Sexual Reproduction in Higher Plants : Proceedings of the Tenth International Symposium on the Sexual Reproduction in Higher Plants, 30 May - 4 June 1988 University of Siena, Siena, Italy

Based on papers presented at the International Symposium on Sexual Reproduction in Higher Plants, this volume covers the topics: micro- and macrosporogenesis, the activation and recognition of mature pollen, pollen germination and tube emission in vivo and in vitro, pollen and pollen tube cytoskeleton, stigma and style morphology, pollen/stigma interactions, incompatibility mechanisms and gene expression. The reinvestigation of classical topics using modern methods such as immunofluorescence, micromanipulation, freeze-substitution, electron microscopy, etc., is the common basis of all results presented. Especially applied aspects of sexual reproduction important e.g. for crop improvement, are discussed in detail.

Gene-Expression and Transcription.- Differential gene-expression during microsporogenesis with Nicotianatabacum.- Variations of nucleolar ultrastructure in relation to transcriptional activity during G1,S, And G2 periods of microspore interphase.- Pre and post anthesis gene expression in maize pollen.- Testing the genomic instability during the haploid life cycle.- Method development for applying pollen selection in cucumber breeding programmes: effects of centrifugation on pollen competence.- Pollen Quality and Selection.- Male gametophytic selection in higher plants.- Pollen selection for stress tolerance or the advantage of selecting before pollination.- Breeding for frost resistance in Eucalyptus using pollen selection: screening on viability using flow-cytometry.- Invitro pollen selection in Brassicanapus L.- Possibility of expanding genetic variation by limited pollination based on the reproductive success rate (RSR) of pollen grains deposited on stigma.- 31P and 1H NMR as a non-destructive method for measuring pollen viability.- The effect of pollen load on pollen tube performance in apple, pear and rose styles.- DNA repair in Petuniahybrida pollen.- Gametophyte and Sporophyte Transformation and Manipulation.- Transformation, T-DNA and sexual reproduction in higher plants.- Wide hybridization in crop brassicas.- Preparation of sporoplasts for studies of pollen physiology.- Structure and variability of embryos, endosperm and perisperm during in vitro culture of sugar beet, Betavulgaris ovules.- Cytological aspects of invitro androgenesis in cereals.- A micromanipulation method for artificial fertilization in Torenia.- The isolated embryo sac of Zeamays: structural and ultrastructural observations.- Potential of unreduced pollen for breeding tetraploid perennial ryegrass.- Sporophytes and male gametophytes from invitro cultured, immature tobacco pollen.- Microsporogenesis and Pollen Development.- Extranuclear extrusions of nucleolar material during diplotene in microsporocytes of Larixdecidua Mill.- Evolution of nuclear interchromatin structures during microspore interphase periods.- Effect of gamma irradiation on nucleus DNA amount and syntheses of nucleic acids in microsporocytes and tapetum of Nicotianatabacum L.var.Xanthi Dulieu issued from irradiated seeds (DNA) or from directly irradiated excised inflorescences (DNA, RNA).- Why do nuclear vacuoles appear in the prophasic nucleus of pollen mother cells? facts and hypotheses.- Aspects of sporopollenin biosynthesis: phenols as integrated compounds of the biopolymer.- Organelle aggregations during microsporogenesis in Stangeria, Nymphaea, and Malva.- Amylogenesis and amylolysis during pollen grain development.- Histological and biochemical analyses of microsporogenesis in the normal and male sterile, stamenless-2 mutant of tomato.- Pollen Tube and Sperm Cells.- The pollen tube: motility and the cytoskeleton.- Presence of kinesin in tobacco pollen tube.- Analysis of the structure, organization and role of cytoskeleton during pollen germination and tube growth in Pyruscommunis L.- The cytoskeleton apparatus of the generative cell in different angiosperm species.- The male germ unit of Zeamays: quantitative ultrastructure and three-dimensional analysis.- Interaction of vegetative nucleus and generative cell (then sperms).- A technique to isolate sperm cells of mature spinach pollen.- Ultrastructural observations on isolated and cultured protoplasts of Lily pollen.- Isolation and characterization of viable sperm cells from tricellular pollen grains.- Ultrastructural aspects of Epidendrum male gametogenesis.- Stressed Gametophyte.- The effects of stresses (cold or/and darkness) on pollen viability of two varieties of grain-sorghum.- Air pollution effects on pollen germination of forest species.- Forced pollen shedding effects on pollen diameter and early seedling growth in maize.- Heat shock proteins in germinating pollen of Nicotianatabacum before and after heat shock.- From Pollination to Fertilization.- The relationship between potato pollen and true seed : effects of high temperature and pollen size.- Pollen maturation and desiccation tolerance.- Pollen pistil interaction in the ovary in fruit trees.- In vitro pollen-style interactions in Malusdomestica.- Normal and abnormal embryo development after invitro fertilization in maize.- Pollen-style interaction in ZeaMays L.- Pistil treatments for improved fertility in hybridization of Eucalyptusgunnii (Hook).- Induced polarity as an index of pollination - triggered stylar activation.- Evidence for non-random fertilization in the common zucchini, Cucurbitapepo.- An ultrastructural study of fertilization in douglas fir (PseudotsugaMenziesii (Mirb.) Franco).- Secretion and composition of the pollination drop in the Cephalotaxusdrupacea (Gymnosperm Cephalotaxaceae).- Pollination and reproduction in Dianthussilvester Wulf.- Ovular development and pollen tube growth in the ovary of Gasteriaverrucosa (Mill.) H.Duval as condition for fertilization.- Cytochemical study of adenylate cyclase in pollen-pistil interactions and its relation to incompatibility.- The influence of double pollination and pollen load on seed set and seedling vigour of apple and pear.- From Ovule to Seed.- Cytology of seed development in perennial ryegrass, LoliumPerenne L.- Embryology of barley II: synergids and egg cell, zygote and embryo development.- Quantitative data on Petunia embryogenesis: mitotic activity and characteristics of the cell cycles.- Chalaza-micropyle element concentration gradients in the endosperm tissue during embryogenesis.- Immunocytochemical visualization of the microtubular cytoskeleton in developing kernels of wheat (Triticumaestivum).- Post-pollination phenomena and embryo development in the Onciidinae (Orchidaceae).- Polyembryony in Oenothera.- The suspensor is a major route of nutrients into proembryo, globular and heart stage Phaseolusvulgaris embryos.- “Structural reserves” in embryo development.- Embryology and Taxonomy.- Sporo-gametogenesis and fertilization of Escallonia and Brexia with comments on their taxonomy.- Embryological problems of the family rosaceae.- Some aspects of reproductive biology: asexual reproduction and heterogenity of seeds.- Final Remarks.- Present status and future prospects of sexual reproduction research in higher plants.- Abstract of Poster Presentations.- Author Index.