KARYOTYPE ASYMMETRY IN GALTONIA AND PSEUDOGALTONIA (HYACINTHACEAE)

2003 ◽  
Vol 60 (3) ◽  
pp. 569-579 ◽  
Author(s):  
L. L. FORREST ◽  
K. JONG

The karyotype of a recently described species of Galtonia (Hyacinthaceae), G. regalis, is described and its cytotaxonomic relationship to other members of the genus examined. Since conflicting cytological patterns for the genus exist in the literature, the chromosome compositions of the three other species, G. candicans, G. princeps and G. viridiflora, are re-investigated. This study demonstrates that the karyotype of Galtonia is uniformly asymmetrical and distinctively trimodal, with 2n=16. Also included in this investigation is the allied monotypic genus Pseudogaltonia. Its karyotype is also asymmetrical, but differs from Galtonia in its chromosome number of 2n=18, and in certain other features.

Author(s):  
Julieta Rodríguez ◽  
Rocío Deanna ◽  
Franco Chiarini

AbstractWithin the cosmopolitan family Solanaceae, Physalideae is the tribe with the highest generic diversity (30 genera and more than 200 species). This tribe embraces subtribe Physalidinae, in which positions of some genera are not entirely resolved. Chromosomes may help on this goal, by providing information on the processes underlying speciation. Thus, cytogenetic analyses were carried out in the subtribe in order to establish its chromosome number and morphology. Physalidinae is characterized by x = 12 and most species shows a highly asymmetric karyotype. These karyotype traits were mapped onto a molecular phylogeny to test the congruence between karyotype evolution and clade differentiation. A diploid ancestor was reconstructed for the subtribe, and five to six polyploidy independent events were estimated, plus one aneuploidy event (X = 11 in the monotypic genus Quincula). Comparative phylogenetic methods showed that asymmetry indices and chromosome arm ratio (r) have a high phylogenetic signal, whereas the number of telocentric and submetacentric chromosomes presented a conspicuous amount of changes. Karyotype asymmetry allow us to differentiate genera within the subtribe. Overall, our study suggests that Physalidineae diversification has been accompanied by karyotype changes, which can be applied to delimit genera within the group.


Phytotaxa ◽  
2016 ◽  
Vol 257 (3) ◽  
pp. 280 ◽  
Author(s):  
Hao Zhou ◽  
Si-rong Yi ◽  
Qi Gao ◽  
Jie Huang ◽  
Yu-jing Wei

Aspidistra revoluta (Asparagaceae) is described and illustrated as a new species from limestone areas in southern Chongqing Municipality, China. The new species can be distinguished from the other Aspidistra species by its unique umbrella-like pistil with large revolute stigma lobes that bent downwards and touch the base of the perigone. A detailed morphological comparison among A. revoluta, A. nanchuanensis and A. carnosa is provided. The pollen grains of A. revoluta are subspherical and inaperturate, with verrucous exine. The chromosome number is 2n = 38, and the karyotype is formulated as 2n = 22m + 6sm + 10st. The average length of chromosome complement is 4.50 μm, and the karyotype asymmetry indexes A1 and A2 are respectively 0.37±0.03 and 0.49±0.01.


Phytotaxa ◽  
2013 ◽  
Vol 115 (2) ◽  
pp. 55 ◽  
Author(s):  
DONG-HUI PENG ◽  
ZHONG-JIAN LIU ◽  
JUN-WEN ZHAI

Changnienia Chien (1935: 89) is a monotypic genus of tribe Calypsoeae endemic to eastern and central China (Chen et al. 1999, 2009, Freudenstein 2005), previously with only the species C. amoena Chien (1935: 90), which was listed in the Chinese Redbook in 1992 (Fu 1992). Yang & Zhu (1984) reported a chromosome number for it of 2n=46. Sun et al. (2006) observed pollination and found that Bombus trifasciatus was its pollinator. Zhai et al. (2013) confirmed the phylogenetic placement of this species as a member of tribe Calypsoeae (sensu Pridgeon et al. 2005). A new species of Changnienia is described and illustrated here based on molecular and morphological evidence. It is discovered in Malipo, Yunnan Province, China.


Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Paola Jara-Arancio ◽  
Pedro Jara-Seguel ◽  
Claudio Palma-Rojas ◽  
Gina Arancio ◽  
Raul Moreno

AbstractThe karyotype of fifteen Leucocoryne taxa was studied, assessing characteristics such as chromosome morphology and size, secondary constriction location, and asymmetry level. Two groups of Leucocoryne taxa were described based on chromosome number (2n = 10 and 2n = 18) and karyotype asymmetry. The haploid karyotype formula for the group 2n = 10 was 3m + 2st (or 2t), whereas for the group 2n = 18 was 7m + 2st (or 2t). Such results corroborate the karyotype descriptions previously carried out for some taxa of the genus. Leucocoryne taxa showed a high resemblance in chromosome morphology, but inter-specific differences were found in mean chromosome size. These data and previous studies based on gross chromosome morphology support Crosa’s hypothesis, which suggests that the cytotype 2n = 10 is diploid and perhaps ancestral, whereas that the cytotype 2n = 18 is tetraploid but with an additional chromosome fusion being probably a derived status.


Genome ◽  
2021 ◽  
pp. 1-10
Author(s):  
Xiaomei Luo ◽  
Zhoujian He

Hibiscus exhibits high variation in chromosome number both within and among species. The Hibiscus mutabilis L. karyotype was analyzed in detail using fluorescence in situ hybridization (FISH) with oligonucleotide probes for (AG3T3)3 and 5S rDNA, which were tested here for the first time. In total, 90 chromosomes were counted in prometaphase and metaphase, and all exhibited similarly intense (AG3T3)3 signals at both ends. (AG3T3)3 showed little variation and thus did not allow discrimination among H. mutabilis chromosomes, but its location at both ends confirmed the integrity of each chromosome, thus contributing to accurate counting of the numerous, small chromosomes. Oligo-5S rDNA marked the proximal/distal regions of six chromosomes: weak signals on chromosomes 7 and 8, slightly stronger signals on chromosomes 15 and 16, and very strong signals on chromosomes 17 and 18. Therefore, 5S rDNA could assist in chromosome identification in H. mutabilis. Metaphase chromosome lengths ranged from 3.00 to 1.18 μm, indicating small chromosomes. The ratios of longest to shortest chromosome length in prometaphase and metaphase were 2.58 and 2.54, respectively, indicating karyotype asymmetry in H. mutabilis. These results provide an exact chromosome number and a physical map, which will be useful for genome assembly and contribute to molecular cytogenetics in the genus Hibiscus.


Caryologia ◽  
2018 ◽  
Vol 71 (4) ◽  
pp. 315-321
Author(s):  
Oscar Toro-Núñez ◽  
Alan Leiva-Salcedo ◽  
Naomi Fernández-Alarcón ◽  
Andrea Ruiz-Lozano ◽  
Carlos M. Baeza ◽  
...  

Biologia ◽  
2009 ◽  
Vol 64 (6) ◽  
Author(s):  
Huseyin Inceer ◽  
Deniz Guney ◽  
Sema Hayirlioglu-Ayaz ◽  
Melahat Ozcan ◽  
Ibrahim Turna ◽  
...  

AbstractKaryological studies have been investigated within 8 native Anatolian populations of oriental spruce (Picea orientalis (L.) Link) in Turkey. The somatic chromosome number of 2n = 2x = 24 has been observed in all accessions. The karyotypes are generally asymmetrical with most of the chromosomes having median to median-submedian centromeres. Inter-population variability of the karyotype was summarized with cluster analysis. We found that the karyotypes have positively correlated with the altitudes of the natural habitats. The high value of karyotype asymmetry may be attributed to both microenvironment and natural regeneration methods used in oriental spruce.


Phytotaxa ◽  
2014 ◽  
Vol 186 (3) ◽  
pp. 148 ◽  
Author(s):  
Giovanni Astuti ◽  
Giovanni Cristofolini ◽  
Lorenzo Peruzzi ◽  
Paolo Pupillo

Populations of Pulmonaria with unique features associated with shady and dry conditions were found in high beech woods on the west side of Mt. Marzola and in other dolomitic sites of Trentino (southern Italian Alps). Morpho-statistical and karyological analyses suggest that these populations represent a new subspecies of P. officinalis, Pulmonaria officinalis subsp. marzolae. The change of the basal leaf shape during the year, peculiar traits of foliar spots and hairs as well as a divergence of the karyotype asymmetry parameters suggest that this taxon is distinct from the typical form of P. officinalis. General form, the major hair types, inflorescence morphology and the chromosome number 2n = 16, however, suggest its affinity to this species.


2001 ◽  
Vol 26 ◽  
pp. 19-37 ◽  
Author(s):  
Alexander B. Doweld

ABSTRACT. Carpology and phermatology of Gomortega (Gomortegaceae): Systematic and evolutionary implications. The anatomy and morphology of the fruits and seeds of Gotnortega keule (Mol.) Baill., comprising a monotypic genus in the monogeneric family Gomortegaceae Reiche, have been studied in an effort to clarify its systematic position. The fruits are fleshy inferior cocnocarpous drupines, giving the appearance (due to the lateral concrescence of spirally arranged 2-6 carpels) of mostly 2-3-locular or rarely pseudomonomcrous syncarpous fruit. Seeds are flattened, exarillatc, abundantly albuminous with a small embryo, originate from hemianatropous crassinucellate, bitegmic ovules. The seed coat is endotestal- endotegmic; the endotesta, only testal layer preserved in the mature spermoderm, is of tracheotestal type, having peculiar numerous spiral or annular projections penetrating into the cell cavities. Evidence, mainly from seed anatomy and morphology, emphasizes phylogenetic unity of Gomortega having aberrant inferior fruits with Monimiaceae s.l. or more correctly, a group of the families Monimiaceae s. str., Amborellaceae, Hortoniaceae, Siparunaceae, and Atherospermataceae. Gomortegaceae especially have common roots with Atherospermataceae, sharing similar tracheotestal endotestal type of seed coats, albuminous seeds with small embryos, similar chromosome number, morphology of sieve-element plastids, palynomorphology, xylem anatomy, and distinctive staminodial appendages and valvular dehiscence of anthers. With the addition of more data on the fruit and seed anatomy and morphology of Atherospermataceae, the interrelationships of Gomortega and Atherospermataceae would be defined more precisely.Key words. Gomortega keule (Mol.) Baill., keule (queule), carpology, pericarp, seed anatomy and evolution, Gomortegaceae, Atherospermataceae, Monimiaceae, Lauraceae, Magnoliidae, Ranunculidae, Caryophyllidae, Hamamelididae, Rosidae, Dilleniidae.RESUMEN. Carpología y morfología de la cubierta de la semilla de Gomortega (Gomortegaceae): implicaciones sistemáticas y evolutivas. En un esfuerzo de clarificar la posición sistemática del género Gomortega, en el presente trabajo se estudia la morfología y anatomía de los frutos y semillas de Gomortega keule (Mol.) Baill., perteneciente al género monotípico anteriormente citado, de la monogenérica familia Gomortegaceae Reiche. Los frutos son drupas cenocarpicas carnosas, que ofrecen la apariencia de frutos sincárpicos bi- o triloculares, o más raramente uniloculares, debido a la concrescencia lateral de los 2-6 carpelos que lo componen y que se encuentran espiraladamente dispuestos. Las semillas son aplanadas, desprovistas de ardo, con albtímen abundante y embrión pequeño, originadas a partir de primordios seminales bitegmicos, anatropos y crasinucelados. La cubierta de la semilla es endotestal-endotégmica; la endotesta (sólo la base testal se preservó en la espermodermis madura) es de tipo traqueotestal, presentando la peculiaridad de poseer mumerosas proyecciones anulares o espiraladas que penetran en las cavidades celulares. Las evidencias encontradas, fundamentalmente en base a la morfología y anatomía de las semillas, apoyan la relación filogenetica existente entre Gomortega, con frutos ínferos aberrates, y Monimiaceae s.l. o, más correctamente, con el grupo de las familias Monimiaceae s. str., Amborellaceae, Hortoniaceae, Siparubaceae y Atherospermataceae, que comparten un tipo similar de cubierta seminal endotestal y traqueotestal, semillas albuminadas, con embrión pequeño, similar número de cromosomas, morfologia de los plastidios de los elementos cribosos del flocma, morfología polínica, anatomía del xilema, los apéndices de los estaminodios y la dehiscencia valvar de las anteras. Con la aportación de una mayor cantidad de datos sobre la morfología y anatomía de los frutos y semillas de Atherospermataceae, las interrelaciones existentes entre Gomortega y Atherospermataceae podrían ser definidas de manera más precisa.Palagras clave. Gomortega keule (Mol.) Baill., keule (queule), carpologia, pericarpo, anatomia seminal y evolucion, Gonzortegaceae, Atherospermataceae, Monimiaceae, Lauraceae, Magnoliidae, Ranunculidae, Caryophyllidae, Hamamelididae, Rosidae, Dilleniidae


2018 ◽  
Vol 25 (2) ◽  
pp. 215-226 ◽  
Author(s):  
Neslihan Taşar ◽  
Gülden Doğan ◽  
Yaşar Kiran ◽  
M. Oliur Rahman ◽  
Uğur Çakilcioğlu

Morphological, anatomical and cytological features of three Turkish taxa of Centaurea L., viz. C. polypodiifolia Boiss. var. polypodiifolia, C. urvillei DC. subsp. urvillei and C. urvillei subsp. armata Wagenitz were investigated. Stem anatomy revealed the presence of a thick cuticle layer outside the stem, and epidermis with dense hairs was observed in the lower part. Investigation on leaf anatomy showed that different types of hairs on the outside of the leaf were very intense. Palisade parenchyma was observed below the upper and lower epidermis. In Centaurea polypodiifolia var. polypodiifolia, chromosome number was found to be 2n=16, while in C. urvillei subsp. urvillei and C. urvillei subsp. armata 2n=20. Total karyotype length of C. polypodiifolia var. polypodiifolia, C. urvillei subsp. urvillei and C. urvillei subsp. armata was 22.9 µm, 37.84 µm and 40.01 µm, respectively. Among the investigated taxa the karyotype asymmetry index was found lowest in C. urvillei subsp. armata. Satellite was detected in C. urvillei subsp. urvillei and subsp. armata, while it was absent in C. polypodiifolia Boiss. var. polypodiifolia. 


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