A new species of Chiliotrichiopsis (Asteraceae: Astereae) from Peru

Chiliotrichiopsis peruviana Nesom, H. Rob. & Granda, a new species from Dept. Ayacucho in southwestern Peru, is described and illustrated. It is the only rayless species of the genus, now expanded to four species, and the only one that occurs outside of Argentina.Chiliotrichiopsis is one of six shrubby South American genera of Astereae (subtribe Hinterhuberinae) with paleate receptacles. Observations on morphology and a key to these genera provide perspective for the generic placement of the new species.     

Karyology and phylogeny of some Mesoamerican species of Zamia (Zamiaceae)

Chromosome numbers and karyotypes of four species of Zamia L. (Zamiaceae) are described. Plants of Z. manicata from Colombia are 2n = 18 with eight metacentric (M), four submetacentric (S), two acrocentric (A), and four telocentric (T) chromosomes. Plants of Z. ipetiensis from Panama are 2n = 23 with 3M + 4S + 2A + 14T. Plants of Z. cunaria from Panama have two different chromosome numbers, 2n = 23 with 3M + 4S + 2A + 14T and 2n = 24 with 2M + 4S + 2A + 16T. Plants of Z. acuminata from Costa Rica and Panama are 2n = 24 with 2M + 4S + 2A + 16T. On the basis of the occurrence of a one-to-two-ratio in the variation of M- and T-chromosome numbers in the karyotypes, centric fission or fusion are considered for their potential involvement in the chromosome variation of these plants. Data deriving from morphology and karyology, interpreted in a cladistic framework, suggest that centric fission rather than centric fusion is involved in the karyotype diversification of the four species and their closest Mesoamerican allies.     

Cytotaxonomical analysis of <Emphasis Type="Italic">Momordica</Emphasis> L. (Cucurbitaceae) species of Indian occurrence

Somatic chromosome number and detailed karyotype analysis were carried out in six Indian Momordica species viz. M. balsamina, M. charantia, M. cochinchinensis, M. dioica, M. sahyadrica and M. cymbalaria (syn. Luffa cymbalaria; a taxon of controversial taxonomic identity). The somatic chromosome number 2n = 22 was reconfirmed in monoecious species (M. balsamina and M. charantia). Out of four dioecious species, the chromosome number was reconfirmed in M. cochinchinensis (2n = 28), M. dioica (2n = 28) and M. subangulata subsp. renigera (2n = 56), while in M. sahyadrica (2n = 28) somatic chromosome number was reported for the first time. A new chromosome number of 2n = 18 was reported in M. cymbalaria against its previous reports of 2n = 16, 22. The karyotype analysis of all the species revealed significant numerical and structural variations of chromosomes. It was possible to distinguish chromosomes of M. cymbalaria from other Momordica species and also between monoecious and dioecious taxa of the genus. Morphology and crossability among the dioecious species was also studied. Evidence from morphology, crossability, pollen viability and chromosome synapsis suggests a segmental allopolyploid origin for M. subangulata subsp. renigera. The taxonomic status of the controversial taxon M. cymbalaria was also discussed using morphological, karyological and crossability data.     

Dental incremental lines in some small species of the European vespertilionid bats

The dentine and cementum of the mammals exhibit incremental lines (IL) that may be seen as dark and light rings in properly prepared sections of teeth. Counting of IL provides a potential method to evaluate the absolute age of many wild species. The aim of the present study was to evaluate IL in small bat species and to test whether the number of IL is associated with the absolute age of bat when its minimal age was known based on ringing data. Teeth of 26 specimens of the following species were examined:Myotis daubentonii (n = 12),Barbastella barbastellus (n = 4),M. brandtii (n = 2),M. nattereri (n = 2),Pipistrellus nathusii (n = 2),Plecotus auritus (n = 2),M. dasycneme (n = 1),Vespertilio murinus (n = 1). Transverse morphological sections of canines, incisors and postcanine teeth were analysed by a light microscopy. In 4 cases, the minimal age of animals examined in this study was known. The IL were revealed in the dentine of 14 bats examined. The cementum of all animals was devoid of IL. The mean distance between the first and second juxtaposed IL ofM. daubentonii was 3.2 ± 0.2 mm, but it was significantly fewer among the subsequent adjacent lines. Due to a thinness of the IL, an accurate counting was considerably difficult in the canines containing more than 10 IL, as well as in the incisors and postcanine teeth with more than 3-6 IL. The IL of roots showed the most contrast, but they were almost obscured from view at the cingulum and crown. In bats of known-age, the numbers of IL were significantly lower than minimal age of those animals examined, and IL were either revealed only in certain teeth or absent entirely in all teeth. The present findings suggest that the number of the IL varies in different teeth and is strongly dependent on section level. Consequently, age determination in small bats using dental IL is doubtful and requires a reevaluation.     

Chromosomes of three freshwater stingrays (Rajiformes Potamotrygonidae) from the Rio Negro basin, Amazon, Brazil

Potamotrygonidae is the representative family of South American freshwater elasmobranchs. It is a monophyletic group containing 20 species grouped into three genera. Three species belonging to two genera of this family were collected from the middle Negro River, Amazonas, Brazil, and studied cytogenetically: Paratrygon aiereba, Potamotrygon motoro and Potamotrygon orbignyi. Paratrygon aiereba presented 2n = 90 chromosomes and 4M+2SM+10ST+74A. Both species of Potamotrygon presented 2n = 66 chromosomes and differed in their chromosomal formulas: P. motoro had 18M+12SM+10ST+26A and P. orbignyi had 22M+10SM+8ST+26A. No sex heteromorphism was detected. The Fundamental Number (FN) was 106 for the three species. A system of multiple NORs was found in the three species, but with interspecific differences in terms of location and position of the active Ag-NORs sites. Paratrygon aiereba presented only four sites on the short arms of two chromosomal pairs, both in terminal regions. Potamotrygon motoro presented seven sites, on the long and short arms, all in terminal regions of non-homologous chromosomes; P. orbignyi presented eight sites on the long arms, all in terminal regions, of non-homologous chromosomes. The constitutive heterochromatin was in pericentromeric regions of all chromosomes, and no significant interspecific difference was found in relation to this marker.     

Karyomorphology of Maianthemum sensu lato (Polygonatae, Ruscaceae)

We report results of karyotype analyses using nine species of Maianthemum from China. The species, except M. atropurpureum (with 2n=72), had 2n=36, and the results support the earlier suggestion that Maianthemum has x=18 with 2n=36 in most species. The species examined, however, showed marked differences in karyotype, particularly in the numbers of metacentric, submetacentric, and acrocentric chromosomes as well as in the number of satellites. In addition, we distinguished three different modes based on the number of clear gaps in chromosome length variation: unimodal, bimodal, and trimodal. The unimodal variation (with no gap) was found in M. dahuricum and M. atropurpureum, the bimodal variation (with one gap) in M. tatsienense, and the trimodal variation (with two gaps) in M. bifolium, M. forrestii, M. japonicum, M. henryi, M. purpureum, and M. lichiangense. In the trimodal variation, the positions of the two gaps may differ from species to species. In addition, the frequency of acrocentric chromosomes per complement was generally higher in the trimodal variation than in the unimodal and bimodal variations. Results of our analyses, which had not been clearly presented prior to this, may provide a better understanding of species evolution in the tribe Polygonatae.     

Cytological Studies on Monnina

Three species of Monnina have been studied cytologically for the first time. The following chromosome numbers were found, M. brachystachya n = 9 and 2n = 18; M. dictyocarpa 2n = 40; M. rusbyi n = 10 and 2n = 20. Evolutionary trends in the genus are discussed.     

Chromosome numbers and taxonomic notes for Mexican coreopsis,sections electra and pseudoagarista (compositae: heliantheae)

Notes on morphology and chromosome numbers are given for several species of MexicanCoreopsis, most of which were poorly known prior to recent collections.Coreopsis parvifolia (sectionElectra) is a large, shrubby, octoploid (2n=112) species apparently restricted to a small area in Puebla. It andC. cuneifolia (a diploid with 2n=28) appear to be closely related but differ by a number of morphological features in addition to ploidy level. A first chromosome report forC. pringlei (sectionPseudoagarista) shows this rare species to be diploid (2n=26), a fact which is in agreement with the base number of the section, i.e.,x=13. Additional collections of the very rareC. rudis andC. mcvaughii show them to be similar yet distinct species. Chromosome determinations forC. petrophila from Nayarit and Durango agree with previous counts for Jalisco populations of the species, i.e., 2n=26. Considerable morphological variation exists within this species but no subspecific entities are recognized.     

A CYTOGENETIC STUDY OF A THREE-PAIRED RACE OF HAPLOPAPPUS GRACILIS

Haplopappus gracilis (Nutt.) Gray is an aneuploid species of Compositae of wide distribution in the southwestern U.S.A. and northern Mexico. Except for 2 types of supernumeraries, cytological samples from throughout its range have regularly shown 2 pairs of chromosomes. However, recent collections from a small area in south-central Arizona had 2n = 4, 2n = 5, and 2n = 6 in the same population. The 2n = 5 plants were hybrids between the 2n = 4 and 2n = 6 types. Both natural and artificial F₁ hybrids show preferential disjunction from a trivalent and produce genetically balanced gametes with n = 2 and n = 3. In backcrosses of the F₁ to n = 2 plants, a 1:1 ratio of 2n = 4 and 2n = 5 plants was obtained. The possible mechanisms for the evolution of n = 2 from n = 3 and vice versa are discussed.     

Phenotypic plasticity in the greater mouse-eared bat in extremely different roost conditions

Bats use various roost types with a wide spectrum of ecological features. The greater mouse-eared bat Myotis myotis (Borkhausen, 1797), creates nurseries in attics and caves in Central Europe. The stable low temperature and high humidity cave microclimate contrasts that of attics, which may alter species adaptations and life strategies. We analysed population characteristics (composition, body condition, parasite load, and immune response) and genetic relatedness of two proximal M. myotis populations. Age, sexual and parasite species composition were similar between the cave and attic sites. However, a significantly higher parasite load and body condition was detected in the post-partum females and juveniles of the cave colony (n = 263 bats from the cave, 231 from the attic), with the cave colony females having a significantly stronger immune response (n = 2 caves and 2 attics, 20 females per site). There was no evidence for genetic divergence between cave and attic populations (n = 3 caves and 3 attics, 24 females per site), indicating that different population characteristics are not genetically based and that M. myotis is an example of a species with rather unique phenotypic plasticity.     

Structure in solution of protected homo-oligopeptides of L-valine,L-isoleucine,and L-phenylalanine: An infrared absorption study

Monodisperesed, N-and C-Protected homo-oligopeptides [number (n) of resides from 2 to 5] of L -valine, L -isoleucine, and L -phenylalnine were studied by ir absorption spectroscopy between 1200 and 350 cm^?1 at various solvents. The solvents and chain-length effects were examined for non-hydrogen-bonded peptide groups. The frequencies of the self-associated species are consistent with a model derived from the amide data. Self-association species are consistent with a model derived from the amide data. Self-association is favored by higher values of n = 2, the peptide is insoluble when more than two chains are bonded. For n = 3, 4, several chains may be associated by sliding along one another and remain soluble. For n = 2, the peptide is insoluble when more than two chains are bonded. For n = 3, 4, several chains may be associated by sliding along one another and remain slouble. For n = 5, the effect of n is to favour a model in which two chains exactly face each other so that the peptide precipitates at relatively low concentration.     

CYTOGENETIC STUDIES OF CARTHAMUS DIVARICATUS WITH ELEVEN PAIRS OF CHROMOSOMES AND ITS RELATIONSHIP TO OTHER CARTHAMUS SPECIES (COMPOSITAE)

Carthamus divaricatus (Beg. et Vacc.) Pamp., found only in Libya, has 11 pairs of chromosomes, a new chromosome number in the genus. The species is distinct morphologically. It has yellow, purple, and white corollas, yellow pollen, dark-purple striped anthers, horizontal branches, and strongly divaricate outer involucral bracts. The terminal portion of the middle involucral bracts is dentate and reddish brown. It is self-incompatible. Meiosis is regular in the different corolla-color types of C. divaricatus and their intraspecific hybrids. C. divaricatus was crossed to six species with n = 12, to three species with n = 10, to C. lanatus with n = 22, and to two species with n = 32 chromosomes. The morphological characteristics and cross-ability of the parental species plus the pollen viability, seed-set, and meiotic behavior of the hybrids involving C. divaricatus and other Carthamus species indicated that C. divaricatus is very closely related to species with n = 10, closely related to C. lanatus with n = 22, and less closely related to C. tinctorius with n = 12 chromosomes. C. divaricatus seems to be distantly related to C. nitidus (n = 12). It is proposed that C. divaricatus be included provisionally with 10-chromosome species in Section II. Alternative hypotheses for the development of the three basic chromosome numbers are discussed.     

A new dwarf shrubby species of <Emphasis Type="Italic">Baccharis</Emphasis> subg. <Emphasis Type="Italic">Baccharis</Emphasis> (Asteraceae,Astereae) from southeastern Brazil

Baccharis dichotoma, a new dwarf shrubby species, with small leaves and few heads, of high-altitude grasslands from southeastern Brazil, is described, illustrated, and assigned to subgenus Baccharis.     

Karyotype analysis and new chromosome number reports in <Emphasis Type="Italic">Achillea</Emphasis> species

Cytological analyses were performed in nineteen accessions belonging to seven Achillea species. The results indicate that two species, A. filipendulina and A. tenuifolia, are diploid (2n = 2x = 18) and three species, A. bieberstinii, A. pachycephala, and A. aucheri are tetraploid (2n = 4x = 36). For two latter species, the chromosome numbers are new. Two ploidy levels of 2n = 6x = 54 and 2n = 8x = 72 in A. millefolium and two ploidy levels of 2n = 2x = 18 and 2n = 4x = 36 in A. santolina species were found. Cluster analysis based on chromosomal characteristics and karyotype asymmetry indices clustered the studied genotypes into three major groups. The first group included the diploid species (A. filipendulina, A. santolina and A. tenufolia), while the second group comprised tetraploid species (A. santolina, A. aucheri and A. pachycephala). A. millefolium (hexaploid, octaploid) and A. bieberstinii (tetraploid) were classified in the third group. Total form percentage (TF%) in groups 1, 2 and 3 were 42.03, 42.15 and 41.08, respectively. Group 1 possessed the highest average of symmetry index (S% = 70.8). Stebbins classification method grouped all accessions in class A. Moreover, group 1 (diploid level species), had the most symmetric karyotype from point of view of centromere and chromosome length. Therefore, it can be concluded that the genotypes belonging to group 1 are the earliest evolutionary form.     

The cytology of Brachycome lineariloba

A study of approximately 300 plants in the taxonomic species B. lineariloba is reported. Five biological species differing in chromosome number exist in this species complex. The species with the lowest number (species A, n = 2) often carries B chromosomes, which may be large, or minute. It also exists in three racial forms which differ in karyotype. Observations on naturally occurring hybrids in zones of overlap show that two of the races differ by an unequal interchange. — The species with n = 8 (species C) is probably of amphidiploid origin from the cross A X B. Species B, E and D, with n = 6, 5 and 4 respectively, may represent a series of reductions in chromosome number. They show close karyotypic relationships. The relationship of species A with D, E and B is obscure.     

INTERSPECIFIC HYBRIDIZATION IN HAPLOPAPPUS AND ITS BEARING ON CHROMOSOME EVOLUTION IN THE BLEPHARODON SECTION

Jackson , R. C. (U. Kansas, Lawrence.) Interspecific hybridization in Haplopappus and its bearing on chromosome evolution in the Blepharodon section. Amer. Jour. Bot. 49 (2) : 119–132. Illus. 1962.—Cytological analyses of interspecific hybrids between H. gracilis (n = 2) and H. spinulosus ssp. australis (n = 8) indicate that ssp. australis is a segmental allotetraploid, derived from past hybridization between 2 taxa with chromosome numbers of n = 4. Analysis of hybrids between H. gracilis (n = 2) and H. ravenii (n = 4), a previously undescribed species, has shown that the chromosome segments of these 2 species are almost completely homologous. Differential contraction is suggested as the explanation for the disappearance in late pachytene of presumed non-homologous segments which were evident in some cells at early pachytene. The pairing relationship of gracilis and ravenii chromosomes at pachytene and later prophase I stages of meiosis indicates that gracilis has evolved from ravenii by an aneuploid reduction process similar to that described for Crepis. The close morphological relationship of the 2 species adds further support to this proposition. Data from the cytological analysis of both interspecific hybrids indicate that x = 4 is the basic chromosome number for the Blepharodon section of Haplopappus.     

Palaeoecological implications of the sympatric distribution of two species of Machairodus (Felidae,Machairodontinae, Homotherini) in the Late Miocene of Los Valles de Fuentidueña (Segovia,Spain)

In this paper, we study a sample of cranial, mandibular and dental remains of two species of the machairodontine felid genus Machairodus from the Early Vallesian (MN 9, around 10 Ma) site of Los Valles de Fuentidueña (Segovia, Spain): the tiger-sized Machairodus aphanistus, and the smaller and more primitive M. alberdiae; a species which is only known from this site. The fossils of these two sympatric populations are compared with the most abundant samples of M. aphanistus from the Late Vallesian (MN 10), younger sites of Batallones-1 and Batallones-3 (Torrejón de Velasco, Madrid, Spain). The results support the specific separation of M. alberdiae from M. aphanistus based on several differences in teeth size and proportions. Besides this, we observed differences among the analysed samples of M. aphanistus, indicating a differentiation between the older and more primitive form from Los Valles de Fuentidueña, and the younger and more derived one from the two Batallones sites. These differences fit well with the morphological evolution of this lineage towards the more derived Turolian Amphimachairodus giganteus. Finally, a relatively structured, patched habitat, combining the presence of open landscapes with shrubby and wooded areas, is inferred to explain the sympatric distribution of these two large machairodontines in Los Valles de Fuentidueña.     

CHROMOSOME NUMBERS IN THE COMPOSITAE. IV. NORTH AMERICAN SPECIES,WITH PHYLETIC INTERPRETATIONS

Turner , B. L., W. L. Ellison , and R. M. King . (U. Texas, Austin.) Chromosome numbers in the Compositae. IV. North American species, with phyletic interpretations. Amer. Jour. Bot. 48(3): 216–223. Illus. 1961.—Chromosome counts from 116 different plant populations representing 75 taxa (72 species in 39 genera) are reported. These include the first species counts for the following genera: Actinospermum (x = 19), Baltimora (x =15), Calea (x = ca. 17, 18), Calyptocarpus (x = 12), Hecubaea (x = 17), Lagascea (x = 17), Schistocarpha (x = 8), Melanthera (x = 15), Pectis (x = 12), Perymenium (x = 15), Sanvitalia (x = 8), and Trigonospermum (x = 15). Chromosome counts for Chrysopsis trichophylla (n = 5), Cirsium horridulum (n = 16), Hidalgoa ternata (n = 16,) Tridax balbisioides (n = 10), Tridax trilobata (n = 10), and Verbesina crocata (n =18) differ from the reported basic numbers as determined from other species in these genera. Taxa closely related to Tridax procumbens were found to have the diploid number n = 9, thus establishing the polyploid nature (n = 18) of this widespread polymorphic species. When appropriate, the chromosomal information has been related to systematic problems.     

Heterochromatin study and geographical distribution of Microtus species (Rodentia,Arvicolinae) from Greece

In a sample of 108 underground voles from 23 Greek localities, the species Microtus felteni, M. guentheri, M. rossiaemeridionalis and M. subterraneus were identified, based on external body morphology and karyotype. Moreover, the implemented C-banding staining technique revealed the heterochromatin distribution in the chromosomes of the above species. All M. guentheri (2n=54, FN=54) and M. rossiaemeridionalis (2n=54, FN=56) specimens displayed the typical karyotypes of these species, respectively. The M. subterraneus specimens belonged to the chromosomal race with 2n=52, FN=60 of this species, apart from a single individual that demonstrated a medium-sized, subtelocentric autosome in heterozygous condition (2n=52, FN=61). Furthermore, M. felteni individuals, trapped again after many years, were karyologically studied (2n=54, FN=56) and the C-banding pattern for this species is hereby presented for the first time. Finally, the study of meiotic preparations in M. guentheri and M. rossiaemeridionalis males verified the asynaptic behaviour of their sex chromosomes. The karyotype of the four studied Microtus species does not seem to have diversified much from the putative ancestral arvicoline karyotype (2n=56, FN=56). On the other hand, the heterochromatin accumulation in the sex chromosomes, particularly prominent in M. felteni and M. rossiaemeridionalis, represents this common tendency in several Microtus species.     

Plutarchia ecuadorensis (Ericaceae,Vaccinieae): a new species and a new generic record for Ecuador

Plutarchia, a shrubby páramo genus, is here reported for the first time in Ecuador where two species are recognized: P. angulata A. C. Smith and the new P. ecuadorensis Luteyn. These two species are keyed, described, and the new species illustrated.