PDF | Agave cupreata Trel. & Berger is an endemic plant naturally distributed in the Balsas Depression, a semiarid region in the states of Guerrero and. Agave Species, Dwarf Cowhorn, Century Plant, Maguey. Agave cupreata. Agave cupreata by palmbob · Thumbnail #2 of Agave cupreata by palmbob. Agave cupreata Trel. & Berger is an endemic plant naturally distributed in the Balsas Depression, a semiarid region in the states of Guerrero and Michoacán in .
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Genetic diversity of Agave cupreata Trel. Considerations for its conservation. Their populations are heavily decimated because mature individuals just before their single life flowering period are harvested to produce mescal, an alcoholic beverage. The genetic variation among and within 12 natural populations was examined for nine isozyme loci. To protect the natural genetic variation, it is suggested to design and manage A.
Commercial plantations and ex situ FGRCUs need to be established to gradually develop a sustainable management, perhaps at higher altitudes than current locations, as a management measure for adaptation to the climatic change.
Agavaceae, population genetics, minimum viable effective population size. Harvesting prevents the species reproduction because A. The effect of harvesting in the population demography is aggravated because plants need between 7 and 15 years to reach their sexual maturity Illsley et al. There are a few examples of well organized Indian communities to conduct some management of the A. Although such actions are an encouraging start, a more sophisticated management program is required which should combine a sustainable harvesting with a biological conservation program to protect the genetic variation of A.
For reaching this goal, the patterning of genetic variation of natural populations needs to be determined. In general, high levels of expected heterozygosity H e were observed, and high genetic differentiation among populations F ST agwve G ST in one case, and medium to low in most cases, has been documented: However, to our present knowledge there are no previously published studies of the genetic variability of A.
The objectives of the present study are: Studied populations and material collection. The groups of individual plants represented by the samples are termed populations while the location where a aave was collected is called provenance. Starch gel electrophoresis and staining protocols were conducted following standard methods Conkle et al. Sections of fresh, young leaves were crushed into 0.
The extracts were adsorbed in Whatman No. Two systems of electrode and gel buffers, cuperata seven enzymes with good resolution were used.
A total of 9 loci were analyzed. System LiOH 8 Soltis et al.
System C Stuber et al. Gels were electrophoresed at 60 mA for 7 to 8 h. Enzymatic systems with more than one locus were numbered according to their mobility relative to the alleles of standard individuals present in all gels and systems. Allelic variants were numbered sequentially from anode to cathode.
The numbers of loci and alleles genetically controlling the enzyme activity were inferred from the observed banding patterns and from data on quaternary structure Wendel and Weeden, However, since we included Gdhl, Pgml and Pgm2, our final number of examined agaave 9 was not much different than that used by A. A Mantel test Manly, was performed between genetic and geographic distances.
Minimum viable effective population size N e was estimated based on the average H e using the linear model fitted cupraeta regressing N e values against H e values, as used by Millar and Libby in several conifer species. This result should be taken with caution because we used only 9 loci; there is a possibility that by examining a larger number of loci agzve estimated heterozygosity could be lower, if by chance our sample could be biassed.
Such differentiation is lower than the values reported for other Agave species: The UPGMA dendrogram does not follow a geographic pattern since geographically distant populations clustered together for example: Despite the heavy exploitation pressure to which A. This can be related to the mating cuprezta of A.
Agave Species, Dwarf Cowhorn, Century Plant, Maguey
Thus, this outcrossing system apparently plays a relevant role to prevent the accumulation of inbreeding, even when the population sizes are reduced. This value is very large, as a result of the very large average heterozygosity value. In general, for conservation of genetic variability the suggested N e sizes range between Franklin, ; Frankham et al. In our case it would be more realistic to use much more modest N e sizes than the estimated value 16considering that natural populations of A.
Thus, in order to designate A.
A sustainable management program of A. In parallel, it would be needed to protect natural populations and to establish additional ones to be managed as forest genetic resource conservation units FGRCUs. Provided that the estimated minimum viable effective population agavw N e for such FGRCUs is larger than the actual largest natural populations, it would be required to establish plantations between large natural populations, to serve as corridors for pollinators, in order to maintain the genetic flow among populations and also for increasing N ecounterbalancing in that way the loss of individuals that could have cureata due to past harvesting.
On this regard, although the recent establishment of commercial plantations of A. The predicted decoupling between genotypes and climate due to factual climatic change could be diminished if new commercial plantations are established at altitudes higher than those of present populations, in order to match genotypes fitness to predicted future climates.
There is not significant isolation by distance. Three anonymous reviewers contributed to significantly improve the manuscript.
En lo Ancestral hay Futuro: Pacific Southwest Forest and Range xperiment Station. United States Forest Service.
Research on Forest Climate Change: Franklin I R Evolutionary change in small populations. Haldane J B S An exact test for randomness of mating. Lande R Mutation and conservation. Ledig F T The conservation of diversity in forest trees.
Why and how should genes be conserved? Millar C I, W J Libby Strategies for conserving clinal, ecotypic, and disjunct population diversity in widespread species. Genetics and Conservation of Rare Plants. A windows program for the analysis of allozyme and molecular population genetic data. Computer software distributed by author. Sgave M The theory of genetic distance and evolution of human races.
Pitel JA,WM Cheliak Effect of extraction buffers on characterization of isoenzymes from vegetative tissues of five conifers species: Chalk River, Ontario, Canada.
Agave cupreata – Wikipedia
Floral characteristics, visitors and fecundity. Genetic variation, differentiation and inbreeding estimates. The Iowa State University Press. Cuprwata Carolina State University.
Isozymes in Plant Biology. Franco from British Columbia. Genetic variation patterns in coastal populations. Informe final de proyecto. First International Conference on Sustainable Cities. Abstract Agave cupreata Trel. Isozyme electrophoresis Starch gel electrophoresis and staining protocols were conducted following standard methods Conkle et al.
Considerations for conservation A sustainable management program of A.