Effect of Calcarisporium arbuscula on adventitious root development and peroxidase activity in two elepidote rhododendron cultivars

Abstract

Effect of Calcarisporium arbuscula on adventitious root development in leaf-bud cuttings of two elepidote rhododendron cultivars was studied. Guaiacol peroxidase activity was determined and anatomical study was performed in untreated cuttings (control), and cuttings treated with 1% indole-3-butyric acid (IBA) or C. arbuscula. In rhododendron cv. 'Babītes Lavanda' both IBA and C. arbuscula treatment slightly delayed adventitious root formation; the overall rooting percentage remained high (94 and 92%, respectively) but lower than in the control (96%). IBA and C. arbuscula treatments had a strongly positive effect on long term survival of rooted cuttings (73 and 70%) compared to the control (54%). There was no difference in peroxidase activity between the treatments. In rhododendron cv. 'Nova Zembla' , IBA and C. arbuscula treatments promoted formation of adventitious root initials and primordia as well as strongly increased rooting percentage (63 and 70%) compared to the control (38%). In addition, peroxidase activity was significantly higher in C. arbuscula treated cuttings during the whole experiment.