High genetic diversity in the only known population of Aechmea tuitensis (Bromeliaceae)

2000 ◽  
Vol 48 (5) ◽  
pp. 645 ◽  
Author(s):  
Liz Y. Izquierdo ◽  
Daniel Piñero

Aechmea tuitensis (P. Magaña and E. Lott) is a narrow endemic species from Mexico. Only one population has been reported. We studied the genetic variation and structure, and clonal diversity of this rare bromeliad by using starch gel electrophoresis. Six enzyme systems encoded by nine gene loci were resolved in nine subpopulations. The percentage of polymorphic loci was high (77.8%). Mean expected heterozygosity for the population was 0.12. All loci except CPX-1 were in Hardy–Weinberg equilibrium. Genetic diversity was substantially larger within subpopulations (mean Fis = 0.631) than between them (Fst = 0.196). We detected 33 genetically distinguishable clones from 109 plants (ramets) sampled. One clone had a frequency of 32.1%, others showed frequencies ranging from 1.8 to 9.2%, and 19% of the total samples were unique multilocus genotypes. Aechmea tuitensis exhibits high genetic diversity even though it has an extremely narrow distribution. Our results also suggest that the effect of genetic drift on genetic structure in A. tuitensis might be counteracted by the influence of vegetative reproduction.

1977 ◽  
Vol 7 (2) ◽  
pp. 343-347 ◽  
Author(s):  
D. P. Fowler ◽  
R. W. Morris

Starch gel electrophoresis was used to survey for genetically determined enzyme mobility differences among 297 megagametophytes of red pine (Pinusresinosa Ait.) from five widely separated geographical sources. Consistent and reproducible enzyme banding patterns were observed with five of the seven isozyme systems assayed. No variation in band mobility was observed in any of these systems. This result stands in contrast with those reported from surveys of allozyme variation in other coniferous species but is consistent with the low degree of genetic variation observed in red pine for higher levels of genetic organization. It is concluded that red pine is genetically depauperate.Possible explanations for restricted genetic diversity are discussed. The most plausible explanation suggests that red pine was at sometime, possibly during the Pleistocene, reduced to a small refugial population and has yet to reestablish equilibrium heterozygosity.


2019 ◽  
Vol 85 ◽  
pp. 81
Author(s):  
Fabiola Magallán Hernández ◽  
Mahinda Martínez ◽  
Luis Hernández Sandoval ◽  
Ken Oyama

<em>Eriocaulon bilobatum</em> is an aquatic species that inhabits temporary wetlands in central Mexico. It is annual, herbaceous, emergent, with sexual and asexual reproduction, monoecious and insect pollinated. It is a rare and vulnerable species due to its endangered habitats. The objectives of this study were to determine the diversity and genetic structure of <em>E. bilobatum </em> and to know if there is a correlation with genetic diversity and its ecological and life history traits. Using horizontal starch-gel electrophoresis, we screened 160 individuals from four populations. <em>E. bilobatum</em> has a higher genetic diversity (A=2.32, Ae=1.31, P=69.65, Ho=0.134, He=0.197, HT=0.221) than species with similar ecological and life history traits, moderate levels of inbreeding (FIS = 0.312) and low genetic differentiation among populations (FST = 0.053 y GST = 0.048). Its diversity and genetic structure are determined by the mating system and life history traits, more than by inhabiting aquatic environments.


2003 ◽  
Vol 1 (2-3) ◽  
pp. 143-149 ◽  
Author(s):  
Agnese Kolodinska Brantestam ◽  
Roland von Bothmer ◽  
Isaak Rashal ◽  
Jens Weibull

AbstractIn this study an evaluation was made of changes in the genetic variation of barley (Hordeum vulgare L.) of Nordic and Baltic origin, from the end of the 19th century until today. A comparison of Nordic and Baltic material with exotic material that has not been subjected to intense selection was also made. A total of 293 accessions, including 160 Nordic and 80 Baltic landraces, cultivars and breeding lines, and another 53 landraces of exotic origin (Central Asia), were surveyed using isozyme starch gel electrophoresis. For the four isozymes studied, 28 alleles at 11 loci were observed. The average total genetic diversity value (HT) for individual loci ranged between 0 and 0.519. In the exotic material nine loci were polymorphic and two monomorphic, compared to seven polymorphic and four monomorphic loci in the Nordic and Baltic material. Some of the rare alleles were detected only in the exotic material. The studied isozyme loci of Nordic and Baltic material indicated that modern cultivars have a lower average genetic diversity value compared to the landraces, old and exotic material.


1988 ◽  
Vol 39 (3) ◽  
pp. 317 ◽  
Author(s):  
J Salini ◽  
JB Shaklee

Barramundi, L. calcarifer, were collected from seven localities in the Northern Territory, the Daly, Finniss, Mary, Glyde, Roper and McArthur rivers and Blue Mud Bay, and from the Ord River in Western Australia. Barramundi were sampled seven times from the Daly and Finniss rivers over a 14-month period. In total, 46 loci were identified using starch-gel electrophoresis of enzymes and polyacrylamide electrophoresis of muscle proteins. Twelve loci were polymorphic at the P0.99 level. Most loci were in Hardy-Weinberg equilibrium. A contingency Χ2 analysis for homogeneity of alleles over all loci and all localities was highly significant (P < 0.001). Comparisons of data from adjacent pairs of localities revealed that the overall heterogeneity was attributable to heterogeneity among seven of the eight localities; the Daly and Finniss river areas were not significantly different from one another. No evidence of heterogeneity over time was found among the collections from the Daly River area. The considerable amount of heterogeneity observed suggests that each of these seven localities supports a genetically discrete stock of barramundi; this conclusion is consistent with the documented life history of Australian barramundi. The genetic heterogeneity of the stocks should be considered when management policies for L. calcarifer are being formulated.


2014 ◽  
Vol 70 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Andrzej Lewandowski ◽  
Maciej Filipiak ◽  
Jarosław Burczyk

The genetic structure of silver fir (<em>Abies alba</em> Mill.) was investigated among 8 populations from Sudety Mts. and 2 additional populations from other parts of Poland. Nine enzyme systems controlled by 13 allozyme loci were analyzed using starch gel electrophoresis. The mean expected heterozygosity, ranging from 0.06 to 0.11 and was lower compared to that found in other conifers. The mean genetic distance among all silver fir populations was 0.005. The Sudeten group of populations appeared to be genetically different from the two populations from other parts of Poland, indicating that at least two different centers are responsible for the current distribution of allozyme polymorphism in the tested populations.


Genetics ◽  
1973 ◽  
Vol 74 (3) ◽  
pp. 489-508
Author(s):  
Esko Suomalainen ◽  
Anssi Saura

ABSTRACT The genetic variability at enzyme loci in different triploid and tetraploid parthenogenetic weevil populations has been elucidated by starch gel electrophoresis. The overall genotype of individual weevils belonging to different populations has been determined for over 25 loci. The results are compared with those obtained for diploid bisexual races of either the same or closely related species. The variation within a parthenogenetic population differs from that in diploid, sexually reproducing populations, i.e. the allele frequencies are not in a Hardy-Weinberg equilibrium. The results indicate that apomictic parthenogenetic populations can differentiate genetically. The genotypes within a population resemble each other more than genotypes belonging to different populations. It is evident that evolution still continues-even if slowed down—in parthenogenetic weevils. A comparison between the allele relationships in geographically isolated polyploid parthenogenetic populations and related diploid bisexual forms does not support the hypothetical hybrid origin of parthenogenesis and polyploidy in weevils. Parthenogenesis within a parthenogenetic weevil species is evidently monophyletic.


1964 ◽  
Vol 12 (01) ◽  
pp. 126-136 ◽  
Author(s):  
Karl H. Slotta ◽  
J. D Gonzalez

SummaryWhen urea or ε-amino caproic acid were used as solublizing agents for plasminogen in electrophoretic experiments, only one broad band of the proenzyme was obtained on acetate cellulose, in starch block, and in acrylamide gel. In starch gel electrophoresis, however, both forms of plasminogen – the native or euglobulin and Kline’s or Pseudoglobulin plasminogen – separated into six bands. These migrated toward the cathode at room temperature in borate or veronal buffer in the alkaline range and showed full activity in fibrinagar-streptokinase plates.


Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 595-603
Author(s):  
D Borden ◽  
E T Miller ◽  
D L Nanney ◽  
G S Whitt

ABSTRACT The isozymic patterns of tyrosine aminotransferase, NADP malate dehydrogenase, NADP isocitrate dehydrogenase, and tetrazolium oxidase were examined by starch-gel electrophoresis in Tetrahymena pyriformis, syngen 1. The genetics of the alleles controlling these enzymes was studied through a breeding program. Each enzyme locus was shown to assort vegetatively, as do other loci in this organism. A detailed analysis of the assortment process for the tyrosine aminotransferase locus indicated that the rate of stabilization of heterozygotes into pure types was essentially identical to previously-reported rates for other loci.


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