Tephrocactus aoracanthus (Lem.) Lem. sexual and clonal reproduction in dominant cacti of the argentine hyper-arid desert

Resumen

By comparing the results of rooting cladodes trials (controlling solar radiation, temperature and type of substrate) with results of germination trials with different light and temperature conditions, we attempt to increase the information about the use of the two different reproductive mechanisms by Tephrocactus aoracanthus (Lem). Lem (Opuntioideae; Cactaceae). This species is highly dominant in the hyper-arid desert of the Central Argentine Monte and unlike other cacti, their spatial distribution is random with respect to potential nurses shrubs and highly grouped in intraspecific association with others individuals, possibly like results of their propagation strategies. The low proportion of successful in all germination treatments, added to the successful rooting of cladodes, predict that this species is primarily spread for agamic replication, although T. aoracanthus too generates a significant amount of seeds that could potentially germinate on more favorable conditions, like years with high soil moisture and lower temperature or protected sites beneath the canopy of shrubs.