Re: Chromosome counts and breeding

Juerg Steiger (steiger@iae.unibe.ch)
Thu, 9 May 1996 22:10:56 +0100

>One plant has 32 chromosomes and the other 48. The base number
>therefore. From other literature sources, it seems that the base number
>for Pinguicula is 16, making the 48 plant a triploid. Triploids are
>generally sterile.

Sorry Guido thats an error. The base number - within a group of relative
species - is usually the chromosome number of the haploid genome of the
species with the lowest chromosome number. As Ping. corsica, P. crystallina
subsp. hirtiflora and P. villosa have 2n=16 and no species has a lower
number, the basic number is x=8. P. mundi has 2n=48=6x and is hexaploid,
not triploid. But even the really triploid P. crystallina subsp. hirtiflora
specimens (2n=24=3x) from the Lithochoron gorge in central Greece are very
fertile! If you don't believe it I can send you seeds. The two other base
numbers in the genus Pinguicula are x=n=6 (P. lusitanica) and x=n=11 (e.g.
P. moranensis). An unusual number (2n=18) is found in P. ramosa which is
likely to be of hybridogene origin (P. alpina/P. villosa) with combined
chromosome fusions and dysploidy. But also P. ramosa is fertile.

Kind regards Juerg

___________________________________________________
Juerg Steiger, Institut fuer Aus-, Weiter- und Fortbildung IAWF
University of Bern, Inselspital 37a, CH-3010 Bern, Switzerland
Office: ++41 31 632 98 87, Fax: ++41 31 632 98 71