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GrainGenes Reference Report: TAG-103-398

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Reference
TAG-103-398
Title
The Ph1 and Ph2 loci play different roles in the synaptic behaviour of hexaploid wheat Triticum aestivum
Journal
Theoretical and Applied Genetics
Year
2001
Volume
103
Pages
398-405
Author
Martinez M
Cunado N
Carcelen N
Romero C
Abstract
Summary: Triticum aestivum is an allohexaploid wheat (AABBDD) that shows diploid-like behaviour at metaphase-I. This behaviour is influenced by the action of several loci, Ph1 and Ph2 being the main loci involved. To study the effect of these two loci on chromosome pairing in T. aestivum we have analysed the synaptic pattern in fully traced spread nuclei at mid- and late-zygotene, and at pachytene, of three different genotypes of cv Chinese Spring: standard line, ph1b and ph2b mutants. The analysis of the synaptic progression showed that only a few nuclei accomplish synapsis in the ph2b genotype, whereas most nuclei completed synapsis in the standard and ph1b genotypes. This result indicates that the Ph2 locus affects synaptic progression. The number of synaptonemal complex (SC) bivalents and of the different SC multivalent associations were determined in each nucleus. The mean number of lateral elements involved in SC multivalent associations (LEm) at mid-zygotene was relatively high and showed similar values in the three genotypes. These values decreased progressively between mid-zygotene and pachytene in the genotypes with the Ph1 locus because of the transformation of multivalents into bivalents. In the ph1b genotype, this value only decreased between late-zygotene and pachytene. Therefore, multivalent correction was more efficient in the presence than in the absence of the Ph1 locus. It is concluded that the Ph1 and Ph2 loci bring about diploidization of allohexaploid wheat via a different mechanism
External Databases
http://link.springer-ny.com/link/service/journals/00122/bibs/1103002/11030398.htm
Keyword
[ Hide all but 1 of 42 ]
allohexaploid wheat
associations
bivalents
chinese
chinese spring
chromosome
chromosome pairing
complexes
diploid-like behaviour
element
genome
genotype
hexaploid
hexaploid wheat
hybrid
inbred lines
loci
locus
mechanism
metaphase-i
mutant
nuclei
nucleus
pachytene
pairing
pattern
ph1
ph1 locus
ph2 locus
progression
recognition
recombination
roles
rye
spread
spring
synapsis
synaptonemal complex
synaptonemal complex formation
transformation
triticum
triticum aestivum

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