Cytological evidence for generic limits in tribe Cladothamneae (Ericaceae)

1980 ◽  
Vol 58 (9) ◽  
pp. 1119-1120 ◽  
Author(s):  
Richard J. Hebda ◽  
C. C. Chinnappa
Keyword(s):  
Meiotic Chromosome ◽  
Chromosome Counts ◽  
Cytological Evidence ◽  
Single Genus ◽  
First Time

Meiotic chromosome counts for Elliottia paniculata (Siebold & Zuccarini) Hooker, Elliottia bracteata (Maximowicz) Hooker, and Elliottia pyroliflora (Bongard) Brim and P. F. Stevens (Cladothamneae, Ericaceae) are reported for the first time. In all these species it was determined that n = 11, the same as in Elliottia racemosa Muhlenberg. These results support the conclusion of Brim and Stevens that all the members of Cladothamneae belong in a single genus Elliottia.

CYTOTAXONOMIC STUDIES IN THE TRIBE CYNAREAE (COMPOSITAE)

1962 ◽  
Vol 40 (2) ◽  
pp. 281-293 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton
Keyword(s):  
Chromosome Numbers ◽  
Chromosome Counts ◽  
Cytological Evidence ◽  
First Time

Chromosome numbers of 40 taxa of nine genera of the Cynareae together with discussions of pertinent taxonomic problems are presented. Chromosome counts for 26 taxa are presented for the first time; the chief of these are: Carduus cernuus, n = 11; C. pycnocephalus and C. tenuiflorus, 2n = 54; Cirsium arachnoideum, C. obvallatum, C. pendulum, C. tricholoma, 2n = 34; Echinops (six species), 2n = 30; Notobasis syriaca, 2n = 34; Onopordum (two species), 2n = 34; Saussurea densa, 2n = 26; Silybum eburneum, n = 17. The morphology of the chromosome complements is discussed in relation to the interrelationships and phylogeny of these genera. Cytological evidence supports the retention of Notobasis and Chamaepeuce as distinct from Cirsium.

Can morphology and chromosome number contribute to species delimitation? A case in the Hibiscus trionum complex (Tribe Hibisceae, Malvaceae)

Phytotaxa ◽  
2019 ◽  
Vol 416 (4) ◽  
pp. 278-286
Author(s):  
MOHAMED OWIS BADRY ◽  
JENNIFER A. TATE ◽  
PRASHANT JOSHI ◽  
AHMED MAHMOUD ABBAS ◽  
SOHAIR THABET HAMED ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Species Delimitation ◽  
Taxonomic Revision ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
Comprehensive Description ◽  
Hibiscus Trionum ◽  
The World ◽  
First Time

A taxonomic revision of Hibiscus trionum from Egypt was undertaken using morphological and cytological studies of field collections and herbarium specimens. The data indicate that all specimens so far collected in Egypt belong to H. tridactylites, rather than H. trionum. This paper includes a comprehensive description of H. tridactylites, its occurrence, a comparison with other species in the H. trionum complex, and comments on habitat, along with images for easy identification. In addition, chromosome counts for this species from Egypt have been determined for the first time, which add to existing information on chromosome counts for the species from different regions of the world.

XXIII.—Chromosome Number in the Blue, Fin and Sperm Whales

1955 ◽  
Vol 65 (3) ◽  
pp. 358-368
Author(s):  
B. J. A. Nowosielski-Slepowron ◽  
A. D. Peacock
Keyword(s):  
Resting State ◽  
Sperm Whale ◽  
Common Source ◽  
Sexually Active ◽  
Sperm Whales ◽  
Cytological Evidence ◽  
Fin Whale ◽  
The Third ◽  
The Antarctic ◽  
First Time

SynopsisTesticular material from a Blue Whale (Balœnoptera musculus Rafinesque), a Fin Whale (Balœnoptera physalus Lacepède) and a Sperm Whale (Physeter catodon L.), obtained 6–24 hours after death in the Antarctic during the whaling season 1946–47, showed that the testes of the first two animals were in the resting state and those of the third animal were active. Despite being collected some hours after death, the material has allowed estimation to be made for the first time of chromosome numbers from spermatogonia and spermatocytes in the prophase stage. The diploid and haploid numbers approximate to 48 and 24 respectively. These results are discussed along with those obtained by Makino (1948), the first worker to record counts of cetacean chromosomes, in his study of freshly fixed material from Dall's Porpoise, Phocœnoides dallii (True). They support this worker in his view that the cytological evidence indicates that Cetacea and Ungulata derive from a common source.Some observations on spermateleosis and cell inclusions in the Sperm Whale are given.Regarding the breeding season, the findings of previous workers are supported for the Blue and Fin Whales. That the Sperm Whale dealt with in this paper was found to be sexually active in December is support of Harrison-Matthews' view that the species has no definite sexual season or cycle.

Diploidy, polyploidy, and agamospermy among species of Eupatorium (Compositae)

1976 ◽  
Vol 54 (24) ◽  
pp. 2907-2917 ◽  
Author(s):  
Victoria I. Sullivan
Keyword(s):  
Normal Embryo ◽  
Herbarium Specimens ◽  
Pollen Production ◽  
Chromosome Counts ◽  
Distribution Maps ◽  
Normal Pollen ◽  
Abortive Pollen ◽  
Chromosomal Pairing ◽  
First Time

Diploids of eight species of Eupatorium, triploids of three species, and tetraploids of four species are reported here for the first time. Meiosisin microsporocytes of triploids and tetraploids either failed to occur resulting in failure of pollen production or less frequently resulted in either incomplete chromosomal pairing or complete asynapsis; the latter two events lead to the production of grossly malformed, abortive pollen with unevenly deposited walls. Megasporogenesis examined in two polyploid plants led to the formation of eight-nucleate, unreduced embryo sacs which formed endosperm and embryos without pollination, indicating that the sporophytes develop asexually through agamospermy. Evidence is given that this may be a facultative characteristic. Megasporogenesis, studied in diploids of four species, produced normal embryo sacs with no indication of agamospermous development. Diploid plants of 11 of 12 species were tested and found to be self-incompatible.Since diploids could readily be distinguished from polyploids by pollen production (diploids produced normal pollen, polyploids produced none or malformed pollen), distributions of a large number of diploid, triploid, and tetraploid individuals could be determined from examining anthers of herbarium specimens. Distribution maps were made using these data as well as those from chromosome counts. Diploid members of species having both diploid, triploid, and (or) tetraploid members consistently had smaller distributional ranges than polyploids of the same species.

scholarly journals Oligo-painting and GISH reveal meiotic chromosome biases and increased meiotic stability in synthetic allotetraploid Cucumis ×hytivus with dysploid parental karyotypes

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Qinzheng Zhao ◽  
Yunzhu Wang ◽  
Yunfei Bi ◽  
Yufei Zhai ◽  
Xiaqing Yu ◽  
...  
Keyword(s):  
Interspecific Hybridization ◽  
Interspecific Hybrids ◽  
Chromosome Doubling ◽  
Meiotic Chromosome ◽  
Genomic In Situ Hybridization ◽  
Meiotic Behavior ◽  
Cytological Evidence ◽  
Meiotic Stability ◽  
Inbred Family

Abstract Background Meiosis of newly formed allopolyploids frequently encounter perturbations induced by the merging of divergent and hybridizable genomes. However, to date, the meiotic properties of allopolyploids with dysploid parental karyotypes have not been studied in detail. The allotetraploid Cucumis ×hytivus (HHCC, 2n = 38) was obtained from interspecific hybridization between C. sativus (CC, 2n = 14) and C. hystrix (HH, 2n = 24) followed by chromosome doubling. The results of this study thus offer an excellent opportunity to explore the meiotic properties of allopolyploids with dysploid parental karyotypes. Results In this report, we describe the meiotic properties of five chromosomes (C5, C7, H1, H9 and H10) and two genomes in interspecific hybrids and C. ×hytivus (the 4th and 14th inbred family) through oligo-painting and genomic in situ hybridization (GISH). We show that 1) only two translocations carrying C5-oligo signals were detected on the chromosomes C2 and C4 of one 14th individual by the karyotyping of eight 4th and 36 14th plants based on C5- and C7-oligo painting, and possible cytological evidence was observed in meiosis of the 4th generation; 2) individual chromosome have biases for homoeologous pairing and univalent formation in F1 hybrids and allotetraploids; 3) extensive H-chromosome autosyndetic pairings (e.g., H-H, 25.5% PMCs) were observed in interspecific F1 hybrid, whereas no C-chromosome autosyndetic pairings were observed (e.g. C-C); 4) the meiotic properties of two subgenomes have significant biases in allotetraploids: H-subgenome exhibits higher univalent and chromosome lagging frequencies than C-subgenome; and 5) increased meiotic stability in the S14 generation compared with the S4 generation, including synchronous meiosis behavior, reduced incidents of univalent and chromosome lagging. Conclusions These results suggest that the meiotic behavior of two subgenomes has dramatic biases in response to interspecific hybridization and allopolyploidization, and the meiotic behavior harmony of subgenomes is a key subject of meiosis evolution in C. ×hytivus. This study helps to elucidate the meiotic properties and evolution of nascent allopolyploids with the dysploid parental karyotypes.

Allonautilus: a new genus of living nautiloid cephalopod and its bearing on phylogeny of the Nautilida

1997 ◽  
Vol 71 (6) ◽  
pp. 1054-1064 ◽  
Author(s):  
Peter D. Ward ◽  
W. Bruce Saunders
Keyword(s):  
Phylogenetic Analysis ◽  
Reproductive System ◽  
New Genus ◽  
Male Reproductive System ◽  
Late Cenozoic ◽  
Extant Species ◽  
Single Genus ◽  
Gill Morphology ◽  
First Time

Living ectocochliate cephalopods have long been thought to be restricted to a single genus, Nautilus Linnaeus, 1758, comprising five or six extant species. The shells of two species, N. scrobiculatus Lightfoot, 1786, and N. perforatus Conrad, 1847, are quite distinct, but no soft-parts were known until 1984, when N. scrobiculatus was seen alive for the first time. Dissections show that significant anatomical differences exist between N. scrobiculatus and other Nautilus species, including differences in gill morphology and details of the male reproductive system. These differences, along with phylogenetic analysis of extant and selected fossil nautiloid species, indicate that N. scrobiculatus, and N. perforatus should be distinguished from Nautilus as a newly defined genus, Allonautilus. This analysis contradicts previous phylogenies proposed for the Nautilida, which placed Nautilus as the last-evolved member of the order. We surmise that Allonautilus is a descendent of Nautilus, that the latter is paraphyletic, and first evolved in the Mesozoic, rather than in the late Cenozoic, as has been previously suggested.

A cytotaxonomic survey of the Pteridophyta of Australia

2002 ◽  
Vol 15 (6) ◽  
pp. 839 ◽  
Author(s):  
Mary D. Tindale ◽  
S. K. Roy
Keyword(s):  
Ploidy Level ◽  
New Combination ◽  
Chromosome Counts ◽  
Ploidy Levels ◽  
Australian Species ◽  
Number Of Species ◽  
Lord Howe Island ◽  
Species Complexes ◽  
Living Material ◽  
First Time

A cytotaxonomic survey of the ferns and fern allies of Australia (including Lord Howe Island) is presented. Five-hundred-and-twenty-six chromosome counts of 268 Australian species, subspecies, varieties, variants and hybrids are recorded, only a small number having been previously investigated by other botanists on Australian material. Diploids represent c. 62% of the counts on species and c. 38% on polyploids, the latter ranging principally from triploids to a single decaploid and dodecaploid (but no heptaploids). More than one ploidy level has been reported in 19 taxa (almost 8% of taxa). Counts of 10x for Asplenium aethiopicum and 12x for A.�flabellifolium are the highest definite ploidy levels for the Australian pteridophyte flora. Chromosome counts for 29 families and 89 genera are cited. Only diploids were reported for Osmundaceae and Cyatheaceae, but only polyploids for the Psilotaceae, Vittariaceae and Ophioglossaceae. An analysis is given of the levels of ploidy in 248 taxa, excluding the Lycopodiaceae and Hymenophyllaceae. The percentages of diploids and polyploids in Australian species are compared with those of nearby countries. Many species reported on here have never been cytologically investigated before, while others have not been studied previously on Australian material. The following genera have been examined cytologically for the first time: Coveniella Tindale, n = 41; Paraceterach (F.Muell.) Copel., n = 29; 'Oenotrichia Copel.', 2n = 82 (2x); Revwattsia (Watts) D.L.Jones, 2n = c. 328 (8x); and Pteridoblechnum Hennipman (2n = 54). The phylogeny of the genera is discussed in the light of these findings. Certain families such as the Adiantaceae, Cyatheaceae, Hymenophyllaceae, Lindsaeaceae and Marsileaceae were given special attention by collecting as much living material as possible. A number of species-complexes has been found and further chromosome counts added to intercontinental species complexes. The Döpp-Manton and Braithwaite forms of reproductive apomixis have been reported amongst some genera. Endemism, hybridity and apogamy amongst Australian pteridophytes are discussed, as well as homosporous and heterosporous species. The new combination Phymatosorus membranifolius (R.Br.) Tindale is made.

The biosystematics of the genus Lotus (Leguminosae) in Canada. I. Cytotaxonomy

1968 ◽  
Vol 46 (5) ◽  
pp. 557-583 ◽  
Author(s):  
Ilse I. Zandstra ◽  
William F. Grant
Keyword(s):  
Native Species ◽  
Cytological Study ◽  
Tube Length ◽  
Herbarium Specimens ◽  
The North ◽  
Size Number ◽  
Single Genus ◽  
Living Material ◽  
Peduncle Length ◽  
First Time

A morphological and cytological study of native and introduced Lotus species found in Canada has been conducted on both living material and on over 600 herbarium specimens from 20 Canadian and American herbaria. Illustrations of flowers, seed, ovaries and styles, habit, and geographical distribution for each species are given. Five native species, L. denticulatus (E. Drew) Greene (annual (A), self-fertilized (S), 2n = 12), L. formosissimus Greene (perennial (P), outcrossing (O), 2n = 14), L. micranthus Benth. (A, S, 2n = 14), L. pinnatus Hook. (P, O, 2n = 14), and L. purshianus (Benth.) Clem. and Clem. (A, S, 2n = 14), and four introduced species, L. corniculatus L. (P, O, 2n = 24), L. krylovii Schischk. and Serg. (A, S, 2n = 12), L. pedunculatus Cav. (P, O, 2n = 12), and L. tenuis Waldst. et Kit. (P, O, 2n = 12) were found in Canada. Chromosome numbers are reported for the first time for L. formosissimus, L. micranthus, and L. pinnatus. Drawings of karyotypes and idiograms based on chromosome analyses are presented. Morphological observations made include style shape, pollen size and shape, seed size, number of flowers, length of standard, calyx index (length of calyx/length of calyx tube), length of peduncle, length of legume, length of petiole, and central leaflet index (leaflet length/leaflet width). Results of hydrocyanide tests on leaves of the native species were negative. The relationships of the different taxa are discussed and it is considered that both the North American and Old World species should be included in a single genus Lotus.

scholarly journals Systematic treatment of morphological fruit types in plants of the class Liliopsida of the flora of Ukraine

2021 ◽  
Vol 12 (3) ◽  
pp. 375-382
Author(s):  
A. V. Odintsova ◽  
O. S. Fishchuk ◽  
K. I. Scrypec ◽  
I. M. Danylyk
Keyword(s):  
Morphological Diversity ◽  
Taxonomic Diversity ◽  
Fruit Morphology ◽  
Systematic Treatment ◽  
Annotated List ◽  
Ecological Aspects ◽  
The World ◽  
Single Genus ◽  
Flora Diversity ◽  
First Time

In this review, the scope of morphological diversity of fruits within the class Liliopsida belonging to the flora of Ukraine compared to the world flora diversity was analyzed. For the first time, the taxonomic diversity of monocot plants of the flora of Ukraine was analyzed, which includes 235 genera and about 1050 species, and the distribution of fruit types in the largest monocot families revealed. It was found that among monocot plants of the world flora, as also of the Ukrainian flora, more than 70% of generic and species diversity is taken up by the Orchidaceae, Poaceae, and Cyperaceae families having dry uniform fruits: inferior capsule (Orchidaceae) and one-seeded enveloped fruit (Poaceae and Cyperaceae). An annotated list of morphological fruit types was compiled for all 38 families of the natural and cultural flora of monocot plants of Ukraine. Among 12 families of the subclass Alismatidae, apocarpous polymerous or trimerous fruits, mostly with one-seeded fruitlets, occur in six families (Alismataceae, Butomaceae, Potamogetonaceae, Ruppiaceae, Scheuchzeriaceae, Zannichelliaceae). In 12 of 16 families of the subclass Liliidae, trimerous capsules are the most common (Agapanthaceae, Agavaceae, Alliaceae, Amaryllidaceae, Asphodelaceae, Colchicaceae, Hemerocallidacae, Hyacinthaceae, Iridaceae, Liliасеае, Melanthiaceae, Orchidaceae), while in six families berry-like fruit occurs in all members or in the single genus (Asparagaceae, Ruscaceae, Dioscoreaceae, Melanthiaceae (Paris), Liliасеае (Streptopus), Smilacaceae). Among 10 families of the subclass Commelinidae, in four families superior dry one-seeded fruits occur (Cyperaceae, Poaceae, Sparganiaceae, Typhaceae), while another four families have trimerous capsules (Cannaceae, Commelinaceae, Juncaceae, Pontederiaceae). In general, the most typical fruit on the familial taxonomical level is the capsule (17 families), berries occur in 10 families, aggregate fruits and one-seeded fruits are represented each in seven families, while the rarest fruit type is the schizocarp (Juncaginaceae). No monomerous follicles, poricide and operculate capsules, winged fruits and loments were found. The most controversial fruit types are found in two groups of families, for both of them the problem is the gynoecium type. These are families with one-seeded fruit (Аrасеае (Lemna), Cyperaceae, Hydrocharitaceae (Najas), Poaceae, Sparganiaceae, Typhaceae, Zosteraceae) and families with initial carpel fusion (Hydrocharitaceae (Stratiotes), Juncaginaceae, Melanthiaceae (Veratrum), Scheuchzeriaceae, Tofieldiaceae). As a result of our work, the key and the most relevant areas of carpological studies in Ukraine were defined, particularly, unifying the terminology, examination of the anatomical structure of the pericarp, revealing of the evolutionary and ecological aspects of fruit morphology.

scholarly journals Chromosome counts of eight Iranian endemic species of Nepeta L. (Lamiaceae)

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 53-61
Author(s):  
Maryam Hasaninejad ◽  
Ziba Jamzad ◽  
Saeid Afsharzadeh ◽  
HojJatollah Saeidi
Keyword(s):  
Chromosome Number ◽  
Species Group ◽  
Chromosome Length ◽  
Basic Chromosome Number ◽  
Chromosome Counts ◽  
Ploidy Levels ◽  
Study Results ◽  
Karyotypic Diversity ◽  
Karyotype Formula ◽  
First Time

In this survey, the chromosome counts of eight Nepeta L. species were investigated and the karyotypic diversity among these species was studied. The examined species belong to N. cephalotes Boiss. species group, namely N. eremokosmos Rech.f., N. gloeocephala Rech. f., cephalotes Boiss., N. pungens (Bunge) Benth., N. ispahanica Boiss., N. mahanensis Jamzad & Simonds, N. hormozganica Jamzad and N. denudata Benth. collected from different habitats in Iran. The ploidy levels, karyotype formula, chromosome length range, total karyotype length, several karyotype asymmetries values and Stebbins classification were determined in this study. Results showed the same chromosome number, 2n = 2x= 18 for all studied species. The basic chromosome number for the above mentioned species are x = 9. Also, the smallest chromosome length is 1.02 μm in N. mahanensis. The largest chromosome length is 2.3 μm in N. ispahanica. The chromosomes of species were metacentric or submetacentric. According to the Stebbins classification, these species were located into three classes 1A, 2A and 3A. The chromosome numbers for six of studied species are reported here for the first time.

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