Meiotic pairing and alpha-amylase phenotype in a 5B/5Rm Triticum aestivum — Secale montanum translocation line in common wheat

1986 ◽  
Vol 73 (1) ◽  
pp. 122-128 ◽  
Author(s):  
M. Montero ◽  
J. Sanz ◽  
N. Jouve
1975 ◽  
Vol 17 (3) ◽  
pp. 329-336 ◽  
Author(s):  
J. Dvořák

It is shown that meiotic pairing between single chromosomes of closely related taxa can be studied in hybrids between alien addition and substitution lines. Using this technique, two chromosomes of diploid A. elongatum which appear to be homoeologous with wheat chromosomes of groups 6 and 7 were shown to pair with chromosomes of decaploid A. elongatum which are also homoeologous with wheat chromosomes of groups 6 and 7. Hence, pairing of these chromosomes verified the suggested homoeology among these chromosomes.Meiotic pairing was also studied in 2 hybrid progenies which carried specific telosomes of diploid A. elongatum in addition to a set of 7 Agropyron chromosomes which came from decaploid A. elongatum. The telosomes paired with the decaploid A. elongatum chromosomes in these hybrids. Hence, four chromosomes of diploid A. elongatum were shown to pair in common wheat with chromosomes of decaploid A. elongatum. Since pairing between diploid A. elongatum and decaploid A. elongatum chromosomes was generally low, it is suggested that the chromosomes assigned to the same group are not homologous but rather closely homoeologous.


2019 ◽  
Vol 74 (1) ◽  
pp. 5-14
Author(s):  
GRZEGORZ SZUMIŁO ◽  
LESZEK RACHOŃ ◽  
BARBARA KROCHMAL-MARCZAK

The 3-year experiment was concerned with the response of spring forms of common wheat (Triticum aestivum L. subsp. aestivum), durum wheat (Triticum durum Desf.) and spelt wheat (Triticum aestivum subsp. spelta L. em. Thell.) to the foliar application of a plant growth stimulant (extract from marine algae Ecklonia maxima), with the commercial name of Kelpak SL (GS), as compared to control treatment (C). The following parameters were analysed: yield of grain, yield components (number of ears, weight of 1000 kernels, number and weight of kernels per ear) and physical indicators of grain quality (test weight, uniformity and vitreosity of grain). The study showed that the level of yielding and the yield components were related primarily with the wheat genotype, but they depended also on the agro-climatic conditions and on the algae extract and control experimental treatments. The application of algae extract, compared to the control, caused a significant increase in the yields of the spring wheat species under study, on average by 7.0%. Canopy spraying with algae extract had a favourable effect on the number of ears, on he number and weight of kernels per ear, but it had no effect on the weight of 1000 kernels. The grain quality of durum wheat, spelt wheat and common wheat was affected more strongly by the weather conditions in the successive years of the study and by the genotype than by the foliar application of algae extract. The spelt genotypes were characterised by lower yields and lower grain quality than common wheat and the durum wheat genotypes.


Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 1199-1208 ◽  
Author(s):  
Juan M Vega ◽  
Moshe Feldman

Abstract The analysis of the pattern of isochromosome pairing allows one to distinguish factors affecting presynaptic alignment of homologous chromosomes from those affecting synapsis and crossing-over. Because the two homologous arms in an isochromosome are invariably associated by a common centromere, the suppression of pairing between these arms (intrachromosome pairing) would indicate that synaptic or postsynaptic events were impaired. In contrast, the suppression of pairing between an isochromosome and its homologous chromosome (interchromosome pairing), without affecting intrachromosome pairing, would suggest that homologous presynaptic alignment was impaired. We used such an isochromosome system to determine which of the processes associated with chromosome pairing was affected by the Ph1 gene of common wheat—the main gene that restricts pairing to homologues. Ph1 reduced the frequency of interchromosome pairing without affecting intrachromosome pairing. In contrast, intrachromosome pairing was strongly reduced in the absence of the synaptic gene Syn-B1. Premeiotic colchicine treatment, which drastically decreased pairing of conventional chromosomes, reduced interchromosome but not intrachromosome pairing. The results support the hypothesis that premeiotic alignment is a necessary stage for the regularity of meiotic pairing and that Ph1 relaxes this alignment. We suggest that Ph1 acts on premeiotic alignment of homologues and homeologues as a means of ensuring diploid-like meiotic behavior in polyploid wheat.


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 18 (5-6) ◽  
pp. 465-482 ◽  
Author(s):  
K. M. Soliman ◽  
J. E. Bernardin ◽  
C. O. Qualset

1986 ◽  
Vol 28 (2) ◽  
pp. 294-297 ◽  
Author(s):  
E. D. P. Whelan ◽  
R. L. Conner ◽  
J. B. Thomas ◽  
A. D. Kuzyk

A translocation between a common wheat (Triticum aestivum L.) chromosome and chromosome 6 of Elytrigia pontica (Podp.) Holub conferred resistance to feeding by Eriophyes (= Aceria) tulipae Keifer, the mite vector of wheat streak mosaic virus and the wheat spot mosaic agent. Resistance was dominant, but differential transmission occurred between the pollen and the egg. Transmission of resistance through the pollen was low, about 3% in 'Cadet', 'Rescue', and 'Winalta', but significantly higher in 'Norstar' (9.1%). Significant differences also were detected in transmission through the egg. 'Cadet' had the highest transmission (50.9%) and 'Rescue' the lowest (40.5%). However, there were no significant differences among varieties in the frequencies of resistance (50.3–54.5%) in the F2. Less than 10% of the F2 plants were homozygous resistant. Selfed progeny from monosomic or disomic F1 plants from crosses between the homozygous translocation and group-6 monosomics all segregated for susceptibility. Meiotic studies of 25 susceptible F2 plants from these F1 monosomics showed that 21 were either monosomic or disomic and only 4 were nullisomic, indicating that the translocation did not involve any of the group-6 homoeologues. The translocation is considered to be a noncompensating translocation involving a whole arm of chromosome 6 of E. pontica.Key words: wheat, mite (wheat curl), translocation, Triticum.


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