Population Differentiation and Introgressive Hybridization of the Flannelmouth Sucker and of Hatchery and Native Stocks of the Razorback Sucker

Author(s):  
Donald G. Buth ◽  
Robert W. Murphy ◽  
Linda Ulmer
Author(s):  
Aparna . Veluru ◽  
Kanwar P. Singh ◽  
Namita . . ◽  
Sapna . Panwar ◽  
Gayacharan . . ◽  
...  

Roses are the most important commercial ornamental plants grown for flowers, perfumery and nutraceutical compounds. Commercially cultivated roses (Rosa × hybrida L.) are complex interspecific hybrids probably derived from 8-10 wild species among the large diversity of 130-200 species in genus Rosa. Wild germplasm is a primary source of variability and plays a major role in improving existing varieties by broadening their genetic base. In the present investigation, we have utilized the previously identified SSR primers for studying the diversity among 148 selected rose genotypes, including wild species and cultivated varieties of Indian and exotic origin. A total of 88 alleles was scored using 30 polymorphic loci; they produced average 2.9±1 alleles per locus. Polymorphism information content (PIC) values for different SSR loci ranged from 0.08 to 0.8 with a mean value of 0.5±0.2. The neighbor-joining tree generated based on Nei’s (1978) genetic distance values grouped the population into three major clusters. Cluster-I and II consists of all modern rose cultivars (Rosa × hybrida L.) originated from India and cluster-III consists of all exotic cultivars, wild species and a few cultivars from India. STRUCTURE analysis based on microsatellite allelic data, partitioned the total rose genotypes into four different sub-populations with some individual genotypes having genomic admixture. Population subdivision estimates, FST between different subpopulations ranged from 0.01-0.15 indicates low to moderate level of divergence existing among the rose cultivars and germplasm. Population differentiation in rose cultivars and wild species corresponds to their geographical origin and lineages. Analysis of molecular variance (AMOVA) results revealed that 83.12 % of the variance was accounted for by within sub-groups followed by significant levels of variation among the populations (10.42%) and least variance (6.46%) was noticed among individuals within groups.


2013 ◽  
Vol 18 (2) ◽  
pp. 275-282
Author(s):  
Xuechun YAN ◽  
Xiaofeng ZHANG ◽  
Cui LIU ◽  
Xiaowen SUN ◽  
Liqun LIANG ◽  
...  

Author(s):  
Boris A.E.S. Savassi ◽  
Gauthier Dobigny ◽  
Jonas R. Etougbétché ◽  
Thalasse T. Avocegan ◽  
François T. Quinsou ◽  
...  

AbstractCercarial emission of schistosomes is a determinant in the transmission to the definitive host and constitutes a good marker to identify which definitive host is responsible for transmission, mainly in introgressive hybridization situations. Our goal was to test the hypothesis that micro-mammals play a role in Schistosoma haematobium, S. bovis, and/or S. haematobium x S. bovis transmission. Small mammal sampling was conducted in seven semi-lacustrine villages of southern Benin. Among the 62 animals trapped, 50 individuals were investigated for Schistosoma adults and eggs: 37 Rattus rattus, 3 Rattus norvegicus, 9 Mastomys natalensis, and 1 Crocidura olivieri. Schistosoma adults were found in four R. rattus and two M. natalensis, with a local prevalence reaching 80% and 50%, respectively. Two cercarial chronotypes were found from Bulinus globosus experimentally infected with miracidia extracted from naturally infected M. natalensis: a late diurnal and nocturnal chronotype, and an early diurnal, late diurnal, and nocturnal chronotype. The cytochrome C oxidase subunit I mtDNA gene of the collected schistosomes (adults, miracidia, and cercariae) belonged to the S. bovis clade. Eleven internal transcribed spacer rDNA profiles were found; four belonged to S. bovis and seven to S. haematobium x S. bovis. These molecular results together with the observed multi-peak chronotypes add M. natalensis as a new host implicated in S. haematobium x S. bovis transmission. We discuss the origin of the new chronotypes which have become more complex with the appearance of several peaks in a 24-h day. We also discuss how the new populations of offspring may optimize intra-host ecological niche, host spectrum, and transmission time period.


2019 ◽  
Vol 97 ◽  
pp. 59-63
Author(s):  
Magdalena Świsłocka ◽  
Magdalena Czajkowska ◽  
Maciej Matosiuk ◽  
Alexander P. Saveljev ◽  
Mirosław Ratkiewicz ◽  
...  

Genetics ◽  
1998 ◽  
Vol 150 (4) ◽  
pp. 1605-1614
Author(s):  
Junyuan Wu ◽  
Konstantin V Krutovskii ◽  
Steven H Strauss

Abstract We examined mitochondrial DNA polymorphisms via the analysis of restriction fragment length polymorphisms in three closely related species of pines from western North America: knobcone (Pinus attenuata Lemm.), Monterey (P. radiata D. Don), and bishop (P. muricata D. Don). A total of 343 trees derived from 13 populations were analyzed using 13 homologous mitochondrial gene probes amplified from three species by polymerase chain reaction. Twenty-eight distinct mitochondrial DNA haplotypes were detected and no common haplotypes were found among the species. All three species showed limited variability within populations, but strong differentiation among populations. Based on haplotype frequencies, genetic diversity within populations (HS) averaged 0.22, and population differentiation (GST and θ) exceeded 0.78. Analysis of molecular variance also revealed that >90% of the variation resided among populations. For the purposes of genetic conservation and breeding programs, species and populations could be readily distinguished by unique haplotypes, often using the combination of only a few probes. Neighbor-joining phenograms, however, strongly disagreed with those based on allozymes, chloroplast DNA, and morphological traits. Thus, despite its diagnostic haplotypes, the genome appears to evolve via the rearrangement of multiple, convergent subgenomic domains.


2000 ◽  
Vol 23 (3) ◽  
pp. 541-544 ◽  
Author(s):  
José Alexandre Felizola Diniz-Filho ◽  
Mariana Pires de Campos Telles

In the present study, we used both simulations and real data set analyses to show that, under stochastic processes of population differentiation, the concepts of spatial heterogeneity and spatial pattern overlap. In these processes, the proportion of variation among and within a population (measured by G ST and 1 - G ST, respectively) is correlated with the slope and intercept of a Mantel's test relating genetic and geographic distances. Beyond the conceptual interest, the inspection of the relationship between population heterogeneity and spatial pattern can be used to test departures from stochasticity in the study of population differentiation.


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