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 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.     

国产毛茛科驴蹄草属两种植物的细胞学研究

为探讨国产毛茛科(Ranunculaceae)驴蹄草属(Caltha L.)植物的细胞学特征,对驴蹄草(C.palustris L.)3个居群和花葶驴蹄草(C.scaposa Hook.f.&Thoms.)5个居群进行了细胞学研究。驴蹄草贵州纳雍居群的染色体数目为2n=32(四倍体),两个云南中甸居群的染色体数目均为2n=64(八倍体)。花葶驴蹄草四川红原、康定、石渠居群的染色体数目均为2n=32(四倍体),该数目为首次报道;西藏林芝和云南德钦居群的染色体数目均为2n=64(八倍体)。驴蹄草的染色体比花葶驴蹄草大。这两种植物的32或64条染色体分别以4条或8条为单位大致能够排列为8组同源染色体,但同一组内的染色体经常具有明显的异形性(heteromorphy),不同居群的核型组成多少具有差异。同时,还分析了驴蹄草和花葶驴蹄草的不同倍性细胞型在我国的地理分布式样。     

What does the nr5S DNA multigene family tell us about the genomic relationship between Dasypyrum breviaristatum and D. villosum (Triticeae: Poaceae)?

The genus Dasypyrum contains two species: the annual and widespread D. villosum (2x = 2n = 14) and the perennial and generally rare D. breviaristatum (2x = 2n = 14 and 4x = 2n = 28). The origin of the latter and its genome constitution have been subject of several studies. There is agreement that the genome of the diploid D. villosum (VV) is different from the diploid cytotype of D. breviaristatum (VbVb), but there is no agreement of the constitution of the tetraploid cytotype, specifically whether is it an autotetraploid or an allotetraploid. This is a long-standing disagreement that this study aims to resolve using the 5S nrDNA as a genomic marker. Our studies suggest that the 4x D. breviaristatum is an allotetraploid (VVVbVb).     

Chromosome numbers in Heterotheca,including Chrysopsis (Compositae: Astereae), with Phylogenetic interpretations

A summation of both previously reported and original data on chromosome numbers is presented for species ofHeterotheca sens. lat. Chromosome numbers are listed for 24 taxa, including 20 different species. Chromosome numbers for the genus aren = 4, 5, 9, 12, and 18. The most common and possibly basic number for the genus isn = 9, with then = 18 taxa considered to be tetraploids, and those withn = 4 and 5 as probable aneuploid derivatives ; alternativelyn = 4 and 5 could be considered the basic numbers withn = 9 the result of polyploidy. Several nomenclatural changes have been made including the following new combinations:Heterotheca bolanderi (Gray) Harms,H. fastigiata (Greene) Harms, andH. villosa var.hispida (Hook.) Harms.     

Impaired male meiosis, morphology and distribution pattern of different cytotypes of Bupleurum lanceolatum Wall. (Apiaceae) from the Western Himalayas

Detailed male meiosis, critical morphological observations and distribution pattern of diploid as well as tetraploid cytotypes of the Western Himalayan species, Bupleurum lanceolatum have been evaluated at present. A diploid (n = 8) cytotype is reported from Kashmir, whereas, both diploid (n = 8) and tetraploid (n = 16) cytotypes are available from two districts Kangra and Sirmaur of Himachal Pradesh. Out of these, the tetraploid cytotype makes new addition for the species on a worldwide basis. As per behavior, a tetraploid cytotype is characterized by abnormal meiosis leading to high pollen sterility and size variation of the pollen grains. Morphologically, tetraploids are noted to be luxuriant in comparison to the diploids.     

Cytogeography and phenomenon of cytomixis in Silene vulgaris from cold regions of Northwest Himalayas (India)

Silene vulgaris is an important ethnobotanical species, but so far no thorough meiotic analysis has been performed, despite its wide occurrence in temperate and alpine Himalayas, this prompted us to undertake present study. We investigated original meiotic chromosome number and effect of cytomixis on meiotic course, microsporogenesis and pollen grain size and fertility. The paper also summarizes the previously published chromosome counts in the species and cytogeography of 2x and 4x cytotypes in the Indian Himalayas and elsewhere. Meiocytes preparations were made through standard squashed technique in 1 % acetocarmine. Two ploidy levels have been determined during the cytomorphological surveys, diploid (2n = 2x = 24) and tetraploid (2n = 4x = 48). Most of the presently scored populations were found to be diploid (2n = 2x = 24). Morphologically 2x and 4x individuals were indistinguishable from each other. Meiosis was perfectly normal in 4x cytotype. However, some of the 2x plants showed the phenomenon of cytomixis and associated meiotic abnormalities. Consequent to cytomixis, hypo-, hyperploid and enucleated pollen mother cells (PMCs) were resulted. Such PMCs combined with other meiotic abnormalities yielded sterile and variable sized pollen grains. On the basis of overall information, it is clear that 2x cytotype is the most widely distributed cytotype in the Indian Himalayas as well as elsewhere. On the other hand, the 4x cytotype seems to be less frequently present in the Indian Himalayas and outside of India.     

A contribution to the study ofChenopodium album agg

Plants gathered in Staré Brno (1979)—classified under the genusChenopodium L. and having K (2n)=54—are hybrids.Chenopodium strictum Roth (n=18) andChenopodium suecicum J. Murr (n=9) are probably parental species. Hybridization may have been linked with amphidiploidy.     

A biosystematic study of Pacific Northwestern blue-eyed grasses (Sisyrinchium,Iridaceae)

Thirteen species of blue-eyed grasses had been described for the Pacific Northwest prior to this study. Contemporary taxonomic treatments vary; some authors recognize several of the taxa as valid species, others recognize only one highly variable, widely distributed species. Work has been directed to achieve an understanding of the biological integrity of all previously described species within the northwest. Living plants from natural populations were utilized in controlled artificial hybridization experiments, analysis of breeding systems, and cytological investigations. Hybrids of intraand interspecific crosses were examined for pollen fertility, and investigated cytologically for meiotic behavior. Eight genetically compatible groups are indicated from these experiments. Additional information gained from cytological analysis, breeding systems, ecology, distribution, and morphological studies substantiates the recognition of each genetically compatible group at the specific level, including the new species,S. hitchcockii, from southern Oregon. The following taxa are recognized for the Pacific Northwest: tetraploids (n = 16)S. bellum S. Wats.,S. halophilum Greene,S. septentrionale E. P. Bicknell; octoploids (n = 32)S. idahoense E. P. Bicknell (including the vars.segetum,macounii, andoccidentale), andS. hitchcockii D. Henderson; duodecaploids (n = 48)S. idahoense E. P. Bicknell var.idahoense, S. littorale Greene,S. montanum Greene, andS. sarmentosum Suksd. ex Greene.     

Cytomorphological diversity in some selected members of Poaceae from Parvati Valley in Kullu district of Himachal Pradesh,India

The present work includes detailed male meiotic studies on 46 species of grasses falling into 59 accessions from different localities of Parvati Valley in Kullu district of Himachal Pradesh in the altitudinal range of 1,100 to 2,750 m. All the species have been studied cytologically for the first time from the study area. The meiotic chromosome count of n = 14 for Calamagrostis emodensis is the first ever chromosome report. Three species, namely Agrostis alba (n = 21), Avena byzantina (n = 21) and Bromus inermis (n = 14) have been studied cytologically for the first time from India. New intraspecific diploid/polyploid cytotypes have been reported for Arthraxon serrulatus (2n = 4x = 32), Iseilema laxum (2n = 12x = 60), Digitaria albudens (2n = 8x = 72), Festuca kashmiriana (2n = 2x = 14) and Stipa orientalis (2n = 2x = 20). The existence of variable number of B-chromosomes (2n = 60 + 0-5B) has been reported for the first time in the 12x cytotype of Iseilema laxum. Secondary associations of chromosomes in the tetraploid cytotype of Cymbopogon martini (n = 20) indicated its secondary polyploid nature. As many as 18 species showed various meiotic anomalies such as the phenomenon of cytomixis involving inter PMC migration of chromatin material, chromatin stickiness, interbivalent connections, abnormal spindle activity, presence of bridges and laggards during anaphases and telophases and abnormal sporads. These meiotic abnormalities consequently yielded sterile and heterogeneous-sized fertile pollen grains. The polyploidy and aneuploidy have played an active role in the evolution of grasses.     

Ploidy, geographical distribution and morphological differentiation of Parasenecio auriculata (Senecioneae; Asteraceae) in Japan

Parasenecio auriculata is a woodland perennial herb widely distributed in Northeastern Asia, constituted by a poorly understood polyploidy with a diploid (2n=2x=60) and a tetraploid (2n=4x=120). In this study, for a better understanding of the polyploidal evolution, cytogeography and morphological variation were analyzed in Japanese P. auriculata, including two varieties; var. bulbifera endemic to central Hokkaido and var. kamtschatica widely distributed in northern Honshu and Hokkaido. The occurrence of two polyploidal levels was reconfirmed. While var. bulbifera is predominantly tetraploid, var. kamtschatica is comprised of diploid and tetraploid. Morphological variation among 22 quantitative characteristics is continuous and not distinctive among cytotypes or varieties, but plant size tended to be larger in the order, diploid of var. kamtschatica, var. bulbifera, and tetraploid of var. kamtschatica. The cytotype distribution showed a conspicuous geographical pattern. Besides var. bulbifera endemic to the central Hokkaido, the diploid of var. kamtschatica is mainly found in Southern Hokkaido, and the tetraploid has a disjunct distribution in eastern and northern Hokkaido and northern Honshu. Such a geographical pattern is possibly attributable to the differentiation of climatic preference among cytotypes and varieties, and may have been established in association with the climatic cline along the Japanese archipelago.     

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.     

Cytotype-specific ISSR profiles and karyotypes in the Neotropical genus <Emphasis Type="Italic">Eigenmannia</Emphasis> (Teleostei: Gymnotiformes)

The genus Eigenmannia (Teleostei: Gymnotiformes), a widely distributed fish genus from the Neotropical region, presents very complex morphological patterns and many taxonomic problems. It is suggested that this genus harbors a species complex that is hard to differentiate using only morphological characteristics. As a result, many species of Eigenmannia may be currently gathered under a common name. With the objective of providing new tools for species characterization in this group, an analysis of the polymorphism of DNA inter-simple sequence repeats (ISSR), obtained by single primer amplification reaction (SPAR), combined with karyotype identification, was carried out in specimens sampled from populations of the Upper Paraná, São Francisco and Amazon river basins (Brazil). Specific ISSR patterns generated by primers (AAGC)₄ and (GGAC)₄ were found to characterize the ten cytotypes analyzed, even though the cytotypes 2n = 38 and 2n = 38 XX:XY, from the Upper Paraná basin, share some ISSR amplification patterns. The geographical distribution of all Eigenmannia specimens sampled was inferred, showing the cytotype 2n = 31/2n = 32 as the most frequent and largely distributed in the Upper Paraná basin. The cytotype 2n = 34 was reported for the first time in the genus Eigenmania, restricted to the São Francisco basin. Polymorphic ISSR patterns were also detected for each cytotype. Considering our results and the data reported previously in the literature, it is suggested that many of the forms of Eigenmannia herein analyzed might be regarded as different species. This work reinforces the importance of employing diverse approaches, such as molecular and cytogenetic characterization, to address taxonomic and evolutionary issues.     

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.     

Cytogeography of Cenchrus ciliaris (Poaceae) in Tunisia

Belonging to the genus Cenchrus with 16–22 species, Cenchrus ciliaris L. (syn. Pennisetum ciliare (L.) Link, buffelgrass) is a perennial, common in warmer regions of both hemispheres, growing as a C4 grass in a wide range of habitats. In the present study we determined chromosome number and nuclear DNA content (2C DNA) for 28 natural populations collected from northern to southern Tunisia. Three ploidy levels were found: one tetraploid population (2n?=?4x?=?36), three pentaploid (2n?=?5x?=?45), and 24 hexaploid populations (2n?=?6x?=?54). The hexaploid chromosome number has already been reported for Tunisian populations of C. ciliaris but tetraploid and pentaploid (2n?=?45) are new for this area. The tetraploid population was found in the semi-arid north; pentaploids were mostly on the northern side of the arid region, while the hexaploids were located mainly in the arid southern Tunisian and Saharan region. 2C DNA values, assessed using flow cytometry, correlated with chromosome counts. Nuclear DNA content ranged from 2C?=?3.03 to 4.61 pg, revealing three ploidy levels corresponding to 4x, 5x, 6x, and mean 2C DNA amounts were of 3.03, 3.7 and 4.48 pg, respectively. Each cytotype produced viable pollen. Flow cytometric seed screening neither proved nor disproved apomixis. The most frequent hexaploid populations seem best adapted to arid conditions in southern Tunisia. The monoploid value, 1Cx, was constant. The existence of pentaploid cytotype suggests hybridization ability between tetraploids and hexaploids. It appears that polyploidization is the major evolutionary mechanism in the speciation of C. ciliaris.     

Chromosome studies on the Bambusoideae (Gramineae)

Meiotic chromosome numbers and observations were made in eleven species belonging to nine different genera of Bambusoideae. The numbers include counts in eight species that have never been investigated cytologically:Arundinaria aff.amabilis (n=24), Chusquea bambusoides (n=ca. 20),Cryptochloa dressleri (n=11), Olyra ciliatifolia (n=11), Sucrea monophylla (n=11), Raddia brasiliensis (n=11), Strephium distichophyllum (n=11), andPariana aurita (n=22). The generaStrephium andSucrea have not been studied previously with respect to their chromosomes. The significance of these results are discussed in relation to the over 140 published counts in the subfamily, which indicates a preponderance of polyploidy in the woody members, or bamboos, but not in their herbaceous allies. Aneuploidy is rare in the former but frequent in the latter. It is postulated that the herbaceous bambusoids, which flower every year and produce recombinants regularly and in short-time cycles, could have tolerated successive reductions of the linkage groups and their genetic flexibility. These changes would not have been favored in the bamboos, which have more genetic constancy due to the long lapse (often 20–120 years) between flowering generations.     

Chromosome observations on some eastern North American Eleocharis (Cyperaceae)

Chromosome numbers are reported forEleocharis obtusa var.ellipsoidalis (2n = 10),E. obtusa var.peasei (2n =10),E. engelmannii (2n =10),E. olivacea f.olivacea (2n = 20),E. olivacea f.reductiseta (2n = 20),E. flavescens (2n = 30),E. tenuis var.verrucosa (2n = 20),E. tenuis var.tenuis (2n = 24),E. tenuis var.pseudoptera (2n = 39), a possible hybrid betweenE. tenuis var.pseudoptera and var.tenuis (2n = ca. 34 & 68),E. intermedia (2n = 22),E. tuberculosa (2n = 30),E. smallii (2n = 36), andE. ambigens (2n = 46). Noticeable chromosome size differences inE. tenuis, E. smallii, andE. ambigens are consistent with size differences previously reported by other authors. Variable meiotic pairing configurations were observed inE. flavescens, E. intermedia, andE. tenuis. Chromosome data help verify taxonomic relationships of some taxa and indicate the need for further investigation of others.     

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.     

A biosystematic study on polyploid populations of the genusSpiraea (Rosaceae) in Korea

A total of 61 chromosome counts from 11 taxa of Korean Spiraea was made. Our counts are the first report for eight taxa;S. blumei (2n=18, 36),S. chartacea (2n=36),S. chinensis (2n=36),S. fritschiana (2n=27, 36),S. microgyna (2n=18),S. prunifolia var.simpliciflora (2n=18),S. pseudocrenata (2n=36), andS. trichocarpa (2n=18). A new chromosome number of 2n=36 (tetraploid) is reported forS. pubescence. Populations of three species includingS. blumei, S. pubescence and .V.fritschiana, show different ploidy levels; diploid and tetraploid populations are found in the former two species and triploid and tetraploid ones, in latter species. Multiplication of chromosome numbers contributes to increase in size of pollen and stomata in the three species. Populations with different ploidy levels inS. blumei occupy different regions; diploid populations in inland Korea and tetraploid ones in Ullung Island. Island tetraploid population of 5.blumei might be originated from intra-island polyploidization through the introduction of diploid from inland Korea, considering the worldwide distribution of this species. Pollen fertilities of island populations of ,S′.blumei are relatively low, and sometimes no pollen grain is produced in anther sacs; it suggests that tetraploid population of the island is gynodioecious which may serve reduction of inbreeding depression.     

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.