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Huang CC, Hung KH, Hwang CC, Huang JC, Lin HD, Wang WK, Wu PY, Hsu TW, Chiang TY. Genetic population structure of the alpine species Rhododendron pseudochrysanthum sensu lato (Ericaceae) inferred from chloroplast and nuclear DNA. BMC Evol Biol 2011; 11:108. [PMID: 21501530 PMCID: PMC3096940 DOI: 10.1186/1471-2148-11-108] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 04/19/2011] [Indexed: 11/13/2022] Open
Abstract
Background A complex of incipient species with different degrees of morphological or ecological differentiation provides an ideal model for studying species divergence. We examined the phylogeography and the evolutionary history of the Rhododendron pseudochrysanthum s. l. Results Systematic inconsistency was detected between gene genealogies of the cpDNA and nrDNA. Rooted at R. hyperythrum and R. formosana, both trees lacked reciprocal monophyly for all members of the complex. For R. pseudochrysanthum s.l., the spatial distribution of the cpDNA had a noteworthy pattern showing high genetic differentiation (FST = 0.56-0.72) between populations in the Yushan Mountain Range and populations of the other mountain ranges. Conclusion Both incomplete lineage sorting and interspecific hybridization/introgression may have contributed to the lack of monophyly among R. hyperythrum, R. formosana and R. pseudochrysanthum s.l. Independent colonizations, plus low capabilities of seed dispersal in current environments, may have resulted in the genetic differentiation between populations of different mountain ranges. At the population level, the populations of Central, and Sheishan Mountains may have undergone postglacial demographic expansion, while populations of the Yushan Mountain Range are likely to have remained stable ever since the colonization. In contrast, the single population of the Alishan Mountain Range with a fixed cpDNA haplotype may have experienced bottleneck/founder's events.
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Affiliation(s)
- Chi-Chun Huang
- Department of Life Sciences, National Cheng-Kung University, Tainan 701, Taiwan
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Hirao AS. Kinship between parents reduces offspring fitness in a natural population of Rhododendron brachycarpum. ANNALS OF BOTANY 2010; 105:637-46. [PMID: 20202970 PMCID: PMC2850802 DOI: 10.1093/aob/mcq018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 07/16/2009] [Accepted: 01/04/2010] [Indexed: 05/03/2023]
Abstract
BACKGROUND AND AIMS A reduction in offspring fitness resulting from mating between neighbours is interpreted as biparental inbreeding depression. However, little is known about the relationship between the parents' genetic relatedness and biparental inbreeding depression in their progeny in natural populations. This study assesses the effect of kinship between parents on the fitness of their progeny and the extent of spatial genetic structure in a natural population of Rhododendron brachycarpum. METHODS Kinship coefficients between 11,858 pairs of plants among a natural population of 154 R. brachycarpum plants were estimated a priori using six microsatellite markers. Plants were genotyped, and pairs were selected from among 60 plants to vary the kinship from full-sib to unrelated. After a hand-pollination experiment among the 60 plants, offspring fitness was measured at the stages of seed maturation (i.e. ripening) under natural conditions, and seed germination and seedling survival under greenhouse conditions. In addition, spatial autocorrelation was used to assess the population's genetic structure. KEY RESULTS Offspring fitness decreased significantly with increasing kinship between parents. However, the magnitude and timing of this effect differed among the life-cycle stages. Measures of inbreeding depression were 0.891 at seed maturation, 0.122 (but not significant) at seed germination and 0.506 at seedling survival. The local population spatial structure was significant, and the physical distance between parents mediated the level of inbreeding between them. CONCLUSIONS The level of inbreeding between individuals determines offspring fitness in R. brachycarpum, especially during seed maturation. Genetic relatedness between parents caused inbreeding depression in their progeny. Therefore, biparental inbreeding contributes little to reproduction and instead acts as a selection force that promotes outcrossing, as offspring of more distant (less related) parents survive better.
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Affiliation(s)
- Akira S Hirao
- Institute of Mountain Science, Shinshu University, Matsumoto 390-8621, Japan.
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Hanaoka S, Yuzurihara J, Asuka Y, Tomaru N, Tsumura Y, Kakubari Y, Mukai Y. Pollen-mediated gene flow in a small, fragmented natural population of Fagus crenata. ACTA ACUST UNITED AC 2007. [DOI: 10.1139/b07-036] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pollen-mediated gene flow was analyzed in a small, fragmented, natural population of Fagus crenata Blume by surveying five microsatellite markers in seedlings derived from open-pollinated crosses. Paternity of 162 seedlings derived from two maternal trees was assigned by the maximum-likelihood method using CERVUS 2.0, and pollen dispersal patterns within the study site were determined. Most of the trees within the site sired seeds, although we found evidence of limited pollen-mediated gene flow from outside the stand; 92% of the matings that generated the seedlings occurred between trees within the population, and 8% of the matings were mediated by pollen derived from trees located outside the study site. Although the pollen-mediated gene flow within the site was not strongly limited, mating frequencies of paternal trees were found to be weakly negatively correlated with their distance from the mother trees, positively correlated with their stem diameter at breast height, and uncorrelated with their relatedness to the mother trees.
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Affiliation(s)
- So Hanaoka
- Laboratory of Forest Molecular Ecology, United Graduate School of Agriculture, Gifu University, Gifu 501-1193, Japan
- Laboratory of Forest Ecology and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- Department of Forest Genetics, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
- Institute of Forest Resources, Faculty of Agriculture, University of Shizuoka, Shizuoka 422-8529, Japan
| | - Jungo Yuzurihara
- Laboratory of Forest Molecular Ecology, United Graduate School of Agriculture, Gifu University, Gifu 501-1193, Japan
- Laboratory of Forest Ecology and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- Department of Forest Genetics, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
- Institute of Forest Resources, Faculty of Agriculture, University of Shizuoka, Shizuoka 422-8529, Japan
| | - Yamashita Asuka
- Laboratory of Forest Molecular Ecology, United Graduate School of Agriculture, Gifu University, Gifu 501-1193, Japan
- Laboratory of Forest Ecology and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- Department of Forest Genetics, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
- Institute of Forest Resources, Faculty of Agriculture, University of Shizuoka, Shizuoka 422-8529, Japan
| | - Nobuhiro Tomaru
- Laboratory of Forest Molecular Ecology, United Graduate School of Agriculture, Gifu University, Gifu 501-1193, Japan
- Laboratory of Forest Ecology and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- Department of Forest Genetics, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
- Institute of Forest Resources, Faculty of Agriculture, University of Shizuoka, Shizuoka 422-8529, Japan
| | - Yoshihiko Tsumura
- Laboratory of Forest Molecular Ecology, United Graduate School of Agriculture, Gifu University, Gifu 501-1193, Japan
- Laboratory of Forest Ecology and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- Department of Forest Genetics, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
- Institute of Forest Resources, Faculty of Agriculture, University of Shizuoka, Shizuoka 422-8529, Japan
| | - Yoshitaka Kakubari
- Laboratory of Forest Molecular Ecology, United Graduate School of Agriculture, Gifu University, Gifu 501-1193, Japan
- Laboratory of Forest Ecology and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- Department of Forest Genetics, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
- Institute of Forest Resources, Faculty of Agriculture, University of Shizuoka, Shizuoka 422-8529, Japan
| | - Yuzuru Mukai
- Laboratory of Forest Molecular Ecology, United Graduate School of Agriculture, Gifu University, Gifu 501-1193, Japan
- Laboratory of Forest Ecology and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- Department of Forest Genetics, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan
- Institute of Forest Resources, Faculty of Agriculture, University of Shizuoka, Shizuoka 422-8529, Japan
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Hirao AS, Kameyama Y, Ohara M, Isagi Y, Kudo G. Seasonal changes in pollinator activity influence pollen dispersal and seed production of the alpine shrub Rhododendron aureum (Ericaceae). Mol Ecol 2006; 15:1165-73. [PMID: 16599975 DOI: 10.1111/j.1365-294x.2006.02853.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In alpine ecosystems, microscale variation in snowmelt timing often causes different flowering phenology of the same plant species and seasonal changes in pollinator activity. We compared the variations in insect visitation, pollen dispersal, mating patterns, and sexual reproduction of Rhododendron aureum early and late in the flowering season using five microsatellites. Insects visiting the flowers were rare early in the flowering season (mid-June), when major pollinators were bumblebee queens and flies. In contrast, frequent visitations by bumblebee workers were observed late in the season (late July). Two-generation analysis of pollen pool structure demonstrated that quality of pollen-mediated gene flow was more diverse late in the season in parallel with the high pollinator activity. The effective number of pollen donors per fruit (N(ep)) increased late in the season (N(ep) = 2.2-2.7 early, 3.4-4.4 late). However, both the outcrossing rate (t(m)) and seed-set ratio per fruit were smaller late in the season (t(m) = 0.89 and 0.71, seed-set ratio = 0.52 and 0.18, early and late in the season, respectively). In addition, biparental inbreeding occurred only late in the season. We conclude that R. aureum shows contrasting patterns of pollen movement and seed production between early and late season: in early season, seed production can be high but genetically less diverse and, during late season, be reduced, possibly due to higher inbreeding and inbreeding depression, but have greater genetic diversity. Thus, more pollinator activity does not always mean more pollen movement.
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Affiliation(s)
- A S Hirao
- Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, Japan.
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Kenta T, Isagi Y, Nakagawa M, Yamashita M, Nakashizuka T. Variation in pollen dispersal between years with different pollination conditions in a tropical emergent tree. Mol Ecol 2005; 13:3575-84. [PMID: 15488013 DOI: 10.1111/j.1365-294x.2004.02345.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We examined differences in pollen dispersal efficiency between 2 years in terms of both spatial dispersal range and genetic relatedness of pollen in a tropical emergent tree, Dipterocarpus tempehes. The species was pollinated by the giant honeybee (Apis dorsata) in a year of intensive community-level mass-flowering or general flowering (1996), but by several species of moths in a year of less-intensive general flowering (1998). We carried out paternity analysis based on six DNA microsatellite markers on a total of 277 mature trees forming four spatially distinct subpopulations in a 70 ha area, and 147 and 188 2-year-old seedlings originating from seeds produced in 1996 and 1998 (cohorts 96 and 98, respectively). Outcrossing rates (0.93 and 0.96 for cohorts 96 and 98, respectively) did not differ between years. Mean dispersal distances (222 and 192 m) were not significantly different between the 2 years but marginally more biased to long distance in 1996. The mean relatedness among cross-pollinated seedlings sharing the same mothers in cohort 96 was lower than that in cohort 98. This can be attributed to the two facts that the proportion of intersubpopulations pollen flow among cross-pollination events was marginally higher in cohort 96 (44%) than in cohort 98 (33%), and that mature trees within the same subpopulations are genetically more related to each other than those between different subpopulations. We conclude that D. tempehes maintained effective pollen dispersal in terms of outcrossing rate and pollen dispersal distance in spite of the large difference in foraging characteristics between two types of pollinators. In terms of pollen relatedness, however, a slight difference was suggested between years in the level of biparental inbreeding.
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Affiliation(s)
- T Kenta
- Center for Ecological Research, Kyoto University, Kamitanakami-Hirano, Ohtsu, 520-0113 Japan.
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Chaix G, Gerber S, Razafimaharo V, Vigneron P, Verhaegen D, Hamon S. Gene flow estimation with microsatellites in a Malagasy seed orchard of Eucalyptus grandis. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2003; 107:705-712. [PMID: 12750775 DOI: 10.1007/s00122-003-1294-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2002] [Accepted: 03/17/2003] [Indexed: 05/24/2023]
Abstract
Eucalyptus grandis has a mixed-mating reproductive system. Malagasy Eucalyptus seed orchards were established 15 years ago with two aims both based on panmixia: open-pollinated seed production and genetic improvement. The panmixia hypothesis has never been confirmed in the seed orchard. From a seedling seed-orchard stand comprising 349 trees and using data obtained with six selected microsatellite markers, paternity analysis was performed for 724 offspring collected on 30 adult trees. Paternity assignment, based on exclusion procedures and likelihood-ratio method, was achieved with high accuracy; the exclusion probability value was 0.997. The outcrossing rate was very high (96.7%). More than 50% of potential male trees (199 out of 349) in the seed orchard contributed to pollination for 440 offspring of 30 progenies (8.6% of the basic population). The pollination rate from outside the seed orchard was high (39.2%), but might be due to the small size of this seed orchard. This study showed that "panmixia-like pollination" can be assumed.
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Affiliation(s)
- G Chaix
- Cirad-Forêt/Fofifa, B.P. 745, Antananarivo 101, Madagascar.
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Kameyama Y, Isagi Y, Nakagoshi N. Relatedness structure in Rhododendron metternichii var. hondoense revealed by microsatellite analysis. Mol Ecol 2002; 11:519-27. [PMID: 11918786 DOI: 10.1046/j.1365-294x.2002.01447.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The relatedness structure of Rhododendron metternichii Sieb. et Zucc. var. hondoense Nakai was analysed in a 150 x 70-m quadrat in Hiroshima Prefecture, western Japan. The population of R. metternichii occurred as three subpopulations at the study site (A1-A3). Pairwise relatedness based on microsatellite genotypes at eight loci and Mantel tests revealed a hierarchical structure of relatedness within and among subpopulations: (i) relatedness between individuals within 10 m of one another was significantly positive; (ii) relatedness between individuals in the same subpopulation was significantly positive, but negative between individuals in distant subpopulations; and (iii) relatedness was not significantly different from zero among neighbouring subpopulations. In detail, however, relatedness within each subpopulation was significantly positive in subpopulation A1, relatively weak but significantly positive in subpopulation A2, and not significantly different from zero in subpopulation A3. Relatedness within each subpopulation was inversely related to correlations between interindividual distance and relatedness. The aggregation of related individuals at short distances from one another may lead to decreasing relatedness within subpopulations as a whole. Moreover, negative correlations between interindividual distance and relatedness corresponded to high flowering densities at less than 10-m distance, implying that high flowering densities reduce pollinator foraging distance and lead to stronger genetic structure within subpopulations. Small individuals (< 2.0 m in height) showed stronger genetic structure compared with that of large individuals (> or = 2.0 m in height). The different relatedness structure within and among subpopulations may be caused by various degrees of gene flow affected by distribution patterns of individuals and population density.
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Affiliation(s)
- Yoshiaki Kameyama
- Graduate School for International Development and Cooperation, Hiroshima University, Higashi-Hiroshima 739-8529, Japan
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Kameyama Y, Isagi Y, Nakagoshi N. Patterns and levels of gene flow in Rhododendron metternichii var. hondoense revealed by microsatellite analysis. Mol Ecol 2001; 10:205-16. [PMID: 11251799 DOI: 10.1046/j.1365-294x.2001.01181.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Parentage analysis was conducted to elucidate the patterns and levels of gene flow in Rhododendron metternichii Sieb. et Zucc. var. hondoense Nakai in a 150 x 70 m quadrant in Hiroshima Prefecture, western Japan. The population of R. metternichii occurred as three subpopulations at the study site. Seventy seedlings were randomly collected from each of three 10 x 10 m plots (S1, S2, and S3) on the forest floor of each subpopulation (A1, A2, and A3). Almost all parents (93.8%) of the 70 seedlings were unambiguously identified by using 12 pairs of microsatellite markers. Within the quadrant, adult trees less than 5 m from the centre of the seedling bank (plots S1, S2, and S3) produced large numbers of seedlings. The effects of tree height and distance from the seedling bank on the relative fertilities of adult trees were highly variable among subpopulations because of the differences in population structure near the seedling bank: neither distance nor tree height had any significant effect in subpopulation A1; distance from the seedling bank had a significant effect in subpopulation A2; and tree height had a significant effect in subpopulation A3. Although gene flow within each subpopulation was highly restricted to less than 25 m and gene flow among the three subpopulations was extremely small (0-2%), long-distance gene flow from outside the quadrant reached 50%. This long-distance gene flow may be caused by a combination of topographical and vegetational heterogeneity, differences in flowering phenology, and genetic substructuring within subpopulations.
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Affiliation(s)
- Y Kameyama
- Graduate School for International Development and Cooperation, Hiroshima University, Higashi-Hiroshima 739-8529, Japan.
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