Para-Fluorophenylalanine-induced chromosome number changes in higher plants. II. Tomato and rape

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 929-934 ◽  
Author(s):  
P. Banks ◽  
E. J. Britten ◽  
G. H. Gordon
Keyword(s):  
Brassica Napus ◽  
Chromosome Number ◽  
Lycopersicon Esculentum ◽  
Chromosome Numbers ◽  
Higher Plants ◽  
Morphological Changes ◽  
Brassica Napus L ◽  
Tomato Seedlings ◽  
Lycopersicon Esculentum Mill ◽  
Germinating Seeds

Germinating seeds of rape (Brassica napus L.) and of tomato (Lycopersicon esculentum Mill.), and 1-month-old tomato seedlings, were treated with para-fluorophenylalanine to change chromosome numbers. A number of morphological aberrations were found in treated plants of both species, some of which were also observed in progeny of treated tomatoes. Aneuploids and polyploids were confirmed cytologically in treated plants of both species. The investigations confirm the suggestion previously made for maize, that para-fluorophenylalanine is capable of changing chromosome numbers and the resulting morphology of plants of widely different phylogenetic categories.Key words: Para-fluorophenylalanine, chromosome number changes, plants, tomato, rape, aneuploids, polyploids, morphological changes.

Incomplete bivalent pairing in dihaploids of Brassica napus L

Genome ◽  
1988 ◽  
Vol 30 (3) ◽  
pp. 450-457 ◽  
Author(s):  
William Tai ◽  
H. Ikonen
Keyword(s):  
Brassica Napus ◽  
Chromosome Number ◽  
Anther Culture ◽  
Chromosome Numbers ◽  
Meiotic Behaviour ◽  
Homoeologous Pairing ◽  
Brassica Napus L ◽  
Normal Behaviour ◽  
Mother Cells ◽  
Homoeologous Chromosomes

Twenty five polyhaploid plants (2n = 2x = 19, genome formula AC) of Brassica napus (2n = 4x = 38, AACC) were cytogenetically studied. Seven of these were found among field populations and the rest were derived through anther culture of B. napus cv. Regent. Meiotic behaviour at diakinesis and metaphase I revealed nine bivalents and one univalent in more than 40% of the more than 400 pollen mother cells analyzed. However, when the chromosome number of the polyhaploids was doubled using colchicine, 19 bivalents were observed. These doubled plants (2n = 4x = 38, AACC) also had normal behaviour identical to a regular B. napus at other meiotic stages. Quadrivalent associations were observed when the chromosome numbers were doubled to the octaploid level (2n = 8x = 72, AAAACCCC). It is suggested that A and C are homoeologous genomes. If homologous partners are present, chromosomes would pair within the same genome to form bivalents as occurred in the allotetraploids and to form quadrivalents as occurred in the allooctaploids. However, when a homologous partner is not available, the homoeologous chromosomes would then pair to form bivalents in those polyhaploids.Key words: Brassica napus, polyhaploids, genome relationship, meiotic behaviour, homoeologous pairing.

Cytogenetic analysis of plants regenerated from tissue explants and mesophyll protoplasts of winter rape, Brassica napus L.

1984 ◽  
Vol 26 (6) ◽  
pp. 752-761 ◽  
Author(s):  
C. A. Newell ◽  
M. L. Rhoads ◽  
D. L. Bidney
Keyword(s):  
Brassica Napus ◽  
Chromosome Number ◽  
Germ Line ◽  
Male Sterile ◽  
Male Sterile Line ◽  
Winter Rape ◽  
Brassica Napus L ◽  
Mesophyll Protoplasts ◽  
Regenerated Plants ◽  
Chromosome Associations

Plants were regenerated from seedling tissue explants of four lines of winter rape (Brassica napus L.) including a cytoplasmic male sterile line carrying Raphanus sativus L. cytoplasm, and from leaf mesophyll protoplasts of the cytoplasmic male sterile line. Chromosome number variability was investigated in 102 regenerated plants. Mitotic root-tip cells were scored initially; those plants exhibiting mixoploidy or an altered chromosome number were reexamined at meiosis to confirm the presence of alterations in germ line cells. Plants regenerated from seedling explants included 2n = 38 diploids (87.0%) similar to the parental line, monosomics (7.8%), trisomics (2.6%), and 2n = 76 tetraploids (1.3%). The germ line number was not resolved in one mixoploid (1.3%). Protoplast-derived regenerated plants were diploid (44%), hypodiploid (20%), and tetraploid or hypotetraploid (36%). Meiotic analysis of regenerated plants showed a range of multiple chromosome associations with no plants consistently exhibiting bivalent formation only. Chromosomal alterations other than number may have been induced by culture, but could not be substantiated since multiple chromosome associations were also frequent in control plants grown from seed.Key words: plant regeneration, protoplast regeneration, Brassica napus, cytogenetics.

A RootNav analysis of morphological changes in Brassica napus L. roots in response to different nitrogen forms

2017 ◽  
Vol 83 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Qianqian Guo ◽  
Jonathan Love ◽  
Jessica Roche ◽  
Jiancheng Song ◽  
Matthew H. Turnbull ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Morphological Changes ◽  
Nitrogen Forms ◽  
Brassica Napus L

scholarly journals The formation of sulphur-containing amino acids in germinating seeds of rape (Brassica napus L.)

1972 ◽  
Vol 126 (4) ◽  
pp. 985-991 ◽  
Author(s):  
T. T. Ngo ◽  
P. D. Shargool
Keyword(s):  
Amino Acids ◽  
Brassica Napus ◽  
Specific Radioactivity ◽  
Total Radioactivity ◽  
Brassica Napus L ◽  
Free Sulphur ◽  
Germinating Seeds

Sodium [35S]sulphide was fed to batches of germinating rapeseed, in some instances with the addition of unlabelled cysteine. Both the total radioactivity and specific radioactivity of the free sulphur-containing amino acids were examined. Cysteine and homocysteine were rapidly labelled; label subsequently appeared in cystathionine and methionine. The results obtained indicated that both the sulphydration and trans-sulphuration pathways were operating. This conclusion was reinforced by the results of experiments in which batches of rapeseed were incubated with l-[14C]homoserine. These showed the formation of labelled homocysteine, cystathione and methionine. It was thought the trans-sulphuration pathway was making the greater contribution to the biosynthesis of methionine in germinating rapeseed.

Meiotic pairing in haploids and amphidiploids of spontaneous versus synthetic origin in rape, Brassica napus L.

1986 ◽  
Vol 28 (3) ◽  
pp. 330-334 ◽  
Author(s):  
T. Attia ◽  
G. Röbbelen
Keyword(s):  
Brassica Napus ◽  
Chromosome Number ◽  
Chromosome Pairing ◽  
Structural Modification ◽  
Meiotic Pairing ◽  
Chromosome Behaviour ◽  
Preferential Pairing ◽  
Brassica Napus L ◽  
Bivalent Formation ◽  
Homoeologous Chromosomes

Newly resynthesized AC amphihaploids, which were characterized by high meiotic pairing and multivalent formulation, after doubling of their chromosome number showed preferential pairing and bivalent formation in the resynthesized amphidiploid Brassica napus (AACC). However, univalents as well as multivalents were also formed indicating that their chromosome behaviour was not fully diploidized. Stabilization of chromosome pairing in newly resynthesized amphidiploids can be achieved through genetic control or structural modification of the homoeologous chromosomes. A comparison of the meiotic behaviour of spontaneous haploids of natural rapeseed with that of the newly synthesized AC amphihaploids provides some evidence that both processes may be involved in the regulation of chromosome pairing in Brassica.Key words: Brassica, amphihaploid, amphidiploid, meiosis, univalents, multivalents.

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