Cytotaxonomic Studies Research Articles

A Cytotaxonomical Study in Some Freshwater Cottoid Fishes (Cottidae, Pisces)

A Cytotaxonomical Study in Some Freshwater Cottoid Fishes (Cottidae, Pisces)

Cytotaxonomic studies of Draba nivalis and its close allies in Canada and Alaska

The cytotaxonomy of seven closely related species of Draba is discussed and a key is given. The species are as follows: D. fladnizensis Wulfen (n = 8); D. lactea Adams (n = 24); D. lonchocarpa Rydberg (n = 8); D. nivalis Liljebl (n = 8); D. palanderiana Kjellman (n = ?); D. porsildii G. A. Mulligan, sp. nov. (n = 16); and D. subcapitata Simmons (n = 8). Characteristics of sterile artificial and of natural hybrids, between some of these species and between them and other species of Draba, are discussed. Draba fladnizensis, D. lonchocarpa, and D. nivalis are diploids, each with two homologous sets of eight chromosomes that are partly homologous with sets of the other two species. Draba porsildii contains two sets of 16 chromosomes, each with two completely homologous genomes, and each genome from both sets of 16 is partly homologous with either of the genomes in the other set. All four genomes of D. porsildii are partly homologous with each genome of D. fladnizensis, D. lonchocarpa, and D. nivalis.

Taxonomic Revision of the Polypodiaceous Genera of India-VI. Lepisorus excavatus Group

In an earlier paper Bir and Trikha (1972) treated 13 species of the Polypodium lineare complex in the Himalayas, one of which was Lepisorus excavatus (Bory) Ching. Further examination of herbarium material obtained from the Central National Herbarium, Howrah, India, and the U. S. National Herbarium, Washington, has shown that there are a few more species in the Himalayas belonging to the L. excavatus complex. Taxonomically, Lepisorus (J. Smith) Ching is a most confusing and difficult genus because of the great similarity of its species and their variation (hybridization occurs between some of the species, especially those of the L. excavatus and L. kashyapii complexes). The systematic position of Lepisorus is itself controversial. It has been recognized as a distinct genus (Christensen, 1938, p. 547; Ching, 1940, p. 258; Nayar, 1961; Holttum, 1968, p. 151; Bir & Trikha, 1968a, 1972) or merged with Pleopeltis (Copeland, 1947, p. 183; Panigrahi & Patnaik, 1965). Furthermore, Lepisorus (and also Pleopeltis) have similarities with Microsorium (Bir & Trikha, 1968b). Some species of the genus also have a superficial resemblance to Phymatodes because of the similar fronds and soral arrangement, but Phymatodes can be distinguished by its hair-like, club-shaped, elongate paraphyses and by the prominent lateral veins of its laminae. Holttum (1968, p. 151) separated Lepisorus from other polypodiaceous genera and mentioned the characteristic umbrella-shaped paraphyses which protect the sporangia, especially in young stages. Although the under surface of the laminae of some of the taxa described here is covered with scales, these scales are different from those of Pleopeltis, like P. macrocarpa (Bory ex Willd.) Kaulf. In Lepisorus the laminar scales are absent or deciduous, but in Pleopeltis they are persistent. Furthermore, the rhizome scales in Lepisorus are attached towards the base, but in Pleopeltis they are centrally attached. The distinction between these two genera does not appear to be very sharp. But for the very close resemblance in external morphology and scale structure of the scaly Lepisorus species (e. g., L. oligolepidus, L. suboligolepidus, L. excavatus var. himalayensis and var. mortonianus, and L. amaurolepidus var. longifolius) with the non-scaly ones, the scaly species could have easily been included in Pleopeltis. As a consequence of our cytotaxonomic studies on the Himalayan members of Lepisorus, we discovered several new taxa. All the species treated resemble each other very closely and are sympatric. The chief diagnostic characters are in the rhizome scales and spores. The total number of fully described and illustrated

A Cytotaxonomic Study of the Round Whitefishes, Genus Prosopium

The karyotypes for Prosopium spilonotus, P. abyssicola and P. gemmiferum (subfamily Coregoninae, family Salmonidae), the Bear Lake endemics (Utah-Idaho), were determined from squashed blastulae. Their diploid numbers are 74, 72 and 64, respectively. These data plus those from the karyotypes previously determined on the other species in this genus (P. coulteri, 2n = 82; P. cylindraceum, 2n = 78; P. williamsoni, 2n = 78) were assessed along with morphological characters to propose a phylogeny for these fishes. It appears that there was a common ancestor for P. cylindraceum and P. williamsoni. P. williamsoni gave rise to the Bear Lake forms with lower diploid numbers by means of Robertsonian translocations. P. coulteri would represent a specialized form in this genus which was derived early within the phylogeny of this taxon.

The cytotaxonomic study of theVicia cracca complex 2. The taxa of the southern part of northern Europe

In the southern parts of Scandinavia there occur two species of theVicia cracca L. complex:Vicia cracca L., represented by the chromosome race 2n=28, andV. oreophilaŽertova. WhereasV. oreophila predominantly inhabits habitats of primary character, especially near the coast, the tetraploid race ofV. cracca, which is the commonest in other parts of area, occurs predominantly on sites of secondary character, such as the borders of paths, roads, meadows and bushy places. The two species differ in several characters.

Cytotaxonomic study of theVicia cracca complex 1. Czechoslovak taxa

Three races ofVicia cracca L. have been found on the territory of Czechoslovakia, two with the chromosome number 2n=14 and one with 2n=28. Diploid races seem to be more primitive and are less widely distributed. They occur mostly in the primary communities while the tetraploid race is very plastic in the ecological respect and is common both in primary and secondary communities. These races are characterized by some morphological and ecological features. As far as the vertical distribution is concerned, one of the diploid races and the tetraploid occur mostly in the lowland and in the colline zone, the second diploid race has a mountain character. The related tetraploid speciesVicia oreophilaŽertova, with the chromosome number 2n=28 is distributed at similar altitudes.

Ricerche citotassonomiche nelleEuphorbiaceae:Euphorbia angulataJacq. edE. dulcisL.

Abstract Cytotaxonomical studies in Euphorbiaceae: Euphorbia angulata Jacq. and E. dulcis L. — E. dulcis and E. angulata can be easily distinguished by the following key: rhizome long, thicker than the stems, swollen and jointed, usually with swellings like ovoid, curved, obliquely jointed bulbils at the base of the stems; ovary and capsule with green or red, uneven tubercles; glands reddish at the anthesis. E. dulcis. rhizome long, jointed, with globular swellings at the base of the stems; ovary and capsule green, with minute hemispherical tubercles; glands yellow at the anthesis … … … … E. angulata. Chromosome number of E. angulata observed in root tips and in gynospore mother cells is n=5, 2n=10. All chromosomes of the complement are M (middle length) type; two pairs bear nucleolar constrictions. The E. angulata embryo sac development is monosporic (Polygonum type) and, moreover, the ovule development differs from that of E. dulcis. New cytological and embryological data are reported about E. dulcis (2...

Cytological Studies in Indian Cyperaceae

Cytotaxonomical studies have been carried out on 30 species and varieties under 4 genera belonging to the tribe Scirpeae, as part of a programme of investigation of Indian representatives of the family Cyperaceae with the aid of suitable schedules. Detailed karyotype analysis shows a general resemblance of the chromosome morphology, testifying to the homogeneity of the group as a whole. The genus Fimbristylis has been found to represent a very primitive level of evolution as compared to the genus Eleocharis. On the basis of evidences, it has been pointed out that possibly the evolution from diffuse to localised centromere has been achieved in a short step, since both types of centromere have been recorded in the species of Scirpus and Eleocharis.

Ricerche Citotassonomiche inArtemisia VulgarisL. EdArtemisia VerlotorumLamotte

Abstract Cytotaxonomical studies in Artemisia vulgaris L. and Artemisia verlotorum Lamotte. — Karyotype analysis of A. vulgaris and A. verlotorum has shown in the first species, in agreement with previous data, a chromosome number of 2n=16 and in the second the chromosome number of 2n=48 which does not agree with previous data. This seems to be the first case of polyploidy observed in Artemisia with basic number eight. A few specimens of A. verlotorum had shown 2n=48 + 2B chromosomes. The comparison of karyotypes has shown that, while the two species have, in some respect, the same degree of symmetry (ΣL%=57; ΣC9% = 43), the quality of their chromosomes is different (see karyotype formulas). We see no explanation for such an unlikely phenomenon.

Cytotaxonomic studies of Draba glabella and its close allies in Canada and Alaska

The cytotaxonomy of the following group of leafy-stemmed, white-flowered species of Draba is discussed and a key is presented: D. glabella Pursh (2n = 64 and 80), D. arabisans Michx. (2n = 96), D. borealis DC. (2n = 80), D. longipes Raup (2n = 64), D. incana L. (2n = 32), and D. norvegica Gunn. (2n = 48). Scanning electron microscopic examinations were made on the morphology of pollen grains and basal leaf hairs.

Cytotaxonomic studies in the Adiantum caudatum complex of Africa and Asia

Cytotaxonomic studies in the Adiantum caudatum complex of Africa and Asia

Cytotaxonomic studies in the Adiantum caudatum complex of Africa and Asia. II. Autoploidy and alloploidy in African representatives of A. incisum

A hybridization programme involving populations attributable to A. incisum Forsk. sens. lat. from several parts of Africa has shown that, while all those sampled are tetraploid (unlike the Indian equivalents which are predominantly diploid), they are not all genetically identical. One ecologically differentiated allotetraploid has been collected from Tanganyika (Mt. Kilimanjaro) and the pairing behaviour of its chromosomes analysed in a range of crosses involving oriental and African cytotypes. All the other African samples investigated appear to be of autoploid origin. This is the first demonstration of autoploid derivation in the genus Adiantum.

A Cytotaxonomic Study in the Genus Zingiber

The objective of the study was to know the taxonomic structure of the genus of Zingiber based on cytological characters such as ratio of number, shape and size of chromosome. Zingiber specimens were mainly from Bogorbotanical garden. There were seven species studied, Z. amaricans Nor., Z. aromaticum Val., Z. cassumunar Roxb., Z.gramineum Bl., Z. officinale Roxb., Z. ottensii Val. and Z. zerumbet (L.) J.E. Smith. Z. officinale (local name: Jahe)consinsting of 4 varieties, big ginger (jahe gajah), red ginger (jahe merah), small ginger (jahe emprit) and blue-darkbrowny ginger (jahe wulung). Species identification was based on the literature such as of Backer and Bakhuizen van den Brink (1968), Holttum (1950), and Burkill (1935). Semi permanent squash method using acetoorcein dye was used to prepare the sample (Darnaedi, 1991; Okada, 1981; Robert and Short, 1979). The results of the study indicate that the number of chromosomes of all species studied were the same, 2n=32. The length size of the first chromosome pair was about 2μm. The shape of the chromosomes was mostly metacentric. Length and shape of each pair of chromosomes were hard to be determined accurately using this method, so that the chromosomal karyotype map unable to be constructed in this study. Giemsa C-banding method might be used to solve theproblems.© 2000 Jurusan Biologi FMIPA UNS Surakarta

Cytological Observations on some Northwest Himalayan Orchids

SUMMARYA cytotaxonomic study in the Himalayan orchids was undertaken to delineate the evolutionary trends and to unravel problems of phylogeny and taxonomy. Cytological observations on 20 species from northwest Himalayan region are reported. On the basis of secondary association among bivalents and chromosome numbers in multiples, it has been suggested that all the species of Habenaria investigated by us were hexaploid. The formation of bivalent chains and occurrence of dicentric bridges and fragments in Neottia listeroides were attributed respectively to translocations and inversions at meiosis. In Epipactis belleporine, in addition to four pollen grains in a tetrad, one to two « sporads» were noted. A high proportion of taxa investigated were found to be polyploid. A number of genera had species with aneuploid numbers.

Silica gel chromatographic study of phenolic compounds in some cultivated cucurbits

Phenolic compounds in the leaves of cultivated cucurbits viz. Trichosanthes dioica Roxb., Lagenaria siceraria (Molina) Standl., Luffa cylindrica (L.) Roem., and Luffa acutangula (L.) Roxb. were carried out through silica gel chromatographic separation to ascertain their relative phylogenetic position. On phytochemical analysis, paired affinity, group affinity and isolation value supported the inclusion of these species in the same tribe Cucurbiteae on the basis of earlier cytotaxonomic studies. The two species of Luffa showed the closest phytochemical affinity and occupied as intermediate position between Lagenaria and Trichosanthes. Luffa was distantly related to other two genera having paired affinity values of less than 50%.
 
 Key words: Silica gel chromatography, separation of phenolic compounds, cultivated cucurbits
 
 Himalayan Journal of Sciences 1(2): 123-125, 2003

CHROMOSOME NUMBERS IN COMPOSITAE VII: ASTEREAE III

Reports of 129 new chromosome counts are made for the tribe Astereae of Compositae. They are mostly based on determinations of meiotic material, including first counts for one genus and 43 species or subspecies. Counts are now available for more than 63 of the 100‐120 genera and 564 of the approximately 2,000 species in the tribe. Three of every four genera with more than one species counted show more than one chromosome number; 15 genera have species with populations with different numbers. Such variation is very high and indicates the need for more detailed cytotaxonomical study in the group.

Chromosome Numbers in Compositae VII: Astereae III

Reports of 129 new chromosome counts are made for the tribe Astereae of Compositae. They are mostly based on determinations of meiotic material, including first counts for one genus and 43 species or subspecies. Counts are now available for more than 63 of the 100-120 genera and 564 of the approximately 2,000 species in the tribe. Three of every four genera with more than one species counted show more than one chromosome number; 15 genera have species with populations with different numbers. Such variation is very high and indicates the need for more detailed cytotaxonomical study in the group.

BOTANICAL EDITORS AND BIOCHEMICAL SYSTEMATICS

TAXONVolume 17, Issue 3 p. 259-260 Article BOTANICAL EDITORS AND BIOCHEMICAL SYSTEMATICS William F. Grant, William F. GrantContribution from the Department of Genetics, McGill University at Macdonald College, Macdonald College Post Office, via Montreal, Quebec, Canada.Search for more papers by this author William F. Grant, William F. GrantContribution from the Department of Genetics, McGill University at Macdonald College, Macdonald College Post Office, via Montreal, Quebec, Canada.Search for more papers by this author First published: June 1968 https://doi.org/10.2307/1217703Citations: 2 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume17, Issue3June 1968Pages 259-260 RelatedInformation

A Cytotaxonomic Study of French's Shooting Star

A Cytotaxonomic Study of French's Shooting Star

Cytotaxonomic studies on Indian Commelinaceae: A review*

The review summarizes the progress achieved in the revision of the Indian species of Commelinaceae and analyses how far the synthetic approach coupled with orthodox taxonomy has helped to clarify the many ambiguities prevalent in the family. Cytotaxonomic studies have definitely contributed to a proper understanding of such genera as Commelina, Cyanotis (sensu lato) and Pollia, and also the various ‘species complexes’ in the above genera, though the evidence is not as forthright with reference to Aneilema and Murdannia. In the genus Commelina, polyploidy has played a rather prominent role in speciation, and intra-specific aneuploidy is relatively of minor significance. The main evolutionary trend follows the pattern with predominantly x= 15 for a majority of both the Indian and African species and even though a few African species do exhibit x= 14, this basic number is infrequent and at any rate not encountered in any of the Indian species analysed so far. In sharp contrast to this, in the genus Cyanotis, both inter- and intra-specific polyploidy is very much restricted, but judging from the recent trends both in Indian and African populations, intra-specific aneuploidy has to be reckoned as a factor for further speciation within the genus. All the Indian species of Cyanotis analysed so far share a common basic number x= 12, but nevertheless there is an increasing evidence of secondary basic numbers such as, x= 8, 11 and 13 in at least a few random populations involving three species of Cyanotis. Moreover, both taxonomic and cytological data favour the splitting up of Cyanotis (sensu lato) into three distinct genera, Amischophacelus Holla Rao et Kammathy, Belosynapsis Hassk. and Cyanotis D. Don (sensu stricto). There is ample data to justify the separation of Murdannia Royle from Aneilema (sensu lato). The evolutionary trend in Murdannia seems to follow two different patterns, one with a basic number of x= 10 and the other with x= 6, both the patterns probably arising from a common extinct ancestor with x= 5. Preliminary observations on the Indian species of Aneilema R.Br, (sensu stricto) suggest a basic number of x= 14 (7?) in sharp contrast to x= 13, widely prevalent in a majority of the African species of Aneilema. In Murdannia and Aneilema, polyploidy and also aneuploidy are quite common and these two genera offer a fertile field for further study. There does not seem to be any justification for the separation of Aclisia from Pollia. In Streptolirion, intraspecific aneuploidy coupled with structural differentiation of chromosomes Seems to be responsible for further evolution of new varieties within the species. Cytological data favour the retention of Floscopa in tribe Tradescantieae rather than in Commelineae where Bruckner has placed it. The various species complexes that had baffled the taxonomists especially in Commelina, Cyanotis and Murdannia have been critically analysed and their affinities clarified, on the basis of the present observations and study, 80 species under ten genera have so far been established, representing the Indian sub-continent.