HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Powell, J. B. Articles by Burton, G. W. Search for Related Content PubMed Articles by Powell, J. B. Articles by Burton, G. W. Agricola Articles by Powell, J. B. Articles by Burton, G. W.

Nucleolus-Organizing Accessory Chromosomes in Pearl Millet, Pennisetum typhoides¹

Accessory chromosomes were discovered in an inbred line of pearl millet, Pennisetum typhoides (Burm.) Stapf and C.E. Hubb. The accessory chromosomes organized nucleoli which were independent of the A-chromosome nucleolus in some microsporocytes and associated with the A-chromosome nucleolus in others. Two A-chromosomes in this inbred line associated with a single nucleolus in contrast to only one nucleolus-organizing A-chromosome commonly found in most pearl-millet lines. Accessory chromosomes ranged from one to five within plants, and varied in number from plant to plant, head to head, spikelet to spikelet, and cell to cell. Small, intermediate, and large accessories were obesrved. Characteristic folding back on itself at diakinesis exhibited by the larger accessory suggested an isochromosome derived from the intermediate-sized accessory. The number of accessories per cell appeared to have little effect on A-chromosome pairing. Microsporocytes with the least amount of accessory-chromosome association also had the least A-chromosome pairing.

² Research Geneticist and Principal Geneticist, respectively, Crops Research Division, ARS, USDA, and the University of Georgia, College of Agriculture Experiment Stations, Coastal Plain Experiment Station, Tifton, Georgia.

Received for publication October 5, 1965.