Diploids and tetraploids of Acorus(Acoraceae) in temperate Asia are pseudocryptic species with clear differences in micromorphology, DNAsequences and distribution patterns, but shared pollination biology

Autor: Sokoloff, Dmitry D., Degtjareva, Galina V., Skaptsov, Mikhail V., Vislobokov, Nikolay A., Kirejtshuk, Alexander G., Sennikov, Alexander N., Severova, Elena E., Chepinoga, Victor V., Samigullin, Tahir H., Valiejo‐Roman, Carmen M., Smirnov, Sergey V., Shmakov, Alexander I., Marchuk, Elena A., Remizowa, Margarita V.
Zdroj: Taxon; June 2024, Vol. 73 Issue: 3 p718-761, 44p
Abstrakt: Commonly considered bispecific, Acorusis one of the most phylogenetically isolated angiosperm genera that forms the order Acorales sister to the rest of the monocots. The Acorus calamusgroup is widely distributed in the Holarctic regions of Eurasia and America and has strong medicinal and other practical uses since prehistoric times. Earlier studies interpreted native diploids and invasive triploids occurring in North America as two species that differed in morphology and distribution ranges. In contrast, diploids, triploids, and tetraploids occurring in Eurasia are commonly interpreted as one species because they reportedly cannot be distinguished in collections. We resolve the controversy over taxonomic concepts between Eurasia and America and provide the first detailed multidisciplinary account of Acorusin temperate Asia. We used plastid and nuclear markers, leaf anatomy, seed micromorphology, pollen stainability, flow cytometry, and direct chromosome counts. Diploids and tetraploids show stable molecular and micromorphological differences. Triploids are their sterile hybrids, with the plastid genome inherited from the diploid parent. Diploids of America and Asia tend to differ in leaf characters. Coadaptative coexistence with pollinating beetles Platamartus jakowlewiand Sibirhelus corpulentus(Kateretidae) is conserved between diploids and tetraploids and over a distance of 4700 km between Japan and Western Siberia. Diploids are self‐compatible and can set seeds in the absence of kateretid beetles. Tetraploids are self‐incompatible and/or cannot set seeds in the absence of Platamartusand Sibirhelus. Diploids (A. americanus) and tetraploids (A. verus) are two biological species; the former has two subspecies. Acorus calamusshould be restricted to triploids; it apparently first evolved in temperate Asia. Diploids mostly occur in much cooler climates than triploids and tetraploids. Accessions of A. verusand A. calamusfrom tropical Asia are apparently derived from ancient introductions. Our data provide a new framework for the pharmacological use of Acorus.
Databáze: Supplemental Index