Cytogenetic studies of progenies from crosses between 'Centurk' wheat and its doubled haploids derived from anther culture

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 622-628 ◽  
Author(s):  
Sawsan S. Youssef ◽  
R. Morris ◽  
P. S. Baenziger ◽  
C. M. Papa

Karyotype stability, which is essential when using wheat (Triticum aestivum L.) doubled haploids in a breeding program, was evaluated in 14 anther-derived doubled-haploid lines after at least three generations of selfing, by crossing them as females with the parent cultivar 'Centurk' and doing cytological studies on the progenies. There were no deviations from the hexaploid chromosome number (2n = 42) in root tips. Meiotic chromosome pairing was as stable as that in the control ('Centurk' × 'Centurk') in most progenies. Chromosomal structural changes and (or) behavioral deviations were detected at the metaphase I, anaphase I, telophase I, and quartet stages of meiosis in a minor proportion of the cells. The frequencies of multivalents, lagging bivalents and univalents, bridges, and micronuclei were higher in some progenies than in the control. Chromosomal fragments were infrequent. The ranges in percentages of normal cells were 72.4–90.0 at anaphase I, 76.4–92.6 at telophase I, and 82.6–93.2 at quartet stages in the doubled-haploid progenies, compared with 95–100, 92–100, and 94–96, respectively, in the control. On the basis of these results, the doubled-haploid lines should produce enough normal gametes to provide adequate seed supplies when they are used as parents in wheat cultivar and population improvement.Key words: Triticum aestivum, chromosome pairing, chromosome aberrations, gametoclonal variation.

2020 ◽  
Vol 56 (No. 4) ◽  
pp. 150-158
Author(s):  
Osama Zuhair Kanbar ◽  
Csaba Lantos ◽  
Paul Karumba Chege ◽  
Erzsébet Kiss ◽  
János Pauk

We investigated the anther culture (AC) efficiency of thirteen F<sub>4</sub> combinations of winter wheat (Triticum aestivum L.). The genotype dependency was assessed during the induction of the androgenic entities, i.e. embryo-like structures (ELS), regenerated-, green-, albino-, and transplanted plantlets. The number of green plantlets per 100 anthers (GP/100A) varied from 0.36 to 24.74 GP/100A with a mean of 8.31 GP/100A. Albino plantlets (AP) occurred in each combination, ranging from 0.20 to 22.80 AP/100A with an average value of 5.59 AP/100A. Between 25–87.76 doubled haploid (DH) plants per 100 acclimatised plantlets (DH/100ADP), depending on the combination, with a mean of 59.74% were recovered. We have found the highest DH production in the combinations Béres/Midas, Kalász/Tacitus, Béres/Pamier, and Premio/5009. This improves remarkably the choice of basic genetic material in subsequent crossing programmes. These observations emphasise the usability and efficiency of in vitro AC in producing a large number of DH lines for breeding and the applied researches of winter wheat. Although albinism was found in each combination, it was mitigated by the in vitro AC application.


1981 ◽  
Vol 23 (2) ◽  
pp. 209-219 ◽  
Author(s):  
G. Kimber ◽  
L. C. Alonso ◽  
P. J. Sallee

The use of telocentric chromosomes in the analysis of the genomic relationships of wheat Triticum aestivum L. em Thell. and its relatives is described and 20 examples are given. The connection between this method of analysis and other mathematical theories of chromosome pairing in hybrids is established. A demonstration of the validity of the assumption that all chromosome arms pair at an equal frequency in calculating expected meiotic analyses is presented. This establishes a practical basis for the development of further mathematical models for predicting meiotic chromosome behavior. Numerical values of the genomic relationships of wheat and its immediate relatives are given.


2007 ◽  
Vol 20 (2) ◽  
pp. 37-41
Author(s):  
M. M. Rahman ◽  
A. K. M. Shamsuddin ◽  
U. Asad ◽  
M. N. Islam

Genetic divergence of 17 doubled haploid lines and 3 check varieties of spring wheat were assessed through Mahalanobis’ D2-statistics. The genotypes were grouped into six clusters. The clusters I and III contained the highest number of lines (5). The cluster V contained single genotype. The maximum inter-cluster distance was noticed between the clusters I and V and minimum between III and VI. The highest intra-cluster distance was observed in the cluster IV and lowest in the cluster V.DOI: http://dx.doi.org/10.3329/bjpbg.v20i2.17034


2017 ◽  
Vol 97 (15) ◽  
pp. 5083-5091 ◽  
Author(s):  
Monika Langner ◽  
Karolina Krystkowiak ◽  
Bolesław P Salmanowicz ◽  
Tadeusz Adamski ◽  
Paweł Krajewski ◽  
...  

Genetics ◽  
1995 ◽  
Vol 140 (3) ◽  
pp. 1069-1085 ◽  
Author(s):  
A J Lukaszewski

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.


1980 ◽  
Vol 60 (1) ◽  
pp. 79-85 ◽  
Author(s):  
PIERRE TURCOTTE ◽  
C. A. ST-PIERRE ◽  
KEH MING HO

Pedigree and doubled haploid lines from seven crosses of barley (Hordeum vulgare L.) were compared over 2 years. The lines were tested, in a randomized complete block design, in row plots at Ste-Foy in 1977 and in hill plots at Brawley, California in 1978. There are significant differences between the two methods of pure line production for grain yield, 1000-kernel weight, plant height, resistance to lodging and date of maturity. Furthermore, these significant differences between doubled haploid and pedigree lines seem to be tied to wide crosses. After showing that doubled haploids are superior for resistance to lodging, we conclude that the use of doubled haploid lines must be seriously considered in a barley breeding program on the basis of improved selection efficiency and the short time required to get homozygous lines.


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