A new species,new combinations,and a new name in Acanthaceae from northern South America

A new species of Acanthaceae (Ruellia saülensis) is described and illustrated from French Guiana, and three new combinations (Justicia potarensis, J. flaviflora, andJ. tobagensis) and one new name (Justicia coppenamensis) are proposed. The new species is compared to its closest relative (Ruellia rubra), and a justification of the transfers is provided.     

Seed morphology and endosperm structure of selected species of Primulaceae, Myrsinaceae, and Theophrastaceae and their systematic importance

Seed size and shape, seed coat surface pattern, seed coat thickness, and endosperm structure were investigated in Androsace septentrionalis, Cortusa matthioli, Hottonia palustris, Primula elatior, Soldanella carpatica (Primulaceae), Anagallis arvensis, A. minima, Cyclamen purpurascens, Glaux maritima, Lysimachia nemorum, L. vulgaris, Trientalis europaea (Myrsinaceae), and Samolus valerandi (Theophrastaceae). Three seed size categories were distinguished on the basis of biometric measurements. Almost all seeds examined were found to be small with an angular shape classified as sectoroid or polyhedral. A new type of seed shape, suboval, was identified for H. palustris. Cyclamen purpurascens seeds differed from seeds of all other species examined because of their large size, subglobose shape, and concave hilar area. Despite the different shape types, the length/width ratio of the seeds examined was constant, while their hilum length/width ratio was a highly variable feature. Three types of seed surface patterns were observed: (1) reticulate, (2) tuberculate with secondary striations, and (3) poroid-alveolate with the presence of a spongy outer layer. For seeds of Anagallis arvensis, A. minima, Cortusa matthioli, Lysimachia nemorum, and Soldanella carpatica, secondary seed sculpture was described. The seed coats of all species examined were two-layered, and great differences in testa thickness were found (9.9?C128.6???m). In general, seeds of the Myrsinaceae species were more often characterized by thick testa. Different proportions in thickness of the inner and outer testa layers were observed. In seeds with reticulate seed patterns, the inner testa layer was twice to several times thicker than the outer layer, while the opposite proportions were observed in seeds with the tuberculate or poroid-alveolate seed sculpture pattern. In seeds of all species examined, oxalate crystals were present on the surface of the inner testa layer. Thus, the presence or absence of oxalate crystals in testa is not a feature distinguishing species with angular or subglobose seeds. Four types of endosperm structure were identified according to the thickness of the endosperm cell walls and the relief of their inner surface: (1) with evenly thickened and smooth cell walls, (2) with evenly thickened cell walls and circular or helical thickenings on their inside surfaces, (3) with very thick, but not evenly thickened cell walls with constrictions (??pitted??), and (4) with very thin papery and undulate cell walls. There is no rule concerning the seed shape, type of the seed sculpture, testa thickness, or endosperm structure that corresponds to the family affiliation of the species examined.     

Phylogenetic relationships among Acanthaceae: evidence from noncoding trnL-trnF chloroplast DNA sequences

We used sequence data from the intron and spacer of the trnL-trnF chloroplast region to study phylogenetic relationships among Acanthaceae. This region is more variable than other chloroplast loci that have been sequenced for members of Acanthaceae (rbcL and ndhF), is more prone to length mutations, and is less homoplasious than these genes. Our results indicate that this region is likely to be useful in addressing phylogenetic questions among but not within genera in these and related plants. In terms of phylogenetic relationships, Elytraria (representing Nelsonioideae) is more distantly related to Acanthaceae sensu stricto (s.s.) than Thunbergia and Mendoncia. These last two genera are strongly supported as sister taxa. Molecular evidence does not support monophyly of Acanthaceae s.s., although there is strong morphological evidence for this relationship. There is strong support for monophyly of four major lineages within Acanthaceae s.s.: the Acanthus, Barleria, Ruellia, and Justicia lineages as here defined. The last three of these comprise a strongly supported monophyletic group, and there is weaker evidence linking the Ruellia and Justicia lineages as closest relatives. Within the Acanthus lineage, our results confirm the existence of monophyletic lineages representing Aphelandreae and Acantheae. Lastly, within the Justicia lineage, we develop initial hypotheses regarding the definition of sublineages; some of these correspond to earlier ideas, whereas others do not. All of these hypotheses need to be tested against more data.     

Justicia tetrasperma sp. nov.–a linking species between Justicia and Monechma (Acanthaceae)

Justicia tetrasperma , a new species of Justicia sect. Monechma , is described on material from Shaba in Zaire. Its capsules with four smooth and compressed seeds is a character combination in favour of an inclusion of Monechma in Justicia .     

The seeds of Loasaceae subfam. Loasoideae (Cornales) II: Seed morphology of “South Andean Loasas” (Loasa, Caiophora, Scyphanthus and Blumenbachia)

South Andean Loasas (Blumenbachia, Caiophora, Loasa, Scyphanthus) are a monophyletic group of taxa within Loasaceae subfam. Loasoideae, comprising some 100 species, 49 of which are investigated here. They retain a many-layered testa in the mature seeds and usually have passive transfer testas with complex, spongiose wall outgrowths. Additional modifications concern the undulations of the testa epidermis, presence or absence of the outer periclinal wall, secondary sculpturing, the presence or absence of spines, warts and finally spongiose structures on the anticlinal walls of the testa epidermis and the inner periclinal wall. Seeds of the widespread “deeply pitted” type are plesiomorphic, while various subclades of South Andean Loasas have derivations underscoring their relationships and confirming the relationships found with molecular markers and other morphological characters. The genus Blumenbachia has either seeds with a many-layered testa forming longitudinal lamellae (sect. Angulatae), or balloon seeds with a loose outer testa layer and spongiose wall outgrowths on the inner periclinal walls (sect. Blumenbachia and sect. Gripidea) and is clearly monophyletic. Loasa s.str. (ser. Loasa, ser. Macrospermae, ser. Floribundae, ser. Deserticolae) is characterized by the presence of a subterminal hilum or hilar scar and one subgroup (ser. Loasa, ser. Macrospermae) by very large and heavy seeds with a collapsed testa. L. ser. Pinnatae, ser. Acaules, ser. Volubiles, Scyphanthus and Caiophora share more or less one seed types with minor modifications. Within Caiophora various derivations are observed, of which the gradual loss of the secondary sculpture of the inner periclinal wall is the most striking one. Anemochoria is the most widespread dispersal mechanism in South Andean Loasas and is achieved in at least five structurally different ways.     

MORPHOMETRY OF ORCHID SEEDS. III. NATIVE CALIFORNIA AND RELATED SPECIES OF GOODYERA,PIPERIA, PLATANTHERA AND SPIRANTHES

Morphometric analysis of orchid seeds indicates that testa and embryo dimensions, color and morphology as well as the presence, absence or nature of reticulation on seed coat walls are of diagnostic value. These studies also point to structure and function correlations in orchid seeds.     

Seed coat structure and development in Solanum L. section Solanum (Solanaceae)

Seed coat structure in Solanum L. section Solanum (Solanaceae). Seed coat structure in Solanum L. section Solanum was examined using SEM. The seed coat patterns observed were fairly uniform throughout the section, and thus of little diagnostic use. Moreover, all species are characterized by their seeds being covered by hairlike structures, which are bands of lignified thickening in the lateral (and basal) walls of the outer epidermal cells of the testa, and which only become obvious when the seeds are wetted. The development of the seed coat and its characteristic thickening was followed from the unfertilized ovule to the mature seed in vouchered material of Solanum nigrum L. since this species is the generic type, using sections of freshly fixed material.     

Seed morphology of Rotala L., Ammannia L., Nesaea Kunth and Hionanthera Fernandes & Diniz (Lythraceae)

PANIGRAHI, S. G., 1986. Seed morphology of Rotala L., Ammannia L., Nesaea Kunth and Hionanthera Fernandes & Diniz (Lythraceae) . Seed-surface characteristics of Ammonia lalifolia L., Rotala verticillaris L., Nesaea triflora Comm. ex Kunth and Hionanthera garciae Fernandes & Dinz were studied using the SEM. Seeds from herbarium specimens moistened in water produce cracks along the intercellular walls and distinctive types of invaginating 'hairs'. These 'hairs' are mucilaginous in nature and diagnostic at the species level. They are released in profusion from the upper convex surface of the testa. Viable seeds of Ammonia baccifera L., similarly treated, exude, in addition to the 'hairs', mucilaginous globules from the lower concave surface during germination. The invaginating 'hairs' arise diagonally from the roof of the epidermal cells of the testa and protrude to the lumen of the epidermal cells. A sac of mucilage is observed swelling out on the inner flat surface of the developing seeds. The biological functions of these 'hairs' and mucilage globules in germinating seeds in relation to seed dispersal and regulation of germination in appropriate habitats is discussed.     

Seed micro‐morphology and its systematic significance in Gypsophila (Caryophyllaceae) and allied genera

In order to examine the systematic application of seed‐coat micro‐morphology in Gypsophila and allied genera, seed surfaces of 30 species and two varieties representing four genera of tribe Caryophylleae were examined with scanning electron microscope. The seeds of examined species range between 0.5–2.1 mm in length and 0.3–2.4 mm in diameter. The exomorphology of the seed coat shows two distinctive cell patterns. The epidermis is constructed either of elongated polygonal or of broad polygonal cells. The elongated type is the most common among the studied species, but the variation in alignment of testa cells, their size and shape as well as the density of protuberances may provide further information and useful diagnostic characters at generic and specific rank. The testa cells in Gypsophila and Saponaria are shallowly undulate, deeply undulate, lobed and armed at anticlinal walls. Deeply undulate anticlinal walls were observed in both Gypsophila and Ankyropetalum and a few species of Saponaria. Non‐ or indistinctly grooved anticlinal walls is the more common type in Allochrusa. Seed‐coat characters support the separation of Gypsophila and Saponaria to some extent but disagree with recognition of Ankyropetalum as a genus separate from Gypsophila.     

Taxonomic notes on Mexican Ruellia (Acanthaceae)

The new nameRuellia comonduensis is provided for the species previously known asR. cordata Brandegee.Ruellia chilpancingana, a new species known only from Guerrero in southwestern Mexico, is described and compared to morphologically similar species. It is unique among Mexican species ofRuellia based on the following combination of characters: caducous bracteoles and secondary bracteoles, multiflowered dichasia from leaf axils, yellowish and cylindric-funnelform corollas, exserted stamens, and few (four or fewer) seeds per capsule. Macromorphological features and pollen ofR. chilpancingana are illustrated.     

国产打碗花属植物种子形态及其分类学意义

本文借助于又目解剖镜和扫描电电镜对我国打碗花属５种植物的种子进行了观察。结果表明：１、该属植物的种子可分为两类,一类为旋花型,较小,表面具疣状突起,种皮纹饰呈网状,包括打碗花、毛打碗花及旋花;另一类为藤水苗型较大,无疣状突起,种皮纹饰呈咀烂状,包括藤长苗和肾叶打碗花。２、疠状突起由数个相邻种皮细胞胞间壁强烈突出而成,呈山峰状,相连或单独存在。３、该属植物种子形态存在明显区别,可作为分种的依据。     

Correlated evolution of diaspore traits and potential frugivore-mediated selection in a fleshy-fruited tropical lineage (Artabotrys,Annonaceae)

Dispersal syndromes are often defined by reference to fruit traits that are associated with distinct frugivore guilds. Studies rarely examine the relationship between seed traits and frugivores or test the alternative hypothesis that traits are shaped by climatic variables. We assess whether the evolution of seed size and physical defense are correlated with dispersal-related traits and climatic variables in Artabotrys, a fleshy-fruited tropical lineage. Diaspore traits and WorldClim bioclimatic variables were compiled for 43 species. Correlated evolution was evaluated using phylogenetic regression and model-fitting approaches. The best-fitting multioptima Ornstein-Uhlenbeck model suggests that lineages with smooth testa and thin pericarp (SP) have evolved toward smaller seeds with a thinner testa, whereas lineages with rough testa and/or thick pericarp have evolved toward larger seeds with a thicker testa. A smooth testa facilitates spitting and/or swallowing of intact seeds while fruits with thin pericarp may be preferentially consumed by frugivores with less destructive oral processing, enabling lower investment in seed physical defense in SP lineages. Moreover, small seeds are more likely to be swallowed intact with a food bolus. The effect of climate on seed size and physical defense is equivocal and warrants further investigation.     

<Emphasis Type="Italic">Pityopus californicus</Emphasis>: structural characteristics of seed and seedling development in a myco-heterotrophic species

Pityopus californicus (Eastw.) H. F. Copel., a monotypic member of the Monotropoideae in the family Ericaceae, is a myco-heterotrophic species with distribution limited to the Pacific Northwest of the USA. Young embryos of P. californicus developed mycorrhizal associations in seed packets that had been buried for up to 681 days, suggesting that seeds of P. californicus may require the presence of a fungus to achieve germination. Samples of nongerminated seeds and early stages in embryo and root development were subsequently processed for light microscopy, histochemistry, and transmission electron microscopy (TEM). Nongerminated seeds possessed a thick testa, lacked a shoot and root meristem, and consisted of an embryo with large parenchymatous cells containing protein bodies and starch grains as storage reserves. In the earliest developmental stage (seed coat still attached), fungal hyphae were present on the testa surface and between the testa and embryo. This stage was followed by embryo elongation, the organization of a root apical meristem, and the development of a well-developed fungal mantle surrounding the elongated embryo. At least two morphotypes were identified based on structural characteristics of the mantle. One of these, with ascomycetous septa, had Cenococcum-like features. Late-stage embryo/early root development revealed a typical mantle and Hartig net, with fungal pegs penetrating the outer tangential walls of epidermal cells. Transfer cell-like deposits of wall material, similar to those described in Monotropa spp., enclosed fungal pegs. The development of a Hartig net and fungal pegs suggests that nutrient exchange interfaces are required for seedling development.     

Communication between the maternal testa and the embryo and/or endosperm affect testa attributes in tomato

Two tomato (Lycopersicon esculentum) mutants with dark testae displaying poor germination rate and percentage on both water and 100 microM gibberellin(4 + 7) were recovered. The mutants were allelic (black seed1-1; bks1-1 and bks1-2), inherited in Mendelian fashion as a recessive gene residing on chromosome 11. They are not allelic to bs (brown seed) -1, -2, or -4, which impair seed germination and possess dark testae. The bks/bs mutants accumulated dark pigment in the cell layers of the testa above the endothelium, which itself accumulated proanthocyanidins similar to wild type. The poor germination performance of bks mutant seeds was because of impediment of the mutant testae to radicle egress. Imbibition on gibberellin(4 + 7) did not ameliorate germination percentage or rate. The toughening of the bks testa and associated poor germination were partially overcome when seeds were not dried before germination or were dried under N(2). The seeds of the bks mutant have elevated activity of at least one enzyme responsible for the detoxification of reactive oxygen species. The bks mutant is epistatic to 12 anthocyaninless mutants of tomato. Bio- and physicochemical analysis of the bks testa determined that it accumulated a melanic substance. Inheritance of bks/bs mutations contrasts with that of the anthocyaninless mutants, which are inherited according to the genotype of the maternally derived testa. This suggests that the testa manufactures components before its demise that can maximize testa strength, whereas the endosperm/embryo produces factors that are conveyed to the testa, mitigating this process.     

Seed micromorphology in the genus Neotinea Rchb.f. (Orchidaceae, Orchidinae)

The ultrastructure of testa seed in the genus Neotinea (Orchidaceae, Orchidinae) was examined for the first time. The morphology of the seed and of the anticlinal and periclinal walls was analysed by scanning electron microscopy. Quantitative data concerning the length and width of the seed and embryo, seed and embryo volume, free air space, and number of cells along the longitudinal axis are presented. In all species, the seeds are fusiform in shape with transverse ridges on the inner periclinal walls. This ornamentation pattern is characteristic for the genus Neotinea . It is a good diagnostic value supporting the monophyly of this genus, which has recently been proposed by several authors.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 133–140.     

Ornamentation of the testa inSedum (Crassulaceae)

A SEM investigation of the seeds of 40 European and 5 Asiatic species ofSedum revealed three fundamentally different types of ornamentation of the testa. The most prominent difference in the ontogeny of the seeds differing in ornamentation is the ovular envelope, which is a mucous membrane enclosing the ovules and young seeds and occurring only in plants whose seeds have a simple type of ornamentation. The ornamentation of the testa was found to be a very constant character. Because the ornamentation is highly correlated with the hybridization pattern of the species it is considered to be an important character in the infrageneric classification ofSedum.     

Enzyme Treatment as an Aid in the Study of Seed Surface Structures of Solanum Species

Enzyme treatment of seeds before scanning electron microscopyrevealed interesting surface features which are valuable taxonomiccharacters. The seed surface of Solanum aethiopicum (scarleteggplant) was similar to that of its wild progenitor, S. anguivi(= S. indicum pp.). Solanum violaceum (= S. indicum pp.) fromIndia was distinct. These results confirm previous taxonomicstudies based on hybridization and seed protein electrophoresis. Solanaceae, Solanum aethiopicum, Solanum indicum, eggplant, taxonomy, scanning electron microscopy/SEM, seed, testa, microstructure     

新疆干旱区植物藜的种子异型性及其萌发机理

新疆干旱区分布的植物藜(Chenopodium album)的种子有黑色和褐色两种类型。对藜的异型性种子从形态结构、不同环境因素及激素或化学物质对萌发的影响以及同工酶谱等方面进行了研究,并对其萌发及适应异质环境的机理进行了讨论。结果表明:(1)藜的异型性种子在形态结构、萌发休眠特性等方面都存在明显差异:黑色种子种皮厚且硬,休眠,萌发慢,萌发率低;褐色种子种皮薄而软,不休眠,萌发快且萌发率高;(2)黑色种子的休眠可通过切除胚根外缘种皮得以完全解除;(3)赤霉素、乙烯利对黑色种子的萌发无明显促进作用;KNO3可较显著促进黑色种子的萌发;协同使用乙烯利和KNO3时,可显著提高黑种子萌发率,完全打破休眠;(4)黑色种子和褐色种子的酯酶、过氧化物酶及过氧化氢酶同工酶谱带存在差异;(5)黑色种子的萌发需要光照,而褐色种子则对光不敏感;低温贮藏对二者的萌发均无显著影响,尽管黑色种子的萌发率有波动。研究结果初步显示黑色种子的休眠是内源(胚)和外源(种皮)因素共同所致。藜的种子异型性及其萌发机理的形成是其对新疆干旱区异质化环境的高度适应。     

Regulation of pectic polysaccharide domains in relation to cell development and cell properties in the pea testa

The occurrence of pectic polysaccharide epitopes in cells and tissues of the pea testa during late stages of seed development have been examined in relation to anatomy and cell properties. Homogalacturonan, in a highly methyl-esterified form, was present throughout late development in all pea testa cell walls, including the thickened cell walls of the outer macrosclereid layer. Two epitopes, characteristic of the side-chains of the rhamnogalacturonan-I domain of pectic polysaccharides, occurred in restricted and separate cell layers of the pea testa. A (1-->4)-beta-D-galactan epitope was restricted to regions of the outer cell wall of the testa and to inner regions of the macrosclereid layer at 20 DAA and was absent from the osteosclereid and parenchyma cell walls. By 25 DAA the (1-->4)-beta-D-galactan epitope occurred only in the outer epidermal cell walls. A (1-->5)-alpha-L-arabinan epitope was also dependent on the developmental stage of the seed and was found with greatest abundance in the walls of the inner parenchyma cells. Cell separation studies indicated that, although calcium cross-links were involved in the maintenance of the link between the macrosclereid layer and proximal cell layers, most cell-to-cell adhesion in the testa was not due to calcium- or ester-based bonds.     

Seed after-ripening and over-expression of class I beta-1,3-glucanase confer maternal effects on tobacco testa rupture and dormancy release

'Coat-imposed' seed dormancy of many non-endospermic and endospermic species is released during after-ripening. After-ripening-mediated promotion of tobacco ( Nicotiana tabacum L.) seed germination is mainly due to a promotion of testa rupture and a similar promotion of subsequent endosperm rupture. Treatment of after-ripened or freshly harvested mature seeds with abscisic acid (ABA) delays endosperm rupture and inhibits the induction of class I beta-1,3-glucanase (betaGlu I) in the micropylar endosperm, but does not affect the kinetics of testa rupture. After-ripening-mediated release of photodormancy is correlated with a decreased gibberellin (GA) requirement for testa rupture during dark-imbibition. Reciprocal crosses between wild-type tobacco and sense-betaGlu I transformant lines showed that betaGlu I over-expression in the seed covering layers can replace the promoting effect of after-ripening on testa rupture in light, but only if the mother plant is a sense-betaGlu I line. This maternal effect supports the model of two sites for betaGlu I action: (i) betaGlu I contribution to the after-ripening-mediated release of dormancy in the dry seed state, which is manifested in the promotion and ABA-insensitivity of testa rupture during imbibition. (ii) ABA-sensitive expression of betaGlu I in the micropylar endosperm, which contributes to endosperm rupture. The importance of GA-signaling and testa characteristics appear to be a common feature during the after-ripening-mediated release of coat-imposed dormancy in endospermic and non-endospermic seeds.