Innovative large-scale production of early artichoke transplants

A research was started to standardize an effective system for large-scale production of early type artichoke plantlets in nursery. Cynara cardunculus L. var. scolymus Fiori plants of the “Locale di Mola” type were selected in field on the basis of their marked precocity. Offshoots from these plants were cultured in vitro to obtain artichoke plantlets fungi and bacteria free to improve the quality of propagation material. Once transplanted in pots, the plantlets were inoculated with 10 g Glomus viscosum strain A6 (AM fungus). Acclimatization was clearly facilitated by the addition of the AM fungus. Indeed, the mycorrhizal plantlets showed a higher survival percentage. Plants were grown under greenhouse conditions and, after six months, were cut back at the collar level. A week before cutting, mycorrhizal and not-mycorrhizal plants were treated with 6-benzylaminopurine (BAP 200 mg l-1) to promote offshoot production. For three months after the cut, every month the offshoots of each plants were counted, harvested and weighted. Mycorrhizal inoculation alone stimulated offshoot production while the combination of growth regulator treatment and mycorrhizal symbiosis not increased further offshoot production. Cuttings, with weight ranging from 30 to 45 g, were used to evaluate the effect of mycorrhizal inoculation and two different indolacetic acid concentrations (IAA 100 and 500 mgl-1) on rooting. The highest rooting percentage (87%) was recorded on cuttings inoculated with mycorrhizal fungi. Rooted offshoots were transplanted in field and the morphological and productive parameters were investigated. Data collected confirm the characteristics of the original cultivar. The efficiency of the in vitro propagation material and the role of mycorrhiza optimize the system for large-scale offshoot production in early types of artichoke.