| The CSSA Crop Terminology Committee recommends that the above symbols
for cytoplasmic male - sterility in sorghums be accepted. The Committee wishes to express its gratitude to J. C. Stephans, Agronomist, Cereal Crops Branch, Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture, Chillicothe, Texas, for his assistance in the statement of terminology involved in sorghum hybrids. Sugar Beets (Beta vulgaris L.) Cytoplasmic male - sterility (cms), known in sugar beets for a number of years, is now used in the production of hybrids. Cytoplasm which can induce male - sterility occurs in many commercial open - pollinated varieties, as well as in many wild races of Beta vulgaris. Male - sterility results from the interaction of certain nuclear genes with a male - sterility inducing cytoplasm. The mode of genetic inheritance has not been fully resolved, nor have the various sources of cytoplasm been studied sufficiently to ascertain whether differences exist between them. Sugar beet breeders use male - sterile terms in ways as follows: (a) A cytoplasmic male - sterile line is comprised only of male - sterile individuals, being produced by backcrosses to an O - type line. (b) O-type sugar beets are those with d genotype such that, when the beet is crossed with a male - sterile (cms) beet, the progeny are all male - sterile (cms). O - type sugar beet lines are used as (1) maintainers of male - sterile lines, and (2) as pollen parents of male - sterile F1 hybrids which are used as seed parents of commercial hybrids. The O - type line is understood to have normal cytoplasm. Dr. F. V. OWEN, the originator of the term, meant O (zero) - type. Since the death of Dr. Owen, sugar beet breeders have used the term, O - type, as a tribute to him, i. e., O(wen) type. (c) Sugar beet breeders usually are not concerned with restorer types because the end product is roots rather than seed. Furthermore, no sugar beet breeders or geneticists have reported the existence of any beet with a genotype that will cause complete restoration of viable pollen production in the progeny of a cross with a cytoplasmic male - sterile sugar beet. The Terminology Committee recommends that the above symbols for cytoplasmic male - sterility in sugar beets be accepted. The committee is grateful to Robert K. OLDEMEYER, Director, Seed Development, Agriculture Experiment Station, Great Western Sugar Company, Longmont, Colorado, for his being liaison between the Sugar Beet Breeders Forum and the Terminology Committee as regards the accepted usage of terms for sugar beets. |
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