生物多様性研究室の柴政幸君(日本学術振興会特別研究員PD)と原田栞里さん(博士課程1年) が、11th International Conference on Serpentine Ecology にて発表しました。
Commonality and Diversity of Leaf Morphology Adapted to Serpentine Soil
Masayuki SHIBA (生物多様性研：日本学術振興会特別研究員PD), Hiroshi HAYAKAWA, Kyohei OHGA, Yoshimasa KUMEKAWA, Tomoki TATE and Tatsuya FUKUDA
Abstract: Serpentine soil mosaics are found throughout Japan and some plants have changed their morphology and anatomy to adapt to the chemical and physical properties of serpentine soils. To clarify common morphological changes of plants adapted to serpentine soils, we analyzed representatives from different phylogenetic groups occurring on serpentine soils, such as woody plants Eurya japonica (Ternstroemiaceae and Ligustrum japonicum (Oleaceae), and herbaceous plants Adenophora triphylla var. japonica (Campanulaceae) and Aster hispidus var. leptocladus (Asteraceae). Leaves of plants growing on serpentine soil tended to be smaller and thicker, suggesting that serpentine soil has not only inhibited the growth of leaves, but also changed them to retain moisture. Moreover, the low water retention of serpentine soil was reflected in plant stomata characteristics. Woody plants reduced stomatal size, while herbaceous ones changed stomatal density. Interestingly, As. hispidus var. leptocladus increased its stomatal size along with an increase in epidermal cell size but reduced its stomatal density to avoid excessive transpiration. Unlike the other species, As. hispidus var. leptocladus is endemic to serpentine soils, suggesting that it has been able to adapt to serpentine soils through special changes different from the other three species. In addition, E. japonica, L. japonicum, and Ad. Triphylla var. japonica have many similarities with morphological and anatomical characteristics of plants found in coastal environments, suggesting that their phenotypic plasticity may have enabled them to adopt more adaptive morphologies.
Comparative Morphological Analyses of Fruiting Bodies in Ammonia Fungi from Serpentine and Neighboring Non-Serpentine Areas
Shiori HARADA (生物多様性研：博士課程1年), Hiroto FUKAYAMA (生物多様性研：修士課程修了生), Masayuki SHIBA (生物多様性研：日本学術振興会特別研究員PD), Akira SUZUKI and Tatsuya FUKUDA
Abstract: Ammonia fungi are defined as a chemoecological group of fungi that colonize forest floors after deposition of nitrogenous resources such as animal corpses, feces, and urine. Field studies of ammonia fungi have been conducted in various habitats all over the world, but no studies in serpentine areas have been made so far. Ammonia fungi occur on the forest floors after experimental disturbance using nitrogenous resources such as urea and aqua ammonia. The adaptation strategy of ammonia fungi could be analyzed at a similar growth stage by using nitrogenous resources simultaneously in both serpentine and neighboring non-serpentine areas. It is unknown whether fruiting bodies of ammonia fungi are changing their morphology, similar to the morphological differentiation of some plants in serpentine areas. Our study aims to clarify the morphological differentiation of basidiomata of ammonia fungi grown between serpentine and neighboring non-serpentine areas in Chiba and Shizuoka Prefectures. Since basidiomata of Hebeloma danicum collected in Chiba and those of Sagaranella tylicolor in Shizuoka were relatively abundant in both serpentine and non-serpentine areas, we used them to perform comparative morphological analyses. Our results indicated that these species from serpentine sites had significantly differentiated morphology of basidiomata from those in non-serpentine areas, and the basidiomata of both species in serpentine was not a simple dwarf of each pileus and stipe with a similar ratio, but a characteristic dwarf in that the pileus was very small relative to the stipe. The different dwarfing ratios of pileus and stipe of basidiomata of the species from serpentine could be explained by the thickness of the LF (Litter Fall) layer. Both species had small total resources and the stipes of basidiomata from serpentine had to be lengthened through the thick LF layer, leaving less resources for pileus growth. In H. danicum, the relative lack of resources could be reflected in the formation of their small pilei, but the correlation between the length of the stipe and the diameter of the pileus of S. tylicolor showed that the former became smaller as the latter became shorter. Therefore, small pilei in serpentine areas experienced different formation processes. The supposition that augmented stipe resources have diminished pileus size and spore numbers is a reasonable one; however, both species may have adapted to their environment by undergoing morphological changes at the serpentine site.