Biogeography and Origin of Lilium Longiflorum and L. Formosanum Ii -Intra- And Interspecific Variation in Stem Leaf Morphology, Flowering Rate and Individual Net Production During the First Year Seedling Growth

Abstract

Lilium longiflorum and L. formosanum are closely related species endemic to subtropical islands in the Ryukyu Archipelago and Taiwan. Stem leaf morphology, flowering rate within population and individual net production during the first year seedling growth were determined to clarify whether they can differentiate these two species, and reflect adaptive strategy during species and local population establishment. Four experimental populations of L. longiflorum and five of L. formosanum with different locality covering almost their native distribution were grown under greenhouse condition in the University Farm located in northern Kyushu, Japan. L. longiflorum showed distinct lower ratio of leaf length/width than L. formosanum. Flowering rate and net production tended to decrease along the population location, northward across the archipelago arc and toward higher altitude within the mainland of Taiwan, showing obvious geographic cline (geographically continuous variation). Low degrees of flowering rate and net production in northern L. longiflorum were associated with high frequency of individuals that obtained little net production during spring to summer, indicating an acquired dormancy status. L. formosanum native to about 3000m altitude showed higher resource allocation to the mother bulb. These variations of the growth habits within the species reflect region-specific adaptive strategy of L. longiflorum and L. formosanum for climate during the glacial period and that in highlands of the mainland of Taiwan, respectively. Higher annual net production and an earlier shift to the reproductive phase of L. formosanum is highly likely more advantageous in population establishment under disturbed and competitive environment, where L. longiflorum is rarely found.

Variation of Dormancy and Early Flowering Ability in Lilium longiflorum and L. formosanum Populations in the Ryukyu Archipelago and Taiwan

“…L. longiflorum populations showed annual biomass 3.3 to 13.5 times less than L. formosanum populations (Hiramatsu et al, 2002). In our experiment, FFU populations produced adequate scaly leaves during the six months after seed culture to develop sufficient stem leaves to start the reproductive phase.…”

“…It was shown that the high precocious flowering ability of L. formosanum and L. longiflorum populations in the southern Ryukyu Archipelago and Taiwan shifted the anthesis time from early to mid-summer (August to early September) to ensure biomass accumulation for flowering in the first year of these populations (Hiramatsu et al, 2002;Saruwatari, 2009). Low degrees of flowering rate and slight net production during spring to summer in the first year of northern L. longiflorum populations (Hiramatsu et al, 2002) associated with quiescence in leaf development during summer, suggested the theory that the precocious flowering ability is an adaptive strategy to grow without dormancy throughout the year.…”

“…Low degrees of flowering rate and slight net production during spring to summer in the first year of northern L. longiflorum populations (Hiramatsu et al, 2002) associated with quiescence in leaf development during summer, suggested the theory that the precocious flowering ability is an adaptive strategy to grow without dormancy throughout the year.…”

“…It is considered that this trait was obtained by shifting the anthesis time to late summer to ensure firstyear biomass accumulation (Saruwatari, 2009). Variations in flowering rates of L. longiflorum seedlings (Hiramatsu et al, 2002) and the degrees of selfcompatibility and -incompatibility with flower morphology were also shown in association with their geographic distribution (Sakazono, 2009;Sakazono et al, 2006Sakazono et al, , 2008.…”

Interspecific Lily Hybrids with the Ability to Flower Precociously and to Produce Multiple Flower Stalks from Lilium formosanum

“…Lilium species take several years to start flowering from the time of seed sowing; for example, L. auratum Lindley, L. speciosum Thunb., and L. rubellum Baker take 4-5 years (Shimizu, 1971). Lilium formosanum Wallace, native to mainland Taiwan, exceptionally reaches anthesis within 12 months from the time of seed germination without temperature control during the entire cultivation (Hiramatsu et al, 2002). The strong 'precocious flowering' ability of this species is a highly attractive trait in lily cut flower production for obtaining flowers in a short cultivation period and for rapid rotation of the breeding cycle.…”