scholarly journals The Analysis of Czech Genetic Resources of Nutrias (Myocastor coypus)

2018 ◽  
Vol 49 (2) ◽  
pp. 93-97
Author(s):  
T. Němeček ◽  
E. Tůmová
Keyword(s):  
Genetic Resources ◽  
Population Size ◽  
Effective Population Size ◽  
Litter Size ◽  
Biodiversity Loss ◽  
Effective Population ◽  
Myocastor Coypus ◽  
Colour Type

Abstract The aim of this study is to evaluate the effective population size and fertility in the Czech Genetic Resources of nutrias during the last ten years. This study includes three Czech colour types of nutrias: Czech Type of Standard (ST), Moravian Silver (MS), and Prestice Multicolour (PM). The effective population size of ST shows that this colour type is endangered, while MS and PM are critical. The average number of pregnancy was the highest (P ≤ 0.004) in ST (1.7 pregnancy) and the lowest in PM (1.3 pregnancy). ST and MS nutrias had the significantly biggest litter size (P ≤ 0.004). For the number of kits born per female in a year (P < 0.001) the significantly lowest value was in PM (5.1 kits). For weaned kits the highest value (P ≤ 0.006) was in ST (4.8 kits). The results showed that the population size of MS and PM is low and there is a risk of biodiversity loss in these colour types.

scholarly journals Low effective population size and high spatial genetic structure of black poplar populations from the Oder valley in Poland

2021 ◽  
Vol 78 (2) ◽  
Author(s):  
Błażej Wójkiewicz ◽  
Andrzewj Lewandowski ◽  
Weronika B. Żukowska ◽  
Monika Litkowiec ◽  
Witold Wachowiak
Keyword(s):  
Genetic Structure ◽  
Genetic Resources ◽  
Population Size ◽  
Effective Population Size ◽  
Spatial Genetic Structure ◽  
Demographic History ◽  
River Valley ◽  
Ex Situ ◽  
Effective Population ◽  
Black Poplar

Abstract Context Black poplar (Populus nigra L.) is a keystone species of European riparian ecosystems that has been negatively impacted by riverside urbanization for centuries. Consequently, it has become an endangered tree species in many European countries. The establishment of a suitable rescue plan of the remaining black poplar forest stands requires a preliminary knowledge about the distribution of genetic variation among species populations. However, for some parts of the P. nigra distribution in Europe, the genetic resources and demographic history remain poorly recognized. Aims Here, we present the first study on identifying and characterizing the genetic resources of black poplar from the Oder valley in Poland. This study (1) assessed the genetic variability and effective population size of populations and (2) examined whether gene flow is limited by distance or there is a single migrant pool along the studied river system. Methods A total of 582 poplar trees derived from nine black poplar populations were investigated with nuclear microsatellite markers. Results (1) The allelic richness and heterozygosity level were high and comparable between populations. (2) The genetic structure of the studied poplar stands was not homogenous. (3) The signatures of past bottlenecks were detected. Conclusion Our study (1) provides evidence for genetic substructuring of natural black poplar populations from the studied river catchment, which is not a frequent phenomenon reported for this species in Europe, and (2) indicates which poplar stands may serve as new genetic conservation units (GCUs) of this species in Europe. Key message The genetic resources of black poplar in the Oder River valley are still substantial compared to those reported for rivers in Western Europe. On the other hand, clear signals of isolation by distance and genetic erosion reflected in small effective population sizes and high spatial genetic structure of the analyzed populations were detected. Based on these findings, we recommend the in situ and ex situ conservation strategies for conserving and restoring the genetic resources of black poplar populations in this strongly transformed by human river valley ecosystem.

scholarly journals Conservation Assessment of the State Goat Farms by Using SNP Genotyping Data

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Rabiul Islam ◽  
Zhangfa Liu ◽  
Yefang Li ◽  
Lin Jiang ◽  
Yuehui Ma
Keyword(s):  
Genetic Resources ◽  
Population Size ◽  
Effective Population Size ◽  
Management Practices ◽  
Genetic Erosion ◽  
The State ◽  
Genomic Relationship ◽  
Effective Population ◽  
Conservation Assessment ◽  
Goat Farm

Conservation of genetic resources is of great concern globally to maintain genetic diversity for sustainable food security. Comprehensive identification of the breed composition, estimation of inbreeding and effective population size are essential for the effective management of farm animal genetic resources and to prevent the animals from genetic erosion. The Zhongwei male (ZWM), Arbas Cashmere male (ACM) and Jining Grey male (JGM) goats are conserved in three different state goat farms in China but their family information, level of inbreeding and effective population size are unknown. We investigated the genomic relationship, inbreeding coefficient and effective population size in these three breeds from three state goat farms using the Illumina goat SNP50 BeadChip. Genomic relationships and phylogenetic analysis revealed that the breeds are clearly separated and formed separate clusters based on their genetic relationship. We obtained a high proportion of informative SNPs, ranging from 91.8% in the Arbas Cashmere male to 96.2% in the Jining Grey male goat breeds with an average mean of 96.8%. Inbreeding, as measured by FROH, ranged from 1.79% in ZWM to 8.62% in ACM goat populations. High FROH values, elevated genomic coverage of very long ROH (>30 Mb) and severe decline in effective population size were recorded in ACM goat farm. The existence of a high correlation between FHOM and FROH indicates that FROH can be used as an alternative to inbreeding estimates in the absence of pedigree records. The Ne estimates 13 generations ago were 166, 69 and 79 for ZWM, ACM and JGM goat farm, respectively indicating that these goat breeds were strongly affected by selection pressure or genetic drift. This study provides insight into the genomic relationship, levels of inbreeding and effective population size in the studied goat populations conserved in the state goat farms which will be valuable in prioritizing populations for conservation and for developing suitable management practices for further genetic improvement of these Chinese male goats.

scholarly journals EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON CORRELATED RESPONSES TO SELECTION FOR POSTWEANING GAIN IN MICE

Genetics ◽  
1973 ◽  
Vol 74 (1) ◽  
pp. 157-170
Author(s):  
E J Eisen ◽  
J P Hanrahan ◽  
J E Legates
Keyword(s):  
Body Weight ◽  
Population Size ◽  
Effective Population Size ◽  
Litter Size ◽  
The Body ◽  
Selection Intensity ◽  
Correlated Responses ◽  
Effective Population ◽  
Population Sizes ◽  
Selection For

ABSTRACT Correlated responses to selection for postweaning gain in mice were studied to determine the influence of population size and selection intensity. Correlated traits measured were three-, six- and eight-week body weights, litter size, twelve-day litter weight, proportion infertile matings and two indexes of reproductive performance. In general, the results agreed with observations made on direct response: correlated responses in the body weight traits and litter size increased as (1) selection intensity increased and (2) effective population size increased. Correlated responses in the body weight traits and litter size were positive in the large population size lines (16 pairs), as expected from the positive genetic correlation between these traits and postweaning gain. However, several negative correlated responses were observed at small population sizes (one and two pairs). Within each level of selection intensity, traits generally associated with fitness tended to decline most in the very small populations (one and two pairs) and in the large populations (16 pairs) for apparently different reasons. The fitness decline at the small effective population sizes was attributable to inbreeding depression. In contrast, it was postulated that the fitness decline at the large effective population size was due to selection moving the population mean for body weight and a trait positively correlated genetically with body weight (i.e., percent body fat) away from an optimum

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