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2020年7月初旬，京都大学芦生研究林の標高630m付近において，トチノキの樹幹上でラン科クモキリソウ属植物が開花しているのが発見された．形態観察と分子系統分析により種同定を行ったところ，芦生研究林新産のアキタスズムシソウであることが判明した．1930年代の古い標本記録も含め，京都府下では3地点の産地のみが知られる希少種であり，芦生研究林は府下第4番目の重要産地となった．, In early July 2020, flowering individuals of an unidentified Liparis sp. (Orchidaceae) were found on the trunks of Japanese horse chestnut trees at 630 m a.s.l. in Ashiu Forest Research Station, Kyoto University. Based on the results of morphological and molecular phylogenetic analyses, the species was identified as L. longiracemosa Tsutsumi, T. Yukawa et M. Kato, which is a new record for Ashiu. Liparis longiracemosa is an endangered orchid with only three known localities in Kyoto Prefecture (including an old herbarium record from the 1930s), and our discovery revealed Ashiu Research Forest as a new important locality for this species in Kyoto., ファイルを差し替え（2023-06-29）

[Aim] The Sino-Japanese Floristic Region has extremely high species diversity with respect to temperate plants; however, the reasons for this diversity are poorly understood because most studies have only considered geographic isolation caused by climatic oscillations. In some plant groups, high floral trait diversity and uneven species diversity between insular systems and the continental area suggest other factors may have important roles too. The primary purpose of this study is to reveal how abiotic and biotic factors have shaped the species diversity anomaly of Heterotropa between the insular systems and the continental area. [Location] The Sino-Japanese Floristic Region. [Taxon] Section Heterotropa (genus Asarum; Aristolochiaceae). [Methods] Using ddRAD-seq and chloroplast genome data, we built a time-calibrated phylogenetic tree including 79 species. We estimated the patterns of floral traits (flowering time and floral size) evolution using macroevolutionary modelling, and tested the correlation of speciation rate with the trait evolution rates. Finally, we estimated the isolation factors of all taxa pairs and sister-taxa pairs based on distribution range and floral traits. [Results] Phylogenetic analysis indicated that Heterotropa was diverged into two clades (continental clade and insular clade) in the Miocene, and the major subclades corresponded to geographic entities. Most rate shifts accelerating floral trait's evolution occurred during the Pleistocene period. Evolution rate of floral traits showed positive correlation with the speciation rate. Large proportion of taxa in the insular clade are distributed allopatrically. Several sister pairs showed floral trait divergence with geographic overlap. [Main Conclusions] The diversification of Heterotropa appears to have been triggered by geographic and climatic events, and subsequent repeated floral trait evolution with and without geographic isolation. Furthermore, the high species diversity in the insular systems would have been formed by the repeated range fragmentations and contractions. Our study demonstrates the importance of multidimensional studies to understand the diversification process of temperate plants in the Sino-Japanese Floristic Region.

Interspecific hybridization is a critical issue in conservation biology because it may drive small populations to extinction through direct or indirect processes. In this study, to develop a conservation strategy for an endangered rear-edge population of Carex podogyna in Ashiu, Kyoto, Japan, we performed a molecular genetic analysis of the wild population and an ex-situ population established from wild seeds. Microsatellite genotypic data revealed a complete loss of genetic diversity in the wild population, suggesting that it has long been prone to genetic drift due to isolation as a small population. In contrast, microsatellite analysis of 13 ex-situ individuals detected multiple alleles that are not harbored in the wild C. podogyna population. Sequence analysis revealed that these individuals are likely natural hybrids between C. podogyna and a co-occurring species, C. curvicollis, although established hybrids have never been found in the natural habitat. Based on our observation of variegated leaves in hybrid individuals, we propose that hybrids have been excluded by natural selection and/or interspecific competition caused by insufficient productivity of photosynthesis, although other genetic and ecological factors may also be influential. Overall, this study indicates that natural mechanisms selectively removing the hybrids have maintained the genetic purity of this rear-edge population of C. podogyna, and also emphasizes the importance of genetic assessment in ex-situ conservation programs.

Understanding the geographic variation of leaf trichome in wild radish accessions would help to elucidate how morphological variation can be molded by natural selection. Here, we investigated the geographic variation of leaf trichomes in wild radish populations across Japan covering Ryukyu Islands and mainland. And we also sought the possible selection pressures involved in the evolution and maintenance of leaf trichome polymorphism. Results showed leaf trichome density in wild radish was highly variable across the Japanese archipelago, with plants from southern insular populations tending to exhibit glabrous leaves, while those of northern mainland Japan were completely covered by dense trichomes. This trichome variation in Japanese populations of wild radish was probably attributing to external stress involving in protecting against frost damage and resistance to herbivores. This study will be helpful to understand the morphological variation under divergent selections in wild radish and contribute to the areas of breeding and evolutionary studies in radish., ハマダイコンは日本においては西表島から北海道までの幅広い緯度の海岸に生育する。著者らの従来の観察では，琉球列島では葉や茎が無毛である傾向があり，反対に本州北部では粗長毛が密に生える傾向が見られた。そこで本研究では曖昧な印象であった毛の密度について調べるために，日本列島内の緯度に沿った11集団に由来する個体の，葉の向軸側の毛の密度を実体顕微鏡で計測した。その結果，琉球列島だけにおいて無毛の個体が存在するとともに，少数ながら粗長毛が密に生える個体も共存した。その一方で，北緯33度以上の本州の集団ではすべての個体で葉に粗長毛が密に生えていた。近年のアブラナ科植物での研究では，毛が草食性昆虫などの食害を防ぐなどの役割があると報告されており，今後には，なぜ南西諸島の集団で無毛の個体が共存できるのかという検討が必要である。

In plants, timing of flowering is an essential factor that controls the survival rates of descendants. The circadian clock genes E1 and GIGANTEA (GI) play a central role in transmitting signals to flowering locus T (FT) in leguminous plants. Lotus japonicus is a wild Japanese species that ranges from northern Hokkaido to the southern Ryukyus and exhibits a wide range in terms of the time between seeding and first flowering. In this study, we first identified LjGI and analyzed polymorphisms of LjE1 and LjGI among wild populations covering the entire distribution range of this species in Japan. LjGI had a coding sequence (CDS) length of 3495 bp and included 14 exons. The homologies of DNA and amino acid sequences between LjGI and GmGI were 89 and 88% (positive rate was 92%), respectively. LjE1 harbored five nucleic acid changes in a 552 bp CDS, all of which were nonsynonymous; four of the changes were located in the core function area. LjE1 alleles exhibited partial north-south differentiation and non-neutrality. In contrast, the LjGI harbored one synonymous and one nonsynonymous change. Thus, our study suggests that LjE1 may be involved in the control of flowering times, whereas LjGI may be under strong purifying selection.

琵琶湖に内陸隔離されている海浜植物ハマヒルガオCalystegia soldanella（L.）Roem. et Schult. が，海岸の個体との間で葉の厚さに分化を起こしているかを検証した。比較をしたのは，琵琶湖の自生地6集団と海岸の自生地9 集団である。葉の厚さを測定して多重比較検定にかけたところ，5 グループに分類された。そのうちの1 グループに全ての琵琶湖の集団が含まれ，海岸の集団は残りの4 グループに含まれた。琵琶湖のハマヒルガオの葉は，海岸のものに比べて，有意に厚さが薄くなっていることが示唆された。琵琶湖は淡水湖であるために，塩ストレスへの適応が不要であることが，その要因の一つとして考えられる。

Sixteen populations of Cycas revoluta（Cycadaceae）, covering almost all distribution areas on the Ryukyu Islands and Kyushu, Japan, were examined to determine geographical differences in leaflet morphology. We assessed four morphological characteristics of leaflets and applied one-way analysis of variance（ANOVA）to test thedifference in each morphological character. Cluster analysis based on four morphological properties resulted in two clear major clusters comprising northerly and southerly populations that were demarcated north of Yorontou and south of Tokunoshima Islands, respectively. Northern cycads tended to have leaflet margins with shallow recurving and narrower leaflet lamina width, while the southern populations had deeply recurved leaflet margins and wider leaflet lamina width. The morphological differentiation may imply intraspecific differentiation., 琉球列島から九州にかけて分布するソテツ（Cycas revoluta Thunb.）の自生地16 集団を対象にして，小羽片の形態の地理的な分化を検証した。小羽片の横断面における小羽片の幅と厚さ，中肋の厚さ，小羽片の縁の巻き込みの高さの4 形質を測定してクラスター解析にかけたところ，北方型と南方型の2 つのグループに分かれた。北方型には主に与論島以北の集団が含まれ，南方型には主に徳之島以南の集団が含まれる。ただし，この境界にある徳之島は南方型に，沖永良部島は北方型に含まれる。これには，小羽片の幅と縁の巻き込みの高さに南北間で違いがあることが寄与しており，とくに縁の巻き込みの高さは，南側で大きく巻き込む傾向が見られた。

The tree Ilex dimorphophylla Koidz.（Aquifoliaceae）is a vulnerable species that is endemic to the summit of Mt. Yuwan on Amamioshima Island, Japan. This plant hows characteristic leaf dimorphism, which increases its horticultural value, and many individuals have been illegally removed from the natural habitat. We examined the umber of shoots, leaf morphology and plant size of the species in the natural habitat. Based on field observation for two years, we found 84 shoots, of which 32（38.1%）had entire mature leaves, whereas 52（61.9%）had only serrate juvenile leaves. Majority of the examined shoots surveyed fell into the smallest size classes : < 100 cm in eight（ca. 45%）and < 25 mm in diameter at the trunk base（ca. 60%）. Leaf dimorphism was clearly demarcated in trees at 130―210 cm in height and 15―27 mm in diameter at the trunk base., アマミヒイラギモチ（Ilex dimorphophylla Koidz.）は奄美大島の湯湾岳山頂付近に発達した風衝林内に生育するモチノキ科の樹木である。本種における樹木サイズと葉の二型性について自生地で調査した。84 シュートの生育を確認し，そのうちの32 シュートが全縁の成熟葉を，残りの52 シュートが鋭い鋸歯のある幼葉のみをもっていた。葉の二型性は樹木高で約130―210 cm，根元直径で15―27mm を境にして分かれていることが明らかになった。

Locus information and list of the primers (*: internal primers). (DOCX 20 kb)

The distribution of model parameters (â K) and log-likelihood of the data (LnP(D)) based on structure analysis. (PDF 51 kb)

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