An overview on cytogenetics of the genusOnobrychis(Fabaceae) with special reference toO.sect.Hymenobrychisfrom Iran

Ranjbar, Massoud; Hajmoradi, Fatemeh; Karamian, Roya

doi:10.1080/00087114.2012.735887

Cited by 23 publications

(19 citation statements)

References 36 publications

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“…Synaptic irregularity, which influences chromosome pairing during meiosis, may be induced (Prakken 1943, Koduru and Rao 1981, Gulfishan et al 2010, Avijeet et al 2011 or originate spontaneously (Kaul and Murthy 1985, Singh 2002, Sharma et al 2010, Ranjbar et al 2012, Kumar and Singhal 2013.…”

Section: Discussionmentioning

confidence: 99%

Multiple Associations of Chromosomes Due to Structural Heterozygosity in the Wild Plants of Achillea millefolium L. from Northwest Himalayas (India)

et al. 2014

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Summary Presently, A. millefolium, a morphogenetically variable species, has been scored from phytogeographically isolated and unexplored areas of the northwest Himalayas for chromosome counts and male meiotic course. All the studied accessions shared the same meiotic chromosome number of n = 9 and existed at diploid level. A majority of the accessions exhibited the normal meiotic course including microsporogenesis and almost cent per cent pollen fertility. However, three accessions scored from Sangla Valley (Chittkul, 3450 m) and Solang Valley (Dhundi, 3000 m and Palchan, 2480 m) showed the presence of multiple associations of chromosomes in PMCs (pollen mother cells). The quadrivalents formed as a consequence to reciprocal translocations are either chain or ring type (typical ring and zigzag). Meiocytes with multivalents depicted relatively higher chiasma frequency than those with normal bivalent formation. In 4.77% of PMCs, chromosomes remained as laggards during anaphase-I and organized into micronuclei during sporad formation. Consequently sterile/unstained pollen grains were observed. This is the first report of structural heterozygosity for reciprocal translocations in the species.

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Section: Discussionmentioning

confidence: 99%

Multiple Associations of Chromosomes Due to Structural Heterozygosity in the Wild Plants of Achillea millefolium L. from Northwest Himalayas (India)

et al. 2014

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“…The present analysis is in accordance with De Nettancourt and Grant (1964), who suggested that cytomixis is a speciality of plants lacking balanced gametes such as aneuploids, haploids or hybrids. Ranjbar et al (2011Ranjbar et al ( , 2012 showed the occurrence of similar meiotic irregularities along with coenocytes due to cytomixis. In some cases the cells were left completely empty, showing migration of all chromatin materials.…”

Section: Discussionmentioning

confidence: 99%

Consequences of colchicine induced intermeiocyte connections inHelianthus annuus

Gautam

Kumar

2013

Caryologia

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During microsporogenesis sometimes the chromatin materials migrate from one cell to another by intermeiocyte connections. In the present study, during induction of tetraploidy in sunflower, changes in the normal behaviour of chromosomes was detected. Besides chromosomal aberrations, cytomictic connections were frequently recorded. Cytomixis has been reported by many researchers in many diploid or tetraploid plants. In sunflower, cytomixis in colchiploids has not been recorded. In the current study high numbers of cytoplasmic connections were observed in the plants failing to reach higher ploidy level. Formation of cytoplasmic connections was very high, leading to many hyperploids, hypoploids and even empty pollen mother cells (PMCs). Cytomixis occurred frequently, with two to many meiocytes engaged in exchange of chromatin through one or multiple cytoplasmic connections. Few rare polyploid PMCs with cytoplasmic connections were observed, which favours formation of aneuploids and polyploids. Besides various chromosomal anomalies, fertility was also significantly affected. This work envisages the possibility that although polyploidy was not achieved in some plants there is tendency to form higher ploidy levels in this species. This illustrates the potential for formation of various genetic combinations and thus novel traits. Cytomixis is also an additional source of male sterility in sunflower and thus requires intense research.

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“…Some researchers in Iran and Turkey have contributed to this subject with a few species (Akpinar and Yildiz 1999;Yildiz and Gücel 2006;Hejazi et al 2010;Arslan et al 2012;Karamian et al 2012;Ranjbar et al 2012). The relationship between the genus Hedysarum and Onobrychis was also addressed by Lewke-Bandara et al (in press).…”

Section: Introductionmentioning

confidence: 99%

Meiotic behaviour and karyotype features of endangered endemic fodder speciesHedysarum perrauderianum(Fabaceae) in some populations from Algeria

Benhizia

Ghernoub

et al. 2013

Caryologia

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The Mediterranean basin is considered to be one of the 33 mega biodiversity hotspots with the greatest number of endemic plants. This region has been exposed to a prolonged anthropogenic influence rendering its biodiversity prone to a rapid change. The first cytogenetic data are presented for Hedysarum perrauderianum Coss. and Durieu (Fabaceae), an endangered stenoendemic fodder species from Algeria. Karyotype features, heterochromatin organization, physical mapping of rRNA genes and meiotic behaviour were studied in six native populations. The transcriptional rDNA activity was evaluated by nucleoli number. The tetraploid chromosome number 2n = 4x = 32 was found in all populations studied. However, in two roadside populations we observed cells of the same individuals that had 32 and 18 chromosomes. Constitutive heterochromatin is mainly present in intercalary and telomeric positions. Four strong GC-rich DNA bands situated on two pairs of satellite chromosomes are colocalized with 18S-5.8S-26S rDNA loci. Sixteen additional weak CMA bands are also observed in centromeric regions. FISH revealed two loci of both 18S and 5S rDNA, distributed on different chromosome pairs. The similarity of certain chromosome pairs (morphological type of chromosome, constitutive heterochromatin) and presence of univalents, trivalents and tetravalents suggest an autotetraploid origin of this species. One to four heterochromatic B chromosomes were also observed in some populations. The frequencies of different types of chromosome pairing and meiotic abnormalities revealed two groups of populations according to environmental conditions.

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An overview on cytogenetics of the genusOnobrychis(Fabaceae) with special reference toO.sect.Hymenobrychisfrom Iran

Cited by 23 publications

References 36 publications

Multiple Associations of Chromosomes Due to Structural Heterozygosity in the Wild Plants of <i>Achillea millefolium </i>L. from Northwest Himalayas (India)

Multiple Associations of Chromosomes Due to Structural Heterozygosity in the Wild Plants of <i>Achillea millefolium </i>L. from Northwest Himalayas (India)

Consequences of colchicine induced intermeiocyte connections inHelianthus annuus

Meiotic behaviour and karyotype features of endangered endemic fodder speciesHedysarum perrauderianum(Fabaceae) in some populations from Algeria

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