Genome analysis of Elytrigia caespitosa, Lophopyrum nodosum, Pseudoroegneria geniculata ssp. scythica, and Thinopyrum intermedium (Triticeae: Gramineae)

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 102-111 ◽  
Author(s):  
Zhi-Wu Liu ◽  
Richard R.-C. Wang
Keyword(s):  
Karyotype Analysis ◽  
Diploid Species ◽  
Pollen Grains ◽  
Root Tip ◽  
Meiotic Pairing ◽  
Tetraploid Species ◽  
Thinopyrum Intermedium ◽  
Male Sterile ◽  
Stainable Pollen ◽  
C Banding

To elucidate the genome constitutions of the tetraploid (2n = 4x = 28) species Elytrigia caespitosa, Lophopyrum nodosum, and Pseudoroegneria geniculata ssp. scythica and the hexaploid (2n = 6x = 42) Thinopyrum intermedium, meiotic pairing was studied in these species as well as 10 hybrids. Karyotype analysis with aceto-orcein stained root-tip cells was performed for the four species and the hybrids of T. bessarabicum with E. caespitosa, P. geniculata ssp. scythica, and T. intermedium. Karyotype analysis by Giemsa C-banding was carried out with the three tetraploid species and the two triploid hybrids involving T. bessarabicum. The species behaved as strict allopolyploids. All hybrids were male sterile with few stainable pollen grains. It is concluded from the results that the three tetraploid species have the genome formula JeJeSS and T. intermedium has the formula JeJeJeJeSS. The chromosomes of the Je and S genomes in these species had C-banding patterns differing from each other and from those of the extant diploid species. Based on these findings, the four species investigated should be placed in the same genus or the same section of a genus. However, new combinations are not proposed at this time pending future taxonomic investigation of the genome constitution of Elytrigia repens (L.) Nevski.Key words: genome, hybrid, meiosis, karyotype, chromosome banding, speciation.

Cytological identification of some trisomics of Russian wildrye (Psathyrostachys juncea)

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1271-1278 ◽  
Author(s):  
Jun-Zhi Wei ◽  
W. F. Campbell ◽  
G. J. Scoles ◽  
A. E. Slinkard ◽  
R. Ruey-Chyi Wang
Keyword(s):  
Crop Improvement ◽  
Diploid Species ◽  
Pollen Grains ◽  
Morphological Characters ◽  
Cereal Crop ◽  
Banding Patterns ◽  
C Banding ◽  
Psathyrostachys Juncea ◽  
Double Deletion ◽  
Russian Wildrye

Russian wildrye, Psathyrostachys juncea (Fisch.) Nevski (2n = 2x = 14; NsNs), is an important forage grass and a potential source of germplasm for cereal crop improvement. Because of genetic heterogeneity as a result of its self-incompatibility, it is difficult to identify trisomics of this diploid species based on morphological characters alone. Putative trisomies (2n = 2x + 1 = 15), derived from open pollination of a triploid plant by pollen grains of diploid plants, were characterized by Giemsa C-banding. Based on both karyotypic criteria and C-banding patterns, four of the seven possible primary trisomics, a double-deletion trisomic, and two tertiary trisomics were identified.Key words: Russian wildrye, Psathyrostachys juncea, trisomic, C-banding, karyotype.

Karyotype Analysis and Giema C-Banding Patterns in Thinopyron elongatum

2011 ◽  
Vol 183-185 ◽  
pp. 877-881 ◽  
Author(s):  
Qu Min
Keyword(s):  
Karyotype Analysis ◽  
Root Tip ◽  
Banding Patterns ◽  
C Banding ◽  
Cytological Data ◽  
Banding Analysis ◽  
Karyotype Formula ◽  
Tip Cells ◽  
Root Tip Cells

Giemsa C-banding patterns and karyotype of chromosomes were analyzed in the root-tip cells of diploid Thinopyron elongatum. A modified seed germinating method was developed for obtaining the C-banding patterns in diploid Thinopyron elonggatum. The results of The C-banding analysis showed the significant differences among the seven pairs of chromosomes in diploid Thinopyron elonggatum. The intensive C-bands were stained steadily on the intercalary, terminal, subcentromeric and centromeric regions of Chromosomes. We found that there are three pairs of metacentric chromosomes and four pairs of submetacentric chromosomes in diploid Thinopyron elonggatum. The karyotype formula is 2n=2x=14=6m+8sm. Present results provided a basic cytological data and will be useful for the further studies in Thinopyron elongatum.

Karyotype analysis and genome relationships of 22 diploid species in the tribe Triticeae

1986 ◽  
Vol 28 (1) ◽  
pp. 109-120 ◽  
Author(s):  
Catherine Hsiao ◽  
Richard R.-C. Wang ◽  
Douglas R. Dewey
Keyword(s):  
Chromosome Pairing ◽  
Karyotype Analysis ◽  
Diploid Species ◽  
Root Tip ◽  
Diagnostic Features ◽  
Genome Relationship ◽  
Microcomputer Program ◽  
Basic Set ◽  
Genome Content ◽  
Tribe Triticeae

Karyotypes were analyzed on 24 diploid taxa (mostly perennials) belonging to eight Triticeae genera, which are defined by genome content (basic set of seven chromosomes): (i) Agropyron (P genome), (ii) Thinopyrum (J genome), (iii) Secale (R genome), (iv) Hordeum (i genome), (v) Pseudoroegneria (S genome), (vi) Psathyrostachys (N genome), (vii) Australopyrum (W genome), and (viii) Critesion (H genome). In addition to traditional karyotype preparations, the metaphase root-tip chromosomes were analyzed by an interactive microcomputer program that printed an idiogram in which chromosomes were arranged by length. Genomes, arranged by decreasing length, are R, I, P, N, J, S, H, and W (with lengths ranging from 61.29 to 39.39 μm). Almost without exception, karyotypes of species within a genus manifest a pattern that is unique to the genome. Morphologically unique genomes are useful diagnostic features in genome identification and can complement interpretation of chromosome pairing in genome analysis.Key words: Triticeae, diploid, karyotype, genome relationship.

Analysis of karyotypes and Giemsa C-banding patterns in eight species of Arachis

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 187-194 ◽  
Author(s):  
Q. Cai ◽  
S. Lu ◽  
C. C. Chinnappa
Keyword(s):  
Close Relationships ◽  
Diploid Species ◽  
Chromosome Morphology ◽  
Tetraploid Species ◽  
Interspecific Relationship ◽  
Banding Patterns ◽  
C Banding ◽  
B Genome ◽  
A Genome ◽  
Structural Differences

The karyotypes and Giemsa C-banding patterns of the chromosomes in eight species of Arachis L. have been studied. Six species are diploid with 20 chromosomes and two are tetraploid with 40 chromosomes. One diploid species (A. rigonii Krap. et Greg.) belongs to the sect. Erectoides and the rest belong to the sect. Arachis. Among the diploid species from the sect. Arachis, A. batizocoi Krap. et Greg, has a unique karyotype while others have similar karyotypes. Two tetraploid species, A. monticola Krap. et Greg, and A. hypogaea L., possess the most similar karyotypes. However, the diploid species, A. rigonii, from sect. Erectoides, has a karyotype distinguishable from those in sect. Arachis. The C-banding patterns of the chromosomes have been obtained for all the species. The centromeric bands have been found in all the chromosomes and the intercalary bands can be identified in a varied number of chromosomes among these complements. However, the telomeric bands only exist in one or two chromosomes. The comparison of banding patterns demonstrated that structural differences exist among the chromosomal complements of the species with similar chromosome morphology. The karyotype variation among the different species and interspecific relationship are discussed. It is suggested that all the diploid species with the A genome are closely related. There are close relationships between the tetraploid species and diploid species with the A or B genome within sect. Arachis. Key words: Arachis, cytology, karyotypes, Giemsa C-banding.

Production of total and stainable pollen grains inOlea europaeaL

Grana ◽  
2007 ◽  
Vol 46 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Giuseppe Ferrara ◽  
Salvatore Camposeo ◽  
Marino Palasciano ◽  
Angelo Godini
Keyword(s):  
Pollen Grains ◽  
Stainable Pollen

scholarly journals Construction of a weight-based seed sorting system for the third-generation hybrid rice

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jianxin Wu ◽  
Shijun Qiu ◽  
Menglong Wang ◽  
Chunjue Xu ◽  
Xing Wang Deng ◽  
...  
Keyword(s):  
Hybrid Rice ◽  
Pollen Grains ◽  
Third Generation ◽  
Male Sterile ◽  
Specific Expression ◽  
The Third ◽  
Genes Encoding ◽  
Wild Type Male ◽  
Sorting System ◽  
Generation Hybrid

Abstract Background The third-generation hybrid rice technology can be constructed by transforming a recessive nuclear male sterile (NMS) mutant with a transgenic cassette containing three functional modules: the wild type male fertility gene to restore the fertility of the mutant, the pollen killer gene that specifically kills the pollen grains carrying the transgene, and the red fluorescence protein (RFP) gene to mark the transgenic seed (maintainer). The transgenic plant produces 1:1 NMS seeds and maintainer seeds that can be distinguished by the RFP signal. However, the RFP signals in the partially filled or pathogen-infected maintainer seeds are often too weak to be detected by RFP-based seed sorting machine, resulting in intermingling of the maintainer seeds with NMS seeds. Results Here we constructed a weight-based seed sorting system for the third-generation hybrid rice technology by silencing the genes encoding ADP-glucose pyrophosphorylase (AGP) essential for endosperm starch biosynthesis via endosperm-specific expression of artificial microRNAs (amiRNAs). In this system, the NMS seeds have normal endosperm and are heavy, but the maintainer seeds have shrunken endosperms and are light-weighted. The maintainer seeds can be easily and accurately sorted out from the NMS seeds by weight-sorting machines, so pure and fully filled NMS seeds are available. Conclusions The weight-based seed sorting system shows obvious advantages over the RFP-based seed sorting system in accuracy, efficiency, and cost for propagation of pure male sterile seeds. These characteristics will significantly increase the value and transgenic safety of the third-generation hybrid rice technology.

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 Reproductive characterization of interspecific hybrids among Capsicum species

2011 ◽  
Vol 11 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Carlos Eduardo da Silva Monteiro ◽  
Telma Nair Santana Pereira ◽  
Karina Pereira de Campos
Keyword(s):  
Male Sterility ◽  
Interspecific Hybrids ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Male Sterile ◽  
Viable Pollen ◽  
Hybrid Combination ◽  
Capsicum Species ◽  
The Cross

The objective of this study was the reproductive characterization of Capsicum accessions as well as of interspecific hybrids, based on pollen viability. Hybrids were obtained between Capsicum species. Pollen viability was high in most accessions, indicating that meiosis is normal, resulting in viable pollen grains. The pollen viability of species C. pubescens was the lowest (27 %). The interspecific hybrids had varying degrees of pollen viability, from fertile combinations (C. chinense x C. frutescens and C. annuum x C. baccatum) to male sterile combinations. Pollen viability also varied within the hybrid combination according to accessions used in the cross. Results indicate that male sterility is one of the incompatibility barriers among Capsicum species since hybrids can be established, but may be male sterile.

scholarly journals Two New Isomers of Palmityl-4-hydroxycinnamate from Flowers of Taraxacum Species

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Matej Dudáš ◽  
Mária Vilková ◽  
Tibor Béres ◽  
Miroslav Repčák ◽  
Pavol Mártonfi
Keyword(s):  
Nmr Spectroscopy ◽  
Pollen Grains ◽  
2D Nmr ◽  
Male Sterile ◽  
2D Nmr Spectroscopy ◽  
First Time

Two isomers, (Z)- and (E)-palmityl 4-hydroxycinnamate [hexadecyl(2Z)-3-(4-hydroxyphenyl)prop-2-enoate and hexadecyl(2E)-3-(4-hydroxyphenyl)prop-2-enoate] were isolated for the first time from ligulate flowers of Taraxacum linearisquameum Soest (sect. Taraxacum). The highest amount of these compounds was detected in pollen grains; 0.26 mg/100 mg DW of the (E)-isomer and 0.096 mg/100 mg DW of the (Z)-isomer. The structures of these compounds were elucidated by a combination of HPLC-ESI-Qtof-MS and ID and 2D NMR spectroscopy. Their presence was confirmed in other species of Taraxacum, but they were not found in the male-sterile triploid agamospermous taxon T. parnassicum.

Chromosomal Differentiation Among Ecotypes of Phalaris aquatica L.

1980 ◽  
Vol 28 (6) ◽  
pp. 645 ◽  
Author(s):  
E Putievsky ◽  
RN Oram ◽  
K Malafant
Keyword(s):  
Pollen Grains ◽  
F1 Hybrids ◽  
Male Sterile ◽  
Geographic Origins ◽  
Meiotic Irregularities ◽  
Structural Differences ◽  
Two Generations ◽  
Chromosomal Differentiation ◽  
Mother Cells ◽  
F2 Progeny

Seventy-two hybrids of P. aquatica were made among 13 diverse Mediterranean ecotypes and cv. Australian, and five indicators of hybrid abnormality were measured in the first two generations. The proportions of stainable, apparently normal pollen grains formed by F, hybrids varied between 5 and 98% and their spikelet fertility ranged from 19 to 77%. Of the 43 hybrids that were derived from pairs of self-incompatible parents, 13 were highly self-compatible. Crosses between lines from different groups of parents produced F2 progeny containing up to 17% of lethal seedlings and up to 39% of male sterile plants. In the cross between cv. Australian and the Moroccan ecotype, CPI 19331: the frequency ofzebra-striped lethal seedlings was as high as 33% in F2 progenies, but only 0 or 1% in back-crosses to either parent. Hence the zebra-striped phenotype was not caused by a mutation existing in the parents but rather by deletions or duplications generated during meiosis in the F1 hybrids. Many meiotic irregularities were observed in the pollen mother cells of the F1 and F2 hybrids between cv. Australian and CPI 19331. These included small loops, acentric fragments, univalents and multivalents at diakinesis, and bridges at anaphase I, indicating that the genomes of these two lines differed by several inversions and interchanges. These structural differences would lead to a range of duplications and deficiencies in the gametes. and hence could account for each of the five kinds of hybrid abnormality observed in the F1 and F2 generations. One aneuploid F2 plant with 25 chromosomes was found. A dihaploid plant in cv. Australian had an average of 4.3 bivalents per pollen mother cell, whereas virtually all chromosomes in the tetraploid parental lines paired as bivalents. Thus, P. aquatica is a segmental allotetraploid with a system which prevents homoeologous pairing in tetraploids but not in dihaploids. The partial barriers to hybridization between P. aquatica lines are not closely related to their geographic origins or varietal classifications. These barriers may hinder but have not prevented the recombination of parental traits during the development of improved cultivars.

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