CYTOPLASMIC HOMOLOGY BETWEEN AEGILOPS TRIUNCIALIS AND AE. UMBELLULATA

1980 ◽  
Vol 22 (2) ◽  
pp. 197-212
Author(s):  
S. S. Maan
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Meiotic Pairing ◽  
Aegilops Triuncialis

The Triticum aestivum L. (2n = 42; AABBDD) and T. durum Desf. (2n = 28; AABB) genomes were substituted into the cytoplasm of two Aegilops triuncialis L. (2n = 28; CCCuCu) accessions. In F1 (ABCCu) and in a 42-chromosome backcross plant (AABBCCu) meiotic pairing between the C- and Cu-genome chromosomes was substantially reduced. Therefore, some of the pairing in the F1 of Ae. caudata L. (2n = 14; CC) × Ae. umbellulata Zhuk. (2n = 14; CuCu) may have been of the homoelogous type. In early backcrosses with T. aestivum, the euploid gametes or zygotes did not function in plants having Aegilops chromosome(s), but euploid plants with Ae. triuncialis cytoplasm were obtained in the fifth backcross. These plants were used as the cytoplasmic source to substitute the T. durum genomes into Ae. triuncialis cytoplasm; euploid durum plants were obtained in the second backcross. Alloplasmic T. durum and T. aestivum plants with Ae. triuncialis cytoplasm had closer resemblance to the plants with Ae. umbellulata cytoplasm than to those with Ae. caudata cytoplasm. These nucleo-cytoplasmic interactions indicated cytoplasmic similarity between Ae. umbellulata and Ae. triuncialis.

scholarly journals Chromatid and chromosome type breakage-fusion-bridge cycles in wheat (Triticum aestivum L.).

Genetics ◽  
1995 ◽  
Vol 140 (3) ◽  
pp. 1069-1085 ◽  
Author(s):  
A J Lukaszewski
Keyword(s):  
Triticum Aestivum ◽  
Ring Chromosome ◽  
Triticum Aestivum L ◽  
Aleurone Layer ◽  
Meiotic Pairing ◽  
Chromosome Type ◽  
Root Tips ◽  
Morphological Marker ◽  
Bfb Cycle ◽  
Tandem Duplications

Abstract During the development of disomic additions of rye (Secale cereale L.) chromosomes to wheat (Triticum aestivum L.), two reverse tandem duplications on wheat chromosomes 3D and 4A were isolated. By virtue of their meiotic pairing, the reverse tandem duplications initiated the chromatid type of the breakage-fusion-bridge (BFB) cycle. This BFB cycle continued through pollen mitoses and in the early endosperm divisions, but no clear evidence of its presence in embryo mitoses was found. The chromosome type of BFB cycle was initiated by fusion of two broken chromosome ends resulting in a dicentric or a ring chromosome. Chromosome type BFB cycles were detected in embryo mitoses and in root tips, but they did not persist until the next meiosis and were not transmitted to the progeny. Active BFB cycles induced breakage of other wheat chromosomes that resulted in additional reverse tandem duplications and dicentric and ring chromosomes. Four loci, on chromosome arms 2BS, 3DS, 4AL, and most likely on 7DL, were particularly susceptible to breakage. The BFB cycles produced high frequency of variegation for pigmentation of the aleurone layer of kernels and somatic chimeras for a morphological marker. With the exception of low mutation rate, the observed phenomena are consistent with the activity of a Ds-like element. However, it is not clear whether such an element, if indeed present, was of wheat or rye origin.

Origin, structure, and behavior of a highly rearranged deletion chromosome 1BS-4 in wheat

Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 591-597 ◽  
Author(s):  
Lili Qi ◽  
Bernd Friebe ◽  
Bikram S Gill
Keyword(s):  
Triticum Aestivum ◽  
Molecular Markers ◽  
Physical Mapping ◽  
Triticum Aestivum L ◽  
Distal Segment ◽  
Distal Region ◽  
Meiotic Pairing ◽  
Aegilops Species ◽  
Pairing Behavior ◽  
And Behavior

Wheat (Triticum aestivum L.) deletion (del) stocks are valuable tools for the physical mapping of molecular markers and genes to chromosome bins delineated by 2 adjacent deletion breakpoints. The wheat deletion stocks were produced by using gametocidal genes derived from related Aegilops species. Here, we report on the origin, structure, and behavior of a highly rearranged chromosome 1BS-4. The cytogenetic and molecular marker analyses suggest that 1BS-4 resulted from 2 breakpoints in the 1BS arm and 1 breakpoint in the 1BL arm. The distal segment from 1BS, except for a small deleted part, is translocated to the long arm. Cytologically, chromosome 1BS-4 is highly stable, but shows a unique meiotic pairing behavior. The short arm of 1BS-4 fails to pair with a normal 1BS arm because of lack of homology at the distal ends. The long arm of 1BS-4 only pairs with a normal 1BS arm within the distal region translocated from 1BS. Therefore, using the 1BS-4 deletion stock for physical mapping will result in the false allocation of molecular markers and genes proximal to the breakpoint of 1BS-4.Key words: Triticum aestivum, wheat, deletion–translocation, physical mapping.

Production and cytogenetic analysis of hybrids between Triticum aestivum and some caespitose Agropyron species

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 537-553 ◽  
Author(s):  
Abdul Mujeeb-Kazi ◽  
Silverio Roldan ◽  
D. Y. Suh ◽  
Lesley A. Sitch ◽  
Shafqat Farooq
Keyword(s):  
Triticum Aestivum ◽  
Chinese Spring ◽  
Cytogenetic Analysis ◽  
Triticum Aestivum L ◽  
Intergeneric Hybrids ◽  
The Other ◽  
Meiotic Pairing ◽  
New Combinations ◽  
Wide Crosses ◽  
Major Variation

Intergeneric hybrids between Triticum aestivum L. cultivars and 12 traditional Agropyron species were produced in variable frequencies, lowest being 0.35% for A. stipaefolium to a high of 41.98% for A. varnense. The crossing success of T. aestivum cultivars ranged from 'Chinese Spring' > 'Pavon-76' = 'Nacozari-75' > 'Fielder' = 'Fremont' > 'Glennson-81'. All F1 hybrids were somatically stable. The new combinations were with A. curvifolium (Thinopyrum curvifolium), A. rechingeri (T. sartorii = rechingeri), A. scythicum (T. scythicum), and A. stipaefolium (Pseudoroegeneria stipaefolia). All hybrids were perennial and possessed a modified phenotype that was intermediate between the parents involved in the hybrid combinations with major variation in spike morphology (elongated spikes with lax internodes). High-pairing hybrids, presumably owing to suppression of the Ph locus were of T. aestivum - A. scythicum (15.31 I + 2.25 II rings + 6.92 II rods + 0.32 III) and T. aestivum - A. stipaefolium (10.6 I + 7.08 II rings + 4.41 II rods + 0.54 III). In the other combinations, the pairing was either low or high, and if high, pairing was attributed to autosyndetic association of the alien genome chromosomes. Based on the meiotic pairing data, alien species that were segmental allotetraploids or partial autopolyploids, or segmental allohexaploids or autoallohexaploids, may be advantageous in developing backcross derivatives with synthetic genomes. Production of fertile amphiploids was restricted to T. aestivum - A. rechingeri. Key words: Triticum aestivum, Agropyron species, Pseudoroegeneria species, Thinopyrum species, intergeneric hybrids, crossability, wide crosses.

ИЗОФЕРМЕНТНЫЙ АНАЛИЗ ЭСТЕРАЗ В ЗРЕЛЫХ СЕМЕНАХ ГЕКСАПЛОИДНОЙ МЯГКОЙ ПШЕНИЦЫ (Triticum aestivum L.)

2016 ◽  
Vol 51 (3) ◽  
pp. 327-334
Author(s):  
А.С. РУДАКОВА ◽  
◽  
С.В. РУДАКОВ ◽  
Н.В. ДАВЫДОВА ◽  
Г.В. МИРСКАЯ ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L

MORPHOPHYSIOLOGICAL FEATURES OF WHEAT (Triticum aestivum L.) SEEDLINGS UPON EXPOSURE TO NICKEL NANOPARTICLES

2018 ◽  
Vol 53 (3) ◽  
pp. 578-586 ◽  
Author(s):  
P.N. Tsygvintsev ◽  
◽  
L.I. Goncharova ◽  
K.V. Manin ◽  
V.M. Rachkova ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Nickel Nanoparticles ◽  
Triticum Aestivum L
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