A systematic histological study of palm fruits. VI. Subtribe Linospadicinae (Arecaceae)

The pericarp structure of representative species of the four genera of the subtribe Linospadicinae is described and compared. Tissues found in the pericarp of this group are similar to those found in other subtribes of the Areceae, with no characters unique to the subtribe and nothing to suggest its closest affinities. The four genera, as well as each species examined, do show distinctive pericarp features, however.Laccospadix andLinospadix are similar, both with a single series of fibrous, bundles and an outer series of prominent raphide-bearing cells dominating the pericarp. In bothHowea andCalyptrocalyx, a complex exocarp forms from a series of fibrous bundles and brachysclereids, but each genus has other distinctive characters.Howea has vascular bundles in the exocarp zone, an outer series of raphide-bearing cells, and a conspicuously thickened locular epidermis. Based on a limited sample of four species, raphide-bearing cells appear to be always interior to the exocarp inCalyptrocalyx, and the locular epidermis is thin.     

A systematic histological study of palm fruits. V. Subtribe Archontophoeniciae (Arecaceae)

Pericarp histology in the Archontophoenicinae provides little to characterize the subtribe as a whole, revealing instead two separate trends with parallels in other subtribes of the Areceae. The data support a close relationship among the three genera occurring in New Caledonia:Chambeyronia, Actinokentia, andKentiopsis, in which there is a complex endocarp consisting of short, oblique fibrous bundles embedded in a thick mantle of brachysclereids, and a loose endocarp of heavily fibrous, flattened vascular bundles adjacent to a relatively thin locular epidermis. The data also support a close relationship between the two genera of the New Zealand/Tasman Sea region:Hedyscepe andRhopalostylis, in which the pericarp is more or less fibrous throughout, with purely fibrous bundles in the outer pericarp and heavily fibrous vascular bundles in the inner pericarp. These results confirm relationships revealed by other morphological data.Archontophoenix appears to be most like the New Caledonian genera in its pericarp structure, with a similar mantle of short fibrous bundles embedded in a a mantle of brachysclereids in the outer pericarp, although it differs significantly in other aspects of morphology and anatomy.     

A systematic histological analysis of palm fruits VII. The Cyrtostachydinae (Arecaceae)

Fruit specimens representing five taxa of the genusCyrtostachys were examined histologically in order to characterize the pericarp anatomy of the monogeneric subtribe Cyrtostachydinae (tribe Areceae, subfamily Arecoideae), as part of an ongoing survey of the family. The pericarp in this genus can be characterized by a combination of papillate epidermis, heavy layer of tanniniferous/pigmented cells below the epidermis, a system of vascular bundles with thick fibrous sheaths with purely fibrous bundles frequently above and below, absence of brachysclereids, and a very thin sclerified locular epidermis. On the basis of pericarp structure alone, the genus might be most closely related to theGronophyllum alliance of the subtribe Arecinae. This diverges somewhat from the hypothesis of relationship with theAreca group of the Arecinae resulting from two DNA-based phylogenetic studies, and even further from the hypothesis of relationship withIguanura suggested by another DNA-based phylogenetic study.     

A systematic histological study of palm fruits. IV. Subtribe Oncospermatinae (Arecaceae)

Pericarp histology in the Oncospermatinae reveals distinctive characters at the generic level but no unique characters at the subtribal level. Pericarp structure is diverse but parallels the diversity found in other subtribes of the Areceae. The subtribe appears to be divisible into two distinct groups: one in which sclereids alone provide the primary protective barrier in the outer fruit and one in which fibrous bundles, some-times in combination with brachysclereids, form the outer barrier. This division of the subtribe supports similar conclusions derived from morphological data.     

A phylogenetic analysis of the palm subtribe Oncospermatinae (Arecaceae) based on morphological characters

Subtribe Oncospermatinae (Arecaceae: Arecoideae: Areceae) is a diverse group of spiny Old World palms. The subtribe includesOncosperma, a widespread Asian genus of five species, along with seven monotypic genera, all endemic to the Seychelles and Mascarene Islands of the western Indian Ocean. A phylogenetic analysis was conducted in order to test the monophyly of subtribe Oncospermatinae with respect to other Old World genera of tribe Areceae. A matrix of 38 morphological characters was scored for 29 taxa, including 11 species of the Oncospermatinae. A single most parsimonious tree was found, resolving the subtribe as a polyphyletic group of two distinct clades. One clade containingAcanthophoenix, Deckenia, Oncosperma, andTectiphiala was placed as sister to a large group that includes members of subtribes Archontophoenicinae, Arecinae, Iguanurinae, and Ptychospermatinae. The other clade of Oncospermatinae, including the Seychelles endemic generaNephrosperma, Phoenicophorium, Roscheria, andVerschaffeltia, was resolved as sister to the Madagascar endemic subtribe Masoalinae, and may have arisen in the western Indian Ocean region.     

A systematic histological study of palm fruits. VIII. Subtribe Dypsidinae (Arecaceae)

Analysis of the pericarp structure in the four genera of the palm subtribe Dypsidinae reveals tissues similar to those in other taxa within the pseudomonomerous Indo-Pacific arecoid palms, but generally in unspecialized configurations consistent with their presumed basal position within this group. Unique tissues within some members of genus Dypsis include thin-walled, tannin-filled fibers around the vascular bundles. Large-fruited members of the presumably related genera Lemurophoenix, Masoala, and Marojejya show more distinctive arrangements of protective tissues and are quite different from one another. Only Marojejya appears to be closely related to Dypsis. Lemurophoenix and Masoala, by possession of both unsheathed vascular bundles and bundles with heavy fibrous sheaths, show possible affinities with genera well-removed from Dypsis.     

A phylogenetic analysis of tribe Areceae (Arecaceae) using two low-copy nuclear genes

 A phylogenetic study of the largest tribe of palms, the Areceae, was conducted using sequences of two low-copy nuclear genes. Previous morphological and plastid DNA studies have not supported the monophyly of the tribe, but have placed its members in a large clade that includes the monophyletic tribes Geonomeae, Cocoeae, Podococceae, and Hyophorbeae. We analyzed this large clade to test the monophyly of tribe Areceae with nuclear data, to explore relationships among its subtribes, and to identify other monophyletic groups. For 54 palm species, including members of all 17 subtribes of tribe Areceae, we sequenced regions of the malate synthase (MS) and phosphoribulokinase (PRK) genes. Simultaneous analysis of these regions revealed 52 shortest trees, all of which resolved tribe Areceae as polyphyletic. Subtribes Iguanurinae, Dypsidinae, Oncospermatinae, and Arecinae were also resolved as polyphyletic. A clade of Indo-Pacific taxa was resolved with strong support, and would be a suitable target for more focused study. Received February 7, 2001; accepted April 9, 2002 Published online: December 3, 2002     

TILOSOMES IN ROOTS OF ORCHIDACEAE: MORPHOLOGY AND SYSTEMATIC OCCURRENCE

Tilosomes, also called “fibrous bodies” or “rod bodies” in older literature, are lignified excrescences from the walls of cells of the innermost velamen cell layer adjacent to thin-walled passage cells of the exodermis in roots of many epiphytic orchids. Seven broad morphological types are recognized: spongy, lamellate, discoid, webbed, meshed, baculate, and plaited. Some types characterize specific genera or subtribes of Orchidaceae. Of the 350 species in 175 genera included in a survey of the family, tilosomes occur in 95 species and 39 genera and are concentrated in tribe Polystachyeae and subtribes Sobraliinae, Coelogyninae, Laeliinae, Pleurothallidinae, Bulbophyllinae, Lycastinae, and Maxillariinae. With the exception of the pantropical genera Bulbophyllum and Polystachya and the Paleotropical subtribe Coelogyninae, tilosomes are almost exclusively Neotropical phenomena.     

Tissue dependent variations of DNA methylation and endoreduplication levels during tomato fruit development and ripening

Tomato fruit cells are characterized by a strong increase in nuclear ploidy during fruit development. Average ploidy levels increased to similar levels (above 50C) in two distinct fruit tissues, pericarp and locular tissue. However, ploidy profiles differed significantly between these two tissues suggesting a tissue-specific control of endoreduplication in tomato fruit. To determine possible relationships between endoreduplication and epigenetic mechanisms, the methylation status of genomic DNA from pericarp and locular tissue of tomato fruit was analysed. Pericarp genomic DNA was characterized by an increase of CG and/or CNG methylation at the 5S and 18S rDNA loci and at gyspsy-like retrotransposon sequences during fruit growth. A sharp decrease of the global DNA methylation level together with a reduction of methylation at the rDNA loci was also observed in pericarp during fruit ripening. Inversely, no major variation of DNA methylation either global or locus-specific, was observed in locular tissue. Thus, tissue-specific variations of DNA methylation are unlikely to be triggered by the induction of endoreduplication in fruit tissues, but may reflect tissue-specific ploidy profiles. Expression analysis of eight putative tomato DNA methyltransferases encoding genes showed that one chromomethylase (CMT) and two rearranged methyltransferases (DRMs) are preferentially expressed in the pericarp during fruit growth and could be involved in the locus-specific increase of methylation observed at this developmental phase in the pericarp.     

The Morphology of Fruits and Starches in Bamboos,and Its Relation to Systematic Position

In this article, 30 speceis of bamboos, including 19 genera in 5 tribes, were collected and the morphology of fruits and starches of them was studied. The results are as follows. I. The morphology of fruits is important in studies of systematic position in bamboos. According to the systems of W. Munro and G. Bentham whether the pericarp is adhesive to or free from the seed coat may be taken as a basis of classification. It is also confirmed in this article. It is found in this work that all taxa with a binding pericarp and seed coat are of caryopsis that also has a ventral suture and hilum, while all others with a separated pericarp and seed coat are of bacca or nut, which has no ventral suture and hilum. The former has a hard and thin pericarp and rich endosperm, while the latter has a fleshy and thick pericarp and no endosperm. These characteristics form a basis of classification of major groups. II. In 1907, Brandis found that no any endosperm in matured fruit of Dinochloa, Melocalamus, Melocanna and Ochlandra. It has been proved by Stapf in at least one genus. We found that the baccae of Qiongzhuea, Melocanna, Ferrocalamus and Chimonobambusa Subg. Oerocalama were empty, with no endosperm. This may be a common character of the bacca. We believe, therefore, that the systematic position of Qiongzhuea, Ferrocalamus and Chimonobambusa Subg. Oreocalama is close to Melocanneae. III. Starch grains of bamboo fruits are complex in structure. They are round or ellipsoidal, consisting of 3-22 polyhedral or apple-like small grains. The morphology of starch grains is not so important as fruit in bamboo classification, but some characteristics are of a high value in the identification of genera and species, when they are combined with other features. In Cephalostachyum, the starch grain is very big, with 20-40 μm in diam, and the starch small grain is polyhedral or apple-like with 7.5-22.5 μm in diam, while in Dendrocalamus, the starch grain is small, with 10-28.9 μm in diam. and the starch small grain is only polyhedral, with 3-11.9 μm in diam. The morphology and size of the starch grain and starch small grain are also different in Melocanna and Chimonobambusa Subg. Oreocalama. IV. W. Munro’s system divided Bambuseae into three major groups according to the morphology of flower and fruit. Because the material was not sufficient at that time, the system wrongly put Cephalostachyum, Dendrocalamus into the group Bacciferea. Now it is found that both Cephalostachyum and Dendrocalamus have a nut. Later G. Bentham found this problem and divided the Bambuseae into four subtribes, treating Dendrocalamus as a separate subtribe, Dendrocalamae, and putting the bacca group into another subtribe, Melocannae. It is better, but it also has some shortcomings. Hackel, Gamble, E. G. Camus, A. Camus and Keng Pojie all accepted the view of Bentham, placing Dendrocalamus and Melocanna into different subtribes or tribes.     

Pericarp structure and phylogeny within Lamiaceae subfamily Nepetoideae tribe Ocimeae

The pericarp structure has been investigated in about 205 species, representing 43 out of the about 50 genera of Lamiaceae subfamily Nepetoideae tribe Ocimeae (Ocimoideae). In its basic structure, the pericarp of Ocimeae corresponds to that of other Nepetoideae. The exocarp has usually both mucilaginous and non-mucilaginous cells. Below it, there are soft cells (mesocarp), a layer of vertically arranged bone cells and a thin innermost cell layer. The differences discovered in pericarp anatomy essentially agree with the traditional subdivisions of Ocimeae (by e.g. Briquet). The subtribes Hyptidinae and Ociminae and the genus Aeollanthus (in subtribe Plectran-thinae) have, with few exceptions crystals in the bone cells. Unlike other Labiatae, Plectranthinae (except Alvesia, Isodon and Siphocranion ) has a plate-like content in the mucilaginous cell. The systematic position of the latter three genera is discussed. Because of their pericarp anatomy, Hoslundia, Fuerstia, Catoferia, Nosema, Benguellia, Octomeron and Ceratanthus are suggested to belong to Ociminae, and Neohyptis to Plectranthinae. On the basis of pericarp characters an informal division of Ociminae is suggested. Considering the distribution of stamen and pericarp characters, the genera Capitanya, Pycnostachys and Solenostemon are suggested to originate from Plectranthus. Ocimeae species which grow in arid habitats tend to produce more mucilage and to have a larger plate-like content in the mucilaginous cells than species from moist or wet habitats.     

Comparative morphology of the foliage leaf epidermis, with emphasis on papillae characters, in key taxa of woody bamboos of the Asian tropics (Poaceae: Bambusoideae)

The foliage leaf epidermis of 35 species representing 12 key genera of woody bamboos of the Asian tropics was investigated using light and scanning electron microscopy. The results indicated that papillae forms and distributional patterns around the stomatal apparatus of the abaxial foliage leaf epidermis were usually constant and were of great taxonomic significance at the specific and generic levels. However, papillae characters were not suitable for dividing subtribes within woody bamboos of the Asian tropics. On the basis of papillae characters, Schizostachyum s.s. and Cephalostachyum were confirmed, but their delimitations should be modified. The transfer of Leptocanna chinensis and Schizostachyum sanguineum into Cephalostachyum was supported, and Cephalostachyum virgatum and C .  pergracile were confirmed to be members of Schizostachyum s.s. The subtribe Racemobambosinae did not obtain support and Racemobambos appeared to be better placed in subtribe Bambusinae. Neomicrocalamus was supported as a close relative and better treated as a synonym of Racemobambos . Gigantochloa was closely related to Dendrocalamus .  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 411–423.     

Pericarp histogenesis and histochemistry during fruit development in Butia capitata (Arecaceae)

Palm fruits show great structural complexity, and in-depth studies of their development are still scarce. This work aimed to define the developmental stages of the fruit of the neotropical palm Butia capitata and to characterize the ontogenesis of its pericarp. Biometric, anatomical, and histochemical evaluations were performed on pistillate flowers and developing fruits. The whole fruit develops in three phases: (I) histogenesis (up to 42 days after anthesis – DAA), when the topographic regions of the pericarp are defined; (II) pyrene maturation (42 to 70 DAA), when the sclerified zone of the pericarp is established; and (III) mesocarp maturation (70 to 84 DAA), when reserve deposition is completed. During pericarp ontogenesis (i) the outer epidermis and the outer mesophyll of the ovary give origin to the exocarp (secretory epidermis, collenchyma, parenchyma, sclerenchyma, and vascular bundles); (ii) the median ovarian mesophyll develops into the mesocarp, with two distinct topographical regions; (iii) the inner ovarian epidermis originates the endocarp; and in the micropylar region, it differentiates into the germination pore plate, a structure that protects the embryo and controls germination. (iv) Most of the inner region of the mesocarp fuses with the endocarp and, both lignified, give rise to the stony pyrene; (v) in the other regions of the mesocarp, carbohydrates and lipids are accumulated in a parenchyma permeated with fiber and vascular bundles. The development of the B. capitata pericarp presents high complexity and a pattern not yet reported for Arecaceae, which supports the adoption of the Butia-type pyrenarium fruit class.

     

Phylogeny of the tribe Fumarieae (Papaveraceae s.l.) based on chloroplast and nuclear DNA sequences: Evolutionary and biogeographic implications

? Premise of the Study: Little research has been done at the molecular level on the tribe Fumarieae (Papaveraceae). Papaveraceae is a model plant group for studying evolutionary patterns despite the lack of a reference phylogeny for this tribe. We investigated the phylogenetic relationships within the tribe to complete the molecular data for this family in order to help understand its character evolution and biogeographic pattern. ? Methods: We used maximum-parsimony and Bayesian approaches to analyze five DNA regions for 25 species representing 10 of the 11 Fumarieae genera and five outgroups. Evolutionary pathways of four characters (habit, life span, type of fruit, and number of seeds per fruit) were inferred on the phylogeny using parsimony. The ancestral distribution areas were reconstructed using dispersal-vicariance analysis. ? Key Results: Fumarieae is monophyletic and includes three groups that agree with the morphology-based subtribes: Discocapninae, Fumariinae, and Sarcocapninae. Within subtribes, the relationships among genera were different from those obtained with morphological data. Annual life span, nonchasmophytic habit, and a several-seeded capsule were the basal character states for the tribe. The ancestor occupied a continuous area between West Eurasia and Africa. Vicariances explain the divergence between lineages Discocapninae (South Africa) and Fumariinae-Sarcocapninae (Mediterranean), and the disjunction of Fumariinae (Mediterranean-Central Asia). ? Conclusions: Molecular phylogeny confirms the subtribal classification of Fumarieae based on morphology. However it provides different results regarding the relationships among genera within each subtribe, which affects the inference of the evolutionary pathway followed by the four selected characters. The disjunct distribution of the tribe is explained by different vicariance scenarios.     

Diversity of non-glandular trichomes in subtribe Lychnophorinae (Asteraceae: Vernonieae) and taxonomic implications

Vernonieae is one of the major tribes in Asteraceae (subfamily Cichorioideae) with ca. 1,100 species placed into 129 genera. Currently, 21 subtribes are recognized in Vernonieae and one of them is Lychnophorinae, almost entirely endemic to Brazil, containing 11 genera and ca. 100 species. About 42 % of Lychnophorinae genera are monophyletic, reflecting the poorly understood relationships among the members of the group. Trichomes are one of the most useful anatomical characters to be used in angiosperm taxonomy; they are diverse, exist in many taxa and are not difficult to study. This work intends to illustrate non-glandular leaf trichome diversity in Lychnophorinae and discuss this diversity in the light of the subtribe’s taxonomy. Sampled material included 67 species of 11 genera. Macerations and free hand sections were performed to be analyzed in the light microscope and photographed. A phenogram was generated using a matrix with 67 terminals (species) and 18 characters coded as binary. The subtribe Lychnophorinae displays a great diversity of non-glandular trichomes (5 types and 18 subtypes). The present study reveals the great diversity of non-glandular trichomes in Lychnophorinae. While trichome complement is of little use to distinguish genera, it appears to be a valuable characteristic at a lower taxonomic level to identify closely morphologically related species.     

内源脱落酸和赤霉素对番茄发育果实和种子水分关系的影响

利用热偶湿度计（ｔｈｅｒｍｏｃｏｕｐｌｅｐｓｙｃｈｒｏｍｅｔｅｒ）研究了野生型、ＧＡ－缺陷型和ＡＢＡ－缺陷型番茄发育过程中果实种子的水分关系,发现除ＡＢＡ－缺陷型种子胶囊和果肉水势变化特殊外,３种类型果实水分状况变化基本一致;在整个发育时期内．前期种子胶囊和果肉水分流向种子,中期种子水分流向种子胶囊和果肉,后期种子和果实间的水势达到平衡。鉴于种胚脱水是一种主动过程,种胚水势一直低于整个种子、种子胶囊和果肉。内源赤霉素可明显增加果实和种子的重量,但对增加种胚溶质的作用不大。由于内源脱落酸可以促使果实成熟和衰老,促进果实细胞解体,大大降低种子胶囊和果肉水势,因而抑制成熟种子在果实内萌发。     

Pericarp development and fruit structure in borassoid palms (Arecaceae-Coryphoideae-Borasseae)

Background and Aims

The Borasseae form a highly supported monophyletic clade in the Arecaceae–Coryphoideae. The fruits of Coryphoideae are small, drupaceous with specialized anatomical structure of the pericarp and berries. The large fruits of borassoid palms contain massive pyrenes, which develop from the middle zone of the mesocarp. The pericarp structure and mode of its development in Borasseae are similar to those of Eugeissona and Nypa. A developmental carpological study of borassoid palms will allow us to describe the process of pericarp development and reveal the diagnostic fruit features of borassoid palms, determine the morphogenetic fruit type in Borasseae genera, and describe similarities in fruit structure and pericarp development with other groups of palms.

Methods

The pericarp anatomy was studied during development with light microscopy based on the anatomical sections of fruits of all eight Borasseae genera.

Key Results

The following general features of pericarp structure in Borasseae were revealed: (1) differentiation of the pericarp starts at early developmental stages; (2) the exocarp is represented by a specialized epidermis; (3) the mesocarp is extremely multilayered and is differentiated into several topographical zones – a peripheral parenchymatous zone(s) with scattered sclerenchymatous elements and vascular bundles, a middle zone (the stony pyrene comprising networks of elongated sclereids and vascular bundles) and an inner parenchymatous zone(s); (4) differentiation and growth of the pyrene tissue starts at early developmental stages and ends long before maturation of the seed; (5) the inner parenchymatous zone(s) of the mesocarp is dramatically compressed by the mature seed; (6) the endocarp (unspecialized epidermis) is not involved in pyrene formation; and (7) the spermoderm is multilayered in Hyphaeninae and obliterated in Lataniinae.

Conclusions

The fruits of Borasseae are pyrenaria of Latania-type. This type of pericarp differentiation is also found only in Eugeissona and Nypa. The fruits of other Coryphoideae dramatically differ from Borasseae by the pericarp anatomical structure and the mode of its development.     

Evolutionary relationships in the showy mistletoe family (Loranthaceae)

Loranthaceae (73 genera and ca. 900 species) comprise mostly aerial hemiparasitic plants. Three monotypic genera considered relicts are root parasites. The family is diverse in tropical areas, but representatives are also found in temperate habitats. Previous classifications were based on floral and inflorescence morphology, karyological information, and biogeography. The family has been divided into three tribes: Nuytsiae, Elytrantheae (subtribes Elytranthinae and Gaiadendrinae), and Lorantheae (subtribes Loranthinae and Psittacanthinae). Nuytsiae and Elytrantheae are characterized by a base chromosome number of x = 12, whereas subtribes Loranthinae (x = 9) and Psittacanthinae (x = 8) numbers are derived via aneuploid reduction. To elucidate the phylogeny of the family, we analyzed sequences from five genes (nuclear small and large subunit rDNA and the chloroplast genes rbcL, matK, and trnL-F) representing most genera using parsimony, likelihood, and Bayesian inference. The three root parasites, Nuytsia, Atkinsonia, and Gaiadendron, are supported as successive sister taxa to the remaining genera, resulting in a monophyletic group of aerial parasites. Three major clades are resolved each corresponding to a subtribe. However, two South American genera (Tristerix and Notanthera) and the New Zealand genus Tupeia, which were previously classified in subtribe Elytranthinae, are weakly supported as part of a clade representing the South American subtribe Psittacanthinae.     

Pericarp structure and phylogeny of tribe Mentheae (Lamiaceae)

Pericarp structure is investigated in 143 specimens belonging to 59 out of ca. 65 genera and 134 out of ca. 2,000 species of Lamiaceae subfamily Nepetoideae tribe Mentheae. Some of the data presented by earlier authors are believed to be incorrect. The variation in pericarp structure has been found to be strongly correlated to the variations in DNA and gross morphological characters. The groups of two-staminate genera (Salvia, etc.) and four-staminate genera of Salviinae (Lepechinia and Chaunostoma) can be distinguished from each other and from other labiates by differences in pericarp structure. The other two subtribes, Menthinae and Nepetinae, differ considerably, but their variations strongly overlap. The differences in pericarp structure also suggest that Menthinae can be divided into three main monophyletic groups based on other data: (1) the main bulk of the tribe, (2) a group of Prunella and Cleonia and perhaps also Horminum, and (3) the characteristic genus Lycopus. Pericarp data disagree with a suggestion that the genus Melissa should be included in the subtribe Salviinae. Modifications of the subtribal classification of Mentheae are discussed.