Cytological studies in Four Endemic Genera of Apiaceae from India (original) (raw)
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Cytological evaluation of Apiaceae Lindl. from Western Himalayas
Cytology and Genetics, 2014
Cytological studies. At present meiotic studies on population basis have been carried out on 31 popula tions belonging to 17 species and 10 genera in the fam ily Apiaceae from different localities in the Western Himalayas. The data regarding locality, altitude, accession number, present chromosome numbers, nature of meiotic course and pollen fertility of the presently worked out species has been given in Table 1. The results for each species with new/varied chromo
Plant Systematics and Evolution, 2013
Tordyliopsis brunonis (Apiaceae) is cytologically investigated here for the first time from India. The chromosome count of 2n = 33, ascertained here, represents a new intraspecific triploid cytotype in the species, supplementing the earlier report of a diploid cytotype with 2n = 22 from Nepal Himalayas. The diploid chromosome count (n = 11) has also been found in some of the presently investigated individuals which showed perfectly normal meiosis with 100 % pollen fertility and normal seed set. However, the individuals with triploid chromosome count showed irregular meiotic behaviour and abnormal microsporogenesis resulting in high pollen sterility (56.26 %) and no seed set. The irregular meiotic behaviour in the triploid individuals is attributed to the occurrence of variable number of univalents (1-7) at diakinesis and metaphase-I. In the subsequent meiotic stages, these univalents lagged at anaphases and constituted micronuclei in sporads. The triploid plants were also observed for natural propagation and it was noticed that no seeds were set. These plants were noticed to propagate vegetatively by rootstocks. Chromosomal pairing in triploid cytotype is typical of an allopolyploid. Based on the characterization of chromosomal pairing during meiosis, we assumed that the triploid individuals are probably alloploid in nature. Hypotheses concerning the possible origin of allotriploid in T. brunonis are also discussed.
Chromosome numbers are presented for 18 species from seven genera of Cyperaceae collected from Api Himal and adjacent areas in Far Western Nepal. The chromosome numbers for Carex cruenta Nees (2n = 44), C. kumaonensis Kük. (2n = 50), C. obscura Nees (2n = 56), C. stracheyi Boott ex C. B. Clarke (2n = 44), Kobresia esbirajbhandarii Rajbh. & H. Ohba (2n = 62), and Schoenoplectiella fuscorubens (T. Koyama) Hayasaka (2n = 42) are reported for the first time. Our finding of 2n = 46 for Blysmus compressus (L.) Panz. ex Link and 2n = 62 for Carex foliosa D. Don differ from previous reports. The chromosome numbers of Carex filicina Nees (2n = 46), C. inanis Kunth (2n = 42), C. longipes D. Don (2n = 46), C. microglochin Wahlenb. (2n = 50), C. myosurus Nees (2n = 44), C. rufulistolon T. Koyama (2n = 46), Eleocharis uniglumis (Link) Schult. (2n = 42), Fimbristylis complanata (Retz.) Link (2n = 10), F. falcata (Vahl) Kunth (2n = 22), and Isolepis setacea (L.) R. Br. (2n = 28 = 14II) agree with earlier studies.
Hacettepe Journal of Biology and Chemistry, 2021
In Turkey, there are eighteen Tordylium (Apiaceae) species out of twenty in the worldwide and seven of them are endemic. In this research, karyotypes of T. apulum, T. pestalozzae, T. syriacum, T. trachycarpum and karyotypes and chromosome numbers of T. cappadocicum, T. aegaeum, T. hasselquistiae, T. ketenoglui (endemic), T. macropetalum (endemic), T. pustulosum (endemic) are provided for the first time. Tordylium species were separated into five cytotypes according to chromosome numbers as 2n=8, 16, 18, 20 and 22. Besides, idiograms of haploid chromosome set, length of the chromosome arms, arm ratios, centromeric index, relative length and haploid karyotype formulas are given. T. ketenoglui has longest chromosome lengths (3,39–1,66 µm) while T. aegaeum has shortest (1,10–0,59 µm). Additionally, principal component analysis (PCA) was performed by quantitified karyological characters. PCA results showed that the median type and haploid chromosome length have significant variants among...
Hereditas, 2004
Meiotic studies are carried out in 7 species of Eryngium L. (Saniculoideae, Apiaceae), belonging to both sections Foetida and Panniculata. The chromosome number of E. dorae Norm. (n0/8) (Foetida) is reported for the first time, while the gametic chromosome number of E. nudicaule Lam. (n0/7) (Foetida) and E. eburneum Decne. (n0/8), E. horridum Malme (n0/8), E. megapotamicum Malme (n 0/16), E. mesopotamicum Pedersen (n0/24), and E. pandanifolium Cham. et Schlechtd. (n0/24) (all belonging to Panniculata) is confirmed in several natural populations. Whereas in section Foetida all species are diploids and two basic chromosome numbers are present (x0/8 and x 0/7), in section Panniculata all species are x0/8 but there are three different ploidy levels (diploid, tetraploid, hexaploid). This study reveals that meiosis in all species is normal, with regular bivalent formation in all studied cells. Furthermore, the pollen stainability is above 80% in all cases. These data, together with the previous karyotype analyses, will contribute to the clarification of the relationships between members of both sections, where different mechanisms of speciation have been postulated.
Karyotype analysis and karyological relationships of Turkish Bunium species (Apiaceae)
Archives of Biological Sciences
Chromosomal data and karyological relationships provide valuable information about karyotype evolution and speciation. For the genus Bunium, the chromosomal data are limited. In the present study, the chromosomal data of 10 taxa are provided, 6 of which are given for the first time, 2 present new chromosome numbers, and 2 agree with previous reports. Four different chromosome numbers (2n=18, 20, 22 and 40) were detected, and 2n=40 is a new number in the genus Bunium. B. brachyactis is the first polyploid species of the genus with a ploidy level of 4x. The most asymmetric karyotypes are those of B. pinnatifolium and B. sayae. Regarding karyological relationships, B. pinnatifolium forms a monophyletic group by quite different karyological features such as large chromosomes, more submedian chromosomes and the most asymmetric karyotypes. In addition, the other 5 taxa form a strong monophyletic group. B. verruculosum and B. ferulaceum are cytotaxonomically very close species, as are B. s...
Despite the presence of intraspecific polyploidy (2x, 4x, 5x and 6x) in Agrimonia eupatoria, origin of these cytotypes has never been addressed adequately. The aim of the present study was to record the original chromosome counts and characterize chromosomal pairing during meiosis and microsporogenesis in the 5x cytotype, and discussing the hypothesis regarding the possible origin of polyploid cytotypes (4x, 5x and 6x) in the species. The geographical distribution pattern of cytotypes in the Indian Himalayas and elsewhere has also been analyzed. The presentmeiotic analysis revealed three chromosomes counts, the tetraploid (2n =4x =56), the pentaploid (2n =5x =70) and the hexaploid (2n =6x =84) cytotypes based on x =14.Meiotic course was perfectly normal in the 4x and 6x cytotypes resulting into high pollen fertility (94–100 %). Meiotic course in the imbalanced 5x cytotype has been found to be irregular characterized by the presence of high frequency of univalents at diakinesis and metaphase-I. Abnormal meiotic course contributed towards high pollen sterility (74–88 %). Even the apparently fertile/stained pollen grains were of irregular shape and of heterogeneous sizes. Meiotic behaviour of the 5x cytotype is like typical of allopolyploid. Individuals of 5x cytotype did not produce seeds and propagate vegetatively (root suckers) while 4x and 6x cytotypes exploited sexual (seeds) as well as vegetative means for propagation. Chromosomal pairing in pentaploid cytotype is like typical of an allopolyploid and we assume that it might have originated owing to natural inter-cytotype hybridization between 4x and 6x cytotypes in a mixed population. Analysis of geographical distribution pattern of cytotypes shows that Indian Himalayas represent the most cytotype-diverse region for A. eupatoria with the existence of all the four cytotypes (2x, 4x, 5x, 6x). This shows the dynamic nature of the species at chromosomal level in this part of the world.
Caryologia, 2017
Chromosome counts including male meiotic studies have been made on 45 species (125 accessions) of Asteraceae collected from the Parvati Valley, Kullu district, Himachal Pradesh. Crepis foetida (n = 5) and Senecio pedunculatus (n = 20) have been counted chromosomally for the first time at global level. The genus Phagnalon has been worked out for the first time from India (P. niveum, n = 9). New chromosome counts/cytotypes have been reported for Gerbera lanuginosa (2n = 4x = 48), Gynura cusimbua (2n = 2x = 16) and Inula grandiflora (2n = 4x = 32). Intraspecific euploid cytotypes have been reported for the first time in Inula grandiflora (2x,4x). Three intraspecific euploid cytotypes (2x,3x,4x) have been reported from the valley in Taraxacum officinale complex. The triploid taxa re-recorded presently for Erigeron annuus (2n = 27), Eupatorium adenophorum (2n = 51) and Taraxacum officinale (2n = 24) exhibit abnormal meiotic course and high pollen sterility but seem to have reproduced successfully through apomictic means. Presence of multivalents in the 4x cytotype of Chrysanthemum leucanthemum (2n = 36) indicates the segmental allotetraploid nature of the taxon. Phenomenon of cytomixis involving chromatin transfer among neighboring meiocytes and associated meiotic irregularities have been detected in Artemisia maritima (n = 9), Aster peduncularis (n = 27), Crepis foetida (n = 5), Erigeron annuus (2n = 27), Inula grandiflora (n = 8), Lactuca dolichophylla (n = 8), Prenanthes brunoniana (n = 8), Senecio graciliflorus (n = 20) and S. rufinervis (n = 20). In the rest of the species, the present findings substantiate earlier chromosome reports from other parts of Himalayas in India. Note 1. As per the abbreviation cited in 'Index Herbarioum' by Holmgren and Holmgren (1998).
Caryologia, 2018
The present study includes chromosome count, meiotic abnormalities, pollen fertility and karyotype of Elymus semicostatus from northwest Himalaya, India. This is the first attempt to present karyotype morphometric data of the species from India [2n = 4x = 28 = 22m (2sat) + 6sm]. At present 28 wild accessions of the species have been analysed, all of which shared the same tetraploid (4x) chromosome count of 2n = 28. In addition, seven accessions also showed the presence of 0-2 B-chromosomes in the meiocytes. Meiotic abnormalities were frequent and 17 accessions showed the phenomenon of cytomixis, involving chromatin transfer among meiocytes and associated meiotic irregularities in spindle activity and chromosomal segregation. Consequent to such meiotic abnormalities, these accessions showed pollen malformation in the form of sterile and variable sized pollen grains. Cytomixis in the species seems to be a natural phenomenon under the control of genetic factors and is responsible for inducing meiotic disturbance and pollen malformation.
CYTOLOGIA, 2022
Trachyspermum ammi (L.) Sprague (Ajwan) is one of the most important industrial and medicinal plants which belongs to the family Apiaceae. A meiotic study of eight populations from Iran was performed. All populations were diploid n=9 (2n=2x=18) forming mainly bivalents with some amount of quadrivalent and hexavalent possibly due to the occurrence of heterozygote translocations. The ANOVA test of meiotic characters showed a significant difference (p 0.05) in chiasma frequency as well as chromosome associations in Ajwan populations. Chromosome migration or cytomixis and syncyte formation and tripolar structure in telophase II were also reported for the first time in natural populations in Iran and led to diploid gamete formation or 2n pollen grains in almost all populations were studied. Cluster analysis of meiotic data showed the distinctness of the populations in their meiotic behavior.