Morphological and Simple Sequence Repeat Analysis to Clarify the Diversity of Natural <i>Lilium japonicum</i> and <i>L. auratum</i> Hybrids in the Hybrid Zone of the Izu Peninsula, Japan

Abstract

Lilium japonicum Thunb. which has pink or white-colored funnel-like flowers, is distributed in Kyushu, Shikoku, and the western part of Honshu, the main island of Japan. L. auratum Lindl. which has large white flowers with yellow central stripes and red spots, is distributed in the eastern part of Honshu. Natural hybridization of these two species has only been found on the Izu Peninsula of Honshu. However, details of the variation and hybridity of the interspecific hybrid population of these species on this peninsula remain unknown. In the present study, we conducted a morphological examination using 43, 21, and 90 individuals of L. japonicum, L. auratum, and the putative hybrid, respectively, from six, four, and ten populations of the Izu Peninsula, respectively. In addition, we performed simple sequence repeat (SSR) analysis using 47, 41, and 106 individuals of L. japonicum, L. auratum, and the putative hybrid, respectively, from six, four, and ten populations, respectively. Putative hybrid populations that resembled L. japonicum in morphology and SSR profile were found in the southern to eastern part of the peninsula, whereas those that resembled L. auratum and those exhibiting an intermediate morphology and SSR profile were found in the southern part of the peninsula. Large morphological variations exist in putative hybrid in the southern population, and interspecific hybridization has occurred in the southern and eastern populations. These results suggest that the center of natural hybridization is located in the southern part of the Izu Peninsula.

Ability of the endangered species Papaver fauriei to produce hybrids with a cultivated poppy (Papaver sp.)

“…Aso, Japan (Matoba et al 2011). However, interspecific hybrids are often found in the mixed zones where both parental species grow (Hasegawa et al 2006;Parsons & Hermanutz 2006;Kobayashi et al 2007;Kothera et al 2007;Yamamoto et al 2018).…”

“…), and between Lilium japonicum and L. auratum (Yamamoto et al . ), are observed in natural habitats where both parental species grow. Because P. fauriei resembles the cultivated poppy in terms of phenotype and ITS sequence, it is possible that these are closely related species or subspecies.…”

“…Closely related species or subspecies sometimes hybridize naturally in wild habitats; for example, hybrids between Hemerocallis fulva and H. citrina (Hasegawa et al 2006), between Rhododendron kiusianum and R. kaempferi (Kobayashi et al 2007), and between Lilium japonicum and L. auratum (Yamamoto et al 2018), are observed in natural habitats where both parental species grow. Because P. fauriei resembles the cultivated poppy in terms of phenotype and ITS sequence, it is possible that these are closely related species or subspecies.…”