scholarly journals Cytomictic Anomalous Male Meiosis and 2nPollen Grain Formation inMertensia echioidesBenth. (Boraginaceae) from Kashmir Himalaya

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Reyaz Ahmad Malik ◽  
Raghbir Chand Gupta ◽  
Santosh Kumari ◽  
Akhtar Hussain Malik
Keyword(s):  
Pollen Grains ◽  
Male Meiosis ◽  
Kashmir Himalaya ◽  
Open Chain ◽  
Chromatin Material ◽  
Translocation Heterozygosity ◽  
Mother Cells ◽  
Chromatin Transfer ◽  
First Time ◽  
Metaphase I

PresentlyMertensia echioidesBenth. (Boraginaceae) collected from Kashmir Himalaya, India, is cytologically analyzed for the first time revealing2n=2x=24(diploid). Interestingly we found 4.3–6.2% syncytic meiocytes/PMCs with2n=4x=48(tetraploid) in addition to normal meiocytes (2n=24) during male meiosis. These comparatively larger PMCs (pollen mother cells) lead to the formation of fertile giant2npollen grains. A frequency of 6.4–13.3% PMCs shows transfer of chromatin material at prophase-I and, therefore, results in aneuploid meiocytes. Whole chromatin transfer by the process of cytomixis could also have led to the formation of tetraploid cells. Translocation heterozygosity is also evident in the form of multivalents in 12–17% diploid (2x) meiocytes at diakinesis and metaphase-I and is reported for the first time in this species. The syncytes formed depict open chain hexavalent and quadrivalent formation in the three populations with different frequencies. Moreover chromatin stickiness at metaphase-I is observed in 45% of PMCs in population-1 (P-1). Syncyte or unreduced PMC formation leading to unreduced fertile gametes is here speculated to act as a possible way out for infraspecific polyploidization in the species.

scholarly journals Male meiosis and pollen morphology in diploid Indonesian wild bananas and cultivars

The Nucleus ◽  
2021 ◽  
Author(s):  
Fajarudin Ahmad ◽  
Yuyu S. Poerba ◽  
Gert H. J. Kema ◽  
Hans de Jong
Keyword(s):  
Hybrid Sterility ◽  
Pollen Grains ◽  
Chromosome Analysis ◽  
Male Meiosis ◽  
Enzyme Treatment ◽  
Unreduced Gamete ◽  
Ploidy Levels ◽  
Scientific Disciplines ◽  
Sterile Pollen ◽  
Mother Cells

AbstractBreeding of banana is hampered by its genetic complexity, structural chromosome rearrangements and different ploidy levels. Various scientific disciplines, including cytogenetics, linkage mapping, and bioinformatics, are helpful tools in characterising cultivars and wild relatives used in crossing programs. Chromosome analysis still plays a pivotal role in studying hybrid sterility and structural and numerical variants. In this study, we describe the optimisation of the chromosome spreading protocol of pollen mother cells focusing on the effects of standard fixation methods, duration of the pectolytic enzyme treatment and advantages of fluorescence microscopy of DAPI stained cell spreads. We demonstrate the benefits of this protocol on meiotic features of five wild diploid Musa acuminata bananas and a diploid (AA) cultivar banana “Rejang”, with particular attention on pairing configurations and chromosome transmission that may be indicative for translocations and inversions. Pollen slides demonstrate regular-shaped spores except “Rejang”, which shows fertile pollen grains of different size and sterile pollen grains, suggesting partial sterility and unreduced gamete formation that likely resulted from restitutional meiotic divisions.

scholarly journals Chromatin Transfer during Male Meiosis Resulted into Heterogeneous Sized Pollen Grains in Anemone rivularis Buch.-Ham. ex DC. from Indian Cold Deserts

CYTOLOGIA ◽  
2009 ◽  
Vol 74 (2) ◽  
pp. 229-234 ◽  
Author(s):  
Vijay Kumar Singhal ◽  
Puneet Kumar ◽  
Dalvir Kaur ◽  
Pawan Kumar Rana
Keyword(s):  
Pollen Grains ◽  
Male Meiosis ◽  
Chromatin Transfer

scholarly journals Secondary associations in ‘Himalayan pink’ (Dianthus angulatus Royle ex Benth., Caryophyllaceae) from cold deserts of Lahaul-Spiti

Genetika ◽  
2017 ◽  
Vol 49 (1) ◽  
pp. 87-94
Author(s):  
Puneet Kumar ◽  
Vijay Singhal ◽  
Sunil Srivastava
Keyword(s):  
Male Meiosis ◽  
Chromosome Count ◽  
Himachal Pradesh ◽  
Current Investigation ◽  
Secondary Association ◽  
Secondary Pairing ◽  
End To End ◽  
The Difference ◽  
First Time ◽  
Metaphase I

In current investigation we studied the male meiosis and details of secondary chromosomal associations or pairing recorded for the first time in Dianthus angulatus Royle ex Benth., from the cold deserts of Lahaul-Spiti (Himachal Pradesh, India). All the presently studied individuals of the species existed at 2x level (x = 15). The present chromosome count of n = 15 in the species is in conformity with the previous counts from India and outside of India. Secondary associations are defined as the affinity of bivalents to be positioned in pairs having gentle connections. The secondary chromosomal associations in the species existed among bivalents/chromosomes were observed in the meiocytes at metaphase-I and continued till the metaphase-II. The bivalents positioned side by side and end to end to form secondary pairing. The difference in the number of bivalents/chromosomes involved in the secondary associations has also been witnessed. A secondary association between bivalents is considered to be of immense importance as it is being taken as a gauge of ploidy in plants. The incidence of such secondary associations of bivalents/chromosomes in D. angulatus which existed at 2x level indicated the secondary polyploid nature of the species.

scholarly journals Meiotic Aberrations Leading To Aneuploidy In Cauliflower (Brassica Oleracea L. var. Botrytis)

2021 ◽  
Author(s):  
Xianwen Ji ◽  
Cilia Lelivelt ◽  
Erik Wijnker ◽  
Hans de Jong
Keyword(s):  
Brassica Oleracea ◽  
Chromosome Pairing ◽  
Tandem Repeats ◽  
Chiasma Formation ◽  
Male Meiosis ◽  
Genetic And Environmental Factors ◽  
Mother Cells ◽  
Selection Of ◽  
Meiotic Aberrations ◽  
Metaphase I

Abstract Aneuploid cauliflower plants (Brassica oleracea L. var. botrytis) display abnormal curd phenotypes causing serious commercial problems in offspring populations. Despite extensive breeding efforts, selection of genotypes producing euploid gametes remains unsuccessful due to unknown genetic and environmental factors. To reveal the origin of aneuploid gametes, we analyzed chromosome pairing, chiasma formation and chromosome segregation in pollen mother cells of selected cauliflower genotypes. To this end we compared different genotypes exhibiting Low with < 5%, Moderate with 5-10% and High with > 10% aberrant offspring. Microscopic observations revealed regular chromosome pairing at pachytene. However, cells at diakinesis and metaphase I showed variable numbers of univalents, suggesting that chiasma formation during meiotic prophase is incomplete or disrupted and results in a partial desynaptic phenotype. Cells at anaphase I – telophase II exhibited various degrees of unbalanced chromosome numbers explaining the aneuploid offspring. Immunofluorescence probed with an MLH1 antibody demonstrated fluorescent foci in all genotypes, but their lower numbers do not correspond to the putative sites of chiasmata. Interchromosomal connections between chromosomes and bivalents are common at diakinesis and metaphase I, and they contain centromeric and 45S rDNA tandem repeats, but such threads seemed not to affect proper disjoin of the half bivalents at anaphase I. Moreover, male meiosis in the arabidopsis APETALA1/ CAULIFLOWER double mutant with the typical cauliflower phenotype did show interchromosomal connections, but there were no indications for partial desynapsis. We now hypothesize that the occurrence of desynapsis in cauliflower is a developmental out-of-phase phenomenon partially or completely controlled by genes involved in flower and curd development.

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.

Medicinal importance of Papra (Podophyllum hexandrum Royle) in Unani System of Medicine

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohd Afsahul Kalam ◽  
Akhtar H. Malik ◽  
Aijaz Hassan Ganie ◽  
Tariq Ahmad Butt
Keyword(s):  
Plant Species ◽  
Podophyllum Hexandrum ◽  
Kashmir Himalaya ◽  
Unani Medicine ◽  
Lymph Glands ◽  
Pharmacological Studies ◽  
Great Scholar ◽  
Endemic Medicinal Plant ◽  
Sinopodophyllum Hexandrum ◽  
First Time

Abstract Podophyllum hexandrum Royle [=Sinopodophyllum hexandrum (Royle) T.S. Ying] is an important, endemic medicinal plant species of Himalaya. It is used in Unani System of Medicine under the name of ‘Papra’. The drug was not mentioned in previous literatures, but the first time it introduced in Unani Medicine by a great scholar Hakim Najmul Ghani. He has mentioned its uses and benefits in his classical book Khazainul Advia. In Unani Medicine the plant species has been used to treat various ailments like constipation, fever, jaundice, liver disorders, syphilis, diseases of lymph glands etc. In Kashmir Himalaya it is used to treat various diseases by local medicinemen, but now it is listed in rare drugs. Various pharmacological studies have been done such as antioxidant, antimicrobial, anti-inflammatory, antifungal, radio-protective etc., recently it has also been reported that podophyllotoxin or podophyllin can be used to treat some forms of cancers also.

CYTOLOGY OF 2n POLLEN FORMATION IN DIPLOID ALFALFA, MEDICAGO SATIVA

1979 ◽  
Vol 21 (4) ◽  
pp. 525-530 ◽  
Author(s):  
Nicholi Vorsa ◽  
E. T. Bingham
Keyword(s):  
Medicago Sativa ◽  
Seed Set ◽  
Pollen Grains ◽  
Genetic Constitution ◽  
2N Pollen ◽  
Diploid Parent ◽  
2N Gamete ◽  
Medicago Sativa L ◽  
Pollen Formation ◽  
Mother Cells

Four diploid (2x) clones of alfalfa, Medicago sativa L., which produced good seed set when used as male parents in 4x-2x crosses were selected for study. The 2x clones descended from 2x haploids of cultivated 4x alfalfa. Fertility in the 4x-2x cross was due to the production of pollen with the unreduced chromosome number (2n pollen) from the 2x parent. The cytological mechanism of 2n pollen formation was found to be disorientation of spindles at metaphase II in up to 38% of the pollen mother cells. Thus, both n and 2n pollen were produced by all four diploids examined. Normal spindles at metaphase II were oriented such that they defined the poles of a tetrahedron and resulted in normal tetrads in a tetrahedral arrangement. Disoriented spindles were basically parallel to each other and resulted in formation of dyads and occasionally a triad. Dyads developed into two 2n pollen grains; triads developed into one 2n and two n pollen grains. Since both n and 2n pollen grains are produced by the diploids, they can be maintained as diploids or they can be used as male parents in crosses to tetraploids. The genetic constitution of 2n pollen resulting from parallel spindles is similar to that expected after first division restitution of meiosis and much of the heterozygosity of the diploid parent is conserved in the gametes. The 2n gamete mechanism has potential application in germplasm transfer and in maximizing heterozygosity in tetraploid hybrids.

scholarly journals Antimicrobial Properties and Melissopalynology, Proximate and Elemental Analyses of Honey Samples from Three Different Ecozones in Nigeria

2016 ◽  
Vol 8 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Peter A. ADEONIPEKUN ◽  
Tiwalade A. ADENIYI ◽  
David EDEN
Keyword(s):  
Antimicrobial Properties ◽  
Pollen Grains ◽  
Antimicrobial Activities ◽  
Proximate Analysis ◽  
Preparation Methods ◽  
Antimicrobial Studies ◽  
Elemental Analyses ◽  
Lowland Rainforest ◽  
Sudan Savanna ◽  
First Time

Honey samples from three different ecozones - coastal freshwater (Ogba), lowland rainforest (Oka-Akoko) and montane Sudan savanna (Mambilla plateau) – were subjected to melissopalynological, proximate and elemental analyses, as well as antimicrobial studies. The aim of the research was to determine the contribution of pollen, if any, in the antimicrobial activities of the studied honey samples. Standard preparation methods were adopted for these studies. The Mambilla honey recorded the highest pollen diversity, while that of Oka-Akoko and Ogba regions had similar diversity, both having lower values. The Ogba honey however contained the highest abundance of pollen. Proximate analysis showed that the Mambilla honey also recorded the highest values of moisture, ash, protein, fats and oil, as well as potassium and reducing sugars. Antimicrobial investigation revealed the highest antimicrobial activities for the Mambilla honey, followed by Oka-Akoko and Ogba against Staphylococcus aureus (gram positive) and Pseudomonas aeruginosa (gram negative). Moisture content, proteins and carbohydrates were significantly different, with positive and negative trends respectively, when related with the antimicrobial activities of the honey samples. The pollen contents were also qualitatively different. This is the first time the antimicrobial activity of honey is ever traced to pollen contents.  More conclusions can be accurately made only after further research upon pollen grains directly.

scholarly journals Pollen morphology of Ukrainian species of the genus Pedicularis L. (Orobanchaceae Vent.)

2012 ◽  
Vol 24 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Olena M. Peregrym ◽  
Zoya M. Tsymbalyuk ◽  
Sergei L. Mosyakin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Taxonomic Revision ◽  
Palynological Data ◽  
First Time ◽  
Scanning Electron

Abstract Pollen grains of 10 species of Pedicularis occurring in Ukraine were investigated using light and scanning electron microscopy. Palynological data on 6 species are reported for the first time. General pollen morphology of the genus Pedicularis is presented. Three types of apertures (2-syncolpate, 3-colpate, and 3-syncolpate) and seven subtypes of sculpture (3-syncolpate pilate, 3-syncolpate microscabrate-tubeculate, 2-syncolpate microscabrate, 2-syncolpate microscabrate-tubeculate, 2-syncolpate microscabrate-tubeculate-perforate, 2-syncolpate microfoveolate, and 2-syncolpate microscabrate-perforate) are indentified. The subgenus Pedicularis is heterogeneous in its types of apertures and sculpture of the surface, which indicates the need of further taxonomic revision of the group.

scholarly journals Pollen morphology of the Balkan-Carpathian endemic Campanula lingulata Waldst. & Kit. (Campanulaceae)

2016 ◽  
pp. 75-82
Author(s):  
Marina Macukanovic-Jocic ◽  
Snezana Jaric
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Endemic Species ◽  
Pollen Morphology ◽  
Average Length ◽  
Pollen Grains ◽  
Polar Axis ◽  
First Time ◽  
Scanning Electron

Palynomorphological characteristics of Campanula lingulata, the Balkan-Carpathian endemic species growing in Serbia, have been investigated using light microscopy and scanning electron microscopy for the first time, in order to provide some information helpful for a better understanding of the taxonomic position of this species within the genus, as well as to contribute to the pollen atlas of Serbian apiflora. The pollen grains are radially symmetrical, isopolar, 3-zonoporate and medium-sized monads oblate-sphaeroidal in shape. Mean of the polar axis (P) is 27.6?1.9 ?m, while the average length of the equatorial axis (E) is 28.8?1.6 ?m. The apertures are operculate. The sculpturing pattern of the exine is microre?ticulate-microechinatae. The exine surface is covered with evenly distributed supratectal spinules of variable length and sparse granules. The longest supratectal spinules are 0.64?0.05 ?m in length and the smallest sculptural elements are less than 0.2 ?m high. The microechinae density per sample area of 5 ?m x 5 ?m averages 17.4?2.4.

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