Genome analysis of Thinopyrum bessarabicum and T. elongatum

1985 ◽  
Vol 27 (6) ◽  
pp. 722-728 ◽  
Author(s):  
Richard R. -C. Wang
Keyword(s):  
Reciprocal Cross ◽  
Parental Species ◽  
Karyotype Analysis ◽  
Pollen Grains ◽  
Structural Rearrangements ◽  
Mitotic Chromosomes ◽  
Hybrid Plants ◽  
Glume Length ◽  
Thinopyrum Bessarabicum ◽  
I Cells

Thinopyrum bessarabicum (2n = 14; JJ) was successfully crossed with T. elongatum (2n = 14; EE) but the reciprocal cross failed. Five of the 19 F1 plants headed in a greenhouse without being vernalized. Spikes of F1 hybrids were intermediate to those of the parents for number of florets per spike, glume length, and the first rachis internode length, but similar to those of T. bessarabicum and T. elongatum for spike length and number of spikelets per spike, respectively. Karyotypes of mitotic chromosomes in the parental species revealed that three of the seven chromosomes in the J and E genomes were similar in length and arm ratio. Meiosis in the F1 hybrids substantiated the conclusion from karyotype analysis that the other four chromosomes had undergone some structural rearrangements such as reciprocal translocation. Metaphase-I cells in hybrid plants averaged 2.68 I, 4.68 II, 0.27 III, 0.27 IV, and 0.01 V. Although 10% of the pollen grains were stainable with I2–KI, F1 plants of T. bessarabicum × T. elongatum did not set seed upon selfing. It is concluded that the J and E genomes are so closely related that the E genome designation should be changed to Je. The evidence reported here supports the transfer of Lophopyrum elongatum to the genus Thinopyrum. Wheat breeders should be able to utilize the genes in T. bessarabicum as readily as those in T. elongatum.Key words: Genome, mitosis, meiosis, karyotype, idiogram, hybrid.

scholarly journals Interspecific Hybridization Processes between Michelia yunnanensis and M. crassipes and Embryogenesis of the Heterozygote

HortScience ◽  
2017 ◽  
Vol 52 (8) ◽  
pp. 1043-1047
Author(s):  
Haiyan Xu ◽  
Folian Li ◽  
Yuezhi Pan ◽  
Xun Gong
Keyword(s):  
Reciprocal Cross ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Blue Staining ◽  
Formation Processes ◽  
Callose Deposition ◽  
Cross Compatibility ◽  
Direct Cross ◽  
Hybrid Seeds ◽  
Aniline Blue Staining

The investigation of hybridization processes and embryogenesis of heterozygote is an effective approach for early hybrids’ identification, which could provide reliable information for successful crossbreeding. In this study, we reported the whole hybridization processes of the direct cross and reciprocal cross between Michelia yunnanensis Franch. ex Finet et Gagnep. and Michelia crassipes Law using fluorescence microscopy after aniline blue staining, with the pollen germination on stigmas, pollen tube growth in styles, and subsequent extension into the embryo sac as well as the double fertilization processes are documented in detail. The M. yunnanensis × M. crassipes combination displayed considerable cross-compatibility, and the heterozygote embryogenesis was further observed with an approach of modified cryosectioning technique. Besides, the whole formation processes of hybrid seeds from artificial pollination to maturation were successfully observed. However, in the reciprocal cross, we found incompatibility between pollen grains of M. yunnanensis and stigmas of M. crassipes for the reason of hysteretic identification, as well as the abnormal callose deposition which belongs to the prefertilization barriers. This is the first study in which the complete and clear hybridization processes in Michelia were reported. We inferred that unilateral incompatibility of M. crassipes detected in this study may also exist in some other Michelia species. In artificial hybridization practices, we suggest some special treatments for overcoming prefertilization barrier should be taken when treating M. crassipes as the maternal parent.

Volatile oils and the study of natural hybridization between Correa aemula and C. reflexa (Rutaceae)

1977 ◽  
Vol 25 (3) ◽  
pp. 291 ◽  
Author(s):  
T Whiffin
Keyword(s):  
Numerical Analysis ◽  
Parental Species ◽  
Volatile Oil ◽  
Natural Hybridization ◽  
Volatile Oils ◽  
Hybrid Swarm ◽  
Hybrid Plants ◽  
Complex Variation

A small hybrid swarm between Correa aemula and C. reflexa was located and examined morphologically and chemically, with an emphasis on volatile oils. The hybrid plants were intermediate morphologically between the two parental species. The volatile oil data were subjected to multivariate numerical analysis, the results of which confirmed the general intermediacy of the hybrid plants. In general it was found that ordination is a more useful technique for the study of hybridization than is classification. It would appear that numerical analysis of volatile oil data will prove a useful technique in the study of the complex variation found within the genus Correa.

Karyotypic Studies in Artificial Hybrids of Solanum Sections Anarrhichomenum and Basarthrum (Solanaceae)

1999 ◽  
Vol 47 (1) ◽  
pp. 147 ◽  
Author(s):  
Laura Stiefkens ◽  
Gabriel Bernardello ◽  
Gregory J. Anderson
Keyword(s):  
Wild Species ◽  
Parental Species ◽  
Statistical Analyses ◽  
The Other ◽  
Genome Length ◽  
Mitotic Chromosomes ◽  
Chromosome Change ◽  
Centromere Position ◽  
Taxonomic Methods

Mitotic chromosomes of seven artificial hybrids fromSolanum L. sect.AnarrichomenumBitter &Basarthrum (Bitter) Bitter were studied(S. caripense Humb. & Bonpl. ex Dunal ×S. basendopogon Bitter,S. caripense × S. muricatumAiton, S. muricatum ×S. basendopogon, S. muricatum× S. caripense,S. muricatum× S. cochoae G.J. Anderson & Bernardello, S. sodiroi Bitter ×S. brevifolium Humb. & Bonpl., andS. sodiroi ×S. caripense).All are wild species except S. muricatum, which is knownonly as a domesticate (‘pepino dulce’). All hybrids were diploidwith 2n = 24. We compare the karyotypes ofparental species and their hybrids to understand chromosome change as acomponent of the evolution of these sections. Statistical analyses ofchromosomes, genome length and centromere position yielded estimates ofkaryotype composition and asymmetry. Comparisons were made by means of ANOVAsand numerical taxonomic methods. Statistical comparisons among the hybridspooled showed much karyotypic similarity among them. Karyotypes of theparental species revealed sharper differences among them. The karyotypes ofthe hybrids except for one combination were not intermediate. In general, thekaryotypes of the hybrids showed relatedness to the karyotype of one parentalspecies. The hybrids involving S. muricatum havechromosomal features closer to it than to the other parental species. Previousstudies showed S. caripense among the wild species to bemost similar to S. muricatum and, as expected, therewere the fewest differences between these species and the hybrids betweenthem. The karyotype of S. sodiroi×S. brevifolium is the most different from the karyotypeof either of its parental species.

Genome constitution of the Australian hexaploid grass Elymus scabrus (Poaceae: Triticeae)

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 147-151 ◽  
Author(s):  
J. Torabinejad ◽  
R. J. Mueller
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Intergeneric Hybrid ◽  
Meiotic Pairing ◽  
Genome Constitution ◽  
Psathyrostachys Juncea ◽  
Hybrid Plants ◽  
Thinopyrum Bessarabicum ◽  
Mother Cells ◽  
Metaphase I

Eight intergeneric hybrid plants were obtained between Elymus scabrus (2n = 6x = 42, SSYY??) and Australopyrum pectinatum ssp. retrofractum (2n = 2x = 14, WW). The hybrids were vegetatively vigorous but reproductively sterile. Examination of pollen mother cells at metaphase I revealed an average of 16.63 I, 5.29 II, 0.19 III, and 0.05 IV per cell for the eight hybrids. The average chiasma frequency of 6.77 per cell in the above hybrids strongly supports the presence of a W genome from A. pectinatum ssp. retrofractum in E. scabrus. Meiotic pairing data of some other interspecific hybrids suggest the existence of the SY genomes in E. scabrus. Therefore, the genome constitution of E. scabrus should be written as SSYYWW. Two other hybrid plants resulted from Elymus yezoensis (2n = 4x = 28, SSYY) crosses with A. pectinatum ssp. pectinatum (2n = 2x = 14, WW). Both were weak and sterile. An average of 0.45 bivalents per cell were observed at metaphase I. This clearly indicates a lack of pairing between W genome of Australopyrum and S or Y genomes of E. yezoensis. In addition, six hybrid plants of E. scabrus with Psathyrostachys juncea (2n = 2x = 14, NN) and one with Thinopyrum bessarabicum (2n = 2x = 14, JJ) were also obtained. The average bivalents per cell formed in both combinations were 2.84 and 0.70, respectively. The results of the latter two combinations showed that there is no N or J genome in E. scabrus.Key words: wide hybridization, chromosome pairing, genome analysis, Australopyrum, Elymus.

Preparation and karyotype analysis of mitotic chromosomes of the freshwater spongeSpongilla lacustris

Chromosoma ◽  
1993 ◽  
Vol 102 (10) ◽  
pp. 724-727 ◽  
Author(s):  
Georg Imsiecke ◽  
Ulrich Pascheberg ◽  
Werner E. G. M�ller
Keyword(s):  
Karyotype Analysis ◽  
Mitotic Chromosomes

scholarly journals SELECTIVE SOMATIC ELIMINATION OF NICOTIANA GLUTINOSA CHROMOSOMES IN THE F1 HYBRIDS OF N. SUAVEOLENS AND N. GLUTINOSA

Genetics ◽  
1973 ◽  
Vol 73 (4) ◽  
pp. 605-612
Author(s):  
S B Gupta ◽  
Pratibha Gupta
Keyword(s):  
Parental Species ◽  
Leaf Shape ◽  
Morphological Characteristics ◽  
Flower Color ◽  
Average Frequency ◽  
F1 Hybrids ◽  
Root Tips ◽  
Mitotic Chromosomes ◽  
Progressive Change ◽  
Nicotiana Glutinosa

ABSTRACT The F, hybrids of Nicotiana suaveolen (subgenus Petunioides, 2n = 32) and N. glutinosa (subgenus Tabacum, 2n = 24), were examined during their development, from seedlings to mature plants. It was observed that in the hybrids, there was a progressive change of dominant N. glutinosa morphological characteristics towards those of N. suaveolens, in leaf shape, stem, flower color and branching pattern. A study of mitotic chromosomes in the root-tips and in very young anthers of the mature plants indicated a significantly high average frequency of aberrant mitotic anaphases (bridges and fragments, 12% and 11 % respectively). As a consequence of this phenomenon, variability in the number and size of chromosomes was observed in the PMC's and in mitotic metaphases (29-24 chromosomes). In order to establish whether the N. glufinosa chromosomes were preferentially last, a karyological study of the parents and their F, hybrids was carried out and it was established that the F, hybrids were losing N. glutinosa chromosomes preferentially. A mechanism was suggested for the loss of these chromosomes by means of a chromatid type of breakage-fusion-bridge cycle (b-f-b cycle) and initiation of the b-f-b cycle in the hybrid due to an interaction of the regulatory mechanism of DNA replication in the haploid genomes of the parental species. However, loss of these chromosomes owing to interaction of certain genes from the two parental species cannot be ruled out.

scholarly journals Variability of pollen grains quality in oat amphiploids and their parental species

2021 ◽  
Author(s):  
Paulina Tomaszewska ◽  
Romuald KOSINA
Keyword(s):  
Parental Species ◽  
Pollen Viability ◽  
Regression Line ◽  
Reproductive Potential ◽  
Low Frequency ◽  
Pollen Grains ◽  
Strongly Correlated ◽  
Hybrid Progeny ◽  
Growing Seasons ◽  
High Level

The reproductive potential of oat species and their hybrid progeny (amphiploids) was evaluated during three vegetation seasons. Morphotypes and viability of pollen grains were described by means of correlations and regression, while relationships between taxa were analysed with the use of numerical taxonomy methods. Size of pollen grains varied between the growing seasons, but the relations between the taxa appeared to be stable. Viability of pollen grains was environmentally modified and showed no correlation with pollen length. In an ordination space, amphiploids were discriminated from parental species. In both group of plants, a positive correlation between the pollen size and the level of ploidy was maintained; however, along a regression line, amphiploids were located among species with a high level of ploidy and were extreme units deviating from the regression line. Developmental anomalies of pollen grains had a low frequency, with the formation of micrograins being the most common event. Such a pattern of development can prove that some pollen grains were chromosomally unbalanced. Anomalous morphotypes of pollen were more common in hybrid types than in species, including pollens with many poruses, which were found only in amphiploids. Frequencies of multiporate grains and micropollens were strongly correlated. In an ordination space, monoporate types (species) were discriminated from multiporate types (amphiploids). In general, the high level of pollen viability in amphiploids can prove their genomic stabilisation through many generations of their reproduction.

Spontaneous structural rearrangements in Solanum phureja Juz. et Buk. 2. Meiotic behaviour and identification of interchange chromosomes using primary trisomics

Genome ◽  
1995 ◽  
Vol 38 (1) ◽  
pp. 140-147
Author(s):  
M. Wagenvoort
Keyword(s):  
Pollen Mother Cell ◽  
Mother Cell ◽  
Solanum Phureja ◽  
Chromosome Identification ◽  
Structural Rearrangements ◽  
Primary Trisomics ◽  
Interchange Heterozygote ◽  
Mother Cells ◽  
I Cells ◽  
Metaphase I

Meiosis was studied in two diploid (2n = 2x = 24) siblings of Solanum phureja Juz. et Buk. and in 11 disomic and 2 trisomic descendants. The diploid siblings carry the same heterozygous interchange and either one or two inversions. The frequency of quadrivalents at diakinesis/metaphase I in these clones was 0.56 and 0.62 per pollen mother cell. In two plants from the first inbred generation (I1) this frequency was about the same but in some other I1 plants and a full sib the frequency was substantially lower, varying from 0.00 to 0.16. Most quadrivalents, 78–83%, were rings. A variety of quadrivalent configurations at diakinesis and metaphase I was observed, giving rise to balanced and unbalanced gametes. The absence of ring quadrivalents in trisomic descendants of one of the siblings implied that tertiary trisomics or primaries being homozygous for the interchange were present in the I1 generation. Regular chromosome distribution (12–12) at anaphase I occurred in 46.5 and 73.2% of the pollen mother cells studied in the two original clones. Irregularities, such as 11–13 distribution, lagging chromosomes, and a bridge and fragment, were detected on average in 2.7, 3.3, and 32.5%, respectively, of the anaphase I cells analysed. In hybrids from crosses between 6 primary trisomics as females with the interchange heterozygote, the involvement in the interchange of chromosomes 3 and 12 was clearly demonstrated.Key words: Solanum phureja, interchange heterozygote, chromosome identification, interchange trisomic, meiosis.

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