Genetic determination of pappus part number in the annual hybridMicroseris B 87 (Asteraceae—Lactuceae)
- 28 Downloads
The ChileanMicroseris pygmaea has a ten-part paleaceous pappus while the CalifornianM. bigelovii has five pappus parts on each achene. Hybrids between the two species have between five and ten pappus parts with averages below 7.5. Hybrid B 87 has an F 1 average value of 6.7 pappus parts. 140 F 2 plants were raised from this hybrid, and 12 F 3 families were obtained by selfing from F 2 plants. One larger F 4 family has been raised. Pappus part number in all of these is still canalized between 5 and 10. Variation within these limits is genetically determined by a quantitatively acting polygenic system. Modeling of this system suggests that a minimum of four, but probably not many more, genes are involved. This opens the possibility of a complete genetic analysis of the system.
Key wordsAngiosperms Asteraceae Lactuceae Microseris Canalized numbers quantitative genetics evolutionary genetics pappus parts
Unable to display preview. Download preview PDF.
- Bachmann, K., Chambers, K. L., 1978: Pappus part number in annual species ofMicroseris (Compositae, Cichoriaceae). — Pl. Syst. Evol.129, 119–134.Google Scholar
- , 1979: Genome size and phenotypic evolution inMicroseris (Asteraceae, Cichorieae). — Pl. Syst. Evol., Suppl.2, 41–66.Google Scholar
- , 1979: Variability of the inflorescence ofMicroseris laciniata (Compositae: Cichorieae). — Pl. Syst. Evol.131, 17–34.Google Scholar
- Chambers, K. L., 1955: A biosystematic study of the annual species ofMicroseris. — Contrib. Dudley Herb.4, 207–312.Google Scholar
- , 1963: Amphitropical species pairs inMicroseris andAgoseris (Compositae:Cichorieae). — Quart. Rev. Biol.38, 124–140.Google Scholar
- Huether, C. A., 1968: Exposure of natural genetic variability underlying the pentamerous corolla constancy inLinanthus androsaceus ssp.androsaceus. — Genetics60, 123–146.Google Scholar
- Rendel, J. M., 1967: Canalization and Gene Control. — London-New York: Logos Press Ltd., Academic Press.Google Scholar
- - Canalization in quantitative genetics. — InPollak, E., Kempthorne, O., Bailey, Th. B., Jr., (Eds.): Proc. Int. Conf. Quant. Genetics, 23–28. — Ames: Iowa State University Press.Google Scholar