scholarly journals Meiotic Studies in Some Species of Tribe Cichorieae (Asteraceae) from Western Himalayas

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Raghbir Chand Gupta ◽  
Henna Goyal ◽  
Vijay Singh ◽  
Rajesh Kumar Goel
Keyword(s):  
Chromosome Number ◽  
Pollen Viability ◽  
Intraspecific Variability ◽  
Pollen Grains ◽  
Early Prophase ◽  
Western Himalayas ◽  
Meiotic Abnormalities ◽  
Unreduced Pollen ◽  
Chromosome Stickiness ◽  
First Time

The present paper deals with meiotic studies in 15 species belonging to 6 genera of the tribe Cichorieae from various localities of Western Himalayas. The chromosome number has been reported for the first time inHieracium crocatum(2n=10) andLactuca lessertiana(2n=2x=16). Further, intraspecific variability has been reported for the first time inH. umbellatum(2n=2x=10and2n=6x=54),Tragopogon dubius(2n=2x=14and2n=4x=28), andT. gracilis(2n=2x=14). The chromosome report of2n=2x=10inYoungia tenuifoliais made for the first time in India. Maximum numbers of the populations show laggards, chromosome stickiness, and cytomixis from early prophase to telophase-II, leading to the formation of aneuploid cells or meiocytes with double chromosome number. Such meiotic abnormalities produce unreduced pollen grains and the reduced pollen viability.

scholarly journals Botanical aspects of Heteropterys umbellata (Malpighiaceae): a cytological and palynological approach

2010 ◽  
Vol 82 (4) ◽  
pp. 868-879 ◽  
Author(s):  
Saulo M. Sousa ◽  
Aryane C. Reis ◽  
Shaiany S.L. Gomes ◽  
Karina B. Bernardo ◽  
Fátima R.G. Salimena ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Chromosome Pair ◽  
Pollen Morphology ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Meiotic Behavior ◽  
Dapi Staining ◽  
Palynological Analysis ◽  
Pollen Content ◽  
First Time

The genus Heteropterys is one of the major genera in Malpighiaceae. However, few cytological and palynological studies were reported. The present work described for the first time the chromosome number, heterochromatin pattern, meiotic behavior, pollen viability and palynological aspects of Heteropterys ubellata, a very spread species. One large Brazilian population was evaluated using conventional techniques for meiotic studies and acetolyse to access the pollen morphology. The species showed 2n = 20 chromosomes, normal meiotic development and viable pollens. Great blocks of heterochromatin were observed around the centromers. DAPI staining was positive for centroeric heterochroatin, hile CMA3 ark as observed just at terinal regions of one pair of hoologues chromosomes. This result and the presence of one chromosome pair attached to the nucleoli during the pachytene and diakinesis suggested the presence of only one pair of NORs. Palynological analysis revealed that pollen grains are apolar, 6 porate and with colpoids associated to all pores. The pollen content was positive for the starch test, and the exine was rugulate with little psilate regions.

scholarly journals Meiotic behaviour and pollen fertility of F1, F2 and BC1 progenies of Iris dichotoma and I. domestica

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenji Xu ◽  
Gangjun Luo ◽  
Xiaoyin Lian ◽  
Fengyang Yu ◽  
Yang Zheng ◽  
...  
Keyword(s):  
Pollen Fertility ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Male Meiosis ◽  
Meiotic Behaviour ◽  
Interspecific Hybridisation ◽  
Meiotic Abnormalities ◽  
Chromosome Bridges ◽  
First Time ◽  
Spindle Fibres

Abstract Pollen characteristics are very important for Iris interspecific hybridisation. In this study, the pollen viability and male meiosis were studied in yellow-flowered Iris dichotoma (Y2), I. domestica (S3) and their hybrids F1, F2 and BC1 (BC1-Y and BC1-S). The BC1-Y hybrids showed higher pollen viability than that of F1, F2 and BC1-S hybrids, which were between I. dichotoma (26.1%) and I. domestica (35.1%). Two sterile hybrids, F2-1 and BC1-S-1, exhibited more meiotic abnormalities (57.3% and 58.7%) than other individuals. During the first meiotic division, a diffuse diplotene stage was observed for the first time in the genus Iris. The meiotic abnormalities included non-congressed chromosomes, chromosome bridges, lagging chromosomes, unequal division, abnormally oriented spindle fibres, nonsynchronous division and polyad, and resulted in reduced pollen fertility. The relatively high frequency of 2n pollen grains was found in hybrids of BC1-Y-2, BC1-Y-1, BC1-S-2, BC1-S-3 and BC1-S-4. Our research provides a new resource for meiotic behaviour and pollen fertility of the genus Iris.

Contribution to the systematic knowledge of Lamium multifidum and L. orientale (Lamiaceae)

Phytotaxa ◽  
2015 ◽  
Vol 203 (2) ◽  
pp. 147 ◽  
Author(s):  
Bayram Atasagun ◽  
Ahmet Aksoy ◽  
Esra Martin
Keyword(s):  
Chromosome Number ◽  
Cross Section ◽  
Pollen Grains ◽  
Morphological Characters ◽  
Previous Description ◽  
Somatic Chromosome Number ◽  
Additional Information ◽  
Naturally Occurring ◽  
First Time ◽  
Systematic Knowledge

Some morphological, anatomical, palynological and karyological features of Lamium multifidum and L. orientale (Lamiaceae) naturally occurring in Turkey have been studied. Additional information was added to the previous description of these species. Anatomically, both L. multifidum and L. orientale had an annual taproot, stems quadrangular in cross-section, leaves bifacial. The nutlets were ovoid in outline and trigonous in cross section, blackish-dark brownish, with glabrous surface. The pollen grains of both species were tricolpate, shape subprolate, ornamentation reticulate. In both species, the somatic chromosome number resulted 2n = 14. The anatomical and palynological features, chromosome number and morphological characters of both species were reported for the first time in this study.

scholarly journals Pollen Morphology and Variability of Abies alba Mill. Genotypes from South-Western Poland

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1125
Author(s):  
Dorota Wrońska-Pilarek ◽  
Monika Dering ◽  
Jan Bocianowski ◽  
Kacper Lechowicz ◽  
Wojciech Kowalkowski ◽  
...  
Keyword(s):  
Pollen Morphology ◽  
Geographical Location ◽  
Abies Alba ◽  
Intraspecific Variability ◽  
Pollen Grains ◽  
Polar Axis ◽  
Seed Orchard ◽  
Diagnostic Features ◽  
Pollen Shape ◽  
First Time

The objective of this study was to investigate pollen morphology and ranges of intraspecific variability of Abies alba Mill. Pollen grains were collected from nine clonal seed orchards of A. alba in the Sudety Mountains, (South-Western Poland). At each seed orchard, 4–6 grafts were selected. Each individual (graft) was represented by 30 pollen grains and 1440 pollen grains were measured totally. Eight quantitative and four qualitative features of pollen grains were analysed. The diagnostic features of pollen grains for the studied species were: Exine surface of pollen corpus (cappa and leptoma) and sacci, the length of the polar axis (P), pollen shape (P/E ratio), and a new trait—saccus shape (A/B ratio — saccus width (A) to his length (B)). Pollen features made possible to differentiate seven individual genotypes (samples). To our knowledge, this is the first time that the intraspecific and interindividual variability of pollen grains of A. alba were investigated. The most different were the pollen grains from samples—genotypes 13 (Bystrzyca Kłodzka) and 18 (Jugów), and also (although to a lesser extent) genotypes—11 (Kamienna Góra), 30, 31 (Jugów), and 44 (Szklarska Poręba). No significant relationships were observed between the pollen grain traits and the geographical location of the collection sites.

scholarly journals Microsporogenesis in Brachiaria bovonei (Chiov.) Robyns and B. subulifolia (Mez) Clayton (Poaceae)

2009 ◽  
Vol 66 (5) ◽  
pp. 691-696 ◽  
Author(s):  
Claudicéia Risso-Pascotto ◽  
Maria Suely Pagliarini ◽  
Cacilda Borges do Valle
Keyword(s):  
Chromosome Number ◽  
High Frequency ◽  
Germplasm Collection ◽  
Meiotic Abnormalities ◽  
Meiotic Behavior ◽  
African Species ◽  
Germplasm Collections ◽  
Chromosome Stickiness ◽  
The Tropics ◽  
New Cultivars

Some African species of Brachiaria have been introduced into the Americas and became the most important forage for pastures in the tropics. New cultivars can be obtained either from direct selections from the natural existing variability in the germplasm collections or from interspecific hybridizations. Polyploidy is predominant in the genus Brachiaria and correlated with apomixis which complicates hybridization. The objective of cytological studies underway on the Brachiaria germplasm collection at Embrapa Beef Cattle is to determine the chromosome number and meiotic behavior of accessions. For the breeding of Brachiaria species, compatible sexual and apomictic accessions need to be identified. Microsporogenesis was evaluated in two accessions of Brachiaria bovonei (BO01 and BO05) and one accession of B. subulifolia (SU01). BO01 is pentaploid (2n = 5x = 45), BO05 is tetraploid (2n = 4x = 36), and SU01 is hexaploid (2n = 6x = 54), derived from x = 9. Meiotic abnormalities typical of polyploids, characterized by precocious chromosome migration to the poles in metaphases, laggard chromosomes in anaphases, and micronuclei in telophases and tetrads, were recorded in high frequency in all the accessions generating unbalanced gametes. Both accessions of B. bovonei presented chromosome stickiness. The results are discussed in the view of the Brachiaria breeding program objectives.

Persistent occurrence of meiotic abnormalities in a new hexaploid cytotype of Thalictrum foetidum from Indian cold deserts

Biologia ◽  
2011 ◽  
Vol 66 (3) ◽  
Author(s):  
Vijay Singhal ◽  
Pawan Rana ◽  
Puneet Kumar ◽  
Dalvir Kaur
Keyword(s):  
Meiotic Chromosome ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Plant Size ◽  
Pollen Sterility ◽  
Male Meiosis ◽  
Meiotic Abnormalities ◽  
Leaf Pubescence ◽  
Karyotypic Analysis ◽  
In The Wild

AbstractThalictrum foetidum L. (Ranunculaceae), a morphologically variable and widely distributed species of temperate and alpine Himalayas is worked out cytologically for the first time from India. Earlier studies from outside India were restricted to chromosome counts and karyotypic analysis. We studied the male meiosis, microsporogenesis and pollen viability in the wild accessions from the cold deserts of Lahaul-Spiti, Kinnaur and Pangi Valley of Himachal Pradesh. Present cytomorphological surveys in the species record the existence of two distinct morphotypes involving plant size; colour and size of leaf/leaflet; dentation of leaflet lobes; and degree of leaf pubescence. All the accessions in the two morphovariants share the same meiotic chromosome number (n = 21) and adds a new intraspecific hexaploid cytotype. The accessions show the phenomenon of cytomixis involving transfer of chromatin material among proximate pollen mother cells (PMCs) and associated meiotic abnormalities like, out of plate bivalents, interchromosomal connections, and laggards, bridges and micronuclei at anaphases/telophases. Microsporogenesis results into abnormal sporads (tetrads with micronuclei, dyads, triads and polyads). The products of such sporads resulted into some pollen sterility and pollen grains of heterogeneous sizes. The persistent occurrence of phenomenon of cytomixis and associated meiotic abnormalities and consequently pollen sterility and pollen grains of heterogeneous sizes in the hexaploid cytotype of T. foetidum seems to be under some genetic factors associated with the genome.

Cytology of the genus Artemisia (Anthemidae, Asteraceae) in the Western Himalayas

Biologia ◽  
2014 ◽  
Vol 69 (9) ◽  
Author(s):  
Raghbir Gupta ◽  
Henna Goyal ◽  
Vijay Singh
Keyword(s):  
Pollen Fertility ◽  
Chromosomal Abnormalities ◽  
Pollen Grains ◽  
Western Himalaya ◽  
Himachal Pradesh ◽  
B Chromosomes ◽  
Meiotic Behaviour ◽  
Western Himalayas ◽  
Fertile Pollen ◽  
First Time

AbstractThe present study revealed the varied frequency of natural chromosomal abnormalities in 13 populations pertaining to 9 species of the genus Artemisia L. from different localities of Himachal Pradesh (Western Himalaya). Intraspecific chromosome variability has been reported for the first time on worldwide basis in Artemisia vestita (2n = 2x = 36) and from India in A. macrocephala (2n = 2x = 18) and A. scoparia (2n = 2x = 36). Besides, B-chromosomes have been reported here for the first time in A. nilagirica and A. roxburghiana. Most of the populations show anomalous meiotic behaviour resulting in cytomixis, chromosomal stickiness, unoriented bivalents, formation of laggards and bridges which leads to abnormal microsporogenesis, and production of heterogeneous-sized fertile pollen grains along with reduced pollen fertility.

scholarly journals Pollen morphology and variability of species from the genus Rubus L. (Rosaceae) alien and invasive in Poland

Webbia ◽  
2021 ◽  
Vol 76 (1) ◽  
pp. 109-121
Author(s):  
Kacper Lechowicz ◽  
Jan Bocianowski ◽  
Dorota Wrońska-Pilarek
Keyword(s):  
Alien Species ◽  
Pollen Morphology ◽  
Pollen Viability ◽  
Intraspecific Variability ◽  
Pollen Grains ◽  
Polar Axis ◽  
Exine Ornamentation ◽  
The Family ◽  
Rubus Species

Rubus L. is one of the most species-rich and most taxonomically challenging genera in the family Rosaceae. The aim of this study was to investigate pollen morphology and the ranges of inter- and intraspecific variability of the studied Rubus alien species, as well as verify the taxonomic usefulness of these traits in distinguishing studied taxa from this genus. We analysed six quantitative pollen characteristics and the following qualitative ones: exine ornamentation, pollen outline and shape. The study was conducted on 24 samples of six alien Rubus species found in Poland. 720 pollen grains were measured in total. The most important pollen features included exine ornamentation and length of the polar axis (P). In the conducted studies there were no features of pollen indicating “invasiveness”. The results of our research fill the gap in knowledge on pollen structure in Rubus species alien to Poland and Europe. They may constitute a foundation for further research on the reproduction of these species (e.g. pollen viability and fertility), thus facilitating identification of features determining their expansive character.

scholarly journals A Duplicated Copy of the Meiotic Gene ZIP4 Preserves up to 50% Pollen Viability and Grain Number in Polyploid Wheat

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 290
Author(s):  
Abdul Kader Alabdullah ◽  
Graham Moore ◽  
Azahara C. Martín
Keyword(s):  
Pollen Viability ◽  
Pollen Grains ◽  
Wheat Chromosome ◽  
Grain Number ◽  
Meiotic Gene ◽  
Chromosome 5B ◽  
Mutant Pollen ◽  
Female Gametogenesis ◽  
Chromosome 3B

Although most flowering plants are polyploid, little is known of how the meiotic process evolves after polyploidisation to stabilise and preserve fertility. On wheat polyploidisation, the major meiotic gene ZIP4 on chromosome 3B duplicated onto 5B and diverged (TaZIP4-B2). TaZIP4-B2 was recently shown to promote homologous pairing, synapsis and crossover, and suppress homoeologous crossover. We therefore suspected that these meiotic stabilising effects could be important for preserving wheat fertility. A CRISPR Tazip4-B2 mutant was exploited to assess the contribution of the 5B duplicated ZIP4 copy in maintaining pollen viability and grain setting. Analysis demonstrated abnormalities in 56% of meiocytes in the Tazip4-B2 mutant, with micronuclei in 50% of tetrads, reduced size in 48% of pollen grains and a near 50% reduction in grain number. Further studies showed that most of the reduced grain number occurred when Tazip4-B2 mutant plants were pollinated with the less viable Tazip4-B2 mutant pollen rather than with wild type pollen, suggesting that the stabilising effect of TaZIP4-B2 on meiosis has a greater consequence in subsequent male, rather than female gametogenesis. These studies reveal the extraordinary value of the wheat chromosome 5B TaZIP4-B2 duplication to agriculture and human nutrition. Future studies should further investigate the role of TaZIP4-B2 on female fertility and assess whether different TaZIP4-B2 alleles exhibit variable effects on meiotic stabilisation and/or resistance to temperature change.

Aspidistra revoluta, a new species from limestone areas in Chongqing, China

Phytotaxa ◽  
2016 ◽  
Vol 257 (3) ◽  
pp. 280 ◽  
Author(s):  
Hao Zhou ◽  
Si-rong Yi ◽  
Qi Gao ◽  
Jie Huang ◽  
Yu-jing Wei
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Average Length ◽  
Chromosome Complement ◽  
Pollen Grains ◽  
The Other ◽  
Morphological Comparison ◽  
Chongqing Municipality ◽  
Karyotype Asymmetry ◽  
A New Species

Aspidistra revoluta (Asparagaceae) is described and illustrated as a new species from limestone areas in southern Chongqing Municipality, China. The new species can be distinguished from the other Aspidistra species by its unique umbrella-like pistil with large revolute stigma lobes that bent downwards and touch the base of the perigone. A detailed morphological comparison among A. revoluta, A. nanchuanensis and A. carnosa is provided. The pollen grains of A. revoluta are subspherical and inaperturate, with verrucous exine. The chromosome number is 2n = 38, and the karyotype is formulated as 2n = 22m + 6sm + 10st. The average length of chromosome complement is 4.50 μm, and the karyotype asymmetry indexes A1 and A2 are respectively 0.37±0.03 and 0.49±0.01.

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