研究者詳細 - 三村　真紀子

我々は「生態リスク」とどう向き合うのか?

森章, 三村真紀子, 黒川紘子

日本生態学会誌 60 ( 3 ) 323 - 325 2010年

分布域のダイナミクス--シトカトウヒの分布拡大と局所適応招待査読

三村真紀子

林木の育種 236 ( 236 ) 1 - 6 2010年

Mycorrhizal colonization of transgenic Eucalyptus camaldulensis carrying the mangrin gene for salt tolerance 査読

Kipkorir E. Lelmen, Xiang Yu, Akira Kikuchi, Takayoshi Shimazaki, Makiko Mimura, Kazuo N. Watanabe

PLANT BIOTECHNOLOGY 27 ( 4 ) 339 - 344 2010年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JAPANESE SOC PLANT CELL & MOLECULAR BIOLOGY

Transgenic products and the creation of new organisms with innovative transgenic traits generally raise risk assessment concerns because of potential risks to nontarget organisms. Cartagena Protocol on Biosafety and Japanese government regulations require scientific environmental risk assessments of living modified organisms prior to release to avoid adverse effects on the environment. Soil microorganisms, such as the arbuscular mycorrhizal fungi, aid in plant nutrient acquisition and protection from environmental stresses such as salt stress. In this study, we used a salt-tolerant transgenic Eucalyptus camaldulensis transformed with the mangrin gene from a mangrove plant and evaluated the interactions between environmental stress-tolerant transgenic plants and arbuscular mycorrhizal fungi. Our results indicated that these transformants were substantially equivalent to nontransformants in terms of arbuscular mycorrhizal fungi colonization under both saline and nonsaline conditions, and that the arbuscular mycorrhizal fungi colonization could potentially enhance the salt tolerance of the transgenic plant.

DOI： 10.5511/plantbiotechnology.27.339

Comparison of contemporary mating patterns in continuous and fragmented Eucalyptus globulus native forests 査読

Makiko Mimura, Robert C. Barbour, Brad M. Potts, Rene E. Vaillancourt, Kazuo N. Watanabe

MOLECULAR ECOLOGY 18 ( 20 ) 4180 - 4192 2009年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

While habitat fragmentation is a central issue in forest conservation studies in the face of broad-scale anthropogenic changes to the environment, its effects on contemporary mating patterns remain controversial. This is partly because of the inherent variation in mating patterns which may exist within species and the fact that few studies have replication at the landscape level. To study the effect of forest fragmentation on contemporary mating patterns, including effective pollen dispersal, we compared four native populations of the Australian forest tree, Eucalyptus globulus. We used six microsatellite markers to genotype 1289 open-pollinated offspring from paired fragmented and continuous populations on the island of Tasmania and in Victoria on mainland Australia. The mating patterns in the two continuous populations were similar, despite large differences in population density. In contrast, the two fragmented populations were variable and idiosyncratic in their mating patterns, particularly in their pollen dispersal kernels. The continuous populations showed relatively high outcrossing rates (86-89%) and low correlated paternity (0.03-0.06) compared with the fragmented populations (65-79% and 0.12-0.20 respectively). A greater proportion of trees contributed to reproduction in the fragmented (de/d >= 0.5) compared with the continuous populations (de/d = 0.03-0.04). Despite significant inbreeding in the offspring of the fragmented populations, there was little evidence of loss of genetic diversity. It is argued that enhanced medium-and long-distance dispersal in fragmented landscapes may act to partly buffer the remnant populations from the negative effects of inbreeding and drift.

DOI： 10.1111/j.1365-294X.2009.04350.x

Genetic variation of chloroplast DNA in Zingiberaceae taxa from Myanmar assessed by PCR-restriction fragment length polymorphism analysis 査読

D. Ahmad, A. Kikuchi, S. A. Jatoi, M. Mimura, K. N. Watanabe

ANNALS OF APPLIED BIOLOGY 155 ( 1 ) 91 - 101 2009年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL PUBLISHING, INC

We examined genetic variation in 22 accessions belonging to 11 species in four genera of the Zingiberaceae, mainly from Myanmar, by PCR-restriction fragment length polymorphism analysis to investigate their relationships within this family. Two of 10 chloroplast gene regions (trnS-trnfM and trnK2-trnQr) showed differential PCR amplification across the taxa. Restriction enzyme digestion of the PCR products revealed interspecific variability. The restriction patterns were used to classify the regions as either highly conserved or variable across the taxa. None of the regions was highly conserved across the four genera, and the level of conservation varied. The gene region trnS-trnfM appeared to display interspecific variability among most of the species. However, the relative efficiency of different restriction enzymes depended on the gene regions and genera investigated. Cluster analysis revealed interspecific discrimination among the taxa. The two Curcuma species (Curcuma zedoaria and Curcuma xanthorrhiza) appeared to be identical, thus supporting their recent classification as synonyms. The results provide the basis for selecting specific combinations of restriction enzymes and gene regions of chloroplast DNA (cpDNA) to identify interspecific variation in the Zingiberaceae and to identify both highly conserved and variable regions. Overall, cpDNA depicted comparatively diverse genetic profile of the studied germplasm. The genetic information revealed here can be applied to the conservation and future breeding of Zingiber and Curcuma species.

DOI： 10.1111/j.1744-7348.2009.00322.x

Relationships of Zingiber species, and genetic variability assessment in ginger (Zingiber officinale) accessions from ex-situ genebank, on-farm and rural markets 査読

Shakeel Ahmad Jatoi, Akira Kikuchi, Makiko Mimura, San-San-Yi, Kazuo N. Watanabe

BREEDING SCIENCE 58 ( 3 ) 261 - 270 2008年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JAPANESE SOC BREEDING

The Zingiber species comprises rhizomatous plants with special significance due to their multiple uses. Previously, we reported the additional use and suitability of primer pairs of rice microsatellite markers as RAPDs for diversity assessment in representative accessions of diverse taxa in the family Zingiberaceae. The current study aimed to investigate the genetic structure of Z. officinale at a genebank, small-scale subsistent farms and commercial markets, and the genetic relationships of three Zingiber species. A difference among accessions at the inter-specific level was observed and amplification of species-specific bands led to high polymorphism. Genetic variability in Z. officinale was exhibited by the three collection sources; however, some of the accessions from each source tended to cluster. AMOVA also displayed significant divergence among the three collection sources and explained most of the variance (87%) within the collection sources. In general, small-scale local farms displayed higher genetic variability in Z. offcinale compared to those from the genebank and markets. Comparative assessment displayed high allelic diversity in ginger from Myanmar as compared to other Asian countries. Genetic resources of Zingiber species, particularly available on farms, can be a useful source to capture and utilize diversity for conservation as well as further improvement in gingers.

DOI： 10.1270/jsbbs.58.261

Impact of Environmental Stress-Tolerant Transgenic Potato on Genotypic Diversity of Microbial Communities and Soil Enzyme Activities under Stress Conditions 査読

Makiko Mimura, Kipkorir E. Lelmen, Takayoshi Shimazako, Akira Kikucho, Kazuo N. Watanabe

MICROBES AND ENVIRONMENTS 23 ( 3 ) 221 - 228 2008年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE

Transgenic crops able to tolerate environmental stress are being developed throughout the world. However, little data is available on the impact of environmental stress-tolerant transgenic crops on soil microorganisms and biochemistry. Recently developed transgenic potato plants carrying an environmental stress-related gene, DREB1A, with a stress-inducible promoter, are being evaluated for growth performance in greenhouses. In this study, we investigated microbial diversity and soil function to assess potential environmental risks of these transgenic potato lines, Genotypic diversity of the 16S-23S rRNA intergenic spacer region and activity levels of four enzymes were used as indicators of microbial genetic diversity and soil function, respectively. Salinity had a major effect on both bacterial (88-93%) and fungal (54-55%) diversity, while the transgene had a relatively small effect on genotypic structure (0-5%,) based on the analysis of variance. However, a few genotypes appeared only in soils planted with the transgenic lines. Some enzyme activities were found to differ significantly between the transgenic and non-transgenic lines, although the results were not repeatable in the second trial. These results suggest that abiotic growth environments had a stronger impact on soil microorganisms and biochemistry than did plant genotypes.

DOI： 10.1264/jsme2.23.221

Adaptive gradients and isolation-by-distance with postglacial migration in Picea sitchensis 査読

M. Mimura, S. N. Aitken

HEREDITY 99 ( 2 ) 224 - 232 2007年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE PUBLISHING GROUP

Fossil pollen records suggest rapid migration of tree species in response to Quaternary climate warming. Long-distance dispersal and high gene flow would facilitate rapid migration, but would initially homogenize variation among populations. However, contemporary clinal variation in adaptive traits along environmental gradients shown in many tree species suggests that local adaptation can occur during rapid migration over just a few generations in interglacial periods. In this study, we compared growth performance and pollen genetic structure among populations to investigate how populations of Sitka spruce (Picea sitchensis) have responded to local selection along the historical migration route. The results suggest strong adaptive divergence among populations (average Q(ST) 0.61), corresponding to climatic gradients. The population genetic structure, determined by microsatellite markers (R-ST = 0.09; F-ST = 0.11), was higher than previous estimates from less polymorphic genetic markers. The significant correlation between geographic and pollen haplotype genetic (R-ST) distances (r = 0.73, P < 0.01) indicates that the current genetic structure has been shaped by isolation-by-distance, and has developed in relatively few generations. This suggests relatively limited gene flow among populations on a recent timescale. Gene flow from neighboring populations may have provided genetic diversity to founder populations during rapid migration in the early stages of range expansion. Increased genetic diversity subsequently enhanced the efficiency of local selection, limiting gene flow primarily to among similar environments and facilitating the evolution of adaptive clinal variation along environmental gradients.

DOI： 10.1038/sj.hdy.6800987

Increased selfing and decreased effective pollen donor number in peripheral relative to central populations in Picea sitchensis (Pinaceae) 査読

Makiko Mimura, Sally N. Aitken

AMERICAN JOURNAL OF BOTANY 94 ( 6 ) 991 - 998 2007年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：BOTANICAL SOC AMER INC

Because mating system can be influenced by effective neighborhood size, density, and isolation, populations at range peripheries may differ from those in the center. The importance of peripheral populations to conservation and evolution is controversial, and additional information about their genetic structure and evolutionary dynamics will inform conservation strategies. In wind-pollinated species, selfing rate is generally negatively correlated with population size and density, and inbreeding may therefore increase toward range peripheries. Picea sitchensis has a long and narrow range along the Pacific Coast of North America that tapers toward the northern and southern peripheries. We investigated whether central and peripheral populations differ in mating system parameters. The results suggest that population position within the range has a strong effect on mating system, and geographic isolation appears to be associated with higher selfing. The estimated effective number of pollen donors was much higher in the center of the range (mean = 18.5) than at the periphery (mean = 3.6), while selfing rate increased from 7.3% in central populations to as high as 35.2% in the northern, isolated population. These strong geographical patterns suggest mating system is influenced by both population size and isolation at range peripheries.

DOI： 10.3732/ajb.94.6.991

SSR diversity of vegetable soybean [Glycine max (L.) merr.] 査読

Makiko Mimura, Clarice J. Coyne, Marie W. Bambuck, Thomas A. Lumpkin

GENETIC RESOURCES AND CROP EVOLUTION 54 ( 3 ) 497 - 508 2007年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

Edamame [Glycine max (L.) Merr.] is a type of soybean selected for fresh or frozen vegetable use at an immature stage. Since edamame has a similar protein content, milder flavor, nuttier texture, and is easier to cook when compared to grain soybean, it is being promoted as a new vegetable for global consumption. Global production will require breeding programs for local adaptation; however, limited research has been published on genetic diversity of edamame varieties for the assessment of genetic resources. Simple sequence repeats (SSRs) were used to study the genetic diversity among 130 accessions, including edamame cultivars and landraces from Japan, China and the US, and also the new breeding lines in the US. Although it is assumed that elite edamame cultivars would have narrow genetic diversity, seventeen SSRs detected polymorphism to distinguish 99 of the 130 accessions. The cluster analysis generated nine clusters and 18 outliers. Genetic diversity within Japanese edamame was lower than that within Chinese vegetable soybean accessions (maodou), even though only 10 Chinese maodou were analyzed compared to 107 Japanese edamame. Cluster analysis revealed that the patterns of SSR diversity in edamame can generally distinguish maturity classes and testa color. We concluded that Japanese edamame have a narrow genetic base different from others and that SSRs can describe the patterns of genetic diversity among the elite vegetable soybean.

DOI： 10.1007/s10722-006-0006-4

RAPD variation in wild, weedy and cultivated azuki beans in Asia 査読

M Mimura, K Yasuda, H Yamaguchi

GENETIC RESOURCES AND CROP EVOLUTION 47 ( 6 ) 603 - 610 2000年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：KLUWER ACADEMIC PUBL

RAPD (Random Amplified Polymorphic DNA) variation was assessed in 42 accessions of azuki bean (Vigna angularis) including wild, weedy and cultivated races and in three accessions of two related species used as outgroups. A much lower level of genetic variation was observed in cultivated and weedy azuki beans compared to wild azuki bean. Wild azuki bean (V. angularis var. nipponensis) has relatively high genetic variation in subtropical highlands of Asia compared to the Far East. Although cultivated azuki bean has low RAPD variation, accessions from subtropical highlands and Southeast Asia showed different RAPD features compared to those of the Far East. It is hypothesized that the cultivated azuki bean has been derived from wild azuki bean in the Far East; the high variation in wild azuki bean has been created through its natural dissemination; and the relatively low variation in cultivated azuki bean has come about through human dissemination after genetic bottleneck reduced by domestication. In addition, high genetic diversity in wild azuki bean in subtropical highlands of Asia is regarded as an important genetic resource in azuki improvement.

DOI： 10.1023/A:1026584824584