Correlation between hypericin content and the ploidy of somaclones of Hypericum perforatum L.

An altered ploidy level was observed in plants regenerated by adventitious shoot formation from seedlings of Hypericum perforatum L. (2n = 4x = 32). Among the somaclones of the R-0 generation, the presence of diploids (2n = 2x = 16), triploids (2n = 3x = 24), tetraploids (2n = 4x = 32) and mixoploids was detected. Cytogenetic analyses of the R-1 and R-2 progenies showed that the chromosomal instability of the Ro somaclones was transferred onto the next generations. While almost all the seed progeny of diploids (100% in R-1 and 94% in R-2) and more than 60% of tetraploids (61% in R-1 and 73% in R-2) retained their chromosome number, cytogenetic diversity was observed in the progeny of triploids, mixoploids and some tetraploids. Somaclones and their offspring were analyzed for hypericin content. Statistical evaluation showed a correlation between hypericin content and ploidy during a two-year cultivation of Ro somaclones and in their R-1 and R-2 progenies.