Search

The fern genus Microlepia is a natural fern group, while large morphological differences of this genus lead to some classification controversies. The leaf epidermal micromorphology of 18 species( include 3 varieties )of Microlepia was observed and compared under light microscope( LM )and scanning electron microscope( SEM ). Hairs were on the veins of the upper and lower epidermis. The form of epidermal cells was irregular, with the anticlinal walls sinuous or sinuate. The stomatal apparatus of all species were restricted to abaxial epidermises and generally could be described as polocytic and axillocytic type, and copolocytic, coaxillocytic, aisocytic and anomotetracytic type only appears in a few species. The similarity of the micromorphological characteristics of leaf epidermis support that the genus Microlepia is a monophyletic group in Dentaedtiaceae. The hairs characteristics between veins of the leaves support that M. calvescens, M. marginata var. villosa and M. marginata var. bipinnata should be treated as a variety of M. marginata. Under SEM, the cuticle of the upper epidermis was mostly ridged, and most of them had filiform ornamentation. The characteristics of leaf cuticle ornamentation were correlated with pinnate compound leaves. The inner margin of the outer stomatal rim was often smooth, sinuous or odontoid. “T” sharp, upright outer stomatal rims occurred in most species, and outer stomatal ledge was mostly depressed. The differences among the leaf micromorphology of these species were shown, which provides references for the classification, evolution and system location of Microlepia. [ABSTRACT FROM AUTHOR]

Species of sect. Chrysantha have high ornamental value, but their classifications are controversial. In order to study the morphological characteristics and taxonomic significance of pollen in sect. Chrysantha, we observed morphological shape, exine ornamentations and perforation characteristics of 10 species of sect. Chrysantha pollen grains by scanning electron microscope, and the polar axis, equatorial axis and length of germination groove were analyzed by clustered. The results were as follows:(1)The pollen of sect. Chrysantha was medium-sized and most of them were subspherical, only C. indochinensis var. tunghinensis was oblate sphere and C. impressinervis was prolate; The extine ornamentation of pollen could be broadly divided into three types: tuberculate-baculate, ornate and verrucate, and the size and density of surface perforation were obviously different.(2)Cluster analysis showed that the pollen morphology of C. perpetua, C. petelotii var. grandiflora, C. petelotii and C. euphlebia were proximity; C. flavida, C. indochinensis, C. micrantha and C. indochinensis var. tunghinensis had similar characteristics; However, C. pubipetala and C. impressinervis were clearly different from the others. The extine ornamentation and perforation of pollen were different, but it was still necessary to combine the polar axis, equatorial axis and the length of germination groove to clearly distinguish the 10 species of sect. Chrysantha. From the perspective of palynology, the pollen of sect. Chrysantha has the general characteristics of Camellia without specificity, and this group plants may not be an independent group, but the pollen morphology of this group plants has obvious inter-specific differences, which can be used as the basis for taxonomy. The results of this study provide the basis for the taxonomic status among species of sect. Chrysantha. [ABSTRACT FROM AUTHOR]

To study pollen characteristics of triploid Salvia miltiorrhiza(tetraploid S. miltiorrhiza f. alba × diploid S. miltiorrhiza)hybrid, morphological variation of triploid pollen during the triploid process was examined. Triploid and diploid pollen were observed at microscopic and ultra-microscopic level using light and scanning electron microscopes. Pollen size and shape data were analyzed to determine statistical significance. The results were as follows:(1)Compared to typical 6-colpate diploid pollen grains, triploid S. miltiorrhiza are 6- or 8-colpate, with increased number of colpi and heterogenous granules on colpus membranes, and abnormal colpate.(2)Exine sculpturing of triploid pollen was reticulate like the diploid. Both 6- and 8-colpate triploid pollen had no perforation or a few small perforations, whereas diploid pollen had many large polygonal perforations in each lumen.(3)In terms of size, mean of the polar axis(P)and equatorial axis(E)in triploid pollen were significantly smaller than that of diploid pollen. The pollen size of triploid hybrid followed a skewed normal distribution, and the coefficient of variation(CV)in P*E value of triploid was greater than that of diploid and existed extreme values. Comparison data revealed variance in colpi and sculpture between triploid and diploid, however no significant differences in pollen shape is found. Overall, the triploid S. miltiorrhiza pollen has more morphological variations due to genetic effect of both ploidy level and heterozygosity. [ABSTRACT FROM AUTHOR]

In order to explore the difference and taxonomic significance through the characteristics of the lenticel, stomatal apparatus and lower epidermis of leaf of different kiwifruit species, the optical microscope was used to observe kiwifruit lenticels on one-year-old phloem of nine samples from five different species. Kiwifruit lenticels showed long elliptical or spindle shape. The values of length × width, lenticle density, lenticle area and percentage of lenticle area of different species were different and no obvious rule with species division. However, the four Actinidia chinensis varieties from selected samples could be clearly distinguished by the width of the lenticels. The results of scanning electron microscope showed that the stomatal apparatus only existed in blade back and mesophyll area with wide oval and elliptical shape, and the stomatal apparatus types were actinotytic, cyclocytic, anisocytic and anomocytic. Among these species, the stomatal apparatus shape of A. chinensis was actinotytic, the stomatal apparatus shape of A. deliciosa was cyclocytic, the stomatal apparatuses shapes of A. latifolia and A. eriantha were anisocytic, and the stomatal apparatus shape of A. longicarpa was anomocytic. Guard cells were arranged around stomatal apparatus, horizontal or protruding from the lower epidermis. The lower epidermal cells were papillose or anomocytic with sinuate or sinuolate anticlinal wall. The lower epidermis was granulated with furcal pubescence and bifurcate single cell without glandular trichome. Some germplasm had papillose or flake-like waxy layer. Inner margin of outer stomatal rim were sinuolate with ornamentation. According to the measure of length × width, axis and density of stomatal apparatus, there was no obvious rule with kiwifruit species division. However, the stomatal apparatus type and the species division were consistent well. Four A. chinensis varieties could be distinguished by the length, axis of stomatal and density of stomatal apparatus. In addition, there were significant differences in the microapparent morphology between A. longicarpa and other species, which provides microcosmic basis for its identification [ABSTRACT FROM AUTHOR]

The evolution of different kinds of vessel molecules is always related to plant evolution. Ranunculaceae(Ranunculales)is a key family which links the basal angiosperm and the core-eudicots in the angiosperm phylogeny group system. Studies on the vessel perforation plates of this important family have great systematic significance, but few studies have been addressed till now. Here, the vessel elements and their perforation plates in the secondary xylem of Ranunculeae, including seven genera and eight species, were observed with the scanning electron microscope and the semithin section, in order to know the relationship betweenthe vessel with their environments in different species in Ranunculaceae of Ranunculeae. The results were as follows: Simple perforation plates were found in seven species, except for the Batrachium bungei; Scalariform perforation plates were found in four species, i.e. Callianthemum taipaicum, Adonis sutchuenensis, Ranunculus sceleratus and Halerpestes cymbalaria, but not for Ranunculus chinensis, Oxygraphis glacialis and Ceratocephalus orthoceras; Perforation plates of vessel elements of Adonis sutchuenensis were diverse, including simple perforation plate, scalariform perforation plate, reticulate perforation plate, gnetum type perforation plate, and scalariform-reticulate perforation plate; Simple perforation plate, scalariform perforation plate, and reticulate perforation plate were found in Halerpestes cymbalaria. In this study, we did not found vessel elements by dissociation the root and stem of Batrachium bungei. On the contrary, we found that there were annular vessels by semithin section. We also found that the side walls, and the pit membranes were unbroken or residual. The length diversities of those vessel elements of Ranunculeae were very high. There were significant differences in the average length of vessel elements in different species of Ranunculeae. At the same time, the differences were conspicious among different types of vessel elements even in the same species. We also discussed the adaptive significance of different types of vessel elements and the systematic position of Ranunculeae in the family Ranuculaceae. The results indicate that micro-structures of the vessel elements are also adapted to their growing environments. The vessel elements of Callianthemum taipaicum, Adonis sutchuenensis and Oxygraphis glacialis were related to their cold environments and those of Ceratocephalus orthoceras and Batrachium bungei were related to xerophytic and aquatic environment, respectively [ABSTRACT FROM AUTHOR]

In order to study the morphological diversity of Hibiscus syriacus cultivars and their relationships, we observed morphological characteristics and exine sculpture of 22 H. syriacus pollen grains by scanning electron microscope, and used R-type cluster analysis and principal component analysis to extract appropriate indicators for UPGMA cluster analysis. The results were as follows:(1)The pollen of H. syriacus was single-spherical, nearly spherical with diameter of 148.98-111.65 μm with thorn-like ornamentation on the surface with length of 27.42-14.79 μm; The tip of the thorn was sharp, and the thorns distributed around scattered pores; The pollen surface was distributed with granular protrusions and the apertures were irregular.(2)UPGMA cluster analysis was performed after extracting principal components of the measured indicators. When the Euclidean mean distance threshold was 6, 22 H. syriacus cultivars were divided into six categories. The single-petal blue-violet cultivars 'Bluebird', 'Dan Ban Zi Fen' and 'Xi Ye' had close relationships, and semidouble cultivars 'Lavender Chiffon' and 'China Chiffon', 'Pink Chiffon' had close relationships, while white single-petal 'Wood Bridge' and 'Hamabo' were relatively close. It was believed that the single-petal blue-violet cultivars in H. syriacus were more primitive than the pink and white semidouble cultivars, while purple semidouble cultivars were more evolved and the white single-petal cultivars were highly evolved. The results of this study provide theoretical basis for genetic evolution, taxonomic status, and genetic relationship studies in H. syriacus. [ABSTRACT FROM AUTHOR]

In order to reveal the developmental process of the deuterogenic placenta of Adinandra latifolia from the family Pentaphylacaceae, and the relationship between deuterogenic placenta, carpellary placenta and free central placenta, the flower buds and mature fruits of A. latifolia were observed in detail by scanning electron microscope(SEM)and stereoscopic microscope. Floral buds at different stages of development were collected and fixed in formalin-aceticacid-alcohol, and then dehydrated through an ethanol/amylacetate series, critical point dried with CO2, Au/Pt sputter coated, prepared samples were examined with SEM. Mature fruits were dissected under a stereoscopic microscope directly without preparation. The results showed that during the floral development, 5 carpel primordia were growth rapidly after the stamens initiation, and then ovary was combined with the axial placenta on the upper part and cavity on the bottom part. After the placenta grew on the carpels(named carpellary placenta), several mounds appear at the top of the receptacle within the position opposite to the carpel in the lower cavity. The mounds combined gradually into a hemispherical deuterogenic placentation. And some fertile ovules appeared on the surface of both the carpellary placenta and deuterogenic placenta. Finally, in mature fruits the fertile ovules turn to seeds on both types of placenta in which vascular bundles are discrete. Therefore, deuterogenic placenta appeared independently and was later than the carpellary placenta. The development of deuterogenic placenta in A. latifolia was different from that of the free central placenta in both Caryophyllaceae and Phytolaccaceae(the axial placenta turned into a free central placenta by the septa disappear), but it is basically identical to that of Primulaceae, Theophrastaceae, Maesaceae, Myrsinaceae from Ericales(the free central placenta formed on top of the receptacle directly). [ABSTRACT FROM AUTHOR]

In order to study taxonomic value and systematic significance of Hydrangea L. as well as clarify phylogenetic relationships among the genus and its related ones, pollen samplings of 41 species of Hydrangea and its related species from China and surrounding areas were observed under scanning electron microscope(SEM). The results were as follows: the pollens of all these species were tricolporate; the pollen morphology were most subprolate and a few subspheroida; ellipse or circular in equatorial view; circular or sometimes triangular in polar view. The ornamentations on the exine can be reticulate ornamentations or perforate ornamentations. The ornamentation in the mesh could be smooth or granular bulged. The above-mentioned species could be divided into four groups according to the pollen morphology and ornamentations on the exine, the characters of each group were respectively pollen morphology subprolate, ornamentation on the exine reticulate; pollen morphology subprolate, ornamentation on the exine perforate; pollen morphology subspheroida, ornamentation on the exine reticulate; pollen morphology subspheroida, ornamentation on the exine perforate. according to the ratio of polar axis to equatorial axis, these species can be further divided into eight types. These indicate that the pollen characters can provide valuable evidence for infrageneric taxonomic treatments and species circumscription. However, this evidence shows limited value in diagnosing some major clades of phylogenetic trees reconstructed in previous studies. Further studies including broader sampling and new evidence of Hydrangea pollen are needed to explore its taxonomic and systematic values. [ABSTRACT FROM AUTHOR]