http://amborella.net/2010PlantSystematics/DATA/3-24-APG%202003%20Bot%20J%20Linn%20Soc%20APGII.pdf

An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II

Chloroplast DNA sequences are a primary source of data for plant molecular systematic studies. A few key papers have provided the molecular systematics community with universal primer pairs for noncoding regions that have dominated the field, namely trnL-trnF and trnK/matK. These two regions have provided adequate information to resolve species relationships in some taxa, but often provide little resolution at low taxonomic levels. To obtain better phylogenetic resolution, sequence data from these regions are often coupled with other sequence data. Choosing an appropriate cpDNA region for phylogenetic investigation is difficult because of the scarcity of information about the tempo of evolutionary rates among different noncoding cpDNA regions. The focus of this investigation was to determine whether there is any predictable rate heterogeneity among 21 noncoding cpDNA regions identified as phylogenetically useful at low levels. To test for rate heterogeneity among the different cpDNA regions, we used three species from each of 10 groups representing eight major phylogenetic lineages of phanerogams. The results of this study clearly show that a survey using as few as three representative taxa can be predictive of the amount of phylogenetic information offered by a cpDNA region and that rate heterogeneity exists among noncoding cpDNA regions.

The tortoise and the hare II: relative utility of 21 noncoding chloroplast DNA sequences for phylogenetic analysis

INTRODUCTION. Internal Organization of the Plant Body. Summary of Types of Cells and Tissues. General References. DEVELOPMENT OF THE SEED PLANT. The Embryo. From embryo to the Adult Plant. Apical Meristems and Their Derivatives. Differentiation, Specialization, and Morphogenesis. References. THE CELL. Cytoplasm. Nucleus. Plastids. Mitochondria. Microbodies. Vacuoles. Paramural Bodies. Ribosomes. Dictyosomes. Endoplasmic Reticulum. Lipid Globules. Microtubules. Ergastic Substances. References. CELL WALL. Macromolecular Components and Their Organization in the Wall. Cell Wall Layers. Intercellular Spaces. Pits, Primary Pit--Fields, and Plasmodesmata. Origin of Cell Wall During Cell Division. Growth of Cell Wall. References. PARENCHYMA AND COLLENCHYMA. Parenchyma. Collenchyma. References. SCLERENCHYMA. Sclereids. Fibers. Development of Sclereids and Fibers. References. EPIDERMIS. Composition. Developmental Aspects. Cell Wall. Stomata. Trichomes. References. XYLEM: GENERAL STRUCTURE AND CELL TYPES. Gross Structure of Secondary Xylem. Cell Types in the Secondary Xylem. Primary Xylem. Differentiation of Tracheary Elements. References. XYLEM: VARIATION IN WOOD STRUCTURE. Conifer Wood. Dicotyledon Wood. Some Factors in Development of Secondary Xylem. Identification of Wood. References. VASCULAR CAMBIUM. Organization of Cambium. Developmental Changes in the Initial Layer. Patterns and Causal Relations in Cambial Activity. References. PHLOEM. Cell Types. Primary Phloem. Secondary Phloem. References. PERIDERM. Structure of Periderm and Related Tissues. Development of Periderm. Outer Aspect of Bark in Relation to Structure. Lenticels. References. SECRETORY STRUCTURES. External Secretory Structures. Internal Secretory Structures. References. THE ROOT: PRIMARY STATE OF GROWTH. Types of Roots. Primary Structure. Development. References. THE ROOT: SECONDARY STATE OF GROWTH AND ADVENTITIOUS ROOTS. Common Types of Secondary Growth. Variations in Secondary Growths. Physiologic Aspects of Secondary Growth in Roots. Adventitious Roots. References. THE STEM: PRIMARY STATE OF GROWTH. External Morphology. Primary Structure. Development. References. THE STEM: SECONDARY GROWTH AND STRUCTURAL TYPES. Secondary Growth. Types of Stems. References. THE LEAF: BASIC STRUCTURE AND DEVELOPMENT. Morphology. Histology of Angiosperm Leaf. Development. Abscission. References. THE LEAF: VARIATIONS IN STRUCTURE. Leaf Structure and Environment. Dicotyledon Leaves. Monocotyledon Leaves. Gymnosperm Leaves. References. THE FLOWER: STRUCTURE AND DEVELOPMENT. Concept. Structure. Development. References. THE FLOWER: REPRODUCTIVE CYCLE. Microsporogenesis. Pollen. Male Gametophyte. Megasporogenesis. Female Gametophyte. Fertilization. References. THE FRUIT. Concept and Classification. The Fruit Wall. Fruit Types. Fruit Growths. Fruit Abscission. References. THE SEED. Concept and Morphology. Seed Development. Seed Coat. Nutrient Storage Tissues. References. EMBRYO AND SEEDLING. Mature Embryo. Development of Embryo. Classification of Embryos. Seedling. References. Glossary. Index.

Anatomy of Seed Plants

Angiosperm phylogeny inferred from 18S rDNA, rbcL, and atpB sequences

Calcium oxalate (CaOx) crystals are distributed among all taxonomic levels of photosynthetic organisms from small algae to angiosperms and giant gymnosperms. Accumulation of crystals by these organisms can be substantial. Major functions of CaOx crystal formation in plants include high-capacity calcium (Ca) regulation and protection against herbivory. Ultrastructural and developmental analyses have demonstrated that this biomineralization process is not a simple random physical-chemical precipitation of endogenously synthesized oxalic acid and environmentally derived Ca. Instead, crystals are formed in specific shapes and sizes. Genetic regulation of CaOx formation is indicated by constancy of crystal morphology within species, cell specialization, and the remarkable coordination of crystal growth and cell expansion. Using a variety of approaches, researchers have begun to unravel the exquisite control mechanisms exerted by cells specialized for CaOx formation that include the machinery for uptake and accumulation of Ca, oxalic acid biosynthetic pathways, and regulation of crystal growth.

CALCIUM OXALATE IN PLANTS: Formation and Function

Operculina is a pantropical genus of 14 species, perhaps one of the most stable in taxonomic delimitation in Convolvulaceae. Its operculate-capsular fruit is distinctive and unique in the family, and shared by all species it comprises, despite great variation in other macromorphological traits. Recent molecular phylogenetic results have demonstrated Operculina is monophyletic with high support, re-enforcing the generic concept. However, revisionary studies of its taxonomy and morphology are limited, and information about its species is mostly scattered in regional works. Particularly in palynology, there are few studies that have included this genus, and usually only the most common species O. turpethum. Here, we provide an overview of the palynological diversity in 12 Operculina species and discuss the evolution and taxonomic relevance of aperture heteromorphism in this genus.

The systematic value of pollen morphology in Operculina (Convolvulaceae)

We examined pollen of 19 genera of Hemerocallidaceae by using scanning electron microscopy (SEM), and one genus (Dianella) by using transmission electron microscopy (TEM) Pollen was generally small in size, with a rounded triangular outline when hydrated, and a characteristic three-armed aperture, a distal trichotomosulcus The pollen surface was finely sculptured and the exine was thin Microreticulate pollen is a potential synapomorphy for several species of the ‘crown phormioid’ subclade recognised in molecular analyses Perforate and fossulate pollen supports a relationship between several species of Dianella Microrugulate pollen is more frequent in the johnsonioids than in the phormioids Hemerocallis is distinguished by elongated monosulcate pollen, a relatively thick exine with a pronounced reticulate surface, and large globules of attached pollenkitt We hypothesise that Hemerocallidaceae are ancestrally buzz-pollinated, and their pollen morphology is an adaptation to this pollination type A reversal to butterfly or moth pollination occurred in Hemerocallis, with associated changes in pollen morphology

The trichotomosulcate asparagoids: pollen morphology of Hemerocallidaceae in relation to systematics and pollination biology

Dioscorea ridleyi Prain & Burkill and D. palawana Prain & Burkill were previously described from limited material of one sex. Recent collections of plants of the other sex have come to light in both species. These are used to complete morphological descriptions of the two species. Both species appear to be of very restricted distribution. The new data allows reappraisal of the relationships of the two species to each other and with D. sect. Stenophora Uline, in which they were placed by Prain & Burkill. Their unique cerebroid perforate pollen ectexine morphology and several macromorphological characters suggest either that they do not belong in D. sect. Stenophora or that they are a highly specialised group nested within it.

Dioscorea ridleyi and D. palawana: new systematic data on two rare South-East Asian yam species

Regular ArticlesMicrosporogenesis and systematics of Aristolochiaceae

Within monocotyledons, monosulcate pollen is the predominant type and probably represents the plesiomorphic condition, but considerable variation occurs in sulcus morphology. An operculum is an exine thickening that covers most of an aperture. Monocot opercula are usually associated with sulci, although they can occur in ulcerate apertures, as in Poaceae. There are several other aperture types closely related to the monosulcate-operculate type, and confusion occurs in the palynological literature between monosulcate-operculate, pontoperculate, disulculate, disulcate, and zona-aperturate (zonasulculate or zonasulcate) pollen. Transmission electron microscopy (TEM) was used to determine the distribution of the thick apertural intine and to accurately identify these aperture types. Operculate pollen most frequently was present in Asparagales (particularly Agavaceae, Doryanthaceae, Iridaceae, and Tecophilaeaceae), Liliales (particularly Liliaceae, Melanthiaceae, and Uvulariaceae), and relatively infrequently among commelinid monocots, except for some Arecaceae, Dasypogonaceae, and Poales. Thus, we conclude that opercula have probably evolved several times independently within monocots, particularly in taxa from dry or seasonally dry habitats, and that this adaptation may be related to their function in protecting the aperture. Two transformation series of related aperture types are proposed, one of which involves monosulcate-operculate pollen, although further testing will be required.

/pdf/the-operculum-in-pollen-of-monocotyledons-3gn14olyns.pdf

Carol A. Furness

Papers

The systematic value of pollen morphology in Operculina (Convolvulaceae)

The trichotomosulcate asparagoids: pollen morphology of Hemerocallidaceae in relation to systematics and pollination biology

Dioscorea ridleyi and D. palawana: new systematic data on two rare South-East Asian yam species

Regular ArticlesMicrosporogenesis and systematics of Aristolochiaceae

The operculum in pollen of monocotyledons