02634nas a2200277   4500008004100000245014400041210006900185490001300254520174100267653004302008653001202051653001502063653001002078653001902088653002002107653001102127653002402138100001602162700001602178700001302194700001702207700001802224700001802242700001802260856007802278       2011                        eng d00aGenomic and resistance gene homolog diversity of the dominant tallgrass prairie species across the U.S. Great Plains precipitation gradient0 aGenomic and resistance gene homolog diversity of the dominant ta0 v6:e176413 a<p>Background Environmental variables such as moisture availability are often important in determining species prevalence and intraspecific diversity. The population genetic structure of dominant plant species in response to a cline of these variables has rarely been addressed. We evaluated the spatial genetic structure and diversity of Andropogon gerardii populations across the U.S. Great Plains precipitation gradient, ranging from approximately 48 cm/year to 105 cm/year. Methodology/Principal Findings Genomic diversity was evaluated with AFLP markers and diversity of a disease resistance gene homolog was evaluated by PCR-amplification and digestion with restriction enzymes. We determined the degree of spatial genetic structure using Mantel tests. Genomic and resistance gene homolog diversity were evaluated across prairies using Shannon&#39;s index and by averaging haplotype dissimilarity. Trends in diversity across prairies were determined using linear regression of diversity on average precipitation for each prairie. We identified significant spatial genetic structure, with genomic similarity decreasing as a function of distance between samples. However, our data indicated that genome-wide diversity did not vary consistently across the precipitation gradient. In contrast, we found that disease resistance gene homolog diversity was positively correlated with precipitation. Significance Prairie remnants differ in the genetic resources they maintain. Selection and evolution in this disease resistance homolog is environmentally dependent. Overall, we found that, though this environmental gradient may not predict genomic diversity, individual traits such as disease resistance genes may vary significantly.</p>10aAmplified fragment length polymorphism10aCloning10aHexaploidy10aMaize10aPlant genomics10aPlant pathology10aPloidy10aPopulation genetics1 aRouse, M.N.1 aSaleh, A.A.1 aSeck, A.1 aKeeler, K.H.1 aTravers, S.E.1 aHulbert, S.H.1 aGarrett, K.A.  uhttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.001764101067nas a2200145   4500008004100000245008500041210006900126300001300195490000800208520054500216100001700761700001900778700001700797856010700814       2002                        eng d00aClone size of Andropogon gerardii Vitman (Big Bluestem) at Konza Prairie, Kansas0 aClone size of Andropogon gerardii Vitman Big Bluestem at Konza P  a295 -3040 v1473 aClone size of plants of Andropogon gerardii from Konza Prairie Biological Station, Manhattan, Kansas was estimated from spatial patterns of genetic variation, using proteins detected by starch gel electrophoresis and DNA content (ploidy) measured by flow cytometry. Unique multi-locus protein banding patterns and differences in ploidy were used to exclude plants as members of the same clone. Individual clones averaged about 2 m in diameter and areas of prairie of 100 m2 were calculated to contain an average of 31.8 genetic individuals.1 aKeeler, K.H.1 aWilliams, C.F.1 aVescio, L.S.  uhttp://knz.lternet.edu/content/clone-size-andropogon-gerardii-vitman-big-bluestem-konza-prairie-kansas00473nas a2200121   4500008004100000245008300041210006900124300001300193490000700206100001700213700001600230856010500246       1999                        eng d00aComparison of common cytotypes of Andropogon gerardii (Andropoganeae, Poaceae)0 aComparison of common cytotypes of Andropogon gerardii Andropogan  a974 -9790 v861 aKeeler, K.H.1 aDavis, G.A.  uhttp://knz.lternet.edu/content/comparison-common-cytotypes-andropogon-gerardii-andropoganeae-poaceae01148nas a2200145   4500008004100000245015900041210006900200300001300269490000700282520061100289100001900900700001700919700001700936856004900953       1997                        eng d00aEvolutionary implications of meiotic chromosome behavior, reproductive biology, and hybridization in 6X and 9X cytotypes of Andropogon gerardii (Poaceae )0 aEvolutionary implications of meiotic chromosome behavior reprodu  a201 -2070 v843 aAndropogon gerardii, big bluestem, has 60 and 90 chromosome cytotypes. Meiosis in the hexaploid was shown to be regular, although some secondary associations of bivalents form. Meiosis in the enneaploid (2n = 9z = 90) is irregular, leading to most gametes having unbalanced chromosome complements. Both cytotypes show considerable self-incompatibility. Cytotypes crossed freely, forming a variety of fertile euploids and aneuploids. Indistinguishable exomorphology, intermixing in natural populations, and compatibility suggest that A. gerardii is best understood as a cytotypically complex single species.1 aNorrmann, G.A.1 aQuarin, C.L.1 aKeeler, K.H.  uhttp://www.amjbot.org/content/84/2/201.short00412nas a2200145   4500008004100000245002500041210002500066260003600091300001100127100001900138700001700157700001900174700001700193856005600210       1995                        eng d00aPopulation Processes0 aPopulation Processes  aOxfordbOxford University Press  a82 -991 aHartnett, D.C.1 aKeeler, K.H.1 aJoern, Anthony1 aKeeler, K.K.  uhttp://knz.lternet.edu/content/population-processes00439nas a2200109   4500008004100000245007800041210006900119300001500188490000700203100001700210856010200227       1992                        eng d00aLocal polyploid variation in the native prairie grass Andropogon gerardii0 aLocal polyploid variation in the native prairie grass Andropogon  a1229 -12320 v791 aKeeler, K.H.  uhttp://knz.lternet.edu/content/local-polyploid-variation-native-prairie-grass-andropogon-gerardii00540nas a2200121   4500008004100000245012400041210006900165300001200234490000700246653002200253100001700275856012600292       1990                        eng d00aDistribution of polyploid variation in big bluestem (Andropogon gerardii , Poaceae) across the tallgrass prairie region0 aDistribution of polyploid variation in big bluestem Andropogon g  a95 -1000 v3310atallgrass prairie1 aKeeler, K.H.  uhttp://knz.lternet.edu/content/distribution-polyploid-variation-big-bluestem-andropogon-gerardii-poaceae-across-tallgrass02292nas a2200145   4500008004100000245008300041210006900124260004600193520173200239100001701971700001601988700001602004700002102020856010502041       1989                        eng d00aPolyploid polymorphism in the prairie grass big bluestem (Andropogon gerardii)0 aPolyploid polymorphism in the prairie grass big bluestem Andropo  aLincoln, NEbUniversity of Nebraska Press3 a<p>A suprising number of plant species contain individuals of a variety of levels of polyploidy, so that the species is polymorphic for polyploidy. This paper considers possible general causes for this phenomenon in plants of the Great Plains of North America. First we compared the frequency of intraspecific polyploidy in three major plant families, Poaceae, Asteraceae, and Fabaceae. The majority of grass species (Poaceae) and the minority of composite and legume species (Asteraceae and Fabaceae) are polyploid polymorphic. The frequency of grass species with intraspecific polyploidy suggests shared causatin or at least shared tolerance of this character. Having established that the situation occurs frequently in grasses, we analyzed a single species, big bluestem, Andropogon gerardii, looking for information on the function of polyploid polymorphism. We used flow cytometry to determine amount of nuclear DNA per cell; In big bluestem this correlates with chromosome number. Individuals with 7 pg nuclear DNA had 2N=60 chromosomes, and were therefore hexaploid, since in Andropogon x=10. Most other individuals had approximately 10 pg nuclear DNA and 80 (occasionally 90) chromosomes. Seven-pg DNA individuals were predominatnt everywhere, but the frequency of higher polyploids (10 pg nuclear DNA) went from virtually 0 on the eastern end of the tallgrass prairie region to 40% at the western end. Within native prairies in the west, the full range of variation existed between sites. A recent origin for polyploid polymorphism is suggested in big bluestem and probably other Great Plains grasses, and the data seem most compatible with a transitional situation, although other explanations cannot be ruled out</p>1 aKeeler, K.H.1 aKwankin, B.1 aBragg, T.B.1 aStubbendieck, J.  uhttp://knz.lternet.edu/content/polyploid-polymorphism-prairie-grass-big-bluestem-andropogon-gerardii