A new hybrid from Taiwan, Elatostema ×hybrida (Urticaceae), is the first confirmed natural hybrid for Urticaceae

Abstract

Explosive pollen dispersal is common in Urticaceae and they are thought to be wind-pollinated. Despite a lack of obvious mechanism for preventing cross-species pollination, putative hybrid species in Urticaceae are rarely documented. Here we described the first natural hybrid in Urticaceae Elatostema ×hybrida from Taiwan. Morphological characters in E. ×hybrida are intermediate between putative parental species: E. lineolatum var. majus and E. platyphylloides. Six hybrid populations of E. ×hybrida were found in Taiwan that exhibited largely overlapping distribution patterns with its putative parents. Phylogenetic analysis of chloroplast DNA showed that the hybrid species is more closely related to E. lineolatum var. majus suggesting that the latter is the maternal parent and that hybridization is unidirectional. The chromosome number of E. ×hybrida remains the same as its putative parents (2n = 26). We speculate that the examined hybrids are natural first-generation results of independent hybridization events. Based on the morphology, spatial distribution, DNA sequence data, pollen viability and cytological observations, we hypothesize that E. ×hybrida is derived from natural hybridization events between E. lineolatum var. majus (♀) and E. platyphylloides (♂).

Cytology and sexuality of 11 species of Elatostema (Urticaceae) in limestone karsts suggests that apomixis is a recurring phenomenon

“…We may therefore conclude that the basic chromosome number of Elatostema species found in Guangxi is x = 13. This result is in agreement with previous reports that the base chromosome number of Elatostema is x = 13, 14, 16 (Friis , Kanemoto and Yokota , Yamashiro et al , Tseng and Hu ). However, although all species studied by us have 2n = 26 or 2n = 39, E. acuminatum Brongn., widely distributed in both India and China (Lin et al ), has a different chromosome number (2n = 24; Subramanian and Thilagavathy ).…”

“…Cytological data has been recognized and used as a powerful tool in resolving relationships among the genera and studying evolution and diversification in Urticaceae (Fedorov , Subramanian and Thilagavathy , Wu et al ). However, the few exsiting cytological studies in Elatostema (Krause , Subramanian and Thilagavathy , Kanemoto and Yokota , Yamashiro et al ), particularly in China (Tseng and Hu , Kanemoto et al ) do not provide a basis for using this approach.…”

A new natural allotriploid, Lycoris × hubeiensis hybr. nov. (Amaryllidaceae), identified by morphological, karyological and molecular data

“…Morphological intermediacy has been reported in some artificial and natural hybrid populations (Rieseberg and Ellstrand 1993, Qiu et al 2011, Tseng and Hu 2014. However, hybrids sometimes exhibit extreme or novel characters, but this is considered to be rather rare (Rieseberg and Ellstrand 1993).…”

“…Meng (http://orcid.org/0000-0001-9839-1959), L. Zheng, J.-W. Shao, S.-B. Zhou, K. Liu (hudixiao@126.com), Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal Univ., Anhui, P. R. China. plastid maternal inheritance (Morgensen 1996), are commonly used to reveal the maternal parent of hybrids (Moody and Les 2002, Du et al 2009, Qiu et al 2011, Tseng and Hu 2014, Yan et al 2017. During recent years, by karyotype and molecular marker analyses many species of Lycoris have been confirmed to be of hybrid origin (Shi et al 2006, 2014, Liu et al 2011.…”

Elatostema qinzhouense (Urticaceae), a new species from limestone karst in Guangxi, China

“…Cytological data can also provide additional evidence to confirm generic placement in Urticaceae (Subramanian & Thilagavathy, 1988;Kanemoto & Yokota, 1998;Yamashiro et al, 2000;Kanemoto et al, 2015). Within Elatostema, it has also been successfully used for recognizing hybrid taxa (Tseng & Hu, 2014), as well as inferring ploidy and reproductive systems (Fu et al, 2017b).…”