Chromosome Number Variation in the Myrtaceae and Its Taxonomic Implications

1979 ◽  
Vol 27 (5) ◽  
pp. 547 ◽  
Author(s):  
BL Rye
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Evolutionary Potential ◽  
The Family ◽  
Number Variation ◽  
Taxonomic Implications ◽  
Chromosome Number Variation ◽  
Australian Flora ◽  
Base Chromosome Number ◽  
Western Australian

New chromosome number determinations are reported for some 150 Western Australian species of the Myrtaceae. These include the lowest number (n = 5) so far recorded in the family and several newly recorded descending dysploid series. Dysploid chromosome numbers are far less common than the base chromosome number of n = 11 but parallel dysploid series have occurred in many groups and some have played a role in the origin of genera. Polyploidy has been successful at the intraspecific and interspecific levels but is of limited evolutionary potential. The cytoevolutionary trends in the Myrtaceae are examined in relation to taxonomic problems within the family and in relation to cytoevolution in the woody Australian flora as a whole. Smith- White's suggestion that a more natural generic classification in the Chamelauciinae could be obtained by grouping species with the same base chromosome numbers is found to be untenable.

INVESTIGATIONS ON THE SPORTING PROCESS IN GREENHOUSE CHRYSANTHEMUMS

1958 ◽  
Vol 38 (3) ◽  
pp. 346-356 ◽  
Author(s):  
D. R. Sampson ◽  
G. W. R. Walker ◽  
A. W. S. Hunter ◽  
Marie Bragdø
Keyword(s):  
Water Treatment ◽  
Chromosome Number ◽  
Chromosome Numbers ◽  
Flower Colour ◽  
Hot Water ◽  
Hot Water Treatment ◽  
Colour Mutation ◽  
Number Variation ◽  
Chromosome Number Variation

The chromosome numbers of 56 varieties of greenhouse chrysanthemums were determined. Fifty-one varieties belonged to 10 'families' of sports and the chromosome numbers of the sports were compared with those of their vegetative parents. Sporting, mostly flower colour mutation, was accompanied by the gain or loss of a few chromosomes in about 30 per cent of the cases. Two plants with different chromosome numbers but with the true varietal flower colour were found.The most frequent chromosome number in the authors' material was 2n = 57. The range was 2n = 45–64. Mitotic irregularities and chromosome number variation within individuals were observed. Attempts to induce sporting by hot water treatment failed.Varieties with large inflorescences had higher chromosome numbers (2n = 58–64) than varieties with medium or small inflorescences (2n = 54–58), but in most of the material varieties with small inflorescences differed little in chromosome number from those with medium-sized inflorescences. Five additional varieties with very small inflorescences had lower chromosome numbers (2n = 45–55).

scholarly journals Malpighiaceae: correlations between habit, fruit type and basic chromosome number

2003 ◽  
Vol 17 (2) ◽  
pp. 171-178 ◽  
Author(s):  
Ricardo A. Lombello ◽  
Eliana R. Forni-Martins
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Basic Number ◽  
Basic Chromosome Number ◽  
Basic Chromosome ◽  
Monophyletic Origin ◽  
The Family ◽  
Number Variation ◽  
Family Based ◽  
The Relationship

The family Malpighiaceae presents species with different habits, fruit types and cytological characters. Climbers are considered the most derived habit, followed, respectively, by the shrubby and arboreal ones. The present study examines the relationship between basic chromosome numbers and the derivation of climbing habit and fruit types in Malpighiaceae. A comparison of all the chromosome number reports for Malpighiaceae showed a predominance of chromosome numbers based on x=5 or 10 in the genera of sub-family Malpighioideae, mainly represented by climbers with winged fruits, whereas non-climbing species with non-winged fruits, which predominate in sub-family Byrsonimoideae, had counts based on x=6, which is considered the less derived basic number for the family. Based on such data, confirmed by statistic assays, and on the monophyletic origin of this family, we admit the hypothesis that morphological derivation of habit and fruit is correlated with chromosome basic number variation in the family Malpighiaceae.

Karyotypes of Leptarrhena and Tanakaea (Saxifragaceae)

1984 ◽  
Vol 62 (4) ◽  
pp. 671-673 ◽  
Author(s):  
Douglas E. Soltis
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosomal Evolution ◽  
Conservative Nature ◽  
Chromosomal Data ◽  
Base Chromosome Number ◽  
Flavonoid Chemistry

In an attempt to clarify subtribal relationships in tribe Saxifrageae, chromosome numbers and karyotypes were determined for the two species comprising subtribe Leptarrheninae: Leptarrhena pyrolifolia and Tanakaea radicans. In both species 2n = 14, a common chromosome number throughout Saxifrageae. The two species have distinctive karyotypes that appear to differ in the centromeric positions of three pairs of chromosomes. These findings, in conjunction with earlier studies, demonstrate that genera of Saxifrageae often differ karyotypically. Leptarrhena exhibits considerable karyotypic similarity to genera of subtribe Saxifraginae characterized by a base chromosome number of x = 7. Chromosomal data, therefore, do not clearly differentiate subtribes Saxifraginae and Leptarrheninae. This observation is in agreement with evidence from paly-nology and flavonoid chemistry. Karyotypic studies continue to demonstrate the conservative nature of chromosomal evolution in tribe Saxifrageae.

scholarly journals Genome size stability despite high chromosome number variation in Carex gr. laevigata

2015 ◽  
Vol 102 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Marcial Escudero ◽  
Enrique Maguilla ◽  
João Loureiro ◽  
Mariana Castro ◽  
Sílvia Castro ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
High Chromosome Number ◽  
Size Stability ◽  
Number Variation ◽  
Chromosome Number Variation
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