A phylogeographic study of two species of Carpinus, C. japonica Blume and C. tschonoskii Maxim. (Betulaceae), based on the distribution patterns of their chloroplast DNA haplotypes, is reported. In Japan, these species are mainly distributed in Pacific-type deciduous broad-leaved forests. Using 439-440 and 627-629bp nucleotide sequences of noncoding regions of chloroplast DNA, we detected 5 and 6 haplotypes among 217 and 181 individuals sampled from 52 and 49 populations of C. japonica and C. tschonoskii, respectively. The geographic distribution patterns of the haplotypes were highly structured. We investigated the common phylogeographic patterns between the two species that would indicate the influence of common historical factors such as climate change since the last glacial maximum (LGM). Based on our results, we concluded that the Pacific-type Japanese deciduous broad-leaved forests were split into at least three refugia during the LGM. After the LGM, the species expanded to northern areas or moved to higher altitudes from each refugium, thus now occupying northeastern, central, and southwestern Japan.
Arabidopsis thaliana (Brassicaceae) and its closely related species serve as model systems for evolutionary studies. Although much information about the genome of the species of Arabidopsis has been collected, knowing the genomic structure of targeted systems is required for determining which genes are involved in adaptation to particular environments. In this study using amplified fragment length polymorphisms (AFLP), we determined the genomic structure of A. halleri subsp. gemmifera (Brassicaceae) on Mt. Ibuki, Japan, where two ecotypes adapted to lowland and highland environments grow. Based on 273 loci (4.4% of the loci were outliers), genotypes of 17 and 14 individuals of lowland and highland ecotypes, respectively, were determined. When excluding outliers, genetic differentiation between the two ecotypes was low (F_<ST>=0.017). The genotypes of each ecotype, however, were distinguishable using principle coordinate analysis. The genome-wide investigation of the two ecotypes of A. halleri subsp. gemmifera on Mt. Ibuki therefore suggests that morphological divergence as well as adaptation to local environments between lowland and highland ecotypes occurred recently and the two ecotypes share a similar genomic structure. These two ecotypes are therefore appropriate for studies to reveal the genetic basis of morphological divergence as well as local adaptation using genomic information from A. thaliana.
Five new species of Tupistra from the Malay Peninsula, T. elegans N. Tanaka, T. robusta N. Tanaka, T. malaiana N. Tanaka, T. kressii N. Tanaka, and T. urceolata N. Tanaka & W.J. Kress, are described, illustrated and compared with closely related congeners. Tupistra elegans and T. robusta are morphologically close to each other, sharing a sigmoid floriferous stem (including inflorescence), a campanulate perianth with anthers located around the orifice of the tube, and an umbraculate lobed stigma. Tupistra malaiana, T. kressii and T. urceolata appear to have close affinity, sharing an urceolate perianth with anthers inserted subdistally on the tube. In Tupistra, the urceolate perianth is very likely an apomorphy.
Musa itinerans Cheesman (Musaceae) is a highly polymorphic species, dispersed across continental Southeast Asia from Northeast India to Vietnam and the adjacent islands, with six previously described varieties viz. var. annamica, var. chinensis, var. guangdongensis, var. itinerans, var. lechangensis, var. xishuangbannaensis. This work is a continuation of the earlier study from the mainland of China and it is extended to the islands of Hainan and Taiwan. A new combination Musa itinerans var. formosana is proposed and M. itinerans var. hainanensis is described as new. A table and key for the distinguishing characteristics are provided. These studies are based on morphological characteristics observed in the field, in various herbaria as well as the literature on Musaceae.
The order Malpighiales, which comprises 39-40 families of flowering plants, are poorly understood in terms of their morphological characters and the relationships among the families. Here, we present the first chromosome counts of Irvingiaceae, Ixonanthaceae, Lacistemataceae, and Peraceae, based on one or two species each, using somatic cells from young leaves. The chromosome numbers were 2n=30 for Irvingia malayana (Irvingiaceae), 2n=28 for Ixonanthes icosandra and I. reticulata (Ixonanthaceae), 2n=44 for Lacistema aggregatum (Lacistemataceae), and 2n=36 for Chaetocarpus castanocarpus (Peraceae). The relationships of individual families based on chromosome numbers are discussed briefly.