Genetic components of chromosome behaviour in Papaver somniferum L.

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 677-679 ◽  
Author(s):  
N. K. Patra ◽  
S. P. Chauhan
Keyword(s):  
Chiasma Frequency ◽  
Dominant Gene ◽  
Papaver Somniferum ◽  
Chromosome Behaviour ◽  
Diallel Crosses ◽  
Pollen Mother Cells ◽  
Dominant Component ◽  
Genetic Components ◽  
Mother Cells

Three nuclear variables, namely chiasma frequency, internuclear variation of chiasmata, and numerical deviations in the chromosomes of pollen mother cells, referred to as meiotic lability, were studied in 5 × 5 diallel crosses of Papaver somniferum L. Chiasma frequency and meiotic lability were controlled by both additive and dominant gene actions and internuclear chiasmata variance was controlled by the dominant component. High values for chiasma frequency and meiotic lability were dominant over their low values, whereas low values of internuclear variation of chiasmta were dominant over the corresponding high values.Key words: chromosome behaviour, genetic components, Papaver somniferum.

Persisting demibivalents: a unique meiotic behaviour in Cuscuta babylonica Choisy

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Batia Pazy ◽  
Uzi Plitmann
Keyword(s):  
Key Words ◽  
Chromosome Segregation ◽  
Meiotic Behaviour ◽  
Chromosome Behaviour ◽  
Chromosome Movement ◽  
Pollen Mother Cells ◽  
Key Words Meiosis ◽  
Mother Cells ◽  
Telomeric Association

Idiosyncratic chromosome behaviour during meiosis was found in pollen mother cells of Cuscuta babylonica Choisy, a thread-like holoparasitic herb. Its main features are among the following: (i) telomeric association between homologues through most stages of the process, which leads to persisting chromatid bivalents (= "demibivalents"); (ii) uncommon chromosome segregation in first and second anaphase; and (iii) prolonged intensified heterochromatinization. Although "regular" in its own way, this process leads to the formation of unviable products. Its further investigation might contribute to our understanding of the role of the spindle and chromosome movement in the ordinary process of meiosis. Key words: meiosis (abnormal), persisting demibivalents, Cuscuta babylonica.

CHROMOSOME BEHAVIOUR IN F1 WHEAT HYBRIDS: I. PENTAPLOIDS

1941 ◽  
Vol 19c (9) ◽  
pp. 351-369 ◽  
Author(s):  
R. Merton Love
Keyword(s):  
The Other ◽  
Spindle Fibre ◽  
Chromosome Behaviour ◽  
Pollen Mother Cells ◽  
Triticum Vulgare ◽  
Attachment Region ◽  
Wheat Hybrids ◽  
Mother Cells ◽  
Relationship Of ◽  
Fibre Attachment

Meiosis was studied in varieties of Triticum vulgare (2n = 42), T. dicoccum (2n = 28), T. durum (2n = 28), T. Timopheevi (2n = 28), and in 16 of their pentaploid hybrids as part of a study in an attempt to establish criteria indicating relationships between 42- and 28-chromosome wheats, with particular reference to the possible relationship of the new 42-chromosome wheat, McMurachy's Selection, to T. dicoccum or T. durum.One plant each of T. vulgare var. Hope and Marquillo had only 41 chromosomes. One plant of T. durum var. Pentad had three times as many unpaired chromosomes as the other plants of this variety.A nucleus with 14 pairs and 7 univalents was not detected among the 86 pollen mother cells analysed in the cross involving T. Timopheevi. In the remaining crosses the frequency of this association of chromosomes was lowest in the three hybrids involving T. durum var. Pentad, greater in the three involving T. dicoccum var. Khapli, still greater in the three involving T. dicoccum var. Vernal, and greatest in the nine hybrids involving T. durum var. Iumillo.Of the seven "extra chromosomes" of T. vulgare only six remained unpaired in some pollen mother cells of the hybrids involving Vernal or Iumillo and five in those involving Khapli or Pentad. One pollen mother cell of F1 Marquis × Pentad contained only four unpaired chromosomes.Associations of four chromosomes were rare in some, and not seen at all in others, of the hybrids involving Vernal or Iumillo, more frequent in hybrids involving Khapli, and very frequent in hybrids involving Pentad. In the latter, from 47 to 57% of the nuclei had from one to three such multiple associations, and even chains of five and six chromosomes were observed.Fragmentation of unpaired chromosomes at or in the spindle fibre attachment region was observed in a number of first anaphase figures.There were statistically significant differences in the frequencies of occurrence of micronuclei in tetrads of the 15 hybrids studied at the second reduction division.The crosses R.L. 1544 (genetically related to T. durum var. Iumillo) × Iumillo and Hope (genetically related to T. dicoccum var. Vernal) × Vernal were used as standards for comparison. On the basis of the results, the following criteria were used in attempting to establish relationships between the other 42- and 28-chromosome wheats: (1) the percentage of pollen mother cells with 14 pairs and 7 univalents (greatest in the hybrids between related varieties); (2) the average number of chromosomes involved in multiple associations (lowest in hybrids between related varieties); (3) fertility (greatest in hybrids between related varieties). McMurachy's Selection appeared to be most closely related to T. durum var. Iumillo. On the basis of Criteria (1) and (2), Marquis appears to be more closely related to T. dicoccum var. Vernal than to T. durum var. Iumillo, but in respect of fertility it seems closer to the latter.Chromosome behaviour in the 16 hybrids cannot be neatly summarized. Even varieties within a species gave different results—results that are not in agreement with earlier published reports on chromosome behaviour in pentaploid wheat hybrids in which it has been stated that 14 bivalents and 7 univalents are most commonly found. The difficulties encountered in attempting to establish criteria indicating relationships between the 42- and 28-chromosome wheats suggest that the utmost caution must be used in drawing phylogenetic conclusions on the basis of such data.

Genetically controlled desynapsis in diploid Critesion violaceum and its hybrids with autotetraploid Psathyrostachys juncea

1984 ◽  
Vol 26 (5) ◽  
pp. 532-537 ◽  
Author(s):  
Richard R-C. Wang
Keyword(s):  
Chromosome Pairing ◽  
Chiasma Frequency ◽  
Intergeneric Hybrid ◽  
Dosage Effect ◽  
The Other ◽  
Pollen Mother Cells ◽  
Psathyrostachys Juncea ◽  
Self Pollination ◽  
Meiotic Irregularities ◽  
Mother Cells

Segregation for chiasma frequency was observed in the progeny of a diploid (2n = 14) Critesion violaceum strain following self-pollination. One S1 plant had normal metaphase pairing with an average of 0.43I + 6.78II, giving a high chiasma frequency, 12.03 per cell. The other S1 plant averaged 7.89I + 3.08II and a low chiasma frequency, 3.47 per cell. Examination of pollen mother cells at early prophases revealed that chromosome pairing was not totally prevented. It was concluded that desynapsis was responsible for the meiotic irregularities observed in the variant progeny. The same phenomena were observed in F1 hybrids of the cross between diploid C. violaceum and an induced autotetraploid (2n = 28), Psathyrostachys juncea. The normal F1 hybrid had a chiasma frequency of 12.81, but the desynaptic hybrid had a chiasma frequency of 6.94. A dosage effect of the desynaptic gene, which was probably recessive, was suggested. The implications and significance of this discovery are discussed.Key words: asynapsis, chiasma, meiosis, intergeneric hybrid.

A separate control for frequency and within-bivalent distribution of chiasmata in rye (Secale cereale L.)

Genome ◽  
1987 ◽  
Vol 29 (3) ◽  
pp. 419-424 ◽  
Author(s):  
V. Lein ◽  
T. Lelley
Keyword(s):  
Secale Cereale ◽  
Chiasma Frequency ◽  
Positional Distribution ◽  
Pollen Grains ◽  
Female Parent ◽  
Close Correlation ◽  
Strong Negative Correlation ◽  
Pollen Mother Cells ◽  
Chiasma Distribution ◽  
Mother Cells

Six genetically different inbred genotypes of spring-type rye Secale cereale with differences in the average number and in the positional distribution of chiasmata were used in this study. The line with the lowest chiasma frequency was chosen as the female parent and crossed with the other five lines. Parental, F1, and F2 data were collected on chiasma number and on chiasma distribution between and within bivalents. Evidence for a polygenic control of both phenomena was found. Chiasma distribution between bivalents within pollen mother cells obviously follows a binomial distribution. This is effected by a mechanism that prevents the formation of a second chiasma on a chromosome arm as long as chromosome arms without chiasma remain; i.e., with 14 chiasmata seven ring bivalents will generally be formed. This mechanism causes a very strong negative correlation between frequency and between-cell variance of chiasmata. The number of chiasmata is independent of their position within the bivalents. A very close correlation between the number of pollen mother cells without univalents and the number of fertile pollen grains was found. Key words: inbred rye, genetic control, chiasma frequency, chiasma distribution, heterosis.

New cytogenetic information on Allium iranicum (Alliaceae) from Iran

Biologia ◽  
2006 ◽  
Vol 61 (4) ◽  
Author(s):  
Seyed Ghaffari
Keyword(s):  
Detailed Analysis ◽  
Related Species ◽  
Karyotype Analysis ◽  
Chromosome Complement ◽  
Chromosome Behaviour ◽  
Homologous Chromosomes ◽  
Pollen Mother Cells ◽  
Satellite Chromosomes ◽  
Mother Cells ◽  
Metaphase I

AbstractKaryotype analysis and chromosome behaviour in tetraploid Allium iranicum is reported. The somatic karyotype 2n = 32, consists of 12 pairs of metacentric chromosomes, two pairs of submetacentric chromosomes and two pairs of submetacentric satellite chromosomes. Chromosome complement follows two sets of 16 pairs of homologous chromosomes. A detailed analysis of Pachytene, Diplotene and Metaphase I of meiosis in pollen mother cells in this taxon showed that the most common chromosome configurations were bivalents at all subphases mentioned. It is concluded that A. iranicum is most likely a natural allotetraploid and certainly differs from related species A. ampeloprasum, A. commutatum and A. porrum.

Chromosome localization of genes that control synchronous development of pollen mother cells in wheat

Caryologia ◽  
2003 ◽  
Vol 56 (3) ◽  
pp. 275-279 ◽  
Author(s):  
Wei Li ◽  
Jun Yang ◽  
You-Fu Pan ◽  
Guang-Qin Guo ◽  
Guo-Chang Zheng
Keyword(s):  
Chromosome Localization ◽  
Pollen Mother Cells ◽  
Synchronous Development ◽  
Mother Cells

An ultrastructural study of cytomixis in tobacco pollen mother cells

PROTOPLASMA ◽  
2011 ◽  
Vol 248 (4) ◽  
pp. 717-724 ◽  
Author(s):  
Sergey R. Mursalimov ◽  
Elena V. Deineko
Keyword(s):  
Ultrastructural Study ◽  
Pollen Mother Cells ◽  
Tobacco Pollen ◽  
Mother Cells

TETRAPLOID TARAXACUM KOK-SAGHYZ: I. CHARACTERS OF THE LEAVES AND INFLORESCENCES IN THE PARENTAL COLCHICINE-INDUCED GENERATION

1945 ◽  
Vol 23c (4) ◽  
pp. 131-143 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Guard Cells ◽  
Stages Of Development ◽  
Pollen Mother Cells ◽  
Mother Cells

Seedlings at different stages of development were treated with colchicine. Successive selections on the aspect of the seedlings soon after treatment, on size of the guard cells at the time of repotting, and finally, after overwintering, on counts of the chromosomes in the pollen mother cells yielded a few hundred plants with tetraploid crowns. These plants bore fewer, broader leaves and fewer, bigger inflorescences with larger achenes than did selected large-celled diploids given the same treatment, but in general the plants were no bigger. A few of the tetraploids were self-fertile (if not apomictic) early in the spring, but later all tested plants proved self-sterile.

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