Chromosome numbers of dominican compositae

Chromosome numbers of 34 species of Dominican Compositae in 26 genera and nine tribes are reported. First counts are given forCoreopsis buchii (2n = 64),Lagascea mollis (2n = 34),Spilanthes urens (n = 16),Liabum subacaule (n = 18),Eupatorium sciatraphes (2n = 40),Hieracium gronovii (2n = 18),Vernonia buxifolia (2n = 34),V. sprengeliana (2n = 34),V. racemosa (2n = 28), andChaptalia leiocarpa (2n = 48,ca. 58). Our report forNarvalina domingensis (2n = 120) is the first for any species of this genus.     

Chromosome numbers in some North American species of the genus Cirsium. III. Western United States,Mexico, and Guatemala

New data are presented on chromosome numbers for 36 species, two varieties, and two hybrids ofCirsium (Compositae). These include first reports forC. rhothophilum (2n = 34),C. andrewsii (2n = 32),C. crassicaule (2n = 32),C. quercetorum (2n= 32, 112),C. pascuarense (2n= 32),C. douglasii var.canescens (2n = 30, 34),C. hydrophilum (2n = 32),C. neomexicanum (2n = 30),C. cymosum (2n = 30, 34),C. acantholepis (2n= 34),C. radians (2n = 34), C.grahami (2n = 32),C. nigriceps (2n = 36),C. andersonii (2n= 32, 64),C. anartiolepis (2n = 34), andC. subcoriaceum (2n= 34). The published data on chromosome numbers of Eurasian and AmericanCirsium are summarized. In Eurasia, speciation has taken place primarily at the diploid level but is occasionally reinforced by polyploidy. The ancestral base number of 17 has been preserved in almost all species, and there is little evidence that reduction in chromosome number has played a significant role in speciation. In America speciation has proceeded exclusively at the diploid level, but the ancestral genome of 17 chromosomes has been retained in only about half of the species examined. In the remaining species, restructuring of the genome has occurred resulting in a reduction in number from 17 to 9 in extreme cases. Polyploidy, when seen, is of no significance. It is suggested that all species with greatly reduced numbers may represent products of a single reduction series.     

Chromosome numbers of Orthocarpus and related monotypic genera (Scrophulariaceae: Subtribe castillejinae)

A chromosome number ofn=12 is reported for the three monotypic genera of subtribe Castillejinae:Clevelandia beldingii, Gentrya racemosa, andOpicopephalus angustifolius. Chromosome numbers ofOrthocarpus correspond mostly with current infrageneric classification. SubgenusTriphysaria hasn=11.Orthocarpus sectionsCastillejoides andCordylanthoides, which are closely related toCastilleja (x=12) and the three monotypic genera above, haven=12 with aneuploid reductions ton=10 inO. linearilobus andn=11 inO. lacerus (a species also withn=12). Tetraploids are found in two species.O. brevistylus (n=24) andO. hispidus (n=12, 24). The polyploid.O. laciniatus (n=36, 48) of Peru is postulated to be of hybrid origin between a species ofCastilleja andOrthocarpus attenuatus. SubgenusOrthocarpus sectionOrthocarpus, which hasn=14 in all species except.O. bracteosus (n=15), stands apart both morphologically and in chromosome number from the remainder of the genus.     

The periparturient rise in fecal egg counts in three strains of Florida native ewes and its value in predicting resistance of lambs to Haemonchus contortus

The periparturient rise in fecal egg counts in three strains of Florida Native ewes and its value in predicting resistance of lambs to Haemonchus contortus. International Journal for Parasitology16: 185–189. Significant (P < 0.05) differences in the magnitude of the periparturient rise in fecal egg counts (PPR) occurred in ewes of three strains of Florida Native sheep. Non-lambing ewes (n = 12) and lactating University strain ewes (n = 31), a strain selected over a 26-year period for parasite resistance by survival at pasture without anthelmintic treatment, had lower fecal egg counts than ewes of either Maxcy strain (n= 17), a commercial strain treated regularly with anthelmintics, or Backlinie strain (n = 16), a strain of Florida Native sheep that had some crossbreeding to Hampshire and Suffolk in their genotype and were regularly treated with anthelmintics. Whereas both Maxcy and Backlinie ewes showed a pronounced PPR, none occurred in non-lambing ewes (n=12) and the slight rise in fecal egg counts observed in University ewes was not significantly different from that of the non-lambing ewes. Backlinie ewes having twin lambs (n = 5) had a higher PPR than Backlinie ewes with single lambs (n = 11) or Maxcy ewes with single lambs (n = 15), but all three groups had higher PPRs than University ewes with single lambs (n = 27). No differences occurred in fecal egg counts of non-lambing ewes regardless of strain. Six weeks after weaning fecal egg counts of all ewes were uniformly low regardless of strain or prior lactation status.Ram lambs born to these ewes showed no significant strain differences in Haemonchus contortus burdens after experimental infection, deworming with levamisole and reinfection, although University lambs (n= 13) had lowest mean worm burdens at necropsy (2437) followed by Maxcy lambs (n= 12, mean =3106) and Backlinie lambs (n= 13, mean =3670). There was no significant correlation between worm burdens in these lambs and the magnitude of the PPR in their dams. Eight to 16 weeks after turn out to a common parasite-infested pasture ewe lambs (n = 13) born to University ewes had lower fecal egg counts than similar ewe lambs (n=8) born to Backlinie ewes. Prior to this time differences were not significant and egg counts were generally low. The magnitude of the PPR in their dams was not significantly correlated with fecal egg counts or PCVs of individual ewe lambs.     

Karyosystematics ofVeronica sect.Beccabunga (Scrophulariaceae) with special reference to the taxa in Turkey

The chromosome numbers ofVeronica beccabunga subsp.abscondita (2n=18),V. anagallis-aquatica subsp.lysimachioides (2n=18),V. anagallis-aquatica subsp.michauxii (2n=36), and of a presumable hybridV. poljensis × V. anagalloides (2n=36) are new for the relevant taxa. — A new number was found forV. anagalloides subsp.heureka (2n=18). The other counts, ofV. scardica (2n=18),V. anagalloides subsp.anagalloides (2n=18), andV. anagallis-aquatica subsp.oxycarpa (2n=36) agree with earlier findings.—Data from the literature have been critically evaluated, in some cases the relevant vouchers have been checked and, where needed, the original determinations have been revised. For several taxa, comments concerning their systematics and remarks on their distribution in Turkey are given.     

Chromosome numbers of miscellaneous Malagasy Acanthaceae

Meiotic chromosome numbers are reported for 12 species in eight genera of Acanthaceae from Madagascar. Chromosome numbers of 11 species are reported for the first time. Counts inMendoncia (n=19) andNeuracanthus (n=20) are the first for these genera. A new chromosome number (n=30) is reported inJusticia. Systematic implications of the chromosome counts are addressed and basic chromosome numbers for these eight genera of Malagasy Acanthaceae 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.     

Chromosome numbers in callirhoe (Malvaceae)

Forty-four chromosome counts from the North American genusCallirhoe are reported, including first-recorded counts ofC. alcaeoides, C. digitata, C. bushii, C. triangulata, andC. involucrata var.tenuissima. Information concerning chromosome numbers from present and previous reports is summarized and evaluated. Observations are presented on meiosis for the genus in general, for male sterile individuals of gynodioecious species, and for selected F₁ hybrids. Pollen fertility data are recorded for the latter. Chromosomally three species groups are recognized: an exinvolucellate, diploid species group withn=14; an involucellate, tetraploid and octoploid species pair,n=28 and 56; and an involucellate, diploid and tetraploid species group withn=15 and 30. Intrageneric relationships and those within the tribe Malveae subtribe Malvinae are discussed.     

Chromosome numbers of goldenrods,Euthamia and Solidago (Compositae: Astereae). II. Additional counts with comments on cytogeography

Chromosome number determinations were made from 407 wild or transplanted individuals and seedlings representing 65 taxa and hybrids inEuthamia andSolidago. The following are first reports:Euthamia remota, 2n=9II;Solidago leavenworthii, 2n=54;S. mollis, 2n=36;S. mollis var.angustata, 2n=36;S. rigida var.glabrata, 2n=9II;S. sempervirens var.azorica, 2n=9II; andS. sparsiflora, 2n=54. Most species have been sampled only a few times or are consistently of one cytotype. Sufficient counts have been made to indicate some general patterns of cytotype distribution in the following species complexes:S. gigantea, S. canadensis, S. flexicaulis, S. rugosa, andS. uliginosa.     

CHROMOSOME NUMBERS IN THE COMPOSITAE. X. NORTH AMERICAN SPECIES

Chromosome counts from 132 plant populations representing 124 taxa (in 67 genera) are reported. These include previously unreported counts for over 70 species and 5 new generic counts (Hofmeisteria, x = 19; Oxypappus, x = 10; Pterocaulon, x = 10; Stenocarpha, x = 8; and Urbinella, x = 8). Two new base numbers are reported for specieis of Perityle (P. californica, x = 13 and P. palmeri, x = 17), and previously unreported n numbers have been found for species of the genera Bidens (n = 17) and Hymenostephium (n = 21). Several gametic cells with differing meiotic configurations were found in the same head of Stevia viscida (n = 11 pairs; 11 pairs and 11 univalents; 33 univalents). When appropriate, the chromosomal information has been related to systematic problems, especially for genera of the subtribes Flaverinae, Coreopsidinae, Galinsoginae and Peritylinae.     

Chromosome numbers and DNA ploidy levels of selected species ofHieracium s.str. (Asteraceae)

Chromosome numbers and /or ploidy levels are reported for 44 species and subspecies ofHieracium s.str. from the following European countries: Andorra, Austria, Bulgaria, Czech Republic, France, Italy, Montenegro, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland and Ukraine. The chromosome numbers/DNA ploidy levels ofH. bocconei (2n ～ 4x),H. bupleuroides subsp.leviceps (2n = 27),H. caesioides subsp.caesioides (2n = 27),H. basifolium (H. caesium agg., 2n = 36),H. plumbeum (H. caesium agg., 2n = 36),H. glaucum subsp.nipholepium (2n= 27),H.gouanii (2n = 18),H. gymnocerinthe (2n = 27),H. ramondii (2n = 27),H. recoderi (2n = 18),H. stelligerum (2n = 18), andH. tomentosum (2n = 18, 2n ～ 2x, 2n ～ 3x) were determined for the first time. New ploidy levels are reported forH. cerinthoides s.str. (2n = 27),H. humile (2n = 36), andH. tommasinianum (2n = 27).     

Chromosome numbers in Pinguicula (Lentibulariaceae): survey, atlas, and taxonomic conclusions

Our study (survey, atlas of 136 microphotographs and 67 drawings) points out the actual chromosome numbers of 82 taxa of the genus Pinguicula L. They were gathered from literature and critically examined. In addition, numerous counts are published for the first time. They represent about 80% of all the taxa known. The basic chromosome numbers are x = 6, 8, 9, 11, and 14; the ploidy levels are 2n (diploid), 4n (tetraploid), 8n (octoploid) and 16n (hexadecaploid). The basic number x = 6 is a one-off, x = 8 and 11 are the most frequent in the genus; x = 14 indicates a hybridogenous differentiation process in the past. The caryological differentiation—chromosome numbers and ploidy level—is discussed with regard to distribution pattern, growth type, and infrageneric classification (at the level of sections).     

Observations of meiotic chromosomes in Gaura (Onagraceae)

Observations of meiotic chromosomes are reported for all 21 species and 3 additional sub species ofGaura (Onagraceae), based upon a study of 647 individuals from 509 naturally occurring populations throughout the range of the genus. The basic chromosome number for the genus isx = 7, and 18 species are diploid withn = 7. Among these, the self-incompatible ones are often highly chromosomally heterozygous, with no homozygous individuals having been found in nature in the perenrennialsGaura lindheimeri andG. villosa, and two-thirds or more of the individuals apparently heterozygous in the following well-sampled species:G. calcicola, G. longiflora, andG. suffulta subsp.suffulta. In contrast, the autogamous species are entirely chromosomally homozygous or nearly so. Two species ofGaura are reported as chromosomal structural heterozygotes, with about 50% pollen abortion:G. biennis andG. triangulata; the translocation systems originated independently of one another. Two of the three polyploid species,G. sinuata andG. drummondii (G. odorata of many authors), are consistently tetraploid (n = 14) and, despite their cytological autotetraploidy, are thought to have originated following interspecific hybridization. They are the only rhizomatous species in the genus and may have had one ancestor in common. The remaining polyploid,G. coccinea, includes populations withn = 7, 14, 21, and 28, as well as evident interploid hybrids and, frequently, supernumerary chromosomes. The relationship among these populations is close and is maintained by frequent hybridization and exchange of genetic material. No other species seems to have participated in their origin, and the association of their chromosomes is consistently that characteristic of autopolyploidy in plants with tetraploid and higher chromosome numbers.     

Chromosome numbers and their taxonomic implications for eight Brazilian andropogons (Poaceae: Andropogoneae)

Eleven chromosome counts are reported for Brazilian populations of eight species ofAndropogon. Counts for five of the species are first reports for the species. Four of these species,A. arenarius, A. glaziovii, A. lateralis, andA. lindmanii, are hexaploids (n=30) and belong to a group of about a dozen species informally referred to as theAndropogon lateralis complex. Two other species of this complex,A. bicornis andA. hypogynus, we also found to be hexaploids, in agreement with previous reports. Diploid counts (n=10) forA. macrothrix (a first report) andA. virgatus (the same as two previous reports) support the morphological affinities of these two species to other species complexes withinAndropogon.     

Notes on Mexican grasses IX. Miscellaneous chromosome numbers—3

Chromosome numbers are reported for 105 collections which represent 59 species belonging to 35 genera. For two of these genera:Blepharoneuron andTriniochloa no documented chromosome counts have been published to date. Records for the following species:Aristida arizonica, A. pansa, A. schiedeana, Blepharoneuron tricholepis, Deschampsia pringlei, Eragrostis palmeri,Leptochloa viscida, Munroa squarrosa, Panicum vaseyanum, Setaria grisebachii, andTriniochloa stipoides are the first for these taxa. Counts of 2n = 28 forAgrostis perennans, 2n = 20 forAegopogon cenchroides, 2n = 20 forBuchloË dactyloides, 2n = 54 forDigitaria filiformis, 2n = 60 and 2n = ca. 74 forEragrostis intermedia, 2n = 32 forErioneuron grandiflorum andE. pilosum, 2n = 44 forHilaria cenchroides, 2n = 38 and 2n = ca. 180 forHilaria mutica, 2n = 40 forPereilema crinitum, 2n = 28 forScleropogon brevifolius, 2n = ca. 108 forSetaria leucopila, and 2n = 36 forOplismenus burmannii are different from any published report for these species. Cytological information on Mexican material of the following ten species:Agrostis perennans, Aristida hamulosa,Bouteloua aristidoides, Eragrostis cilianensis, Sporobolus nealleyi, Tridens muticus,Digitaria filiformis, Hackelochloa granularis, Oplismenus burmannii, andPennisetum ciliare is here presented for the first time.     

Chromosome numbers in Hypericum and related genera

New or confirmatory chromosome counts for 16 taxa ofHypericum in Britain, one of northwest Africa, and 24 of North and Central America are reported. First records for any member of the genusVisma (n = 10) are also included. The counts are discussed with respect to those previously reported forHypericum and related genera. Some of this chromosomal information is incorporated in a diagram showing suggested evolutionary trends withinHypericum. There appears to be a descending series of basic numbers (x = 12, 10, 9, 8, 7), of which all but the last have been recorded in polyploid, as well as diploid, form. Observations of chromosome morphology suggest thatHypericum is cytologically relatively unspecialized. Studies of chromosome morphology, therefore, are not likely to yield much information about the evolutionary history of the genus. It is suggested that the basic number forAllanblackia andPentadesma is 7 or 14, whereas inCalophyllum andMesua it is probably 8 or 16. Known gametic chromosome numbers inMammea (n = 16, 18) andGarcinia (n = 24, ca. 27, ca. 29, ca. 38, ca. 40, and 48) do not indicate an obvious basic number for these genera, although x = 8, 9, and 16 might be involved. Ring-formation of theOenothera-type, possibly indicative of structural hybridity, is reported for the first time inHypericum mitchellianum Rydb., a close relative ofHypericum punctatum Lam., which was previously shown to possess this anomalous chromo some condition.     

Six new species of melampodium (compositae: Heliantheae) from Mexico and Central America

Six species of the genusMelampodium are described as new:M. glabribracteatum, M. nayaritense, andM. pilosum (sect.Melampodium);M. costaricense, M. nutans, andM. sinaloense (sect.Zarabellia). Chromosome numbers forM. nutans andM. pilosum are reported asn = 11 andn = 10 respectively     

Annotated chromosome counts of Czechoslovak plants (16–30) (Materials for “Flóra ČSSR”—2)

Chromosome counts of the following 15 taxa are given:Eupatorium cannabinum, Gypsophila fastigiata, Helianthemum grandiflorum subsp.obscurum, Helictotrichon desertorum subsp.basalticum, Impatiens parviflora, Inula hirta, Jurinea mollis, Kernera saxatilis, Lembotropis nigricans subsp.nigricans, Malva alcea subsp.excisa, Myosotis nemorosa, Otites pseudotites subsp.cuneifolia, Plantago atrata subsp.carpatica, P. atrata subsp.sudetica, Poa badensis. The chromosome numbers ofHelictotrichon desertorum (as subsp.basalticum) andPlantago atrata subsp.sudetica are given for the first time. Chromosome numbers differing from those previously known were found inJurinea mollis (2n=34 as compared to 2n=30) andKernera saxatilis (2n=14 as compared to 2n=16).Rhodax Spach (=Helianthemum L. p. p.) andOtites Adans. (=Silene L. p. p.) are considered as separate genera. Remarks on taxonomy, nomenclature and chorology are given for most of the taxa.     

Relationships among New World species of Hibiscus section furcaria (Malvaceae)

Seventeen species ofHibiscus sectionFurcaria are native to the New World, of which 12 (one diploid, nine tetraploids, one octoploid and one decaploid) have been studied cytotaxonomically. New chromosome counts (2n=4x=72) are reported forH. cucurbitaceus, H. flagelliformis, H. kitaibelifolius, andH. laxiflorus. Seventeen types of tetraploid interspecific hybrids (seven new to this study) all showed complete meiotic chromosome homology (genome formulaGGPP) and normal floral development. That all hybrids were nevertheless almost completely sterile suggests a cytoplasmic component to the genetic differentiation of the species. The diversification of the tetraploid species in habits, habitats and geographical ranges is considerable, despite their similar genome constitutions. A key to 17 native and four introduced African species is presented.Hibiscus cerradoensis sp. nov. is described.