Interspecific hybrids involving the recently described diploid taxon Avena atlantica

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 361-364 ◽  
Author(s):  
J. M. Leggett

Chromosome pairing affinities of interspecific hybrids involving the newly discovered species Avena atlantica with A. strigosa, A. hirtula, A. prostrata, A. damascena, A. maroccana, and A. sativa are described. The complete and regular chromosome pairing observed in the hybrids involving A. hirtula and A. strigosa confirms the genomic designation to be AsAs. The chromosome pairing in the A. prostrata, A. damascena, A. maroccana, and A. sativa hybrids indicates that A. atlantica is no more closely related to these species than the other members of the AsAs genomic group. Key words: Avena, meiosis, hybridization, phylogeny.

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 225-236 ◽  
Author(s):  
Ib Linde-Laursen ◽  
Roland von Bothmer

One-hundred and nineteen progeny plants of crosses between one Hordeum lechleri (2n = 6x = 42) accession and the barley varieties 'Wong' and 'Igri' comprised 54 euploids (2n = 28), 8 hyperploids (2n = 29), 46 hypoploids (2n = 22 - 27), and 11 polyhaploids (2n = 21). Giemsa C-banding showed most interplant chromosome variation to be caused by elimination or, more seldom, duplication of barley chromosomes. The chromosomes of 'Wong' were preferentially lost in the order, 1H-4H-5H-3H-7H-2H-6H (5-4-7-3-1-2-6); those of 'Igri' in the order, 1H-3H or 6H-7H or 5H or 4H-2H (5-3 or 6-1 or 7 or 4-2), indicating different patterns of elimination. Over years chromosome elimination may be continuous. Hypoploid genomes of 'Wong' had the chromosomes arranged in the order, 1H-5H-2H-6H-7H-3H-4H (5-7-2-6-1-3-4), with a discontinuity between chromosomes 1H(5) and 4H(4); whereas in 'Igri' the order was (1H)-5H-2H-4H-7H-6H-3H-(1H) ((5)-7-2-4-1-6-3-(5)) with a discontinuity at 1H(5), indicating varietal differences. The patterns of barley chromosome elimination may be derived from chromosome orders. Elimination starts with a chromosome at the discontinuity, continues with the chromosome at the other end of the order, and proceeds more or less alternately towards the middle. In hybrids including 'Wong', duplication affected the two chromosomes situated at either end of barley chromosome order. A few older hybrids with 2n = 21 had three or four H.lechleri chromosomes substituted for as many barley chromosomes suggesting homoeology. Our observations support the hypothesis of an orderly arrangement of the chromosomes within genomes (Bennett 1981), but they do not agree with the idea of one 'natural karyotype' for each species (Bennett 1984b).Key words: Hordeum, interspecific hybrids, C-banding, chromosome elimination, chromosome order.


1973 ◽  
Vol 15 (3) ◽  
pp. 427-436 ◽  
Author(s):  
K. C. Armstrong

Meiotic chromosome pairing was studied at metaphase I of B. erectus (2n = 28), B. inermis (2n = 56) and interspecific hybrids from B. erectus × B. inermis (2n = 42). The B. erectus material averaged 2.08 IV + 0.11 III + 9.51 II + 0.35 I and B. inermis 0.05 VIII + 0.06 VI + 0.02 V + 2.25 IV + 0.11 III + 22.95 II + 0.25 I. The hybrid plants (2n = 42) averaged 0.18 VI + 1.90 IV + 0.19 III + 16.10 II + 0.39 I and one hybrid with 2n = 41 averaged 0.08 VI + 0.02 V + 0.95 IV + 0.50 III + 17.42 II + 0.72 I. Karyotype evidence supported the conclusion that B. erectus was an autotetraploid. The karyotype contains four large satellites and four subterminal chromosomes but the other four groups of four are median, with one group possibly a submedian. Since chromosome pairing in the hybrids was complete and the quadrivalent frequency in the parents and hybrids was similar, it was concluded that the genomic formula of B. erectus, B. inermis, and the hybrid was AAAA, AAAABBBB, and AAAABB, respectively.


1992 ◽  
Vol 70 (7) ◽  
pp. 1513-1514 ◽  
Author(s):  
S. B. Narasimhulu ◽  
Shyam Prakash ◽  
V. L. Chopra ◽  
V. Arunachalam

Shoot regeneration response in interspecific hybrids of Brassica species were assessed in relation to the diploid pollen parents and amphidiploid female parents. Superior regeneration responses were observed in interspecific combinations of B. carinata and B. nigra (BBC), B. juncea and B. campestris (AAB), and B. napus and B. campestris (AAC). Though synthetic B. napus regenerated with a frequency less than that of the better regenerating parent (B. oleracea), higher regeneration response was observed in the hybrid between B. napus and B. campestris. Two triploid combinations of the genetic constitution ABC, one obtained by crossing synthetic B. napus with B. nigra and the other by crossing natural B. juncea with B. oleracea, showed low regeneration responses. The response improved substantially in a tetraploid of the constitution ABBC obtained by crossing B. juncea with B. carinata. Key words: Brassica, alloploids, shoot regeneration.


Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 1002-1006 ◽  
Author(s):  
Byron L. Burson

Sexual, tetraploid (2n = 4x = 40) vaseygrass (Paspalum urvillei Steud.) was crossed with two apomictic, hexaploid (2n = 6x = 60) dallisgrass (P. dilatatum Poir.) biotypes (Uruguayan and Uruguaiana) to determine their relationships and the reproductive behavior of the hybrids. One vaseygrass × Uruguayan and two vaseygrass × Uruguaiana hybrids were studied and all had 2n = 5x = 50 chromosomes. The mean pairing meiotic association for the vaseygrass × Uruguayan hybrid was 10.18 I and 19.91 II, and for the two vaseygrass × Uruguaiana hybrids was 10.28 I, 19.82 II, 0.006 III, and 0.01 IV. These findings indicate that the parents of both hybrids have two homologous genomes. Because vaseygrass and Uruguayan dallisgrass have the genome formulas IIJJ and IIJJXX, respectively, their hybrid has the formula IIJJX and the two homologous genomes are the I and J genomes. Likewise, chromosome pairing in the vaseygrass × Uruguaiana hybrids demonstrates that both species have two similar genomes, I and J. The Uruguaiana biotype usually has 8–10 univalents per cell and these result from the failure of some members of the third genome to pair. Thus the Uruguaiana biotype has different forms of the X genome, and its genome formula may be designated as IIJJXX2. Cytologically all three hybrids were facultative apomicts but their uniform F2 progeny indicates that only the apomictic embryo sacs are functional. Seed fertility ranged from 10.8 to 16.2%.Key words: Interspecific hybrids, genomes, chromosome pairing, species relationships, dallisgrass, vaseygrass.


Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 671-673 ◽  
Author(s):  
P. K. Gupta ◽  
G. Fedak

Hybrids of Hordeum jubatum (4x) were produced with two isogenic lines of 6x triticale (×Triticosecale Wittmack) cv. DRIRA, one carrying the normal heterochromatic block on the long arm of 7R (cv. DRIRA HH) and the other lacking 90% of it (cv. DRIRA EE). The two hybrids were produced at relative frequencies of 1.1 and 0.9% of pollinated florets, respectively. The chromosome pairing in both of these hybrids was negligible (chiasmata frequencies 0.11 and 0.15), indicating that heterochromatin on 7R had no effect on chromosome pairing in H. jubatum and that the expected autosyndetic pairing between two related genomes of H. jubatum was absent in this combination. Key words: wide crosses, intergeneric hybrids, triticale, Hordeum jubatum, chromosome pairing.


2018 ◽  
Vol 8 (4) ◽  
pp. 65-69
Author(s):  
Mao Nguyen Van ◽  
Dong Tran Nam

Background: Pigmented tumour of the skin is one of the common tumour in human including the benign pigmented tumours (more common) called Nevi tumours and the malignant one called melanoma which was less frequent but the most poor in prognosis. In addition, the others not belonging to these group had the same clinical appearance, so the application of histopathology and immunohistochemistry for the definitive diagnosis was indespensible. Objectives: 1. To describe the macroscopic features of the pigmented tumoral-like lesions; 2. To classify the histopathologic types of the pigmented cell tumours and the other pigmented tumours of the skin. Materials and Method: Cross-sectional research on 55 patients diagnosed as pigmented tumoral lesions by clinician, then all definitively diagnosed by histopathology combining the immunohistochemistry in difficult cases. Results: There was no difference in gender, the disease was discovered most common in adult, especially with the age over 51 years old (58.1%). the most region located was in the face accounting for 60%, following the trunk and limbs (14.6%, 12.8% respectively). All 3 malignant melanomas happened in foot. The most common color of the lesions was black (65.4%), the other ones were rose, grey and blue. Histopathology and immunohisthochemistry showed that the true pigmented cell tumours were 52.6% encompassing benign ones (Nevi tumour) (41.8%), melanoma (5.4%) and lentigo (5.4%). 47.4% was not the true pigmented cell tumour including pigmented basocellular carcinoma (36.4%) and the others less common as histiofibromas, acanthoma and papilloma. Conclusion: the pigmented tumoral-like lesions of the skin could be the true pigmented cell tumours and the others, so the application of the histopathology and the immunohistochemistry after the clinical discovery helps to determine and classify the disease definitely and for the best orientation of treatment as well. Key words: skin tumour, benign pigmented tumour (Nevi), malignant pigmented tumour (melanoma), pigmented basocellular carcinoma


1970 ◽  
Vol 34 (3) ◽  
pp. 425-434 ◽  
Author(s):  
PK Malaker ◽  
IH Mian

The efficacy of seed treatment and foliar spray with fungicides in controlling black point incidence of wheat seeds was evaluated in the field. Two seed treating fungicides, namely Vitavax-200 and Homai-80WP were used @ 0.25% of dry seed weight and foliar spray with Tilt-250EC (0.05%) was applied in six different schedules. Untreated and unsprayed controls were also maintained. Seed treatment with either Vitavax-200 or Homai-80WP significantly increased plant population and grain yield, but none of them was found effective in reducing black point incidence. On the other hand, foliar sprays with Tilt-250EC under all the spray schedules except spraying at 70 and 90 DAS significantly minimized the disease severity over unsprayed control. Among the different spray schedules, spraying at 30, 40, 50, 60, 70, 80, and 90 DAS appeared to be most effective, which was similar to spraying at 30, 45, 60, 75, and 90 DAS in reducing black point incidence and increasing grain yield. Economic analysis on yield advantage showed that the highest additional gross margin of Tk. 6120/ha with BCR 2.57 was obtained from five sprays applied at 30, 45, 60, 75, and 90 DAS. Key Words: Seed treatment, foliar spray, black point, wheat. DOI: 10.3329/bjar.v34i3.3968 Bangladesh J. Agril. Res. 34(3) : 425-434, September 2009


2002 ◽  
Vol 80 (6) ◽  
pp. 565-570 ◽  
Author(s):  
Szilvia Gedey ◽  
Arto Liljeblad ◽  
László Lázár ◽  
Ferenc Fülöp ◽  
Liisa T Kanerva

The Candida antarctica lipase B-catalyzed reactions of five β-amino esters with neat butyl butanoate and with 2,2,2-trifluoroethyl butanoate in diisopropyl ether were studied, as were the reactions of the same β-amino esters and their N-butanamides with neat butanol. The possibility for sequential resolution, where the amino and ester functions of the substrate both react with an achiral butanoate, became less likely with increasing size of the substrate from ethyl 3-aminobutanoate (1a) to pentanoate (1b) or larger. On the other hand, the alcoholyses of N-acylated β-amino esters successfully proceeded in butanol with E > 100. Gram-scale resolution of the N-butanoylated 1a was performed to demonstrate the usefulness of the method. Key words: lipase, interesterification, acylation, alcoholysis, resolution, β-amino esters.


1970 ◽  
Vol 12 (4) ◽  
pp. 790-794 ◽  
Author(s):  
Chi-Chang Chen ◽  
Pryce B. Gibson

Both Trifolium repens (2n = 32) and T. nigrescens (2n = 16) formed bivalents during meiosis. However, their triploid hybrid showed an average of 4.27 trivalents per microsporocyte at metaphase I. The frequency of trivalents in the hybrid between T. nigrescens and autotetraploid T. occidentale (2n = 32) was 5.69. The data are interpreted to indicate: (1) a possible autotetraploid origin of T. repens; and (2) a close phylogenetic relationship among T. repens, T. nigrescens and T. occidentale.


Sign in / Sign up

Export Citation Format

Share Document