CYTOTAXONOMIC STUDIES ON EREMOPYRUM

1958 ◽  
Vol 36 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Priyabrata Sarkar
Keyword(s):  
Diploid Species ◽  
The Other ◽  
Tetraploid Species ◽  
Generic Status ◽  
Annual Habit ◽  
Sterility Barrier

Five species are included in the genus Eremopyrum, namely, E. triticeum, E. hirsutum, E. buonapartis, E. orientale, and E. distans. Of these, the first two are diploids with 2n = 14, while the rest are tetraploids with 2n = 28. The karyotypes of the two diploid species are different from those of any other member, of the Triticineae in that they have chromosomes with extremely subterminal centromeres. The karyotype of each of the three tetraploid species shows a mixture of two types of chromosomes: seven pairs with extreme subterminal centromeres and the other seven pairs with median or submedian centromeres. This indicates that these are amphidiploids between triticeum–hirsutum-like taxa and perhaps some diploid species of crested Agropyron. In view of the karyotypic peculiarity, annual habit, and reported sterility barrier, the decision to give Eremopyrum generic status is supported.

scholarly journals Camelina neglecta (Brassicaceae, Camelineae), a new diploid species from Europe

PhytoKeys ◽  
2019 ◽  
Vol 115 ◽  
pp. 51-57 ◽  
Author(s):  
Jordan R. Brock ◽  
Terezie Mandáková ◽  
Martin A. Lysak ◽  
Ihsan A. Al-Shehbaz
Keyword(s):  
New Species ◽  
Diploid Species ◽  
The Other

Camelinaneglecta is described as a new diploid species and its relationship to the other diploids of the genus and to the somewhat superficially similar tetraploid C.rumelica and hexaploid C.microcarpa, are discussed. SEM of seed and stem trichomes of the new species are presented.

Description, distribution and ecology of endemic Tasmanian quillwort, Isoetes jarmaniae, sp. nov. (Isoetaceae; Lycopodiopsida)

Phytotaxa ◽  
2021 ◽  
Vol 522 (1) ◽  
pp. 27-37
Author(s):  
DANIEL F. BRUNTON ◽  
MICHAEL GARRETT ◽  
PAUL C. SOKOLOFF ◽  
GINTARAS KANTVILAS
Keyword(s):  
Diploid Species ◽  
Geographic Range ◽  
The Other ◽  
South American ◽  
The South ◽  
Triangular Shape ◽  
South West ◽  
Distribution And Ecology ◽  
River Valleys

Isoetes jarmaniae sp. nov. is described as a new lycophyte endemic to Tasmania, Australia, where it is confined to peat-bound karstic wetlands in several river valleys in the south-west wilderness. While seemingly morphologically closest to I. drummondii, this quillwort has features that are globally uncommon in Isoetes and unknown in other Australasian taxa. Most notable are its markedly flattened, strongly recurved leaves and disproportionately large sporangium ligules that are more suggestive of South American than Australian taxa. As well, the exceptionally thin and wide (alate) megaspore equatorial ridge is swollen at suture intersections, presenting a slightly triangular shape suggestive of the Indian taxon I. udupiensis. The microspores of I. jarmaniae exhibit exceptionally, perhaps uniquely, fine-papillate ornamentation. An original key placing I. jarmaniae in context with the other Tasmanian Isoetes species is provided. This diminutive, apparently diploid species is evidently maintaining a self-sustaining population within a regionally unique habitat and small geographic range.

scholarly journals Interploid Hybridizations in Ornamental Cherries Using Prunus maackii

2012 ◽  
Vol 30 (2) ◽  
pp. 89-92
Author(s):  
Margaret Pooler ◽  
Hongmei Ma ◽  
David Kidwell-Slak
Keyword(s):  
United States ◽  
Tissue Culture ◽  
Cold Hardiness ◽  
Diploid Species ◽  
Pest Resistance ◽  
The United States ◽  
Tetraploid Species ◽  
Genetic Base ◽  
Flowering Cherry ◽  
New Cultivars

The United States National Arboretum has an ongoing flowering cherry (Prunus) breeding program aimed at broadening the genetic base of cultivated ornamental cherries by developing new cultivars with disease and pest resistance, tolerance to environmental stresses, and superior ornamental characteristics. Interploid crosses, specifically 2X × 4X, in ornamental Prunus would be beneficial in breeding because they could allow introgression of traits not available in the diploid germplasm (pest resistance, cold hardiness), and could result in the creation of seedless triploids that would not set nuisance fruit and possibly have extended bloom durations. This report documents successful hybridization of P. maackii (Manchurian or Amur cherry), a tetraploid species, with P. campanulata, P. ‘Umineko’, and P. maximowiczii, all diploid species. Chromosomes of one of these resulting triploid hybrids were successfully doubled using oryzalin in tissue culture to create a hexaploid plant.

scholarly journals Relations and evolution in Cheilanthes (Sinopteridaceae, Pteridophita) in Macaronesia and Mediterranean area, deduced from genome analysis of their hybrids

1983 ◽  
Vol 8 ◽  
pp. 101-126 ◽  
Author(s):  
G. Vida ◽  
A. Major ◽  
T. Reichstein
Keyword(s):  
Chromosome Number ◽  
Genome Analysis ◽  
Chromosome Doubling ◽  
Diploid Species ◽  
Mediterranean Area ◽  
Basic Chromosome Number ◽  
The Other ◽  
Experimental Conditions ◽  
Natural Group ◽  
Basic Chromosome

Nine species of "Cheilantoid ferns" are known to grow in Macaronesia and the Mediterranean basin. Two of them (lacking a pseudo-indusium and having the basic chromosome number X = 29), both aggregate species which we prefer to retain in Notholaena, are not included in this study. The other seven species (with distinct pseudo-indusium and the basic chromosome number X = 30), which we accept as members of the genus Cheilanthes Sw. sensu stricto, were subjected to detailed genome analysis of their natural and experimentally produced hybrids and shown to represent an aggregate of four very distinct ancestral diploids and three allotetraploids. The latter must have once been formed by chromosome doubling in the three diploid hybrids of C. maderensis Lowe with the other three diploid species. Theoretically three more allotetraploids would be possible but their formation has obviously been prevented by the geographical separation of the three respective diploids. The most widely distributed of the tetraploids, i.e. C. pteridioides (Reich.) C.Chr. has also been resynthesized from its ancestors (still sympatric) under experimental conditions. The intermediate morphology of the allotetraploids (as compared with their diploid ancestors) is obviously the reason why their status and existence has so long escaped recognition in Europe. These seven species form a natural group and, in our opinion, should not be divided into sections.

Systematic position and cladistic analysis of Gyrasida Koch, a remarkable genus of Praocini (Coleoptera: Tenebrionidae) from Chile

Zootaxa ◽  
2009 ◽  
Vol 1978 (1) ◽  
pp. 48-62 ◽  
Author(s):  
GUSTAVO E. FLORES ◽  
PEDRO VIDAL
Keyword(s):  
South African ◽  
Type Species ◽  
Cladistic Analysis ◽  
Systematic Position ◽  
The Other ◽  
External Morphology ◽  
Distribution Map ◽  
Central Chile ◽  
Generic Status ◽  
Coleoptera Tenebrionidae

Gyrasida Koch (Pimeliinae: Praocini), distributed in central Chile is elevated to generic status and transferred from Asidini to Praocini on the basis of constant tribal level characters. Prior to this study Gyrasida was considered a subgenus of the South African Afrasida Wilke. Character states of Gyrasida shared with the other genera of Praocini and not shared with genera of Asidini are discussed. A cladistic analysis of the six species of the genus is presented including: G. propensa (Wilke) (type species), G. lucianoi Flores & Vidal, G. fernandoi Flores & Vidal, G. tomasi Vidal, G. franciscae Vidal, and G. camilae Vidal. This article includes a redescription of the genus, habitus photographs, illustrations of external morphology and genitalic features, a cladogram, and a distribution map.

The systematics of Clarkia, section Myxocarpa

1971 ◽  
Vol 49 (7) ◽  
pp. 1211-1217 ◽  
Author(s):  
Ernest Small
Keyword(s):  
Diploid Species ◽  
The Other

Two previously described diploid species in Clarkia, section Myxocarpa, have been found to comprise five allopatric groups, which are reproductively isolated by very strong chromosomal sterility barriers, and are divergent ecologically. Two of these groups are each made up of a pair of distinctive races. All of these are extremely difficult to distinguish morphologically, although consistent differences have been found. Emphasizing reproductive, ecological, and distributional criteria, these have been recognized as five species, two of which are composed of a pair of subspecies. The relationships of the proposed taxa to the other two species of section Myxocarpa are examined, and the problem of treating the group taxonomically is considered.

Two closely related Tulipa species with different ploidy levels show distinct germination rates

2020 ◽  
Vol 30 (1) ◽  
pp. 45-48
Author(s):  
Giovanni Astuti ◽  
Sandro Pratesi ◽  
Lorenzo Peruzzi ◽  
Angelino Carta
Keyword(s):  
Ploidy Level ◽  
Comparative Studies ◽  
Diploid Species ◽  
Tetraploid Species ◽  
Natural Conditions ◽  
Ploidy Levels ◽  
Final Length ◽  
Diploid Ancestor

AbstractIn the tetraploid Tulipa sylvestris we found larger and heavier seeds that germinated around 28 days earlier than those of the diploid ancestor Tulipa pumila. The faster germination of the tetraploid species is linked to the faster growth of embryos, which reached their final length much earlier than the embryos of the diploid species. In conclusion, we argue a cautionary approach when dealing with comparative studies on ploidy level and germination to avoid misinterpretation of results when set against the natural conditions.

Diploid ancestry and evolution of Triticum kotschyi and T. peregrinum examined using variation in repeated nucleotide sequences

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 182-191 ◽  
Author(s):  
Hong-Bin Zhang ◽  
Jan Dvořák ◽  
J. Giles Waines
Keyword(s):  
Diploid Species ◽  
Nucleotide Sequences ◽  
Gene Clone ◽  
Rrna Gene ◽  
Tetraploid Species ◽  
Genome Modification ◽  
Aegilops Sharonensis ◽  
5S Rrna Gene ◽  
Aegilops Variabilis ◽  
Allotetraploid Species

Triticum peregrinum Hackel (syn. Aegilops variabilis Eig) and T. kotschyi (Boiss.) Bowden (syn. Ae. kotschyi Boiss.) are closely related allotetraploid species. Previous research indicated that they have a pair of U genomes from diploid T. umbellulatum (Zhuk.) Hackel and a pair of S genomes from a diploid species of Triticum section Sitopsis. To reinvestigate the origin of their genomes, we identified diagnostic bands in Southern blots hybridized with 27 cloned repeated nucleotide sequences and one 5S rRNA gene clone for all diploid species of Triticum L. sensu Bowden. The presence of each diagnostic band was then determined in the two tetraploid species. One pair of the genomes in both tetraploid species was found to be virtually identical to the U genome of T. umbellulatum and the other to the S1 genome of T. longissimum (Schweif. et Muschl.) Bowden or T. sharonense (Eig) Waines &Johnson (syn. Aegilops sharonensis Eig) or the internode in the phylogenetic tree of Triticum immediately preceding the divergence of T. longissimum and T. sharonense. The source of the S genomes in T. kotschyi and T. peregrinum inferred from our data differs from that inferred from cpDNA. This indicates the need to investigate the origin of nuclear genomes with nuclear genetic markers. No evidence for an extensive modification of the S genome relative to that of T. longissimum or T. sharonense was found in either tetraploid.Key words: phylogeny, polyploids, Triticum, Aegilops, Aegilops kotschyi, Aegilops variabilis, genome origin, genome modification.

scholarly journals Karyotypic studies in wild species of Arachis (Leguminosae) belonging to sections Erectoides, Procumbentes and Rhizomatosae Estudios cariotípicos en especies silvestres de Arachis (Leguminosae) pertenecientes a las secciones Erectoides, Procumbentes...

1970 ◽  
Vol 48 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Alejandra M. Ortíz ◽  
María C. Silvestri ◽  
Graciela I. Lavia
Keyword(s):  
Wild Species ◽  
Diploid Species ◽  
The Other ◽  
Karyotype Formula

Summary: Karyotypes of three diploid species belonging to sections Erectoides (Arachis hermannii), Procumbentes (A. rigonii) and Rhizomatosae (A. burkartii) were analyzed by Feulgen’s technique. The karyotype formula was different in each of the taxa analyzed: 2n=2x=16m+4sm in A. hermannii, 2n=2x=18m+2sm in A. rigonii, and 2n=2x=20m in A. burkartii. All species had a pair of satellited chromosomes, which corresponded to type 2 in A. hermannii, type 9 in A. rigonii, and type 8 in A. burkartii. Arachis hermannii and A. rigonii presented chromosomal features similar to those of the other species included in their respective sections. However, A. burkartii showed chromosome characteristics different from those found in the rest of the species of section Rhizomatosae.Key words: Arachis hermannii, A. rigonii, A. burkartii, chromosomes, phylogenetic relationships.Resumen: Estudios cariotípicos en especies silvestres de Arachis (Leguminosae) pertenecientes a las secciones Erectoides, Procumbentes y Rhizomatosae. Los cariotipos de tres especies diploides pertenecientes a las secciones Erectoides (A. hermannii), Procumbentes (A. rigonii) y Rhizomatosae (A. burkartii) fueron analizados mediante la técnica de Feulgen. Las fórmulas cariotípicas obtenidas son diferentes en los taxones analizados, 2n=2x=16m+4sm en A. hermannii, 2n=2x=18m+2sm en A. rigonii, y 2n=2x=20m en A. burkartii. Las tres especies presentaron un par de cromosomas con satélite, en A. hermannii tipo 2, en A. rigonii tipo 9 y en A. burkartii tipo 8. Arachis hermannii y A. rigonii presentaron características cromosómicas similares a las especies incluidas en sus respectivas secciones. Sin embargo, A. burkartii no comparte características cromosómicas con el resto de las especies de la sección Rhizomatosae.Palabras clave: Arachis hermannii, A. rigonii, A. burkartii, cromosomas, relaciones filogenéticas.

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