A new chromosome race of Calycadenia pauciflora (Asteraceae: Heliantheae-Madiinae) from Butte County, California

2000 ◽  
Vol 87 (10) ◽  
pp. 1459-1465 ◽  
Author(s):  
Gerald D. Carr ◽  
Robert L. Carr
Keyword(s):  
Chromosome Race

An additional chromosome race of Phyllodactyllus marmoratus (Gray) (Reptilia : Gekkonidae) and its phylogenetic implications

1977 ◽  
Vol 25 (4) ◽  
pp. 667 ◽  
Author(s):  
M King ◽  
D King
Keyword(s):  
Western Australia ◽  
Chromosome Race ◽  
The South ◽  
Fourth Chromosome ◽  
Chromosome Fusion ◽  
South West ◽  
Phylogenetic Implications ◽  
Additional Chromosome

This paper describes a fourth chromosome race of P. marmoratus. Specimens from this race have 2n = 32 chromosomes and occur in an isolated pocket in the south-west of Western Australia. It is believed that this race has been derived from the 2n = 34 form by an additional chromosome fusion.

A new chromosome race ofSorex araneus L. from Northern Poland

1985 ◽  
Vol 41 (6) ◽  
pp. 750-752 ◽  
Author(s):  
J. M. Wójcik ◽  
S. Fedyk
Keyword(s):  
Chromosome Race ◽  
Northern Poland

scholarly journals Ploidy Level in American Persimmon (Diospyros virginiana) Cultivars

HortScience ◽  
2020 ◽  
Vol 55 (1) ◽  
pp. 4-7
Author(s):  
Kirk W. Pomper ◽  
Jeremiah D. Lowe ◽  
Sheri B. Crabtree ◽  
Jacob Vincent ◽  
Andrew Berry ◽  
...  
Keyword(s):  
Ploidy Level ◽  
Poor Quality ◽  
Commercial Production ◽  
Chromosome Race ◽  
Cross Pollination ◽  
Seedless Fruits ◽  
Tree Fruit ◽  
Native Populations ◽  
Slow Growing ◽  
Fruit Formation

The American persimmon (Diospyros virginiana) is a slow-growing, moderately sized tree fruit native to the forests of Kentucky. This tree fruit is in the early stages of commercial production with many cultivars selected from the wild. Small orchards of commercially available cultivars are planted in Kentucky. Persimmons are normally dioecious, and female trees require cross-pollination to produce fruit. There are two races of persimmon: the tetraploid (60-chromosome) race is centered in the southern Appalachian region, while the hexaploid (90-chromosome) race generally occupies a range north and west of the tetraploid range. These ranges overlap in Kentucky. Because the ranges overlap, cross-pollination may cause sexual incompatibility, resulting in pollination without fertilization, and therefore seedless fruits of poor quality. The objective of this study was to assess the ploidy level of commercially available American persimmon cultivars and native Kentucky persimmon populations. Leaf samples were collected from 45 cultivars and advanced selections, as well as 45 trees from native populations in Bullitt, Barren, and Franklin Counties. Flow cytometer analysis showed that only four of the selected cultivars were from the tetraploid race: Ennis Seedless, Weeping, Sugar Bear, and SFES; the remaining cultivars were from the hexaploid race. Both hexaploid and tetraploid American persimmon trees were identified in the populations sampled in the Bullitt County locations, but only tetraploid races were found in Franklin and Barren Counties. Because pollen from native trees could result in seedless fruit formation of poor quality when native seedlings are used as pollinizers in commercial production of American persimmon, ploidy level of seedlings needs to be considered.

The Gehyra australis species complex (Sauria: Gekkonidae)

1983 ◽  
Vol 4 (2) ◽  
pp. 147-169 ◽  
Author(s):  
Max King
Keyword(s):  
New Species ◽  
Species Complex ◽  
Species Group ◽  
Chromosomal Analysis ◽  
Chromosome Race ◽  
Chromosome Races ◽  
Diagnostic Characteristics

AbstractA chromosomal analysis of the gekko Gehyra australis (KING in press) revealed the presence of a series of genetically distinct chromosome races. Specimens from four of these chromosome races have been analysed morphologically. The present study indicates that each chromosome race can be specified in terms of pattern, colouration, scalation and morphometrics. The species Gehyra australis is therefore redefined, and a number of new species are described. Members of the Gehyra australis species group are listed, and a key to their diagnostic characteristics is provided.

Cytogenetics of the grasshopper Moraba scurra. 1. Meiosis of interracial and Interpopulation hybrids.

1957 ◽  
Vol 5 (3) ◽  
pp. 285 ◽  
Author(s):  
MJD White
Keyword(s):  
Chromosome Pair ◽  
Chiasma Formation ◽  
B Chromosome ◽  
Chromosome Race ◽  
F1 Hybrids ◽  
Completely Regular ◽  
Essentially Normal ◽  
Pericentric Inversions ◽  
History Of ◽  
Regular Meiosis

Numerous F1 hybrids between the races of Moraba scurra Rehn with 2nB = 15 and 2nB = 17 were reared in the laboratory and in artificial colonies established in nature. Most F1 males have almost completely regular meiosis, their chiasma frequency being essentially normal. These individuals show a trivalent, composed of an "A" and a "B" chromosome of the 17-chromosome race paired with the corresponding limbs of an "AB" chromosome derived from the 15-chromosome race. Disjunction of the trivalent is usually extremely regular. Occasionally either the A or the B chromosome fails to pair with the AB. In hybrid individuals which happen to have their CD chromosome pair heterozygous for the Blundell rearrangement (i.e. Standard/Blundell) the proximal end of the A chromosome is occasionally paired with the Blundell-carrying CD chromosome. This suggests that the evolutionary "dissociation" of the AB into separate A and B chromosomes, which is present in the 17-chromosome race, was not a simple fragmentation but a translocation involving a Blundell chromosome, and that the A chromosome received its centromere from the Blundell element. Various types of abnormal synapsis occur in hybrids between individuals from populations situated several hundred miles apart, even when both belong to the 15-chromosome race. Chiasma-formation in CD bivalents homozygous and heterozygous for the three known sequences of the CD chromosome (Standard, Blundell, Molonglo) suggests that Blundell and Molonglo are both related to Standard as pericentric inversions. The bearing of these data on the history of the species is discussed.

A taxonomical re-evaluation of the Valais chromosome race of the common shrewSorex araneus (Insectivora: Soricidae)

2002 ◽  
Vol 47 (3) ◽  
pp. 245-275 ◽  
Author(s):  
Harald Brünner ◽  
Nicolas Lugon-Moulin ◽  
François Balloux ◽  
Luca Fumagalli ◽  
Jacques Hausser
Keyword(s):  
Chromosome Race ◽  
The Common
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