Coastal Adaptation of <i>Adenophora triphylla var. japonica</i> (Campanulaceae)

Abstract

The comparative morphology and anatomy of leaves between the coastal ecotype and the normal type of Adenophora triphylla (Thunb.) A.DC. var. japonica (Regel) H.Hara (Campanulaceae) were examined to clarify the differences in morphological characters between the 2 groups. Morphological and anatomical analyses revealed that the coastal ecotype had a thicker leaf than the normal type, because of the increased size of epidermal and spongy cells. Thus, the main morphological change from the normal type into the coastal ecotype of A. triphylla var. japonica is the increase in leaf size, suggesting that the coastal ecotype may have evolved from the normal type via a heterochronic process.

Leaf Adaptation of Eurya japonica Thunb. (Pentaphylacaceae) in Coastal Area

“…In the present study, we found that coastal E. japonica has significantly smaller stomata and larger epidermal cells than inland area species, indicating that the former gained adaptive characteristics in coastal areas. Many studies have reported that coastal adaptation included a decrease in stomatal density (Tunala et al, 2012;Ohga et al, 2013;Kumekawa et al, 2013). Contrastingly, Takizawa et al (2022) reported that woody Ligustrum japonicum had significantly smaller stomatal sizes in coastal areas than those in inland area species and hypothesized that woody plants could not invade coastal areas from inland areas without stomatal changes, although woody plants could adapt to coastal areas by reducing stomatal size.…”

“…Coastal plants are known for their rich biodiversity and high level of endemism, including a concentration of rare and threatened taxa and high diversity of endemic plant species (Burgess et al, 1998;Lovett, 1998;Myers et al, 2000;Azeria et al, 2007), and they have implications for biodiversity conservation (van der Meulen & Udo de Haes, 1996;Cori, 1999;Schlacher et al, 2008). Particular attention has been focused on understanding ecophysiological mechanisms involved at the cellular and molecular levels (Elhaak et al, 1997;Migahid & Elhaak, 2001;Tunala et al, 2012;Kumekawa et al, 2013;Ohga et al, 2013;Sunami et al, 2013;Takizawa et al, 2022). It is uncertain whether plant species widely distributed from inland to coastal areas have adapted with or without morphological changes.…”

“…Additionally, Sunami et al (2013) reported that leaf hairs on the abaxial side of leaves were correlated with the stomatal density of this variety; the fewer the hairs on the leaf, the lower the stomatal density to avoid transpirational water loss. Ohga et al (2013) suggested that the coastal population of Adenophora triphylla var. japonica (Regel) H.Hara (Campanulaceae) has evolved relatively thick leaves via a heterochronic process to store water.…”

Serpentine Adaptation of Ligustrum japonicum Thunb. (Oleaceae) Based on Morphological and Anatomical Approaches

“…Thicker leaves are caused by increased leaf water content and subsequent accumulation of large amounts of solute without an increase in the osmotic pressure of cells (Suá rez & Sobrado, 2000). Consequently, species with thicker leaves can be found in drought-prone environments (Ohga et al, 2013;Tunala et al, 2012). The edaphic characteristics of serpentine were important in many cases, such as metal toxicity, an adverse Ca/Mg quotient, and drought (Kruckeberg, 1951(Kruckeberg, , 1954.…”

Seed Germination and Seedling Emergence of Lysimachia mauritiana Lam. (Primulaceae)

“…The biodiversity of coastal environments is valuable at the global scale, as these environments have high endemism rates of plant species that occur as a result of the unique environments, with strong persistence of shore winds carrying sand and salt spray that dries leaves and soil (Hassani et al, 2021;Nakajima & Yoshizaki, 2018). Plant species in coastal areas have traits adapted to coastal environments (Kumekawa et al, 2013;Ohga et al, 2013;Shiba et al, 2022;Sunami et al, 2013;Takizawa et al, 2022;Tunala et al, 2012); therefore, the conservation and sustainable use of coastal forests require close attention (Cori, 1999;Schlacher et al, 2008).…”