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Effects of Abiotic Factors on the Geographic Distribution of Body Size Variation and Chromosomal Polymorphisms in Two Neotropical Grasshopper Species (Dichroplus: Melanoplinae: Acrididae)
Claudio J. Bidau,Carolina I. Mi o,Elio R. Castillo,Dardo A. Martí
Psyche , 2012, DOI: 10.1155/2012/863947
Abstract: We review the effects of abiotic factors on body size in two grasshopper species with large geographical distributions: Dichroplus pratensis and D. vittatus, inhabiting Argentina in diverse natural habitats. Geographical spans for both species provide an opportunity to study the effects of changes in abiotic factors on body size. The analyses of body size distribution in both species revealed a converse Bergmannian pattern: body size is positively correlated with latitude, altitude, and seasonality that influences time available for development and growth. Allen’s rule is also inverted. Morphological variability increases towards the ends of the Bergmannian clines and, in D. pratensis, is related with a central-marginal distribution of chromosomal variants that influence recombination. The converse Bergmannian patterns influence sexual size dimorphism in both species but in different fashions. Body size variation at a microspatial scale in D. pratensis is extremely sensitive to microclimatic clines. We finally compare our results with those for other Orthopteran species.
Metroglyph Analysis in Two Species of Hordeum  [PDF]
Mst. Nahida Laiju,M.J. Islam,M. Hasanuzzaman,M.A.S. Mondol
Pakistan Journal of Biological Sciences , 2002,
Abstract: Patterns of morphological variation in Hordeum species were determined by metroglyph analysis which revealed apparently four clusters comprising more than one line out of 15 studied. Cluster I was comprised of Centinella and Conquest of H. vulgare. Cluster II was comprised of single line of H. nudum and four lines (API-19, BEL-34, BEL-72 and BTON-10) of H. vulgare. Cluster III and IV were consisted of BEL-4, BTYN-8 and BTYN-37 and BEL-16, BHV-1, BHV-91, BHV-95 and BHV-105 of H. vulgare respectively. These clusters showed distinct graduation for breadth of flag leaves i.e., low (cluster I), relatively low (cluster III), intermediate (cluster II) and high (cluster IV). The ray`s pattern for 11 morphological characters on the glyph among the clusters revealed a marked variation for the presence or absence of rays.
Dual Origins of Dairy Cattle Farming – Evidence from a Comprehensive Survey of European Y-Chromosomal Variation  [PDF]
Ceiridwen J. Edwards,Catarina Ginja,Juha Kantanen,Lucía Pérez-Pardal,Anne Tresset,Frauke Stock,Luis T. Gama,M. Cecilia T. Penedo,Daniel G. Bradley,Johannes A. Lenstra,Isa?c J. Nijman
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0015922
Abstract: Diversity patterns of livestock species are informative to the history of agriculture and indicate uniqueness of breeds as relevant for conservation. So far, most studies on cattle have focused on mitochondrial and autosomal DNA variation. Previous studies of Y-chromosomal variation, with limited breed panels, identified two Bos taurus (taurine) haplogroups (Y1 and Y2; both composed of several haplotypes) and one Bos indicus (indicine/zebu) haplogroup (Y3), as well as a strong phylogeographic structuring of paternal lineages.
Transferability and polymorphism of barley EST-SSR markers used for phylogenetic analysis in Hordeum chilense
Almudena Castillo, Hikmet Budak, Rajeev K Varshney, Gabriel Dorado, Andreas Graner, Pilar Hernandez
BMC Plant Biology , 2008, DOI: 10.1186/1471-2229-8-97
Abstract: All of the 82 barley EST-derived SSR primer pairs tested for transferability to H. chilense amplified products of correct size from this species. Of these 82 barley EST-SSRs, 21 (26%) showed polymorphism among H. chilense lines. Identified polymorphic markers were used to test the transferability and polymorphism in other Poaceae family species with the aim of establishing H. chilense phylogenetic relationships. Triticum aestivum-H. chilense addition lines allowed us to determine the chromosomal localizations of EST-SSR markers and confirm conservation of the linkage group.From the present study a set of 21 polymorphic EST-SSR markers have been identified to be useful for diversity analysis of H. chilense, related wild barleys like H. murinum, and for wheat marker-assisted introgression breeding. Across-genera transferability of the barley EST-SSR markers has allowed phylogenetic inference within the Triticeae complex.Wild species constitute a potential source of genetic variation for cultivated species. Besides, they can be analyzed to answer the long-lasting questions concerning the origins, evolution and spread of major agricultural crops of the world. Recently, there has been considerable progress in plant genomics, leading to novel molecular breeding tools to reduce the costs and to simplify the assays. Plant genome research has been focused on the major crops and model species and a vast amount of genomic information has been accumulated. This information will provide an opportunity to use it as sources of information for thousands of minor grass species [1].Hordeum chilense Roem et Schultes is a native South American diploid perennial wild barley (2n = 2x = 14), included in the section Anisolepsis [2]. It belongs to a heterogeneous group of South American Hordeum species and it is one of the species of the genus Hordeum with a high potential for cereal breeding purposes, given its high crossability with other members of the Triticeae tribe. H. chilense was us
Karyotypic Study of Seven Species of Hordeum in Fars Province  [cached]
A. R. Nasirzadeh,F. Ansari-Asl
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: A karyotypic study was performed on seven species of Hordeum Genus including, H. vulgare, H. spontaneum, H. glaucum, H. distichon, H. geniculatum , H. bulbosum and H. violaceum. According to the cytological studies in the laboratory, chromosome numbers and ploidy levels of species were identified. Chromosome analysese including the length of each chromosome, long and short arms length and long - short arm ratio were also done. For each species, the karyotype as an ideogram was drawn. The results showed that H. geniculatum, H. bulbosum, and H. violaceum were tetraploid (2n=4x=28) and the other species were diploid (2n=2x=14). Chromosomal study of H. geniculatum and H. distichon is reported for the first time from Iran. Karyotypic formula showed that the diploid species were 7m and tetraploid were 12m +2sm. According to the karyotypic symmetry, all species were in the 1A class. Using the S%, TF%, D.R.L., T.V. and X parameters, karyotypic symmetry of species was analyzed and determined.
Gabriela Capraru,Ion Bara,Sorin Cristian Campeanu,Elena Maxim
Analele ?tiin?ifice Ale Universit??ii Alexandru Ioan Cuza din Ia?i,Sectiunea II A : Genetica si Biologie Moleculara , 2006,
Abstract: The synthesis of nucleic acids (DNA and RNA) displayed modifications in the plantlets of Andra and Flora two-row barley cultivars, as a result of the treatment with Simazine herbicide, at 0.1%, 0.2%, 0.5%, and 1% concentrations, applied for 24 hours and 48 hours. The DNA amount is superior to that of control, the only exception being registered for Flora cultivar, at the variant treated for 24 hours with tested herbicide. RNA synthesis evolved almost in the same manner in the two cultivars: it increases in 24 h treated variants, and decreases in 48 h treated variants. The ratio between nucleic acids (RNA/DNA) decreases consecutively to Simazine increasing concentration, excepting Flora cultivar (24 h treated variant).
Chromosomal distribution of the As51 satellite DNA in two species complexes of the genus Astyanax (Pisces, Characidae)
Abel, Luciano Douglas dos Santos;Mantovani, Monique;Moreira-Filho, Orlando;
Genetics and Molecular Biology , 2006, DOI: 10.1590/S1415-47572006000300008
Abstract: the chromosomal localization of the as51 satellite dna was identified by fluorescent in situ hybridization (fish) in specimens of the characid fish astyanax scabripinnis and astyanax fasciatus, which are considered species complexes because of their extensive karyotypical and morphological variability. a conserved chromosomal distribution of the as51 satellite, coincident with distal c-banded segments was demonstrated. the alternative interstitial localization of this satellite dna and possible alterations of its structure suggest that this sequence underwent quantitative, positional and structural variations, as the a. scabripinnis and a. fasciatus complexes diverged.
Size variation in the vascular cambium and its derivatives in two Alstonia species
Khan, Moin A.;Siddiqui, Badruzzaman;
Acta Botanica Brasilica , 2007, DOI: 10.1590/S0102-33062007000300003
Abstract: two tropical tree species viz. alstonia venenata br. and alstonia neriifolia don. (apocynaceae) were investigated to detect size variation in different elements of the cambium and its derivative tissues. although these two species were grown under identical climatic and edaphic conditions, fusiform initial dimensions and the elements derived from them were larger in a. venenata than in a. neriifolia. ray initials are rectangular in a. venenata but isodiametric in a. neriifolia. an appreciable increase in length was observed in the phloem and xylem ray cells when compared to the mother cells. maximum elongation was observed in xylem fibers during differentiation from the respective fusiform initials.
Chromosomal variation and systematics of Myoxids
Jan Zima,Miloš Macholán,Maria Grazia Filippucci
Hystrix : the Italian Journal of Mammalogy , 1995, DOI: 10.4404/hystrix-6.1-2-4017
Abstract: A synopsis of cytogenetic studies performed on various species and populations of myoxids is presented. Interspecific phylogenetic relationships derived from chromosomal data are evaluated and the evolutionary importance of intraspecific karyotypic variation is discussed. New data on the karyotypes of Dryomys nitedula from Asia and Muscardinus avellanarius from Europe are presented and discussed with special emphasis on the contrasting pattern of chromosomal differentiation in Eliomys vs. Dryomys and other myoxids. A bibliography of myoxid cytogenetics and karyology is compiled. Riassunto Variazione cromosomica e sistematica dei Mioxidi - Viene presentata una sinossi degli studi citogenetici effettuati su varie specie e popolazioni di Mioxidi. Vengono valutate le relazioni filogenetiche interspecifiche derivate da dati cromosomici e viene discussa l'importanza evolutiva della variazione cariotipica intraspecifica. Vengono presentati nuovi dati sui cariotipi di Dryomys nitedula asiatico e di Muscardinus avellanurius europeo e discussi con particolare enfasi sul contrastante pattern di differenziamento cromosomico di Eliomys rispetto a Dryomys ed altri Mioxidi. Viene compilata una bibliografia su citogenetica e cariologia dei Mioxidi.
Untangling Nucleotide Diversity and Evolution of the H Genome in Polyploid Hordeum and Elymus Species Based on the Single Copy of Nuclear Gene DMC1  [PDF]
Dongfa Sun, Genlou Sun
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0050369
Abstract: Numerous hybrid and polypoid species are found within the Triticeae. It has been suggested that the H subgenome of allopolyploid Elymus (wheatgrass) species originated from diploid Hordeum (barley) species, but the role of hybridization between polyploid Elymus and Hordeum has not been studied. It is not clear whether gene flow across polyploid Hordeum and Elymus species has occurred following polyploid speciation. Answering these questions will provide new insights into the formation of these polyploid species, and the potential role of gene flow among polyploid species during polyploid evolution. In order to address these questions, disrupted meiotic cDNA1 (DMC1) data from the allopolyploid StH Elymus are analyzed together with diploid and polyploid Hordeum species. Phylogenetic analysis revealed that the H copies of DMC1 sequence in some Elymus are very close to the H copies of DMC1 sequence in some polyploid Hordeum species, indicating either that the H genome in theses Elymus and polyploid Hordeum species originated from same diploid donor or that gene flow has occurred among them. Our analysis also suggested that the H genomes in Elymus species originated from limited gene pool, while H genomes in Hordeum polyploids have originated from broad gene pools. Nucleotide diversity (π) of the DMC1 sequences on H genome from polyploid species (π = 0.02083 in Elymus, π = 0.01680 in polyploid Hordeum) is higher than that in diploid Hordeum (π = 0.01488). The estimates of Tajima's D were significantly departure from the equilibrium neutral model at this locus in diploid Hordeum species (P<0.05), suggesting an excess of rare variants in diploid species which may not contribute to the origination of polyploids. Nucleotide diversity (π) of the DMC1 sequences in Elymus polyploid species (π = 0.02083) is higher than that in polyploid Hordeum (π = 0.01680), suggesting that the degree of relationships between two parents of a polyploid might be a factor affecting nucleotide diversity in allopolyploids.
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