Gamma-ray induced meiotic chromosome stickiness in tomato

1977 ◽  
Vol 50 (5) ◽  
pp. 247-252 ◽  
Author(s):  
P. N. Rao ◽  
R. N. Rao
Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 39-46
Author(s):  
Orhan Arslan ◽  
Şenol Bal ◽  
Nilgün Venice ◽  
Semra Mirici

SUMMARYIn this study, mitotic effects of gamma rays on Ekiz 1 variety belonging to Helianthus annuus L. (2n= 34) in the M0 (first irradiated seeds), M1 and M2 generations have been investigated. Seeds (M0) were irradiated with gamma rays at 10, 20, 30, 40 and 50 kR doses. Percentage of total abnormalities in the M0, M1 and M2 generations increased parallel to the increasing dose of radiation. These abnormalites have been observed as C-metaphase, chromosome stickiness, laggards and bridges with or without fragment. Mitotic index (M.I.) in the M0, M1 and M2 generations has decreased parallel to the dose increase. When the generations are compared, both the amounts of decrease in mitotic index and in the percentage of mitotic abnormalities were mostly observed in M0.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483d-483
Author(s):  
Yan Ma ◽  
David H. Byrne

The amphidiploid rose 86-7 (Rosa wichuraiana × R. rugosa rubra) and its hybrids with the tetraploid breeding selection 82-1134 were analyzed for meiotic configuration frequencies and meiotic abnormalities. Genomic relationships in these hybrids were interpreted with the aid of a model of meiotic chromosome association in tetraploids. The optimized solutions to this model indicated a pattern intermediate between the “211” pattern, with one pair of closest genomes, and the “ring4” pattern, in which one of three possible pairing arrangements is strongly suppressed. The same configuration frequencies could also reflect a “4:0” pattern of equally similar genomes with more than two independent pairing and chiasma-forming domains per chromosome. The observed meiotic abnormalities included chromosome stickiness and asynchronous chromosome contraction within cells. Pollen stainability varied independently of meiotic irregularity or multivalent frequency.


HortScience ◽  
2000 ◽  
Vol 35 (6) ◽  
pp. 1127-1131 ◽  
Author(s):  
Yan Ma ◽  
Charles F. Crane ◽  
David H. Byrne

The tetraploid (2n = 4x = 28) rose 86-7 (Rosa wichuraiana × R. rugosa rubra) and its hybrids with the thornless tetraploid rose cultivar Basye's Blueberry (2n = 28) were analyzed for meiotic configuration frequencies and meiotic abnormalities. Genomic relationships in these hybrids were interpreted with the aid of a model of meiotic chromosome association in tetraploids. The closest-fitting model solutions indicated a 2:2 (AABB) pattern of genomic relationships, with 65% to 90% of all association between most closely related genomes. Some of the optimal solutions were transitional to a “ring4” pattern, in which one of the possible pairing arrangements is suppressed. The same configuration frequencies could also reflect a “4:0” pattern of equally similar genomes with fractionally more than two independent pairing and chiasma-forming domains per chromosome. Observed meiotic abnormalities included chromosome stickiness and asynchronous chromosome contraction within cells. Pollen stainability varied independently of meiotic irregularity or multivalent frequency. The observed configuration frequencies are consistent with partially tetrasomic inheritance that retains considerable heterozygosity, but allows individual contributions from parental genomes to become homozygous.


1967 ◽  
Vol 31 ◽  
pp. 469-471
Author(s):  
J. G. Duthie ◽  
M. P. Savedoff ◽  
R. Cobb
Keyword(s):  

A source of gamma rays has been found at right ascension 20h15m, declination +35°, with an uncertainty of 6° in each coordinate. Its flux is (1·5 ± 0·8) x 10-4photons cm-2sec-1at 100 MeV. Possible identifications are reviewed, but no conclusion is reached. The mechanism producing the radiation is also uncertain.


1994 ◽  
Vol 144 ◽  
pp. 635-639
Author(s):  
J. Baláž ◽  
A. V. Dmitriev ◽  
M. A. Kovalevskaya ◽  
K. Kudela ◽  
S. N. Kuznetsov ◽  
...  

AbstractThe experiment SONG (SOlar Neutron and Gamma rays) for the low altitude satellite CORONAS-I is described. The instrument is capable to provide gamma-ray line and continuum detection in the energy range 0.1 – 100 MeV as well as detection of neutrons with energies above 30 MeV. As a by-product, the electrons in the range 11 – 108 MeV will be measured too. The pulse shape discrimination technique (PSD) is used.


Sign in / Sign up

Export Citation Format

Share Document