Phylogeny of holoparasitic Orobanche (Orobanchaceae) inferred from nuclear ITS sequences

Orobanche is the largest genus among the holoparasitic members of Orobanchaceae. We present the first molecular phylogenetic analysis (using nuclear ITS sequences) that includes members of all sections of Orobanche, Gymnocaulis, Myzorrhiza, Trionychon, and Orobanche. Orobanche is not monophyletic, but falls into two lineages: (1) the Orobanche group comprises Orobanche sect. Orobanche and the small Near Asian genus Diphelypaea and is characterized by a chromosome base number of x=19 and (2) the Phelipanche group contains Orobanche sects. Gymnocaulis, Myzorrhiza, and Trionychon and possesses a chromosome base number of x=12. The relationships between these two groups and to other genera such as Boschniakia or Cistanche remain unresolved. Within the Orobanche group, Orobanche macrolepis and Orobanche anatolica (including Orobanche colorata) constitute two phylogenetically distinct lineages. Intrasectional structurings proposed by some authors for O. sect. Orobanche are not confirmed by the molecular data. In most cases, intraspecific sequence divergence between accessions, if present, is negligible and not correlated with morphological or ecological traits. In a few cases, however, there is evidence for the presence of cryptic taxa.     

Phylogeny and intraspecific variability of holoparasitic Orobanche (Orobanchaceae) inferred from plastid rbcL sequences

The rbcL sequences of 106 specimens representing 28 species of the four recognized sections of Orobanche were analyzed and compared. Most sequences represent pseudogenes with premature stop codons. This study confirms that the American lineage (sects. Gymnocaulis and Myzorrhiza) contains potentially functional rbcL-copies with intact open reading frames and low rates of non-synonymous substitutions. For the first time, this is also shown for a member of the Eurasian lineage, O. coerulescens of sect. Orobanche, while all other investigated species of sects. Orobanche and Trionychon contain pseudogenes with distorted reading frames and significantly higher rates of non-synonymous substitutions. Phylogenetic analyses of the rbcL sequences give equivocal results concerning the monophyly of Orobanche, and the American lineage might be more closely related to Boschniakia and Cistanche than to the other sections of Orobanche. Additionally, species of sect. Trionychon phylogenetically nest in sect. Orobanche. This is in concordance with results from other plastid markers (rps2 and matK), but in disagreement with other molecular (nuclear ITS), morphological, and karyological data. This might indicate that the ancestor of sect. Trionychon has captured the plastid genome, or parts of it, of a member of sect. Orobanche. Apart from the phylogenetically problematic position of sect. Trionychon, the phylogenetic relationships within sect. Orobanche are similar to those inferred from nuclear ITS data and are close to the traditional groupings traditionally recognized based on morphology. The intraspecific variation of rbcL is low and is neither correlated with intraspecific morphological variability nor with host range. Ancestral character reconstruction using parsimony suggests that the ancestor of O. sect. Orobanche had a narrow host range.     

A plastid gene phylogeny of the non-photosynthetic parasitic <Emphasis Type="Italic">Orobanche</Emphasis> (Orobanchaceae) and related genera

The phylogenetic relationships of the non-photosynthetic Orobanche sensu lato (Orobanchaceae), which includes some of the economically most important parasitic weeds, remain insufficiently understood and controversial. This concerns both the phylogenetic relationships within the genus, in particular its monophyly or lack thereof, and the relationships to other holoparasitic genera such as Cistanche or Conopholis. Here we present the first comprehensive phylogenetic study of this group based on a region from the plastid genome (rps2 gene). Although substitution rates appear to be elevated compared to the photosynthetic members of Orobanchaceae, relationships among the major lineages Cistanche, Conopholis plus Epifagus, Boschniakia rossica (Cham. & Schltdl.) B. Fedtsch., B. himalaica Hook. f. & Thomson, B. hookeri Walp. plus B. strobilacea A. Gray, and Orobanche s. l. remain unresolved. Resolution within Orobanche, however, is much better. In agreement with morphological, cytological and other molecular phylogenetic evidence, five lineages, corresponding to the four traditionally recognised sections (Gymnocaulis, Myzorrhiza, Orobanche, Trionychon) and O. latisquama Reut. ex Boiss. (of sect. Orobanche), can be distinguished. A combined analysis of plastid rps2 and nuclear ITS sequences of the holoparasitic genera results in more resolved and better supported trees, although the relationships among Orobanche s. l., Cistanche, and the clade including the remaining genera is unresolved. Therefore, rps2 is a marker from the plastid genome that is well-suited to be used in combination with other already established nuclear markers for resolving generic relationships of Orobanche and related genera.     

Karyotypes and Giemsa C-banding patterns of Zebrina pendula, Z. purpusii and Setcreasea purpurea, compared with those of Tradescantia ohiensis.

It has been proposed that the genera Zebrina and Setcreasea of the family Commelinaceae should be united and reunited, respectively, with the genus Tradescantia, mainly based on morphological studies. In the present study, karyotypes and Giemsa C-banding patterns in the root-tip cells of three Zebrina and two Setcreasea clones were analyzed, and were compared with those of a triploid Tradescantia clone. Z. pendula and Z. purpusii (both 2n = 24) were found to have similar karyotypes (4 M + 6 ST + 14 T; M = meta-, ST = subtelo-, T = telocentric chromosomes), while Z. pendula cv Quadricolor (2n = 23) had a unique karyotype (6 M + 5 ST + 11 T + 1 SA; SA = short acrocentric chromosome). The only clear difference between Z. pendula and Z. purpusii was that one and two subtelocentric chromosomes, respectively, had satellites at the short arms. Two clones of S. purpurea (2n = 24) had karyotypes (8 M + 8 M' + 8 SM; M' = nearly meta-, SM = submetacentric chromosomes) similar to each other. T. ohiensis (2n = 18) had a symmetric karyotype (9 M + 9 SM) consisting of larger chromosomes than S. purpurea. Many clear Giemsa C-bands were detected, in addition to centromeric bands in all chromosomes of all clones. Z. pendula and Z. purpusii commonly had single clear interstitial bands in eight telocentric chromosomes each, but they also had unique telomeric and other interstitial bands, respectively. Z. pendula cv Quadricolor had a unique banding pattern, i.e., satellite bands in the unique short chromosome, telomeric bands at the long arms of all metacentric chromosomes, and single interstitial bands in six telocentric chromosomes. Two clones of S. purpurea had telomeric bands at many chromosome arms and satellite bands in two nearly metacentric and one submetacentric chromosomes, but some differences were found between them. On the other hand, all the chromosomes of T. ohiensis had telomeric bands at both arms, and three submetacentric chromosomes had satellite bands. These result prove structural differentiation of chromosomes occurred among the clones, especially in Zebrina, and show that S. purpurea is relatively close to T. ohiensis, while Zebrina is obviously distant from the other two genera. Therefore, there remains a question cytologically at least for uniting Zebrina with Tradescantia.     

Chromosomes of the liver fluke, Clonorchis sinensis

A karyological study was carried out in order to compared the chromosome numbers, chromosome morphologies and karyotypes of the oriental liver fluke, Clonorchis sinensis (Trematoda: Opisthorchiidae), collected from Korea and China. Chromosome preparations were made by means of air-drying method. The chromosome number was 2n = 56 in both Korean and Chinese flukes, and chromosomes were divided into two groups based on this size; consisting of 8 pairs of large and 20 pairs of small chromosomes. However, the karyotypes showed some differences between Korean and Chinese flukes. The karyotype of liver flukes from Korea consisted of three metacentric pairs, one meta-/submetacentric pair, 16 submetacentric pairs and eight subtelocentric pairs of chromosomes. On the other hand, liver flukes from China consisted of two metacentric pairs, two meta-/submetacentric pairs, 16 submetacentric pairs and eight subtelocentric pairs of chromosomes.     

A comparative study on karyotypes of 28 taxa in Rubus sect. Idaeobatus and sect. Malachobatus (Rosaceae) from China

Rubus is a taxonomically difficult group and cytological data are expected hopefully to gain insight into the relationships of the genus. In this study the chromosome numbers and karyotypes of 18 taxa from sect. Idaeobatus and 10 taxa from sect. Malachobatus were investigated. Among them, the chromosome numbers of 10 taxa and karyotypes of 26 taxa were reported for the first time and mixoploidy was observed new in the genus. The chromosomes are small in size with a length of less than 3 µm and metacentric (about 90%) or submetacentric. All taxa have karyotypes of “1A” except R. cockburnianus, R. innominatus and R. ellipticus var. obcordatus, which have karyotypes of “2A”. No aneuploids were found in all the 28 taxa studied. Plants of sect. Idaeobatus have diploids with 2n=2x=14, except R. idaeopsis (2n=3x=21) and R. parvifolius (A mixoploid of 2n=2x=14 and 2n=4x=28). However, plants of sect. Malachobatus have tetraploids with 2n=4x=28, except for R. buergeri with 2n=8x=56. In addition, conspicuous karyotype differences existed within the 18 taxa belonging to 11 of 7 subsections in sect. Idaeobatus, and the differences between some species within subsections are greater than that between subsections, while uniform karyotypes within subsections and variable karyotypes between subsections were observed in six of 13 subsections in sect. Malachobatus represented by 10 taxa. Systematic values of the cytological data were discussed for some cases when applicable to the two sections.     

Fatty acids and tocochromanols in seeds of Orobanche

The evaluation of tocochromanols (tocopherols and tocotrienols) in 49 accessions from 21 Orobanche species revealed three well separated groups. The first one, characterized by high gamma-tocotrienol content, included all the accessions of sect. Orobanche. The second one, exhibiting high gamma-tocopherol content, comprised the accessions of O. arenaria Borkh. and O. purpurea Jacq. (sect. Trionychon Wallr.). All the other accessions of this section presented high delta-tocopherol content. Differences for tocochromanol derivatives within sect. Trionychon were paralleled by differences in the fatty acid profile, with the high delta-tocopherol class having also a higher oleic to linoleic acid ratio.     

中国淡水三角涡虫(Dugesia sp)的染色体研究(Ⅰ)

利用空气干燥法对不同产地淡水三角涡虫的染色体进行了研究。核型分析表明：河南淇县鱼泉三角涡虫(Dugesia sp)和浙江杭州龙井三角涡虫(Dugesia sp)体细胞中有16条染色体,为二倍体,核型公式为2n=2x=16=16m,均为具中部着丝粒染色体;河南济源不老泉三角涡虫(Dugesia sp)有24条染色体,为三倍体,核型公式为2n=3x=24=24m,亦全部由中部着丝粒染色体组成。上述3个产地淡水三角涡虫染色体的形态较为接近。北京樱桃沟三角涡虫(Dugesia sp)的体细胞染色体数目为24,为三倍体,核型公式为2n=3x=24=22m 2sm,由中部和亚中部着丝粒染色体组成,其中第2、4号各有一条染色体属于亚中部着丝粒染色体。研究结果表明：4个产地三角涡虫的体细胞染色体数目存在较大差异,包括二倍体(2n=2x=16)和三倍体(2n=3x=24),染色体基数属于x=8类型。     

Different rate of intrapopulation chromosome polymorphism in two species of Black Sea Blennies (Blenniidae,Pisces)

Somatic karyotypes in seven specimens of Blennius sanguinolentus include 22 subtelocentric and 26 acrocentric chromosomes, whereas one male has 2n=47=1M+22ST+24A: polymorphism is evidently a result of centric fusion of two acrocentrics. Blennius tentacularis is characterized by the availability of four karyomorphs out of which three coincide with karyotypes described earlier (Carbone et al., 1987). Karyttype-I consists of a 48 small uni-armed chromosome, but both karyotypes II and III with 2n=48 and 2n=47 respectively include one large acrocentric chromosome, and karyotype-IV has one large submetacentric out of the 47 chromosomes. Karyotypic variability of B. tentacularis is attributed either to polymorphism by 1–3 chromosome rearrangements or to availability of sex-determining mechanism, including the Y-autosome translocation. This diverse series of male karyomorphs may reflect the complicated behavioural structure.     

3个彩色马蹄莲引进品种的核型分析

利用普通压片法对3个引进彩色马蹄莲(Zantedeschia hybrid)品种的染色体数与核型进行了分析。结果表明:所试验品种染色体数均为2n=32。染色体形态比较一致,多是由中部(m)以及近中部(sm)着丝粒染色体组成。其中,‘Allure’为2n=2x=32=14m(2SAT)+2sm,‘Cupdio’的核型公式为2n=2x=32=14m+2sm,Odessa的核型公式为2x=32=1M+15m(1SAT)。3个品种核型不对称系数分别为56.72%,56.25%和56.38%,核型分类显示其均为1A型。     

Karyotype and meiosis studies in three South African Pyrgomorpha species (Orthoptera: Pyrgomorphidae)

Two South African Pyrgomorpha species have reduced chromosome numbers, due to centric fusions between the largest autosomes and the medium and small autosomes. P. rugosa has 2n=11(XO) (4 pairs of submetacentric and 1 pair of acrocentric autosomes) and P. granulata has 2n=13(XO) (3 pairs of submetacentric and 3 pairs of acrocentric autosomes). A third South African species has a typical Pyrgomorphidae number of 2n=19(XO) (acrocentrics). The mean chiasma frequency of the 2n=19 species is higher than that of the other two, although the frequencies of distal chiasmata in all three are similar. The recombination potential of the two species with lower chromosome numbers has been reduced, due to fewer crossovers in comparison to the 2n=19 species, as well as to independent assortment.     

Aneusomaty inOrobanche gracilis

InOrobanche gracilis Sm. (collected in Vienna, Lower Austria, and N. Italy) the somatic chromosome numbers were found to be inter-and intra-individually variable. Most plants yielded counts of around the tetraploid level (2n = 73−91), a few of around the hexaploid level (2n = 112−116). Only 36% of the plants were eusomatic, only 24% eutetraploid (2n = 76). Depending on the variable somatic chromosome number, gametophytic numbers are also variable. Univalents, multivalents, and anaphase anomalies were of regular occurrence during meiosis of plants with more than 2n = 76 chromosomes. This is the first report of variable polyploid chromosome numbers (4x = 76, 6x = 114) inOrobanche sect.Orobanche. Aneusomaty is due to a constitutional tendency to nondisjunction during mitosis. The supernumerary chromosomes are considered to represent A- (= normal) rather than B-chromosomes. A possible causality between the chromosomal and the morphological variation, and the adaptive significance of this phenomenon are discussed.     

Karyotypic analysis of the gobiid fish genus Quietula Jordan and Evermann

The karyotypes of the two species of the gobiid fish genus Quietula, Q. y-cauda (Jenkins & Evermann) and Q. guaymasiae (Jenkins & Evermann), are reported for the first time. The karyotypes contained equal numbers of chromosomes (2 n =42) but differed in chromosome morphology. Quietula y-cauda has 42 acrocentric chromosomes. Quietula guaymasiae has six metacentric, four submetacentric, and 32 acrocentric chromosomes. It is suggested the karyotype of Q. guaymasiae might have been derived from that of Q. y-cauda. In addition, from comparison of the species' karyotypes of the genera Quietula and Gillichthys , it is possible the karyotype of Q. y-cauda might have been derived from that of Gillichthys mirabilis.     

Karyotypic characterization of three weevil species (Coleoptera: Curculionidae, Brachyderini)

Karyotypes of three species, Brachyderes incanus, Brachysomus setiger and Paophilus afflatus, belonging to the tribe Brachyderini, were studied using C-banding technique. The species share the same chromosome number 2n = 22 and meioformula n = 10+Xy(p) at all metaphase 1 plates of spermatid division. Some differences between karyotypes were observed in terms of centromere positions and C-band sizes. Most chromosomes are meta- or submetacentric and form a graded series in respect to length. The chromosomes resemble one another in having a rather small amount of heterochromatin restricted to the pericentromeric region and visible as dark stained blocks mainly during early stages of nuclear division. Only in Brachyderes incanus do larger bands occur at mitotic metaphase and diakinesis. These cytogenetic data are in agreement with karyological findings obtained in other species of Brachyderini so far examined.     

Cytotaxonomy of the apocynaceae

At present there is karyological information on ca 10% of the species and ca 30% of the genera of the Apocynaceae. Basic numbers of x = 6, 8, 9, 10, 11, 12, 16, 18, 20, 21 and 23 have been assessed. Of these x = 11 is primitive, occurring in ca 60% of the genera. Those of x = 6, 8, 9 and 10 have evolved by reduction, and x = 12 by increase from x = 11. In the subtribe Secondatiinae however, x = 12 is most likely the result of doubling x = 6. The numbers x = 16, 18 and 20 are likewise doubles of x = 8, 9 and 10 respectively. Those of x = 21, 23, and in one case, x = 20 are probably aneuploid products of doubles of x = 11. The two larger subfamilies, Plumerioideae and Apocynoideae have the basic numbers x = 8, 9, 10 and 11 in common and are not separable on the basis of chromosomal evidence. The third small subfamily Cerberoideae is more homogeneous according to basic number, i.e. x = 10 and 20. Most genera are characterized by a constant basic number, but some have two basic numbers; these clearly are cases of infrageneric aneuploidy. Based on records in the literature two closely related generaApocynum andTrachomitum appear to be characterized by a basic number of x = 8 as well as x = 11. This conflicting situation should be clarified by further karyological research. From the level of subtribe onwards some taxa have one basic number, but others are characterized by two or more numbers. The occurrence of similar basic numbers in different phylads of the family is considered to be the result of similar chromosomal evolution mechanisms. Approximately 22% of the investigated species are polyploid. Intrageneric polyploidy occurs with a frequency of about 12.5% and infraspecific polyploidy with less than 4%. The karyotypes observed are symmetrical: the chromosomes within a karyotype are similar in length with primary constrictions usually in a median position. In the Tabernaemontaneae however, it was observed that the karyotypes comprise one pair of distinctly heterobrachial chromosomes in addition to the metacentric ones. This tribe is also characterized by chromosomes which are relatively long. Most genera of the African continent, which are well known regarding their chromosome number, are characterized by x = 11. Exceptions areStrophantus (x = 9) with a mainly tropical African distribution. Two other genera with derived numbers, i.e.Gonioma with x = 10 andPachypodium with x = 9, occur in southern Africa and Madagascar. The genera with a non-African distribution are less known for their chromosome number. However, the available evidence suggests that evolution of derived numbers has occurred more frequently outside Africa than on this continent.     

Contributions to the Cytotaxonomy of the Commelinaceae. Gibasis linearis and its allies

Species of the Gibasis linearis alliance collected in Mexico in 1976 are shown to have a chromosome constitution of x = 6, but x = 5 has also been found in some populations of G. rhodantha and G. speciosa. These two basic numbers are associated with distinctive karyotypes, 2M + 4A and 3M + 2A respectively, which show a Robertsonian relationship with each other. The existence of 2n = 22 in G. speciosa , combining both basic numbers at the amphidiploid level provides evidence of pairing between metacentrics and acrocentrics in such a way as to substantiate the view that fusion or fission of chromosomes is responsible for the modification of basic number. This survey provides a basis for other studies which will determine the chromosome relationships of the species irrespective of chromosome number in this family.     

Contributions to the Cytotaxonomy of the Commelinaceae. Gibasis linearis and its allies

Species of the Gibasis linearis alliance collected in Mexico in 1976 are shown to have a chromosome constitution of x = 6, but x = 5 has also been found in some populations of G. rhodantha and G. speciosa. These two basic numbers are associated with distinctive karyotypes, 2M + 4A and 3M + 2A respectively, which show a Robertsonian relationship with each other. The existence of 2n = 22 in G. speciosa , combining both basic numbers at the amphidiploid level provides evidence of pairing between metacentrics and acrocentrics in such a way as to substantiate the view that fusion or fission of chromosomes is responsible for the modification of basic number. This survey provides a basis for other studies which will determine the chromosome relationships of the species irrespective of chromosome number in this family.     

赤斑羚和斑羚核型比较研究

本文对赤斑羚（ＮａｅｍｏｒｈｅｄｕｓＣｒａｎｂｒｏｏｋｉ）和斑羚（Ｎ．ｇｏｒａｌｇｒｉｓｅｕｓ）的染色体Ｇ带、Ｃ带和Ａｇ－ＮＯＲｓ的数目、分布等作了较详细的比较研究。赤斑羚２ｎ＝５６全部为近端着丝粒染色体,Ｎ．Ｆ＝５４;斑羚２ｎ＝５４,除Ｎｏ．３是亚中着丝粒染色体外,具有丰富的异染色质;二者Ｇ带带纹相似程度高,其Ｎｏ．３长臂Ｇ带带纹相似。斑羚的Ｎｏ．３短臂与赤斑羚Ｎｏ．２７近端着丝粒染色体的大小、     

Fruit and seed morphology of the tribe Orobancheae (Orobanchaceae) genera in Turkey and its taxonomic significance

Seed and fruit morphology of four genera of Orobanchaceae: Cistanche, Diphelypaea, Orobanche and Phelipanche, native to Turkey, were studied using light and scanning electron microscopy. In this study, 100 accessions belonging to 39 species were investigated. The examined fruits had loculicidal capsules, generally dehiscing with 2 slits, and the seeds were small and with reticulate ornamentation. The basic shape of the seeds in most of the studied taxa was oblong, ellipsoid to ovoid, globose or subglobose. The results indicate that characters such as seed size, shape and color are useless for identification of the taxa at the species level. However, the anticlinal wall pattern and periclinal wall ornamentation proved useful for identifying the different genera. Four morphological types could be distinguished: smooth, perforate, microfibrillar and granulate. Type I corresponds to the genus Cistanche and Orobanche anatolica, whereas types II, III and IV were found in Diphelypaea, Orobanche and Phelipanche, respectively. The utility of seed characteristics is discussed in terms of inter‐ and intra‐generic taxonomy.     

High chromosomal polymorphism and heterozygosity in Cyclocephala tridentata from Guadeloupe: chromosome comparison with some other species of Dynastinae (Coleoptera: Scarabaeidae)

Very distinct karyotypes have been observed in two Cyclocephala species from Guadeloupe, considered as very close and possibly vicariant: C. insulicola with only metacentric and C. tridentata tridentata with many acrocentric autosomes. This prompted us to study the karyotype of a few other neotropical Dynastinae belonging to four of the eight existing tribes, to find out which one of these two species had the most divergent chromosomes from their ancestral condition. In the four additional species studied, i.e., Cyclocephalamaffafa, Strategus syphax, Ligyrus cuniculus and Megasoma actaeon, a karyotype composed of 20 chromosomes, including 18 meta- or submetacentric autosomes was found, as it was in C. insulicola. Thus, the karyotype of C. t. tridentata, in which most of the 18 autosomes were acrocentric, is apomorphic. In addition, it was highly polymorphic, with six different karyotypes observed among the ten specimens studied. All had one to four heterozygous chromosome pairs formed by one acrocentric and one submetacentric carrying a large juxta-centromeric heterochromatic component. This heterozygosity did not seem to impair either meiotic synapsis or chiasma formation and chromosome segregation. Such high rates of chromosome heterozygosity and polymorphism are infrequent and never described in beetles. This suggests that C. t. tridentata undergoes an active process of chromosome evolution. A possible relationship with insularity and/or pesticide exposure is briefly discussed.