1964 Volume 33 Issue 2 Pages 133-139
The present investigation was undertaken in an attempt to elucidate the physiological basis of pollen degeneration in male sterile vegetable crops. Free amino acids from pollen grains, anthers, female organs and leaves of fertile and sterile plants were analyzed by paper chromatography. The vegetables used in the study were three cultivars of onion, two of Welsh onion, cabbage and tomato, and one of radish and red pepper.
1. Numbers of ninhydrin-positive spots in the chromatograms of fertile anthers prior to the dehiscence were as follows: onion, 17; Welsh onion, 15; cabbage and red pepper, 14; radish and tomato, 13, and no definite varietal difference was found in the amino acid composition in these materials. Marked differences, however, were found in the chromatograms between fertile and sterile anthers in the stage as shown in Figs. 1-3. That is, the chromatograms of fertile anthers had a considerably large spot of proline, which was either lacking or very faint in sterile anthers of any crops. The evidence of a positive relation between the content of praline and pollen fertility was obtained. Moreover, it was found in onion that the spot of asparagine from sterile anthers was considerably smaller than that from fertile ones (Fig. 2a).
2. At the stages from metaphase-I to anaphase-II in tomato, however, proline was very faint both in fertile and sterile anthers, and no chromatographic differences could be detected in the composition of free amino acids, either qualitatively or quantitatively, between fertile and sterile ones (Fig. 4a).
3. No definite difference was found in the free amino acid composition of female organs prior to the anther dehiscence or of leaves at the flowering time between fertile and sterile plants (Fig. 4 b. c and Tables 2 and 3).
4. In conclusion, it may be assumed that the difference in the proline accumulation between fertile and sterile mature anthers is related with the pollen degeneration in male sterile vegetable crops.