Identification of Tertiary Pollen Grains with those of New Guinea and New Caledonian Beeches

ISABEL C. COOKSON

doi:10.1038/170127a0

A contribution to the tertiary occurrence of the genus Dacrydium in the Australian region

Australian Journal of Botany ◽

10.1071/bt9530474 ◽

1953 ◽

Vol 1 (3) ◽

pp. 474 ◽

Cited By ~ 22

Author(s):

IC Cookson ◽

KM Pike

Keyword(s):

Pollen Grains ◽

New Guinea ◽

Fossil Pollen ◽

Australian Region ◽

Living Species

Foliage shoots and seeds of a new Tertiary species, Dacydium rhomboideum, are described; the affinity of D. rhomboideum is discussed.A new sporomorph, Dacrydiumites florinii, is proposed for fossil pollen grains, similar to those of certain species of Dacrydium, isolated from Tertiary deposits in Australia, Tasmania, and New Guinea. Descriptions of the pollen grains of the living species Dacrydium araucurioides and Dacrydium balansae are included.

Download Full-text

Cytogenetics and Reproductive Biology of some BELE (Abelmoschus manihot Linn., Medic Sub-Species manihot) Cultivars

The South Pacific Journal of Natural and Applied Sciences ◽

10.1071/sp02002 ◽

2002 ◽

Vol 20 (1) ◽

pp. 4 ◽

Cited By ~ 1

Author(s):

Anand P. Tyagi

Keyword(s):

Papua New Guinea ◽

Reproductive Biology ◽

Genetic Difference ◽

Pollen Viability ◽

Pollen Grains ◽

New Guinea ◽

Staining Technique ◽

Root Tips ◽

Fiji Islands ◽

Cross Compatibility

Four locally grown (from Fiji Islands) and three imported (from Papua New Guinea), a total of seven BELE (Abelmoschus manihot Linn., Medic sub-species manihot) cultivars were investigated for their cytogenetics and reproductive biology. Chromosome counting from flower buds and root tips showed that chromosome number in all the seven cultivars does not exceed 2n=66. Pollen viability in all the seven cultivars was high, exceeding 85% from pollen staining technique and 78% from pollen germination technique. All the seven Bele cultivars were fully self-compatible. Cross-compatibility among four local cultivars and three cultivars from Papua New Guinea was very high. However cross compatibility between local (Fijian) cultivars and cultivars from Papua New Guinea was partial indicating some degree of genetic difference between cultivars from two countries. This could be due to differences in compatibility alleles between cultivars from Fiji and Papua New Guinea. Procedures such as cutting the style shorter and placing pollen grains to enhance and affect fertilisation to get cross seed were suggested.

Download Full-text

In vitro pollen germination and viability of a Java × New Guinea Impatiens interspecific hybrid

Canadian Journal of Botany ◽

10.1139/b87-270 ◽

1987 ◽

Vol 65 (9) ◽

pp. 1967-1968 ◽

Cited By ~ 1

Author(s):

C. B. Hicks ◽

L. C. Stephens ◽

J. L. Weigle

Keyword(s):

Interspecific Hybrid ◽

Pollen Germination ◽

Agar Medium ◽

Pollen Viability ◽

Pollen Grains ◽

New Guinea ◽

Chi Square ◽

Pollen Diameter ◽

New Guinea Impatiens

Pollen germination on 2% agar medium was investigated as a method of screening pollen viability, using ISU 7851-1, a Java × New Guinea Impatiens interspecific hybrid. A chi-square test showed that percentage pollen germination was related to corresponding seed set. However, some pollinations yielded seeds from pollen that tested in vitro as low as 0.5% germination. Other Impatiens genotypes were screened rapidly for pollen viability by microscopically scanning for pollen germination in vitro. ISU 7851-1 pollen diameter sizes ranged from 18 to 81 μm on agar medium, but only pollen grains of 45 μm and larger were capable of in vitro germination.

Download Full-text

Resolution of Channels in the Exine by Translocation of Colloidal Iron

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065808 ◽

1971 ◽

Vol 29 ◽

pp. 352-353

Author(s):

John R. Rowley

Keyword(s):

Phosphate Buffer ◽

Pollen Development ◽

Osmium Tetroxide ◽

Pollen Grains ◽

Deionized Water ◽

Colloidal Iron ◽

Fixed Material ◽

Epilobium Angustifolium ◽

Untreated Material ◽

Microspore Mitosis

The morphology of the exine of many pollen grains, at the time of flowering, is such that one can suppose that transport of substances through the exine occurred during pollen development. Holes or channels, microscopic to submicroscopic, are described for a large number of grains. An inner part of the exine of Epilobium angustifolium L. and E. montanum L., which may be referred to as the endexine, has irregularly shaped channels early in pollen development although by microspore mitosis there is no indication of such channeling in chemically fixed material. The nucleus in microspores used in the experiment reported here was in prophase of microspore mitosis and the endexine, while lamellated in untreated grains, did not contain irregularly shaped channels. Untreated material from the same part of the inflorescence as iron treated stamens was examined following fixation with 0.1M glutaraldehyde in cacodylate-HCl buffer at pH 6.9 (315 milliosmoles) for 24 hrs, 4% formaldehyde in phosphate buffer at pH 7.2 (1,300 milliosmoles) for 12 hrs, 1% glutaraldehyde mixed with 0.1% osmium tetroxide for 20 min, osmium tetroxide in deionized water for 2 hrs and 1% glutaraldehyde mixed with 4% formaldehyde in 0.1M cacodylate-HCl buffer at pH 6.9 for two hrs.

Download Full-text

Freeze-substitution of rye grass and ragweed pollen grains

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100160984 ◽

1990 ◽

Vol 48 (3) ◽

pp. 686-687

Author(s):

Liza B. Martinez ◽

Susan M. Wick

Keyword(s):

Cell Function ◽

Pollen Grains ◽

Freeze Substitution ◽

Cell Types ◽

Rapid Freezing ◽

Rye Grass ◽

Acrylic Resins ◽

Allergenic Proteins ◽

Cold Embedding ◽

Structural Preservation

Rapid freezing and freeze-substitution have been employed as alternatives to chemical fixation because of the improved structural preservation obtained in various cell types. This has been attributed to biomolecular immobilization derived from the extremely rapid arrest of cell function. These methods allow the elimination of conventionally used fixatives, which may have denaturing or “masking” effects on proteins. Thus, this makes them ideal techniques for immunocytochemistry, in which preservation of both ultrastructure and antigenicity are important. These procedures are also compatible with cold embedding acrylic resins which are known to increase sensitivity in immunolabelling.This study reveals how rapid freezing and freeze-substitution may prove to be useful in the study of the mobile allergenic proteins of rye grass and ragweed. Most studies have relied on the use of osmium tetroxide to achieve the necessary ultrastructural detail in pollen whereas those that omitted it have had to contend with poor overall preservation.

Download Full-text