Asexual Propagation of Campanula pelviformis and Petromarula pinnata—Two Local Endemic Plants of Crete with Multipurpose Crop Potential

The urgency for sustainable propagation methods is increasing as anthropogenic disturbances threaten global biodiversity and plant productivity. This study focused on the cutting propagation of Campanula pelviformis and Petromarula pinnata, two local endemic species of Crete (Greece) with known multipurpose crop potential. For C. pelviformis, the effects of cutting type and indole-3-butyric acid (IBA) treatments applied with or without the commercially available and environmentally friendly fertilizer Theocopper and population were investigated. For P. pinnata, the effects of cutting type and IBA treatments were examined. Rooting success and root dry mass were assessed three weeks after propagation onset, while root number and length were measured in the third week to evaluate overall rooting performance. Vegetative propagation of P. pinnata was straightforwardly achieved across cutting types (>90% rooting success), and superior root traits were observed in young shoot cuttings. In C. pelviformis, high rooting success (90%) was recorded in four of the six treatments using adventitious shoot cuttings, while the combined application of 1% Theocopper and IBA efficiently enhanced both rooting percentages and root traits in young shoot cuttings and sub-apical stem sections. The results further indicated a population effect on rooting success and traits among cutting types. The data produced may guide conservation purposes and/or sustainable utilization of these neglected species as novel multipurpose crops, especially in landscaping design with native plants.