scholarly journals The Conserved Chimeric Transcript UPGRADE2 Is Associated with Unreduced Pollen Formation and Is Exclusively Found in Apomictic Boechera Species

2013 ◽  
Vol 163 (4) ◽  
pp. 1640-1659 ◽  
Author(s):  
M. Mau ◽  
J. M. Corral ◽  
H. Vogel ◽  
M. Melzer ◽  
J. Fuchs ◽  
...  
Keyword(s):  
Chimeric Transcript ◽  
Unreduced Pollen ◽  
Pollen Formation

scholarly journals Cytomixis and unreduced pollen formation in some Festuca L. species of Iran

Caryologia ◽  
2007 ◽  
Vol 60 (4) ◽  
pp. 364-371 ◽  
Author(s):  
Sheidai Masoud ◽  
Elahe-Sadat Bagheri-Shabestarei
Keyword(s):  
Unreduced Pollen ◽  
Pollen Formation

Single-pollen genotyping to estimate mode of unreduced pollen formation in Citrus tamurana cv. Nishiuchi Konatsu

2016 ◽  
Vol 29 (1-2) ◽  
pp. 189-197 ◽  
Author(s):  
Chitose Honsho ◽  
Aisa Sakata ◽  
Hikaru Tanaka ◽  
Shuji Ishimura ◽  
Takuya Tetsumura
Keyword(s):  
Unreduced Pollen ◽  
Pollen Formation

α-Tubulin and F-actin distribution during microsporogenesis in a 2n pollen producer of Solanum

Genome ◽  
1998 ◽  
Vol 41 (5) ◽  
pp. 636-641 ◽  
Author(s):  
G Genualdo ◽  
A Errico ◽  
A Tiezzi ◽  
C Conicella
Keyword(s):  
Single Cell ◽  
Cell Plate ◽  
2N Pollen ◽  
Rhodamine Phalloidin ◽  
Parallel Orientation ◽  
Unreduced Pollen ◽  
Spatial And Temporal Changes ◽  
Spatial Configurations ◽  
Meiotic Spindles ◽  
Pollen Formation

Spatial and temporal changes in configurations of microtubules (MTs) and microfilaments (MFs) were determined during microsporogenesis, using -tubulin immunolocalization and rhodamine-phalloidin staining of F-actin, in a 2n pollen producer of Solanum, to assess the anomalies in meiotic spindles and cytokinesis and their relationships to 2n pollen formation. InSolanum, MTs and MFs generally showed patterns of localization similar to those described in other dicotyledons with simultaneous cytokinesis. However, deviations in spatial configurations of both MTs and MFs that are related to 2n pollen were observed in meiosis II and in cytokinesis. MTs and MFs localized in spindles in parallel orientation at meiosis II. In contrast, in the majority of normal meiocytes, the two spindles were seen to be perpendicular to each other. The parallel spindles altered the position of the postmeiotic nuclei, causing a uniplanar instead of a tetrahedral arrangement. Subsequently, the formation of regular radial MT systems was suppressed and only two MT arrays, which lay parallel on one plane, formed between the nuclei at the end of meiosis. A single cell plate formed across the two MT arrays, giving rise to a dyad containing 2n microspores.Key words: cytokinesis, microfilaments, microtubules, spindle, unreduced pollen.

scholarly journals Influence of Low Temperature before Flowering on the Occurrence of Unreduced Pollen in Japanese Persimmon (Diospyros kaki Thunb.)

HortScience ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 24-28 ◽  
Author(s):  
A. Yamada ◽  
R. Tao ◽  
A. Sugiura
Keyword(s):  
Low Temperature ◽  
Field Condition ◽  
Low Frequency ◽  
Temperature Treatment ◽  
Diospyros Kaki ◽  
Japanese Persimmon ◽  
Unreduced Pollen ◽  
Low Temperature Treatment ◽  
Naturally Occurring ◽  
Pollen Formation

The efficacy of ploidy breeding using unreduced pollen in japanese persimmon (Diospyros kaki Thunb.) is not high because of the low frequency of unreduced pollen in most cultivars. This study was conducted in 2002 and 2003 to determine if the exposure to a low temperature before flowering could enhance the unreduced pollen formation in five cultivars of japanese persimmon including two cultivars that barely produce unreduced pollen under the field condition. The results showed that low-temperature treatment (4 °C for 48 hours) increased the occurrence of unreduced pollen at 15 to 17 and 17 to 18 days after the end of the low-temperature treatment in 2002 and 2003, respectively, in all five cultivars tested. Naturally occurring temperatures below 5 °C in the field also appeared to enhance the unreduced pollen formation in the cultivars that naturally produce unreduced pollen in the field.

Mago Nashi is involved in meristem organization, pollen formation, and seed development in Arabidopsis

Plant Science ◽  
2009 ◽  
Vol 176 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Nam-Il Park ◽  
Edward C. Yeung ◽  
Douglas G. Muench
Keyword(s):  
Seed Development ◽  
Pollen Formation ◽  
Mago Nashi

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.

Pollen Formation, Development of the Pollen Wall and Tapetum

2019 ◽  
pp. 9-15
Author(s):  
Shripad N. Agashe ◽  
Eric Caulton
Keyword(s):  
Pollen Wall ◽  
Pollen Formation

scholarly journals Isolation and Characterization of a 1.7-kb Transposable Element from a Mutator Line of Maize

Genetics ◽  
1987 ◽  
Vol 117 (2) ◽  
pp. 297-307
Author(s):  
Loverine P Taylor ◽  
Virginia Walbot
Keyword(s):  
Direct Repeat ◽  
Repeat Sequence ◽  
Gene Probe ◽  
Gene Transcript ◽  
Chimeric Transcript ◽  
Purple Pigment ◽  
Isolation And Characterization ◽  
Internal Sequence ◽  
Normal Gene

ABSTRACT We have cloned and sequenced a 1.7-kb Mu element from a Mutator line of maize and compared its structure to Mu1, a 1.4-kb element. With the exception of a 385-bp block of DNA present in the 1.7-kb element, these transposable elements are structurally similar, sharing terminally inverted and internal direct repeated sequences. Derivation of 1.4-kb elements from the 1.7-kb class via deletion of internal sequence is suggested by the finding that a portion of the extra DNA in Mu1.7 is part of a truncated direct repeat sequence in the 1.4-kb element. An abundant poly(A)+ RNA homologous to a portion of this extra DNA is present in several tissues of both Mutator and non-Mutator lines. Analysis of transcripts from an unstable mutant bronze1 (bz) allele containing a Mu1.7 element inserted in an exon of the gene detects three species of poly(A)+ RNA that hybridize to a Bz1 (Bronze) gene probe: the largest contains the entire Mu1.7 element in the Bz1 gene transcript; another appears to be a spliced, chimeric transcript; the smallest is normal size Bz1 mRNA. The latter is most likely encoded by the normal-size alleles detected by Southern analysis of tissue expressing purple pigment, suggesting that normal gene function is restored by excision of the Mu1.7 element.

scholarly journals Unreduced Pollen in a Wild Tetraploid Relative of Sweetpotato

1990 ◽  
Vol 115 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Alfred Jones
Keyword(s):  
Ipomoea Batatas ◽  
Gene Action ◽  
Pollen Mother Cells ◽  
Unreduced Pollen ◽  
Wide Range ◽  
Natural Mechanism ◽  
Controlled Crosses ◽  
Mother Cells

Nonreduction of pollen mother ceils was observed in a wild tetraploid morning-g&y related to the sweetpotato (Ipomoea batatas L. Lam.). Techniques for identifying and determining the frequency of expression of the trait are straightforward. Previous strategies for transfer of germplasm from tetraploid (2n = 4x = 60) species to the hexaploid (2n = 6x = 90) sweetpotato involved crosses with diploids (2n = 2x = 30) to obtain triploids that then were doubled to 6x. Nonreduction of pollen mother cells probably represents the natural mechanism for raising 4x to 6x since pollination of 2x ovules with unreduced pollen (4x) should give rise to 6x progeny without need for somatic doubling. Plants carrying this trait should be useful as bridging types for introgressing genes from wild 4x species into sweetpotato. A wide range in nonreduction (up to, 74%) was recovered In progeny of controlled crosses among selected plants, but data were not sufficient to estimate gene action.

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