scholarly journals Genomic data reveal similar genetic differentiation between species with vastly different dispersal capabilities and life histories

2016 ◽  
Author(s):  
Steve Jordan ◽  
Brian K. Hand ◽  
Scott Hotaling ◽  
Amanda DelVecchia ◽  
Rachel Malison ◽  
...  

AbstractLittle is known about the life histories, population connectivity, or dispersal mechanisms of shallow groundwater organisms. Here we used RAD-seq to analyze population structure in two aquifer species: Paraperla frontalis, a stonefly with groundwater larvae and aerial adults, and Stygobromus sp., a groundwater-obligate amphipod. We found similar levels of connectivity in each species between floodplains separated by ~70 river km in the Flathead River basin of NW Montana, USA. Given that Stygobromous lacks the aboveground life stage of P. frontalis, our findings suggest that aquifer-obligate species might have previously unrecognized dispersal capacity.

2019 ◽  
Vol 129 (2) ◽  
pp. 315-322
Author(s):  
Steve Jordan ◽  
Brian K Hand ◽  
Scott Hotaling ◽  
Amanda G Delvecchia ◽  
Rachel Malison ◽  
...  

Abstract Little is known about the life histories, genetic structure and population connectivity of shallow groundwater organisms. We used next-generation sequencing (RAD-seq) to analyse population genomic structure in two aquifer species: Paraperla frontalis (Banks, 1902), a stonefly with groundwater larvae and aerial (winged) adults; and Stygobromus sp., a groundwater-obligate amphipod. We found similar genetic differentiation in each species between floodplains separated by ~70 river km in the Flathead River basin of north-west Montana, USA. Given that Stygobromus lacks the above-ground life stage of P. frontalis, our findings suggest that connectivity and the magnitude of genetic structure cannot be definitively assumed from life history differences.


BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances (Missouri, Iowa, Washington, Louisiana, and Tennessee (USA), and Quebec in Canada) of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) per locus ranged from 0.070 to 0.905, and the average polymorphic information content (PIC) was 0.535. The provenance ‘Was’ had a relatively low genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon’s information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931, respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, individuals distributed in the Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a small gene flow and high degree of genetic differentiation compared with the other provenances, and was classified into one group. There was a significant relationship between genetic distance and geographical distance. Conclusions P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals. Individuals reflecting population genetic information can be selected to build a core germplasm bank. Meanwhile, the results could provide theoretical support for the scientific management and efficient utilization of P. deltoides genetic resources, and promote the development of molecular marker-assisted breeding of poplar.


Author(s):  
Bradley B. Shepard ◽  
Patrick J. Graham ◽  
Karen L. Pratt ◽  
◽  

2019 ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background: Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results: In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) ranged from 0.070 to 0.905, and the average locus polymorphic information content (PIC) was 0.5354. The provenance ‘Was’ had the lowest genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon's information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931 respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, clones distributed in Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a smaller gene flow and higher degree of genetic differentiation compared with the other provenances, and was classified into one group. There was no significant relationship between genetic distance and geographical distance. Conclusions: P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals; however, the genetic variation among provenances has no clear correlation with their geographical locations. Clones reflecting population genetic information can be selected to build a core resource bank, which could provide effective protection and promote the scientific utilization of the P. deltoids resource, laying a solid foundation for poplar breeding.


2019 ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background: Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results: In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) ranged from 0.070 to 0.905, and the average locus polymorphic information content (PIC) was 0.5354. The provenance ‘Was’ had the lowest genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon's information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931 respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, clones distributed in Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a smaller gene flow and higher degree of genetic differentiation compared with the other provenances, and was classified into one group. There was no significant relationship between genetic distance and geographical distance. Conclusions: P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals; however, the genetic variation among provenances has no clear correlation with their geographical locations. Clones reflecting population genetic information can be selected to build a core resource bank, which could provide effective protection and promote the scientific utilization of the P. deltoids resource, laying a solid foundation for poplar breeding.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jon Ahlinder ◽  
Barbara E. Giles ◽  
M. Rosario García-Gil

AbstractInbreeding depression (ID) is a fundamental selective pressure that shapes mating systems and population genetic structures in plants. Although it has been shown that ID varies over the life stages of shorter-lived plants, less is known about how the fitness effects of inbreeding vary across life stages in long-lived species. We conducted a literature survey in the Pinaceae, a tree family known to harbour some of the highest mutational loads ever reported. Using a meta-regression model, we investigated distributions of inbreeding depression over life stages, adjusting for effects of inbreeding levels and the genetic differentiation of populations within species. The final dataset contained 147 estimates of ID across life stages from 41 studies. 44 Fst estimates were collected from 40 peer-reviewed studies for the 18 species to aid genetic differentiation modelling. Partitioning species into fragmented and well-connected groups using Fst resulted in the best way (i.e. trade-off between high goodness-of-fit of the model to the data and reduced model complexity) to incorporate genetic connectivity in the meta-regression analysis. Inclusion of a life stage term and its interaction with the inbreeding coefficient (F) dramatically increased model precision. We observed that the correlation between ID and F was significant at the earliest life stage. Although partitioning of species populations into fragmented and well-connected groups explained little of the between-study heterogeneity, the inclusion of an interaction between life stage and population differentiation revealed that populations with fragmented distributions suffered lower inbreeding depression at early embryonic stages than species with well-connected populations. There was no evidence for increased ID in late life stages in well-connected populations, although ID tended to increase across life stages in the fragmented group. These findings suggest that life stage data should be included in inbreeding depression studies and that inbreeding needs to be managed over life stages in commercial populations of long-lived plants.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
José David Rangel-Medrano ◽  
Edna Judith Márquez

ABSTRACT The Neotropical freshwater catfish Pseudopimelodus atricaudus and Pseudopimelodus magnus are two recently discovered species endemic to the Colombian Magdalena-Cauca River basin. In this study, a set of 13 microsatellite loci were developed by using next generation sequence technology to assess the genetic diversity and population structure in P. atricaudus and test for cross-species amplification in P. magnus. Both species exhibited high genetic diversity (P. atricaudus: Na: 9.000 - 9.769 alleles/locus, Ho: 0.760 - 0.804, HE: 0.804 - 0.840; P. magnus: Na: 12.8 - 5.4 alleles/locus, Ho: 0.638 - 0.683, HE: 0.747 - 0.755) compared to the mean levels of genetic diversity reported for Neotropical Siluriformes, and lack of genetic differentiation among sampling sites within the Cauca River (P. atricaudus: F’ST=0.013 - 0.017, P > 0.05, D’est= -0.004 - 0.023, P > 0.05; P. magnus: F’ST= 0.031, P= 0.055; D’est= 0.045, P= 0.058). This work is the first insight on the diversity and the population genetics of species of the family Pseudopimelodidae and provides a framework to further population genetic and conservation analyses needed in this poorly studied family at the microevolutionary level.


2019 ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background: Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results: In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances (Missouri, Iowa, Washington, Louisiana, and Tennessee (USA), and Quebec in Canada) of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) per locus ranged from 0.070 to 0.905, and the average polymorphic information content (PIC) was 0.535. The provenance ‘Was’ had a relatively low genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon's information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931, respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, individuals distributed in the Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a small gene flow and high degree of genetic differentiation compared with the other provenances, and was classified into one group. There was a significant relationship between genetic distance and geographical distance. Conclusions: P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals. Individuals reflecting population genetic information can be selected to build a core germplasm bank. Meanwhile, the results could provide theoretical support for the scientific management and efficient utilization of P. deltoides genetic resources, and promote the development of molecular marker-assisted breeding of poplar.


2021 ◽  
pp. 126774
Author(s):  
Jia Xu ◽  
Hongbo Ling ◽  
Guangpeng Zhang ◽  
Junjie Yan ◽  
Mingjiang Deng ◽  
...  

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