol. 48(4): 390–399.
DOI: 10.1111/j.1744-7909.2006.00245.xView Article Google Scholar

Zohary, D. 1983. Wild genetic resources of crops in Israel. Isr. J. Bot. 32(2):97–127.

Zohary, D. 1991. The wild genetic resources of cultivated lettuce (Lactuca sativa L.). Euphytica 53(1): 31–35.
DOI: 10.1007/BF00032029View Article Google Scholar