Diploid perennial intergeneric hybrids in the tribe Triticeae. III. Hybrids among Secale montanum, Pseudoroegneria spicata, and Agropyron mongolicum

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 80-84 ◽  
Author(s):  
Richard R.-C. Wang
Keyword(s):  
Key Words ◽  
Embryo Culture ◽  
Intergeneric Hybrids ◽  
Root Tip ◽  
Pseudoroegneria Spicata ◽  
Chromosome Homology ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Secale Montanum ◽  
Tribe Triticeae

Four new intergeneric diploid hybrids were synthesized in the greenhouse with the aid of embryo culture. Hybrids of Pseudoroegneria spicata × Secale montanum and P. spicata ssp. inermis × S. montanum, both having the genome formula SR, averaged 12.97 I + 0.49 II + 0.01 III at metaphase I. The hybrids of Agropyron mongolicum × S. montanum, which have the PR genomes, had an average of 12.86 I + 0.51 II + 0.03 III + 0.004 IV. The hybrid (SP) between P. spicata ssp. inermis and Agropyron mongolicum had a mean configuration of 8.05 I + 2.86 II + 0.07 III + 0.01 IV. All hybrids had intermediate spike morphology, respective to their parents, and were sterile. Mitotic preparations of root-tip cells of these hybrids suggested that the chromosomes of different genomes were spatially separated. The meiotic pairings of these hybrids indicated that chromosome homology between the S and P genomes is higher than either the S and R or the P and R. Both SR and PR hybrids represent new genomic combinations. The SP hybrid is equivalent to the dihaploid of P. tauri. All of these hybrids should be of value for breeding and taxonomy. Key words: intergeneric hybrids, genome, Secale, Pseudoroegneria, Agropyron.

Diploid perennial intergeneric hybrids in the tribe Triticeae. IV. Hybrids among Thinopyrum bessarabicum, Pseudoroegneria spicata, and Secale montanum

Genome ◽  
1988 ◽  
Vol 30 (3) ◽  
pp. 356-360 ◽  
Author(s):  
Richard R.-C. Wang
Keyword(s):  
Meiotic Chromosome ◽  
Embryo Rescue ◽  
Intergeneric Hybrids ◽  
Root Tip ◽  
Pseudoroegneria Spicata ◽  
Genome Phylogeny ◽  
Karyotype Analyses ◽  
Thinopyrum Bessarabicum ◽  
Mother Cells ◽  
Secale Montanum

Diploid intergeneric hybrids among Thinopyrum bessarabicum, Pseudoroegneria spicata, and Secale montanum were synthesized with the aid of embryo rescue. Karyotype analyses of mitotic root-tip cells revealed that all satellited chromosomes in the J, S, and R genomes were present in their hybrid combinations, making it possible to identify these hybrids at the seedling stage. Spikes of these hybrids were intermediate to, but distinctly different from, those of the parental species. Meiotic chromosome associations at metaphase I in the pollen mother cells averaged 4.34 I + 2.77 rod II + 1.42 ring II + 0.24 III + 0.14 IV for P. spicata × T. bessarabicum; 11.05 I + 1.22 rod II + 0.04 ring II + 0.13 III + 0.01 IV for T. bessarabicum × S. montanum; and 12.98 I + 0.52 rod II + 0.01 III for P. spicata × S. montanum. These meiotic data suggest that the S genome of Pseudoroegneria and the J genome of Thinopyrum are more closely related to each other than they are with the R genome of Secale. The R genome is slightly closer to the J genome than to the S genome. Since these synthetic hybrids represent genomic combinations that may not exist in nature, their induced amphiploids should be created and evaluated.Key words: intergeneric hybrids, genome, phylogeny, Thinopyrum, Pseudoroegneria, Secale.

Chromosome pairing failure in an intersectional amphiploid of Bromus altissimus × B. arvensis

1985 ◽  
Vol 27 (6) ◽  
pp. 705-709 ◽  
Author(s):  
K. C. Armstrong
Keyword(s):  
Chromosome Pairing ◽  
Embryo Culture ◽  
Differential Staining ◽  
Root Tip ◽  
Giemsa Banding ◽  
Homologous Pairing ◽  
Hybrid Nature ◽  
Tip Cells ◽  
Root Tip Cells

An intersectional F1 hybrid between Bromus arvensis and B. altissimus was made with the aid of embryo culture. The hybrid nature of the F1 and the amphiploid were confirmed by karyotyping root-tip cells. Following Giemsa banding, the chromosomes of B. arvensis stained darker than those of B. altissimus. Very little chromosome pairing was observed in the F1 hybrid (11.60 I + 1.08 II + 0.10 III). Chromosome pairing in the amphiploid (2n = 28) varied from almost complete pairing to very little pairing in different samples. The chromosome pairing indicated that very little homology exists between the genomes of B. altissimus and B. arvensis. Pairing failure in the amphiploid may result from the action of pairing control genes which are strong enough to prevent homologous pairing but which are variable in expression because of a sensitivity to endogenous and exogenous factors.Key words: Bromus, amphiploid, chromosome pairing, differential staining.

An advanced generation of Aranda orchids

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 608-611 ◽  
Author(s):  
Y. H. Lee ◽  
F. Y. Tham
Keyword(s):  
Somatic Chromosome ◽  
Intergeneric Hybrids ◽  
Root Tip ◽  
Chromosome Counts ◽  
Pollen Mother Cells ◽  
Mother Cells ◽  
Tip Cells ◽  
Somatic Chromosome Numbers ◽  
Root Tip Cells ◽  
Advanced Generation

Aranda orchids are a group of artificially bred intergeneric hybrids between member species (2n = 38) of two natural genera, Vanda and Arachnis, of Orchidaceae. Nine second generation Aranda cultivars were selected for analysis of somatic chromosome numbers, meiotic behaviour, and sporad formation. Eight of the cultivars were derived from Aranda × Vanda crosses and one from an Aranda × Aranda cross. Chromosome counts of their root tip cells showed that eight of them contained 2n = 3x = 57 chromosomes each, presumably resulting from unreduced eggs of the Aranda parent fertilized by haploid Vanda pollen. The ninth revealed 2n = 2x = 38 chromosomes. Pollen mother cells of eight of the cultivars (2n = 3x = 57) commonly formed more than 10 bivalents, presumably between homologous Vanda chromosomes, as well as many univalents, mainly of Arachnis chromosomes. Only 8–10 bivalents were observed in pollen mother cells of the ninth cultivar (2n = 2x = 38). All the cultivars formed a range of dyads containing unreduced microspores. Two mechanisms are proposed for the origin of these dyad sporads.Key words: Aranda orchids, intergeneric hybrids, cytology.

scholarly journals Morphological Characterization of Three Intergeneric Hybrids Among Gloriosa superba ‘Lutea’, Littonia modesta, and Sandersonia aurantiaca (Colchicaceae)

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 115-118 ◽  
Author(s):  
Junji Amano ◽  
Sachiko Kuwayama ◽  
Yoko Mizuta ◽  
Masaru Nakano ◽  
Toshinari Godo ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Pollen Grains ◽  
Morphological Characterization ◽  
Intergeneric Hybrids ◽  
Root Tip ◽  
Gloriosa Superba ◽  
Hybrid Plants ◽  
Tip Cells ◽  
Root Tip Cells

Three intergeneric hybrids among colchicaceous ornamentals, Gloriosa superba ‘Lutea’ (2n = 2x = 22), Littonia modesta (2n = 2x = 22), and Sandersonia aurantiaca (2n = 2x = 24), were subjected to morphological characterization and chromosome observation. Hybrid plants produced flowers 2 to 3 years after transplantation of ovule culture-derived plantlets to the greenhouse. All the hybrid plants, L. modesta × S. aurantiaca, L. modesta × G. superba ‘Lutea’, and S. aurantiaca × G. superba ‘Lutea’, showed a climbing habit like those of L. modesta and G. superba ‘Lutea’. Plants of L. modesta × S. aurantiaca and L. modesta × G. superba ‘Lutea’ were taller and shorter than their respective parents, whereas plant height of S. aurantiaca × G. superba ‘Lutea’ was nearly intermediate between the parents. Leaves of all the hybrids had a tendril at the tip like those of L. modesta and G. superba ‘Lutea’. Flower morphologies of all the hybrids were nearly intermediate between the parents. Flower colors of all the hybrids were similar to the seed or pollen parent. Although hybrids of L. modesta × G. superba ‘Lutea’ showed low pollen fertility as assessed with acetocarmine staining, the other two kinds of hybrids had nondehiscent anthers or no fertile pollen grains. Chromosome observation in root tip cells revealed that all the hybrids had a diploid number of chromosomes: L. modesta × S. aurantiaca (2n = 2x = 23), L. modesta × G. superba ‘Lutea’ (2n = 2x = 22), and S. aurantiaca × G. superba ‘Lutea’ (2n = 2x = 23). Novel morphological characteristics of the hybrids may be valuable for future breeding of colchicaceous ornamentals.

Sunlight decreased genotoxicity of azadirachtin on root tip cells of Allium cepa and Eucrosia bicolor

2010 ◽  
Vol 73 (5) ◽  
pp. 949-954 ◽  
Author(s):  
W. Kwankua ◽  
S. Sengsai ◽  
C. Kuleung ◽  
N. Euawong
Keyword(s):  
Allium Cepa ◽  
Root Tip ◽  
Tip Cells ◽  
Root Tip Cells

Salt Stress-induced Programmed Cell Death in Rice Root Tip Cells

2007 ◽  
Vol 49 (4) ◽  
pp. 481-486 ◽  
Author(s):  
Jian-You Li ◽  
Ai-Liang Jiang ◽  
Wei Zhang
Keyword(s):  
Cell Death ◽  
Salt Stress ◽  
Programmed Cell Death ◽  
Rice Root ◽  
Root Tip ◽  
Tip Cells ◽  
Root Tip Cells

Cytological evidence bearing on the origin of the B genome in polyploid wheats

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 36-43 ◽  
Author(s):  
K. Kerby ◽  
J. Kuspira
Keyword(s):  
Dna Hybridization ◽  
Triticum Turgidum ◽  
Root Tip ◽  
Cytological Evidence ◽  
B Genome ◽  
Genome Donor ◽  
The One ◽  
Genome Donors ◽  
Tip Cells ◽  
Root Tip Cells

To help elucidate the origin of the B genome in polyploid wheats, karyotypes of Triticum turgidum, Triticum monoccum, and all six purported B genome donors were compared. The analysis utilized a common cytological procedure that employed the most advanced equipment for the measurement of chromosome lengths at metaphase in root tip cells. A comparison of the karyotypes of T. turgidum and T. monococcum permitted the identification of B genome chromosomes of T. turgidum. These consist of two SAT pairs, one ST pair, three SM pairs, and one M pair of homologues. Comparisons of the chromosomes of the B genome of T. turgidum with the karyotypes of the six putative B genome donors showed that only the karyotype of Aegilops searsii was similar to the one deduced for the donor of the B genome in T. turgidum, suggesting that Ae. searsii is, therefore, the most likely donor of the B genome to the polyploid wheats. Support for this conclusion has been derived from geographic, DNA-hybridization, karyotype, morphological, and protein data reported since 1977. Reasons why the B genome donor has not been unequivocally identified are discussed.Key words: phylogeny, karyotypes, Triticum turgidum, Triticum monococcum, B genome, B genome donors.

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