Pollen viability and cytogenetic evaluation of three registered guayule (Parthenium) germplasms.

Karyotype and Chromosome Morphology of Parthenium argentatum.

“…However, cytological investigations to date, have been limited primarily to meiotic studies. These include analyses of ploidy (Bergner 1944(Bergner , 1946 and its relation to interspecific hybridization and pollination (Powers and Rollins 1945, Rollins 1945, Hashemi et al 1989, chromosome pairing (Hashemi et al 1986), B-chromosomes (Bergner 1946, Catcheside 1950, apomixis (Bergner 1944, 1946, Gerstal et al 1953, Bashaw 1980) and species and cultivar verification (Rollins 1950, Tysdal et al 1983, Brown and Zaiger 1987. Although meiotic chromosome morphology has been examined (Bergner 1944, 1946, Stebbins and Kodani 1944, Hashemi et al 1989a, data on mitotic chromosome morphology has been scanty, due, in part, to small chromosome size.…”