ITS DNA sequence relationships between Lilium concolor Salisb., L. dauricum Ker-Gawl. and their putative hybrid, L. maculatum Thunb.

 Cycle sequencing of the ITS region of nuclear ribosomal DNA of L. concolor, L. dauricum and L. maculatum generated surprisingly homogenous sequences from these three species. Analysis of the few (13 out of 639) polymorphic nucleotide sites in the ITS region produced results that do not support the belief that L. maculatum is a hybrid of the two other species. Neighbor-Joining analysis of the genetic distances calculated using the Kimura 2-parameter model of base substitution confirmed the close relationship between L. dauricum and L. maculatum. The phylogenetic tree, in conjunction with the distribution pattern and morphological similarities of the two species, suggest that L. maculatum is derived from the more widely distributed L. dauricum. The results also revealed that there is sufficient molecular divergence between L. maculatum and L. dauricum to support their status as separate species. Received: 4 June 1998 / Accepted: 15 July 1998     

PALEOZOIC LYCOPSID FRUCTIFICATIONS. I. LEPIDOCARPON PETRIFACTIONS

A reinvestigation of the 4 American species of Lepidocarpon described from petrifactions and of Illiniocarpon cadyi, also described from petrifactions, shows that they are all conspecific. When they, in turn, are compared with specimens of the British petrifaction L. lomaxi, no significant differences can be demonstrated. The criteria cited as diagnostic for the American petrifaction species of Lepidocarpon were found to fail as bases of discrimination when 400 specimens of Lepidocarpon found in coal balls of Pennsylvanian age were studied. Measurements and observations made of a sample size of 136 of these 400 specimens reveal a degree of variation compatible with that of a single species. All previously described American and British petrifaction taxa fall within (or not significantly beyond) this range of variability of a single species as determined from this sample. Additional evidence concerning the 3-dimensional sporophyll structure of this one species of Lepidocarpon and the configurations obtained by certain planes of section through it have served to demonstrate that Illiniocarpon cadyi is in reality a taxon based on sectioned structures of the sporophyll of this Lepidocarpon species. Under the rules of priority, this species of Lepidocarpon and the following are assigned to Lepidocarpon lomaxi: Illiniocarpon cadyi, Lepidocarpon ioense, L. magnificum (megasporangiate form), L. crenatum and L. palmerensis. On the basis of the morphological evidence, the British petrifaction described as Lepidocarpon wildianum is also equated with L. lomaxi.     

Polytene chromosome maps in four species of tsetse flies Glossina austeni, G. pallidipes, G. morsitans morsitans and G. m. submorsitans (Diptera: Glossinidae): a comparative analysis

Photographic polytene chromosome maps from pupal trichogen cells of four tsetse species, Glossina austeni, G. pallidipes, G. morsitans morsitans and G. m. submorsitans were constructed and compared. The homology of chromosomal elements between the species was achieved by comparing banding patterns. The telomeric and subtelomeric chromosome regions were found to be identical in all species. The pericentromeric regions were found to be similar in the X chromosome and the left arm of L1 chromosome (L1L) but different in L2 chromosome and the right arm of L1 chromosome (L1R). The L2 chromosome differs by a pericentric inversion that is fixed in the three species, G. pallidipes, G. morsitans morsitans and G. m. submorsitans. Moreover, the two morsitans subspecies appeared to be homosequential and differ only by two paracentric inversions on XL and L2L arm. Although a degree of similarity was observed across the homologous chromosomes in the four species, the relative position of specific chromosome regions was different due to chromosome inversions established during their phylogeny. However, there are regions that show no apparent homology between the species, an observation that may be attributed to the considerable intra—chromosomal rearrangements that have occurred following the species divergence. The results of this comparative analysis support the current phylogenetic relationships of the genus Glossina.     

Il sospensore embrionale nelle Cruciferae. I. Morfologia e struttura

Abstract

Embryo suspensor in Cruciferae. I. Morphology and structure. — Embryo suspensors in seven species of Cruciferae (Alyssum argenteum All., Brassica nigra (L.) Koch, Capsella bursa-pastoris (L.) Medicus, Diplotaxis erucoides (L.) DC., Eruca sativa Miller, Lepidium graminifolium L., Matthiola tricuspidata (L.) R. Br.) were morphologically investigated. These species have significant differences in their seeds, so that probable differences could be found in the structure of their ovules and therefore of their suspensors. Results indicate that it is impossible to generalize on the suspensor morphology and structure even in the same family. In Eruca sativa and Brassica nigra polyploidy and polyteny were found, suggesting a probably important metabolic function of their suspensors. In the other species polyteny was not present; a various degree of polyploidy could probably be assumed, suggesting a less active function of suspensors, maybe absorption and transport of nutritive material from the integuments to the developing embryo. The development of the endosperm is almost the same in all species, so that seems to be improbable a negative correlation with the suspensor and endosperm function in the early embryogenesis.     

TAXONOMY OF ADAMSIELLA L.E. PHILLIPS ET W.A. NELSON,GEN. NOV. AND EPIGLOSSUM KÜTZING (RHODOMELACEAE,CERAMIALES)1

In a taxonomic/phylogenetic study of the genus Lenormandia, several species were found to differ significantly from the type species, L. spectabilis Sonder, in apical morphology, blade‐surface pattern, medullary construction, the presence of pseudopericentral cells, and the position of reproductive structures. These species constitute two groups that differ morphologically, a finding largely supported by analysis of 18S rRNA sequences, as reported previously. The two putative Lenormandia species from New Zealand, along with two previously undescribed species also from New Zealand, comprised one such group, designated here by the new genus name Adamsiella L.E. Phillips et W.A. Nelson, gen. nov. and including A. melchiori L.E. Phillips et W.A. Nelson, sp. nov., A. lorata L.E. Phillips et W.A. Nelson, sp. nov., A. angustifolia (Harvey) L.E. Phillips et W.A. Nelson, comb. nov., and A. chauvinii (Harvey) L.E. Phillips et W.A. Nelson comb. nov. Adamsiella differs from Lenormandia by incurved apices, a chevron surface pattern, and reproductive structures on dorsi‐ventrally flattened apically incurved polysiphonous branchlets usually produced at the margins. Two species endemic to Australia formed the second group designated by the resurrected generic name Epiglossum and also characterized by a strongly incurved apex and chevron surface pattern but with reproductive structures produced on terete polysiphonous branchlets found either on the midrib or elsewhere on the blade surface but not the margins. Epiglossum contains E. smithiae (J.D. Hooker et Harvey) Kützing and E. proliferum (C. Agardh) L.E. Phillips, comb. nov.     

Lycium amarum sp. nov. (Solanaceae) from Xizang,supported from morphological characters and phylogenetic analysis

Lycium amarum sp. nov. L. Q. Huang is described based on its general morphology and pollen micromorphology, which were compared with closely related Lycium species. The phylogenetic relationships among the new species and closely related Lycium species belonging to the tribe Lycieae were investigated based on the DNA sequence data of the granule‐bound starch synthase (GBSSI) gene. Morphologically, L. amarum is similar to L. chinense Mill. sharing lanceolate or linear‐oblanceolate leaves, three‐lobed calyx, villous ring slightly above the filament base, and adjacent corolla tube, however, L. amarum may be diagnosed by its prominent tubercles at the base of spines, thinly leathery leaves, and a two‐tine crack on the tip of calyx lobes. According to our results, the new species is close to L. barbarum L., L. chinense, L. dasystemum Pojark, and L. yunnanense Kuang & Lu.     

CHROMOSOME NUMBERS OF CAMPANULACEAE. II. THE LOBELIA TUPA COMPLEX OF CHILE

Gametic chromosome numbers are reported for 27 collections representing the four species of the Lobelia tupa complex (Campanulaceae, Lobelioideae) in Chile; all are n = 21. This represents the first report of chromosome numbers for L. bridgesii Hook. & Arn., L. excelsa Bonpl., and L. polyphylla Hook. & Arn., and confirms previous reports of this number in L. tupa L. As the basic chromosome number of Lobelioideae is x = 7, these species are interpreted as hexaploids. Higher polyploids are extremely rare among Lobelioideae; most of those previously reported have been either sporadic individuals or populations within an otherwise diploid or tetraploid species, or occasional species within an otherwise diploid and tetraploid lineage. This is the first report of an entire complex of lobelioid species that is uniformly hexaploid. This suggests that the Chilean endemics are relatively derived within Lobelia, and offers some support for the monophyly of the complex.     

Isozyme variation and species relationships in the genus Lolium L. (ryegrasses,Graminaceae)

Thirty-two natural populations belonging to the eight species of the genus Lolium (ryegrass) or to Festuca pratensis (meadow fescue) were recorded for allelic frequencies at 13 isozyme loci. Cultivated ryegrass (L. perenne and L. multiflorum), meadow fescue, and the annual L. rigidum, are true outbreeders. The other species are true inbreeders, except for L. canariense, which shows a moderate level of cross fertilisation (20%). Hierarchical clustering from Nei's unbiased distance leads to four groups. The three self-pollinating, weed species, L. temulentum, L. remotum and L. persicum, belong to the first cluster, which is the most differentiated one. The second cluster comprises L. multiflorum, L. subulatum and most populations of L. rigidum. All L. perenne populations belong to the third cluster, as do two of L. rigidum. The average genetic distance within the L. perenne group is very low. Surprisingly, the fourth cluster groups together L. canariense and Festuca pratensis. The data suggest that L. rigidum is the species with the greatest diversity, and could be a common ancestor of the genus. Knowledge of historical processes of domestication could help to calibrate the molecular clock.     

Lagerstroemia menglaensis sp. nov. (Lythraceae) from Xishuangbanna,Yunnan Province,China

Lagerstroemia menglaensis C. H. Gu, M. C. Ji & D. D. Ma, a new species of Lythraceae from Xishuangbanna, Yunnan, China is described and illustrated. The morphological characteristics of the new species and two morphologically similar species (L. guilinensis and L. venusta) are compared, and a key to distinguish between them is provided.     

New species, nomenclatural changes and lectotypifications in Neotropical Lepidagathis Willd. (Acanthaceae)

Summary  Taxonomic and phylogenetic studies of the Neotropical genus Lophostachys showed that it is congeneric with Lepidagathis. The following new combinations of species previously described under Lophostachys are proposed: Lepidagathis chiapensis (Acosta) Kameyama, L. cyanea (Leonard) Kameyama, L. guatemalensis (Donn. Sm.) Kameyama, L. laxifolia (Nees) Kameyama, L. montana (Nees) Kameyama, L. nemoralis (Mart. ex Nees) Kameyama, L. soconuscana (T. F. Daniel) Kameyama, and L. uxpanapensis (Acosta) Kameyama. Five new species are described: Lepidagathis callistachys, L. cuneiformis, L. meridionalis, L. paraensis and L. wasshausenii. Three lectotypes are also designated. A key to the Neotropical secundiflorous species is provided.     

Scanning electron microscopic studies of Centaurea L. s.s. pollen

Abstract

The purpose of this study is to analyse, by means of Scanning Electron Microscopy (SEM), the validity of the typification of the pollen of Centaurea L. s.s., carried out by Wagenitz (1955) with light microscopy and based on the exine structure and sculpturing. The pollen of six species have been analyzed: one species for every type of pollen present in Italy: C. sempervirens L., C. alpina L., C. scabiosa L., C. alba L., C. montana L., C. cyanus L.

The validity of the pollen typification suggested by Wagenitz has been confirmed also at the ultramicroscopic level. The ultrastructure and the sculturing of the sporoderm are described in detail and some discrepancies, mainly due to the different potentialities offered by the two methods, are pointed out.     

A phylogenetic analysis of <Emphasis Type="Italic">Leucothoe</Emphasis> s.l. (Ericaceae; tribe Gaultherieae) based on phenotypic characters

Phylogenetic relationships within the genus Leucothoe s.l. (including all eight species) and related taxa of the Gaultherieae, Andromedeae, and Vaccinieae were investigated by a cladistic analysis based on phenotypic (external morphology, anatomy, chromosome number, and secondary chemistry) characters. The parsimony analysis resulted in two most parsimonious trees, both very similar, which show Leucothoe s.l. to be polyphyletic, with its species distributed among three distinct clades. Our results indicate that L. racemosa and L. recurva form a strongly supported clade, which is sister to Chamaedaphne calyculata, and these three species are probably the sister-group of the wintergreen clade (consisting of Gaultheria and Diplycosia). Leucothoe axillaris, L. fontanesiana, L. davisiae, L. griffithiana, and L. keiskei, consistently form a monophyletic group corresponding to Leucothoe s.s., which is probably sister to the remaining members of the tribe Gaultherieae. Leucothoe grayana, the final species traditionally placed in the genus, belongs to neither of these clades and may be sister to Andromeda. Phenotypic characters provide no support for the monophyly of Leucothoe, instead suggesting that it is polyphyletic, in agreement with preliminary DNA-based analyses. Thus, we redefine the genus Leucothoe, placing its species into three genera: 1) Eubotrys (the E. racemosa + E. recurva clade), 2) Leucothoe s.s. (the L. axillaris + L. fontanesiana + L. davisiae + L. griffithiana + L. keiskei clade), and 3) Eubotryoides (containing only E. grayana).     

The erection of Leporidotaenia n. g. (Cestoda: Anoplocephalidae) for Anoplocephaloides spp. parasitising Leporidae (Lagomorpha)

Leporidotaenia n. g. is proposed for four cestode species parasitising Leporidae (Lagomorpha) which were previously considered as members of the genus Anoplocephaloides. The new genus is differentiated from Anoplocephaloides by the presence of a spinose covering on the tegument, the protrusible genital atrium, the massive cirrus-sac with highly developed musculature, the presence of a retractor muscle associated with the cirrus-sac, the posterior position of vaginal pore relative to the male orifice, the cirrus armed with long spines and its occurrence only in hosts of the family Leporidae (Lagomorpha). The genus includes: L. romerolagi (type-species), L. floresbarroetae, L. pseudowimerosa and L. wimerosa. the species (excluding L. floresbarroetae) are redescribed and figured and a differential key is presented. An attempt is made to explain the range of Leporidotaenia spp. in Central America and the western Palaearctic on the basis of the palaeozoogeography of rabbits and hares.     

Cytogenetic investigations in Cucurbitaceae I. Interspecific hybridization in Luffa

In two interspecific hybrids of Luffa, i.e., L. acutangula x L. graveolens and L. echinata x L. graveolens, various types of chromosome associations, from univalents to quadrivalents were observed. The hydrid L. echinata x L. graveolens showed a much higher frequency of univalents than the other hybrid, but the pairing data of both indicate partial homology among most of the chromosomes of the three species. The study of these F₁ hybrids has been utilised for establishing the phylogenetic relationship among the various species and to trace the trend of evolution in the genus Luffa. The two wild species, L. graveolens and L. echinata, are closely related, whereas, L. graveolens is more distantly related to L. acutangula than to L. echinata. It has also been concluded that dioecism in L. echinata is a derived feature, established after diverging from the monoecious prime species L. graveolens.This research has been financed in part by a grant made by the United States Department of Agriculture under PL 480.     

Isolation and characterization of microsatellites in Echinochloa (L.) Beauv. spp.

Five primer pairs were developed that amplify microsatellite loci in three agronomically important Echinochloa (L.) Beauv. species: E. colona (L.) Link, E. crus‐galli (L.) Beauv. and E. crus‐pavonis (Kunth) Schultes. The microsatellites were tested on 24 individuals representing three species collected in rice fields from different geographical regions and revealed 3–7 alleles per microsatellite. Gene diversity [1 ? Σp_ij²] for four polymorphic loci within E. crus‐galli ranged from 0.12 to 0.61. Alleles at a fifth locus were useful in discriminating the species. The microsatellites should provide useful markers for intraspecific diversity studies and aid classification of species within this complex genus.     

Chromosome association and pollen fertility of parental and interspecific hybrids of Lycopersicon esculentum X L. hirsutum and L. pennellii

Cytological studies were carried out on two wild species (L. hirsutum and L. pennellii) and the cultivated species (L. esculentum) of tomato and their F1 hybrids. Both parents and hybrids show a diploid chromosome number of 2n=24. The meiotic behaviour of the cultivated species showed a high degree of chromosome homology resulting in a high level of chiasmata frequency per bivalent. In contrast, the two wild species showed a slight increase in uniyalent frequency and a decrease in bivalent formation and chiasmata frequency. The meiotic behaviour of the hybrids showed a high level of univalents and low levels of bivalents as well as trivalents. Highly significant decreases in chiasmata frequency and increases in meiotic abnormalities, especially in the L. esculentum X L. pennellii hybrid, also were detected. The high meiotic irregularity and low chiasmata frequency recorded in the second hybrid indicated the disharmony and difference between its parental genomes and also served to predict its sterility. With regard to degree of pairing recorded in the hybrids, there is a possibility that sterility in such cases may refer to genetic factors in addition to the previously mentioned reasons. Pollen fertility showed no great difference between L. esculentum and L. hirsutum and their F1 hybrid, but a significant decrease was recorded in the L. esculentum X L. pennellii hybrid, which was clearly associated with high meiotic irregularity, low chiasmata frequency and chromosome association.     

Taxonomic studies on Zingiber (Zingiberaceae) in China IV: Z. pauciflorum sp. nov. from Yunnan

Zingiber pauciflorum L.Bai, ?korni?k., D.Z.Li & N.H.Xia (Zingibereae, Zingiberaceae), a new species from southern Yunnan, China, is described and colour plates are provided. It belongs to Z . sect. Cryptanthium Horan. and is compared with three similar species, namely Z. tenuifolium L.Bai, ?korni?k. & N.H.Xia, Z. smilesianum Craib and Z. yunnanense S.Q.Tong & X.Z.Liu. A colour plate of the most similar species, Z. smilesianum is also provided for comparison.