Nuclear Cytology of Rhinanthus

Abstract

1. Work relating to the nuclear cytology of Rhinanthus is reviewed. 2. Illustrated chromosome counts of R. minor from a number of British localities indicate a bimodal diploid complement of 14 larger plus 8 smaller chromosomes: i.e. 2n=22. 3. A similar bimodal complement from R. serotinus is also illustrated, whilst investigations of R. hirsutus and R. sp. cf. R. angustifolius showed the 14 larger chromosomes and an intermediate number of smaller ones. 4. It is concluded from the results presented on R. minor and from earlier work of Fagerlind and Wulff on the genus that the basic number (x) for Rhinanthus is 11 and not 7 as has been suggested in much of the literature. 5. The prochromosomal resting nucleus of Rhinanthus and the mitotic cycle are illustrated and discussed. 6. The possible future application of studies on the resting nucleus of the Scrophulariaceae to the elucidation of the phylogeny of the semi-parasitic group is mentioned. © 1962, Japan Mendel Society, International Society of Cytology. All rights reserved.