Grafting globe artichoke on four Tunisian cardoon rootstocks: compatibility and cardoon responses versus Verticillium dahliae
In Tunisia, several prospections have confirmed the presence of one of the most dangerous soil-borne fungus (Verticillium dahliae Kleb.) in many regions. Its presence can threaten the production of various vegetal species such as globe artichoke. Recent studies in Mediterranean countries have shown the existence of tolerant cardoons to some clones of Verticillium. This work has targeted two axes: the evaluation of the response of some Tunisian ecotypes of cardoon to graft compatibility with three globe artichoke hybrids; and the tolerance of these cardoons to a Tunisian fungus clone of V. dahliae. The cardoon ecotypes were collected from four regions (Manouba, Bizerte, Zaghouan and Sousse) and used as rootstocks for three globe artichoke hybrids Symphony, Opera and Madrigal. The same ecotypes of cardoon were inoculated by a clone of V. dahliae and tested for their responses toward this fungus for six weeks. About the grafting test, 73 to 84% of viable grafted plants were revealed in all the combinations of rootstocks and scions. The highest affinity healing between scion and rootstock was revealed with the cultivated ecotype of cardoon collected from Manouba region because the graft point had healed in a shorter time (5 days) than the other combinations (from 8 to 14 days). Concerning Verticillium tolerance, none of the cardoon ecotypes expressed significant tolerance. Despite this, the cardoon collected from Bizerte region showed the lowest symptom severity (60%), the smallest area under curve of wilt propagation (AUDPC) and the minimum percentage of root vascular browning (23%) compared to the other inoculated ecotypes. Also for vegetative biomass parameters, the inoculated cardoon of Bizerte marked the highest values in leaves fresh weight (42.8 g), in leaves dry matter content (13%) and in root fresh weight (8.8 g) compared to the infected ones.
Riahi, J., Nicoletto, C., Riahi, M., Laroussi, A., Abdelhak, F. and Kouki Khalfallah, K. (2020). Grafting globe artichoke on four Tunisian cardoon rootstocks: compatibility and cardoon responses versus Verticillium dahliae. Acta Hortic. 1284, 137-144
Mediterranean countries, scion, Cynara cardunculus L. var. scolymus, Cynara cardunculus subsp. cardunculus, tolerance