Genecology and ecophysiology of the maintenance of foliar phenotypic polymorphisms of Leptospermum recurvum (Myrtaceae) under oscillating atmospheric desiccation in the tropical-subalpine zone of Mount Kinabalu, Borneo

We investigated genecology and ecophysiological mechanisms of the polymorphism of leaf trichome density of Leptospermum recurvum Hook. f. (Myrtaceae) in the deglaciated summit zone above 3, 000 m a.s.l. of Mt. Kinabalu, Borneo. Various phenotypes with variable foliar trichome densities occurred sympatrically in the same population, and the composition of coexisting phenotypes varied substantially among populations. We conducted a common garden experiment by sowing seeds from multiple maternal trees of different leaf trichome densities. We found a significant relation between pubescence of maternal trees and offspring, which indicated that leaf trichome density had a genetic basis. Microsatellite analysis revealed that there was no barrier to gene flows among phenotypes or among populations, and very low neutral genetic differentiation among populations with high gene flows for both directions of phenotypes. The soils in the sites dominated by pubescent trees were significantly more desiccated than in the sites dominated by glabrous trees during a short drought. Glabrous trees had a significantly greater mortality rate than pubescent trees after an intensive El Niño drought (13.7 vs. 3.9%) in the same sites where both phenotypes occurred sympatrically. Pubescent individuals demonstrated a significantly greater photosynthetic water-use efficiency than glabrous individuals. El Niño droughts could cause large difference in soil moisture among sites and that a greater desiccation stress removed glabrous phenotypes as one end of divergent natural selection to form pubescent populations. These results implied that the process shaping the phenotypic polymorphisms involved strong gene flows combined with ongoing divergent selection

Tailor-made Biological Conservation of Endangered Plant Species with Genomic Information

departmental bulletin pape

Development and characterization of nuclear microsatellite markers in Aphananthe aspera (Thunb.) Planch. (Cannabaceae)

Nuclear microsatellite markers were developed for Aphananthe aspera (Thunb.) Planch. (Cannabaceae), a deciduous canopy tree species distributed in East Asia, to evaluate the genetic diversity and genetic structure of A. aspera populations in remnant forest fragments in urbanized areas of Japan. A total of 94 primer pairs were designed based on genomic sequence data. Of the 25 primer pairs which showed clear microsatellite peaks, 20 pairs showed allelic polymorphisms in 57 individuals collected from two distant populations. The length of PCR products ranged from 120 to 482 bp, and expected heterozygosity for the 20 microsatellite markers ranged from 0.017 to 0.768. These newly developed simple sequence repeat markers will be used in population genetic studies of A. aspera to evaluate genetic diversity and the extent of genetic isolation of the fragmented populations in urban areas

Conservation Genetics of Three Endangered Species of the Genus Oxera in the South of New Caledonia

Poster Presentation

Conservation ecology of gigantochloa manggong : an endemic bamboo at Java, Indonesia 【Article】

Ecological study of Gigantochloa manggong, one of the endemic bamboo species at Java was done inthe secondary tropical forest of Meru Betiri National Park, East Java, Indonesia. Distribution was limit-ed in eastern part of the national park. In general, G. manggonggrows well in lowland secondary forestpatches at altitudes 5 - 50 m on the clay loam soil. Absence of large trees caused canopy gaps whichmade bamboo grows well and spread. There were several associate species such as Callamussp.,Erioglussum rubiginosum, Voacanga grandifolia, Pleomelesp., and Ficussp. Throughout the fieldobservation, its sexual reproduction was not found. However, vegetative reproduction by developingnew culms was found in all of the quadrats. Bamboo harvesting in Sukamade forest by villagers was thethreats of G. manggongpopulation at the wild habitat. Furthermore, our study showed that the range ofthe species distribution has contracted substantially from that recorded in 1987, and this has led to itsassessment as an endangered species. Unsustainable exploitation and habitat loss might be importantfactors toward the extinction of G. manggongin the natural habitat

Isolation and characterization of 52 polymorphic EST-SSR markers for Callitris columellaris (Cupressaceae)

Premise of the study: We developed simple sequence repeat (SSR) markers from expressed sequence tags (ESTs) for Callitris columellaris sensu lato (s.l.) to elucidate population genetic structure and detect outlier loci by genome scan. Methods and Results: mRNA from an individual seedling was subjected to cDNA synthesis and then de novo pyrosequencing. Two hundred and nineteen primer pairs bordering sequence regions were designed from the obtained sequence data. In total, 52 showed polymorphism within 16 individuals representative of the species ' entire range, with the number of alleles per locus and expected heterozygosity ranging from two to 10 and 0.06 to 0.84, respectively. Conclusions: The EST-SSR markers developed in this study will be useful for evaluating the range-wide genetic structure of C. columellaris s.l. and detecting outlier loci under selection, as well as providing useful markers to investigate the conservation genetics and reproductive ecology of the species

Application of a Simplified Method of Chloroplast Enrichment to Small Amounts of Tissue for Chloroplast Genome Sequencing

Premise of the study: High-throughput sequencing of genomic DNA can recover complete chloroplast genome sequences, but the sequence data are usually dominated by sequences from nuclear/mitochondrial genomes. To overcome this deficiency, a simple enrichment method for chloroplast DNA from small amounts of plant tissue was tested for eight plant species including a gymnosperm and various angiosperms. Methods: Chloroplasts were enriched using a high-salt isolation buffer without any step gradient procedures, and enriched chloroplast DNA was sequenced by multiplexed high-throughput sequencing. Results: Using this simple method, significant enrichment of chloroplast DNA-derived reads was attained, allowing deep sequencing of chloroplast genomes. As an example, the chloroplast genome of the conifer Callitris sulcata was assembled, from which polymorphic microsatellite loci were isolated successfully. Discussion: This chloroplast enrichment method from small amounts of plant tissue will be particularly useful for studies that use sequencers with relatively small throughput and that cannot use large amounts of tissue (e.g., for endangered species)

Geographic variations in phenotypic traits of the exotic herb Solidago altissima and abundance of recent established exotic herbivorous insects

Many invasive plants increase aggressiveness after introduction. Since evolutionary forces such as herbivore pressure may change over different time scales, understanding the changes in biotic interactions in invasive plants through time can clarify the mechanism of their evolution in aggressiveness. In this study, we examined the geographic variation in phenotypic traits of Solidago altissima and the abundance of two exotic herbivorous insect species (the aphid, Uroleucon nigrotuberculatum and the lacebug, Corythucha marmorata), which are recently expanding their habitat on S. altissima populations over Japan. The two exotic insects were present at high density on S. altissima throughout their range. No differences in growth traits (plant height and number of leaves) were found among populations, and all plants examined appear to be exclusively hexaploid. Future studies on population genetics and common garden experiments are necessary to evaluate the potential evolutionary dynamics of the S. altissima after introduction