A Cytological Study of a Triploid &lt;i&gt;Rhoeo discolor&lt;/i&gt;

Desai, Sharda

doi:10.1508/cytologia.30.260

Cited by 14 publications

(12 citation statements)

References 12 publications

(8 reference statements)

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“…Stickiness at pachytene As mentioned earlier, the pachytene stage was too sticky to be analysed for the pairing behaviour. This observation had also been reported by Coleman (1941), Walters and Gerestel (1948), Desai (1965), and Natarajan and Natarajan (1972). But, Koller (1932) was able to show pairing behaviour between homologous segments of non-homologous chromosomes at pachyene stage.…”

Section: Pollen Mitosis and Fertilitysupporting

confidence: 86%

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Breakdown of the classical meiotic system in Rhoeo spathacea (Commelinaceae).

Verma

Ohri

1979

CYTOLOGIA

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Section: Pollen Mitosis and Fertilitysupporting

confidence: 86%

“…in the tetraploid Rhoeo, whereas Desai (1965) reported two interstitial chiasmata in 150 triploid PMC's. Failure of the chiasmata between the pairing segments leads to break-up of the pachytene multiple of 12 chromosomes into a varying number of chromosome units of chains and rings (Fig.…”

Section: Breakdown Of Chiasma Localizationmentioning

confidence: 99%

Breakdown of the classical meiotic system in Rhoeo spathacea (Commelinaceae).

Verma

Ohri

1979

CYTOLOGIA

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“…Such structures are the result of interchanges between all the 12 chromosomes of the complement with each chromosome sharing partial homology with two others without altering the chromosome number. Owing to its atypical chromosome behavior this plant has been studied extensively for karyotype (Darlington 1929(Darlington , 1938Kato 1930;Sax 1931;Sax and Anderson 1933;Coleman 1941;Lin and Paddock 1973;Golcyzk et al 2005), C-banding (Natrajan and Natrajan 1972;Pettanati 1987;Pattankar andRanjekar 1988, Golcyzk andJoachimiak 1999), arrangement of AT-GC rich chromatin, NORs, 5s and 45s rDNA (Golczyk and Joachimiak 2003, 2008, Golczyk et al 2010Golczyk 2011aGolczyk , 2011b) and the meiotic behavior of chromosomes (Belling 1927;Kato 1930;Koller 1932;Akemine 1937;Bhaduri 1942;Simmonds 1945;Walters and Gerstel 1948;Desai 1965;Wimber 1968;Moens 1972;Satterfield and Mertens 1972;Mertens 1973;Lin 1979aLin , 1979bLin , 1980Lin , 1982aLin , 1982bLin and Paddock 1973;Lin and Lee 1979;Verma and Ohri 1979;Jahan and Vahidy 1994;K...…”

Section: Introductionmentioning

confidence: 99%

Variable multivalent orientations during diakinesis and metaphase I in microsporocytes ofTradescantia spathaceaSw.

Koul¹,

Nagpal²,

Kumar

2013

Caryologia

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Meiotic studies carried out on seven plants/clones of Tradescantia spathacea did not show the expected ring of 12 chromosomes in any of the 1765 cells studied at diakinesis (1202 cells) and metaphase I (563 cells). While at diakinesis the chromosomes resolved into chain configurations of all lengths ranging from one through 12 chromosomes, with the mean per cell being 2.47 ± 1.28, at metaphase I chains carrying up to 10 chromosomes were seen and the mean per cell was 4.18 ± 1.47. However, the larger chains were not the most frequent configurations observed at the two stages. Bivalents and univalents were the most frequent configurations observed in 38.68 and 43.92% cells at diakinesis and 63.94 and 57.72% cells at metaphase I, followed by chains of 10 (29.95% cells) and chains of three (51.50% cells) at the two stages, respectively. The larger chains, though visible at both the meiotic stages, varied significantly in the centromere orientation patterns. While at diakinesis they predominantly showed linear or indifferent orientation, at metaphase I 83.25% chains showed alternate orientation, with the rest showing linear and/or indifferent orientation. A high frequency of alternate orientation was observed in chains of three chromosomes (93.93%), followed by the chains of five and four, where 74.19 and 71.27% chains appeared in alternate orientation, respectively. In 4.97% cells with two chains of six chromosomes each, contrasting behavior was noticed in the two chains in respect of orientation. While one chain appeared zigzagged with alternate centromeres facing the same pole, the other chain invariably appeared in linear configuration. As a result of complex configurations at metaphase I and the high frequency of univalents, anaphase I segregation of chromosomes was highly irregular with 84% cells showing 1-3 lagging chromosomes. The average pollen viability determined for the seven clones studied was very low (17.87 ± 2.57%). The probable cause(s) of the different behaviors of the chain multiples at the two meiotic stages is discussed.

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“…A striking feature of chromosome association at diploid and tetraploid levels is the "complete terminalization" of chiasmata observed by other authors (Walters and Gerstel 1948, Desai 1965, Stack and Soulliere 1984. As observed in diploid desynaptic, parental plant, GAVA 1.1 (Garcia 1991) the tetraploid chromosome association was also disrupted at MI.…”

Section: Tetraploidsmentioning

confidence: 70%

“…Harlan and De Wet (1975) observed in maize, Zea mays L.; than even when (2n-n) and (n-2n) crosses occur, 2n, pollen does not compete well with n pollen especially on diploid stigmas. In Rhoeo spathacea triploids and tetraploids of spontaneous origin have been obtained in diploid plants (Desai 1965, Lin et al 1984, Walters and Gerstell 1948, Garcia 1991. The chromosome number observed in the progeny of ds-SDR plant (GAVA 1.1, Garcia 1991Garcia , 1995 are almost in agreement with expectations based on observed microspores (Garcia 1995).…”

Section: Resultsmentioning

confidence: 99%

Cytogenetical Studies in Rhoeo spathacea (Commelinaceae). IV. Ring-Forming Diploid and Desynaptic Tetraploid Sibs.

Velázquez

2000

CYTOLOGIA

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Summary By selfing a desynaptic-SDR mutant of Rhoeo spathacea (GAVA 1.1) 123 plants were obtained, 90 of those exhibited a diploid chromosomes number, 29 resulted in diplandrogynous autotetraploids and 4 presented an hyperploid condition (2n=13, 2n=25). A sample of 10 diploid and 10 tetraploid plants was studied. In diploids, desynapsis reverts to ring-forming and 56.76% of 2884 PMC analyzed presented a ring of 12 chromosomes while the remaining PMC presented one or two chains. No more than one univalent/PMC was observed. At AI 61.95% PMC presented a 6 : 6 disjunction. Pollen fertility ranged from 0% (in a male sterile plant) to 62.90%. The male sterile mutant is the first recorded in R. spathacea and it is here identified as ms1. In diplandrogynous autotetraploid plants desynapsis was observed in 100% of 942 PMC, with 8 to 24 univalent/PMC. Twenty four univalents were observed in 37.09% of PMC analyzed and 59.9% PMC exhibited a range of 14-22 univalents/cell. At AI a 12 : 12 disjunction was observed in 37.89% of PMC. Pollen stainability of 48.02% was the observed average in tetraploid plants. These results confirm the hypothesis that in the rings observed at TI pairing occurs and therefore interchange of chromosome segments affecting the desynaptic gene is possible. As a result of this pairing at TI only diploid parts of the progeny revert desynapsis to ring-forming. Otherwise only one allele should be present.

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A Cytological Study of a Triploid <i>Rhoeo discolor</i>

Cited by 14 publications

References 12 publications

Breakdown of the classical meiotic system in Rhoeo spathacea (Commelinaceae).

Breakdown of the classical meiotic system in Rhoeo spathacea (Commelinaceae).

Variable multivalent orientations during diakinesis and metaphase I in microsporocytes ofTradescantia spathaceaSw.

Cytogenetical Studies in Rhoeo spathacea (Commelinaceae). IV. Ring-Forming Diploid and Desynaptic Tetraploid Sibs.

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