Recent literature paper which sounds interesting

Title: Chromosomes studies of rose cultivars: application into selection process

Authors: Grossi C, Jay M

Published in: ACTA BOTANICA GALLICA, volumn 149, pages 405-413, (2002).

Abstract: “Mitotic chromosome numbers were determined for 41 roses cv. Except an aneuploid cv. (Parador, 2n = 27), all were belonging to an euploid range 2n = 2x (14), 3x (21), 4x (28) or 5x (35). The most interesting fact is the large ploidy scale into a biological type and the large distribution of the triploid cytotype. Whatever the ploidy level of the parentage, it was possible to obtain a progeny in the most case. Nevertheless, the best success was reached in the crossing situations : parents with the same chromosome number, triploid female or tetraploid male. The successfull progeny from triploid female could be explained by an unequal separation of the chromosome during the meiosis.”

Hello,

This could explain why “Gloire des Rosomanes”, triploid,has had so extraordinary results as a mother.

And why when crossing with two different ploidies, it is better to use the tetraploid as pollen.

Pierre Lauwers.

this report is pretty old. Maybe in the meanwhile somebody has noticed that some roses are reportet with different ploidy, e.g. ‘New Dawn’ = diploid, ‘Veilchenblau’= triploid. Is it possible that the ladies vary their ploidy level ?
regards
bernhard