Cytogenetic studies of Haplopappus gracilis in both callus and suspension cell cultures

Summary Investigations have been carried out on karyotype change in both callus and suspension cell cultures of Haplopappus gracilis (2n=4). It has been found that polyploidization arises directly in culture to give up to six times the normal diploid chromosome number in some cultures. In polyploid cultures, both chromosome loss and chromosome rearrangements occur to give rise to aneuploid karyotypes displaying chromosomes which differ in morphology from the diploid set. Whole or partial chromosome loss has been observed in the form of lagging chromosomes and chromosome bridges at anaphase, and micronuclei, ring chromosomes and chromosome fragments at other stages in mitosis. C-banded preparations have confirmed the occurrence of chromosomal rearrangements. Comparative investigations suggest that (i) more polyploidy occurs in callus cultures than in suspension cell cultures, and (ii) the presence of cytokinin (kinetin) in the culture medium may reduce the extent of karyotype change.     

A biosystematic investigation of the Asplenium lepidum complex

Twenty-nine populations of three closely related taxa, Asplenium lepidum, A. haussknecktii and A. samarkandense , have been raised together in cultivation. There is considerable inter-population variation, and the ranges of variation of the three species overlap. Cytogenetic investigation of artificial hybrids has shown that the three taxa are all allotetraploid and that they share the same diploid parents, A. aegaeum and A. ruta-muraria subsp. dolomiticum. Analysis of F1 and F2 hybrids between different populations indicates high inter-fertility.
The aggregate is re-defined as a single polymorphic species (A. lepidum) consisting of two subspecies (subsp. lepidum and subsp. haussknechtii) distinguished primarily by gland and sporangial characters. A. samarkandense is reduced to a variety of subsp. haussknechtii. It is suggested that the two subspecies have had separate geographical origins from different morphological variants of the same diploid parents, but the polymorphic nature of the aggregate is principally due to divergent evolution in small populations isolated on limestone mountains in southern Europe and western Asia.     

A biosystematic study on Ranunculus subgenus Batrachium in S Sweden

A detailed study of Ranunculus subgenus Batrachium was undertaken on material from SW Skåne, S Sweden. 38 populations were sampled including 5 from outside the study area. A comprehensive morphological investigation of the variation pattern, which included biometric analyses, led to a reassessment of diagnostic characters. 64 chromosome counts were made from 28 populations. Minor differences in karyotype constitution between species were demonstrated. Crossing experiments involving 4 species were carried out, and F, was analysed as regards morphology, compatibility, meiosis and seed set. The two diploid species (2n=16), R. fluitans and R. circinatus , are shown to be homogeneous and reproducing vegetatively in S Sweden. The tetraploid R. peltatus is outcrossing and probably self-incompatible, whereas the likewise tetraploid R. baudotii is self-compatible and mainly self-pollinated. These tetraploids are interfertile, but morphologically distinct and kept apart by different ecological demands. Hexaploids, generally referred to two separate species, R. aquatilis and R. trichophyllus , are automatically self-pollinated in bud (sometimes cleistogamous). All characters used to distinguish these two species are found to be variable and readily modified. Crosses between typical R. aquatilis and typical R. trichophyllus are fully fertile. A division into two species seems untenable. ( R. trichophyllus is treated as conspecific with R. aquatilis ). Semifertile, natural pentaploid hybrid derivates with varying chromosome numbers between R. aquatilis and R. peltatus were found, and have also been experimentally synthesized. The variation pattern in S Sweden deviates in sereral respects from that reported by Cook based mainly on C and W European material.     

A biosystematic study of Coreopsis saxicola (Compositae)

On the basis of morphological, hybridization, genetic, and field studies, it is proposed thatCoreopsis saxicola Alex. be reduced to varietal rank asC. grandiflora var. saxicola.     

The Commelinaceae of West Africa: A biosystematic survey

All the known West African taxa are surveyed and their variation and distribution is discussed. Chromosome numbers for most of the taxa are given, in many cases for the first time, and published cytological data for those genera occurring in West Africa is reviewed. Many of the taxa have been studied under cultivation and most under living conditions in the field. The results of these observations are considered in relation to the evolution of new variations and to the taxonomy of the groups concerned. The following new taxa are described: Aneilema beniniense subsp. leonense, C'ommelina diffusa subsp. montana, Floscopa africana subsp. petrophila and Slanfieldiella axillaris. Several nomenclatural changes have been made, the most important being the recognition that the African species Commelina gerrardi C. B. Clarke and C. vogelii C. B. Clarke are conspecific with the American C. erecta Linn, which thus becomes a pantropie species complex. Several species are recorded from West Africa for the first time including: Coleolrype kiurentii K. Schum. Commelina carsonii C. B. Clarke, C. zambesiaca C. B. Clarke, Cyanotis arachnoidea C. B. Clarke, and Palisota lagopus Mildbr. The pattern of variation in the larger species complexes in the genera Aneilema, Commelina, Cyanotis and Floscopa is considered in detail. These and other groups in the family are considered to be in an active state of evolutionary change. The factors which have stimulated these changes and the biological processes by means of which they are brought about are discussed. Attention is drawn to the suitability of this family for evolutionary studies and its value in the teaching of experimental taxonomy in the tropics.     

A biosystematic and evolutionary study of capsicum baccatum (Solanaceae)

Capsicum baccatum L. has frequently been treated as two distinct species,C. microcarpum Cav. andC. pendulum Willd. A biosystematic study reveals a quantitative and qualitative basis for morphological separation ofC. baccatum into two taxa, while cytological and genetic data indicate their close similarity. A resolution of this apparent contradiction can be found in a “gigas” effect imparted to all the organ systems of cultivatedC. baccatum while the fruit has been under intense subconscious and conscious artificial selective pressures for an increase in size. Few, if any, incipient genetic barriers have arisen to separateC. baccatum into distinct species. CultivatedC. baccatum has been isolated by man in a number of localities outside the range of wildC. baccatum. Where both cultivated and wildC. baccatum occur sympatrically, they are effectively isolated by an inbreeding mechanism and agricultural practices. On the basis of this investigationC. baccatum is treated as a wild variety,C. baccatum L. var.baccatum, and a cultivated variety,C. baccatum var.pendulum (Willd.) Eshbaugh.     

A biosystematic study of theOryza meyeriana complex (Poaceae)

To determine the taxonomic status and to clarify the biosystematic relationships of wild rice species, i.e.,Oryza granulata andO. meyeriana in theO. meyeriana complex (Poaceae), a series of intraspecific and interspecific hybridization experiments, genomic analyses through meiotic pairing, and morphological studies were conducted. Hybridization results demonstrate comparatively high crossability with about 34–39% of seed set, and very limited reproductive isolation betweenO. granulata andO. meyeriana. Chromosome pairing in the parental species and their F₁ hybrids indicate very high genomic affinity between the two taxa. Morphological analyses of the parental accessions and their intra- and interspecific hybrids show a large variation among the samples included, but no appreciable grouping was observed. The traditionally used character, i.e., spikelet length, does not contribute significantly to the grouping of the samples included. Based on the facts that the two taxa have negligible reproductive barriers and share almost identical genomes, the authors believe thatO. granulata andO. meyeriana do not warrant separate taxonomic status, and recommend that they be combined asOryza granulata.     

A biosystematic study of critical species ofLactuca sect.Lactucopsis

In the present paper the results of a biosystematic study of some critical species ofLactuca sect.Lactucopsis are given. After a morphological, chorological, partly cytotaxonomical, chemotaxonomical analysis and experimental crossings the author came to the conclusion that bothL. wilhelmsiana Fisch. etMey ex. DC. andL. chaixii Vill. should be treated as infraspecific taxa ofL. quercina L. No differences were found betweenL. quercina andL. chaixii except in the basic shape of the cauline leaves.L. wilhelmsiana, however, can be distinguished by the length of the beak of the achene and by the distributional area. After revision the correct names of the taxa studied are as follows:Lactuca quercina L.,L. quercina var.integrifolia Bogenh. (Bisch.) forL. chaixii, L. quercina subsp.wilhelmsiana (Fisch. etMey.ex DC.)Feráková forL. wilhelmsiana     

A biosystematic study ofValeriana officinalis (Valerianaceae) distributed in Bulgaria

Valeriana officinalis L. is an extremely polymorphic polyploid complex. On the basis of morphological, cytological, and phytochemical investigations of Bulgarian populations ofV. officinalis the two subspeciesV. officinalis subsp.officinalis (2n = 14, 28) andV. officinalis subsp.collina (2n = 14, 28) were each subdivided into diploid and tetraploid cytotypes.     

Species divergence and relationships in Stephanomeria (Compositae): PgiC phylogeny compared to prior biosystematic studies

We present a maximum likelihood tree of 41 PgiC sequences for the monophyletic Stephanomeria, with 10 perennial and six annual species, widely distributed in western North America and exemplary of different speciation processes. The phylogenetic analysis represents the first use of PgiC sequences for Compositae. The annual species were originally delimited by biosystematic studies that provided evidence of their reproductive compatibility and chromosome structural homology. The perennial species are highly distinctive in morphology and have not been examined similarly. The PgiC tree provides more resolution than our previous ITS/ETS tree and reflects both past and ongoing hybridization and/or incomplete lineage sorting. Two major PgiC clades were resolved in Stephanomeria. One clade contains the genes from the annual species plus the perennial, insular endemic S. guadalupensis, which appears closely related to a monophyletic S. virgata. Stephanomeria exigua is not monophyletic. The second clade includes the genes from all other sampled perennial species and a monophyletic subclade of four genes from two annual species. The results are compared to previous studies, also using PgiC, of Clarkia (Onagraceae). Both molecular systematic and biosystematic approaches are essential to discern the very different courses of evolution in these two, well-studied genera of western North America.     

A prenylated coumarin with antimicrobial activity from Haplopappus multifolius

The coumarins prenyletin, haplopinol and aesculetin were shown to be responsible for the antimicrobial activity of Haplopappus multifolius. The structure of the new coumarin haplopinol was established by analysis of its spectral data.     

A comparison of dermatoglyphic methodologies in population studies

Use of dermatoglyphics in population studies has been marked by a great deal of methodological variation among investigators. We compare various dermatoglyphic approaches using data derived from four groups in the Kumaon region of India. Dermatoglyphic data included ridge-counts and other quantitative variables, and the classification systems of Cummins and Midlo and Penrose and Loesch. Results were evaluated against anthropometric and serological relationships. No clearly superior approach emerges, although it is generally true that palmar variables exhibit more intergroup heterogeneity than digital variables and produce more reasonable results than the other approaches. The conventional method of treating ridge-counts, that of choosing the larger of the two counts, was the most unsatisfactory of the quantitative approaches, leading to the recommendation that both radial and ulnar counts be retained. We conclude that environmental variation may contribute substantially to intergroup variation.     

A new Haplopappus (Asteraceae: Astereae) from Nevada

A new species, Haplopappus graniticus, is described and illustrated. Its relationships seemingly lie with section Tonestus but its narrow heads and imbricated phyllaries are anomalous in that section.     

A biosystematic study of Coreopsis tinctoria and C. cardaminefolia (Compositae)

This paper presents evidence which leads the authors to propose the reduction ofCoreopsis cardaminefolia (DC.) Nutt. to synonymy underC. tinctoria Nutt.Coreopsis cardaminejolia andC. tinctoria overlap morphologically in all characters measured, except for winging vs. non-winging of the achenes. The winging character is shown to be dependent upon segregation at one or two loci. Both “species” have chromosome numbers of 2n = 24 and 2n = 26. The basic number isx = 12, with some plants showing a supernumerary pair of chromosomes, which apparently undergo post-meiotic preferential distribution on both the maternal and paternal sides. The two taxa overlap extensively in range and occupy the same habitat, rather commonly occurring in mixed colonies.Coreopsis tinctoria is redefined to include the intrapopulational variation heretofore designatedC. cardaminefolia.