Showing papers by "Korea University published in 1967"

Studies on Cellular Site of Calcium Action in Promoting Pollen Growth

Abstract: Studies were conducted to determine cellular site of Ca action in promoting pollen growth of Crinum asiaticum and a few other species. The following experimental results have strongly indicated that Ca binding takes place in pectins of the pollen tube walls. This appeared to increase the wall rigidity and to regulate permeability of the pollen cells thereby enhancing pollen growth. Radioactive Ca incorporation was observed exclusively in the pollen tube wall regions. The promoting action of Ca on pollen growth disappeared when pectinase was supplemented to the media. This was not the case with cellulase and other enzymes used. Methyl donors promoted pollen growth, and the promotion was more than doubled if Ca ions were present. Ethionine, on the other hand, inhibited tube elongation and exhibited no Ca effect. Growth of pollen tubes in oscillaled liquid media during elongation was poorer than growth in standing media. The Ca effect was also reduced when pollen was oscillated. The observations made of the reduced rate of 45Ca incorporation when pollen was washed in water, and the hydroxylamineferric chloride test, have indicated that a considerable portion of these pectins are cold-water soluble.

An Improved Method for Culturing Tradescantia Pollen Tubes for Chromosomal Analysis

Abstract: By using pollen from Tradescantia palndosa, it was found that pollen cultural medium containing calcium, magnesium and potassium ions, at a high pH, greatly enhanced growth of the pollen and accelerated the pollen mitosis. The calcium-supplemented medium, unlike conventional pollen growth media, facilitated well aligned mitotic chromosomes in the pollen tubes, resulting in a more distinct appearance of the chromosomes. This allowed the obtaining of more analyzable chromosomes in the pollen tubes.