Cucurbit Genetics Cooperative Report 2:36 (article 21) 1979
Sex Expression in Cucurbita foetidissima HBK
Brenda K. Fulks, J. C. Scheerens, and W. P. Bemis
University of Arizona, Tucson, AZ 85721
Sex expression in Cucurbita species including C. Foetidissima, the Buffalo gourd, have been considered as stable breeding monoecious species. Antherless and male sterile plants were described by Curtis (1). A population of C. foetidissima grown by Curtis in Lebanon from seed collected at one location in Texas segregated 431 monoecious to 129 antherless (gynoecious). Curtis suggested that "Antherless" was recessive and the seed collected in Texas came from a homogeneous colony of plants that were monoecious but heterozygous.
A germplasm nursery containing 63 accessions of C. foetidissima was established from seed in 1976 at Tucson, AZ. In 1977, the plants, which are perennial, were scored for sex expression. Twenty-nine accessions contained at least 1 gynoecious plant, 19 accessions having a population of 6 or more were all monoecious and 15 accessions having a population of 5 or less plants were also all monoecious. The total count from the 29 accessions segregating gynoecious plants were 114 gynoecious to 153 monoecious. In no case was an accession exclusively gynoecious plants.
Populations of plants from selected crosses and monoecious selfs have shown the gynoecious character is conditioned by a dominant gene and is heterozygous, i.e., (Aa), and the monoecious condition is homozygous recessive. This dominant gene appears to be widespread throughout the native range of C. foetidissima. A proposed term "gynomonodioecious" is suggested to describe a population containing gynoecious and monoecious segregates.
- Curtis, L. C. and N. Rebiz. 1972. Antherless male sterility in C. foetidissima and its potential use. Progress Rept. #2, Ford Foundation, Beruit, Lebanon.