In vitro recruitment of Ulva sp. and Enteromorpha sp. on gametophytic and tetrasporophytic thalli of four populations of Chondracanthus chamissoi from Chile

Chondracanthus chamissoiis a red algawhich is acquiring an increasing economic impor-tance in Chile and becoming a target species forcultivation. Because epiphytism is a major problem inthe mariculture of seaweeds, the recruitment ofUlvasp. andEnteromorphasp. on gametophytic (cysto-carpic) and tetrasporophytic thalli ofC. chamissoiwas testedin vitroon four populations from differentlocations in Chile. ForUlvasp., the density, cover andlength of the recruits varied between the reproductivephases of the host and among the studied populationsofC. chamissoi. In most experiments, a larger numberof epiphytic thalli was observed on gametophyticplants ofC. chamissoi; populations from Calderillaand Lechagua had a higher resistance to epiphytism.ForEnteromorphasp., its ability to grow epiphyti-cally on both phases of the host showed a greatervariability, but was inferior to that ofUlvasp. Thedifferential resistance to epiphytism in both reproduc-tive phases and in plant origin indicates the possibilityof obtaining selected strains ofC. chamissoiwithlower susceptibility to epiphytism that could beutilized in planning maricultural programs.