Cytogenetic Studies of Oenothera affinis Camb

Abstract

The cytogenetic behavior of six races of Oenothera affinis and their hybrids has been presented.
The behavior of the hybrids with respect to pigmentation of the hypanthium has been explained on a unifactorial basis. Races Argentina and Palermo were found to be homozygous for R; Florida and Toledo were heterozygous and Buenos Aires and Santa Fe I were homozygous for r.
Three of the races viz.-Palermo, Florida and Toledo were found to be isogamous complex-heterozygotes with θ14 whereas the other three viz.-Argentina, Buenos Aires and Santa Fe I were found to be homozygotes, with 7 pairs.
The phylogenetic relationships between races within O. affinis have been pointed out. It has been concluded that complexes within O. affinis are, in general, closely related segmentally. Further, excepting one of the complexes of Palermo, all complexes of the affinis races were found to be related by a maximum of 3 interchanges with respect to the homozygote Buenos Aires.