Submitted to: Onion Research National Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 25, 2000
Publication Date: N/A
Technical Abstract: Hybrid-onion (Allium cepa) seed is produced using male-sterility systems, including asexual propagation of individual male-sterile plants and cytoplasmic-genic male sterility (CMS). The principle source of CMS used in onion seed traces back to a single plant identified in 1925 in Davis, CA. Other sources of male-sterility have been reported in Europe, Japan, and India; however, the relationships among these male-sterility systems is not clear. I undertook Southern analyses of the organellar genomes of five independent sources of onion CMS: S cytoplasm, T cytoplasm, and sterile cytoplasms from the Japanese population Imai Wa-Se, the Dutch population Rijnsburger, and the Indian population Nasik White Globe. The chloroplast genome of S cytoplasm and four sources of the sterile cytoplasm from Nasik White Globe were identical for all evaluated polymorphisms; the Nasik White populations always possessed at least one of the S-cytoplasmic mitochondrial fragments. T cytoplasm and the sources of sterile cytoplasm from Japanese and Dutch companies were very closely related. These results established that the same or very similar male-sterile cytoplasms have been independently isolated.