Abstract
Current systems of estimating gene segregation in autotetraploids usually are based on two extreme methods: chromosome segregation with absolute centromere linkage, or maximum equational segregation with crossing over always occurring between the centromeres and marker genes. The hiatus between the two methods is unacceptable quantitatively, and segregation of the d gene in tomato shows that neither method predicts an acceptable fit. We present a new meiotic configuration (MC) method of analyzing tetrasomic inheritance in autotetraploids that allows more accurate estimations of all intermediate types of segregation. The method is based on a maximum of two chiasmata per bivalent and four per quadrivalent. The theoretically expected numbers of bivalents and chain and circle quadrivalents are derived first. Chromosome frequencies from these configurations are then used to determine relative contributions from each configuration to the gamete genotypes by way of newly developed tables for gene segregation in various autotetraploid genotypes. The large sample sizes from classic 4x tomato (Solanum lycopersicum L.) data are used to demonstrate the stepwise method of calculating gamete genotypes, and the method gives acceptable fits for the data tested. The interspecific tetraploid hybrid Solanum lycopersicum × S. pimpinellifolium had good fits to expected autotetraploid segregation, supporting its autoploid nature and the fact that taxonomic rank should not be a consideration in designating categories of polyploids. Autotetraploid allozyme segregation data for several genes in one genus of another family had acceptable and usually better fits to the MC expectations than to the standard methods.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 6
Claim · model-written summary
Neither existing segregation method predicts an acceptable fit for segregation of the d gene in tomato.
- Taxon
- tomato
Solanum lycopersicume0 - Gene
- d genee0
- Outcome
- predicts an acceptable fite0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“segregation of the d gene in tomato shows that neither method predicts an acceptable fit”
Claim · model-written summary
The new meiotic configuration method gives more accurate estimations of all intermediate types of segregation in autotetraploids.
- Taxon
- autotetraploidse1
- Outcome
- more accurate estimations of all intermediate types of segregatione1
- Direction
- more accuratee1
Not reportedComparator
Verbatim
e1“We present a new meiotic configuration (MC) method of analyzing tetrasomic inheritance in autotetraploids that allows more accurate estimations of all intermediate types of segregation”
Claim · model-written summary
The meiotic configuration method gives acceptable fits for the classic 4x tomato data tested.
- Taxon
- tomatoSolanum lycopersicume2
- Outcome
- fits for the data testede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“classic 4x tomato (Solanum lycopersicum L.) data are used to demonstrate the stepwise method of calculating gamete genotypes, and the method gives acceptable fits for the data tested”
Claim · model-written summary
The interspecific tetraploid hybrid Solanum lycopersicum × S. pimpinellifolium had good fits to expected autotetraploid segregation.
- Taxon
- Solanum lycopersicum × S. pimpinellifoliumSolanum lycopersicume3
- Outcome
- fits to expected autotetraploid segregatione3
- Qualifier
- supporting its autoploid naturee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“The interspecific tetraploid hybrid Solanum lycopersicum × S. pimpinellifolium had good fits to expected autotetraploid segregation”
e4“supporting its autoploid nature”
Claim · model-written summary
Taxonomic rank should not be a consideration in designating categories of polyploids.
- Taxon
- Solanum lycopersicum × S. pimpinellifoliumSolanum lycopersicume3
- Outcome
- taxonomic rank should not be a consideration in designating categories of polyploidse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“The interspecific tetraploid hybrid Solanum lycopersicum × S. pimpinellifolium had good fits to expected autotetraploid segregation”
e5“taxonomic rank should not be a consideration in designating categories of polyploids”
Claim · model-written summary
Allozyme segregation data for several genes in one genus of another family had acceptable and usually better fits to the MC expectations than to the standard methods.
Verbatim
e6“Autotetraploid allozyme segregation data for several genes in one genus of another family had acceptable and usually better fits to the MC expectations than to the standard methods”
e1“We present a new meiotic configuration (MC) method of analyzing tetrasomic inheritance in autotetraploids that allows more accurate estimations of all intermediate types of segregation”