Evaluation of commercial arbuscular mycorrhizal inoculants on micropropagated early globe artichoke during the acclimatization stage

During the last years, mycorrhizal symbiosis has been used in many micropropagated horticultural crops in order to improve the acclimatization of in vitro plantlets. This root symbiosis, in facts, increases survival and growth rates of plants reducing the transplanting shock and biotic and abiotic stresses. Our previous results on micropropagated artichoke demonstrated the practice of mycorrhizal pure inoculum is effective in improving the quality of the artichoke micropropagated plantlets. The aim of this study was to test the efficacy of two commercial arbuscular mycorrhizal inoculants available in the market (Aegis - Glomus intraradices Italpolline and Symbivit® MYBATEC Ltd.) in promoting mycorrhizal colonization and to analyze the survival and growth of globe artichoke plantlets coming from micropropagation during the acclimatization stage. The trial was carried out in greenhouse on rooted shoots of Cynara cardunculus L. var. scolymus (L.) Fiori) cultivar 'Violet de Provence' obtained in vitro. At the time of the transplant, the microplants were inoculated with two commonly available commercial mycorrhizal inoculants with different fungal composition. Ex vitro survival (%) was measured 30 days after mycorrhizal inoculation. At the same time and at the end of the study (90 days) growth parameters were determined for each plant. Mycorrhizal colonization was evaluated microscopically after clearing the roots in 10% KOH and staining them with trypan blue in lactic acid. The results on early cultivar of artichoke 'Violet de Provence' showed survival rates and measures of morphological parameters comparable, therefore the adoption on large scale of commercial inoculants tested appears very interesting.