Valutazione di diversi metodi di inoculazione di Fusarium solani in semenzali di citrange Troyer

Fusarium solani is the main causal agent of citrus dry root rot disease, in spite of its often reported inability to induce clear disease symptoms in pathogenicity tests, ascribed in part to the methods of inoculation. In this study, different methods were tested. When a conidial suspension of F. solani strain PVCT1A was inoculated in cuttings and leaf midribs of young Troyer citrange seedlings, wilt, defoliation and interveinal chlorosis of leaf were observed within 8 days. Inoculation of Troyer citrange by root immersion in a conidial suspension reduced root weight and length within two months. Two months after soil inoculation, browning of the root apex, reduced growth of roots and stem were observed on citrange seedlings. Seeds poured in inoculated soil showed reduction of root growth. Colonization of Troyer citrange tissues by F. solani was always observed, independently on the inoculation methods used. The tests here described could be used to evaluate rootstocks susceptibility to the pathogen.