Encapsulation of in vitro-derived propagules of two genotypes of Capparis spinosa (L.) from Pantelleria Island

Encapsulation technology, combining the advantages of zygotic or gamic seed with those of micropropagation, has recently attracted the interest of researchers as a new propagation approach, mainly due to the unsatisfying results of the traditional propagation strategies. The encapsulation of uninodal microcuttings (3-4 mm long) from two Sicilian Capparis spinosa (L.) genotypes (from Pantelleria Island: 'Tracino' and 'Scauri') was evaluated, observing the influence of the calcium alginate coating and of three different growth regulators (PGRs): 6-benzylaminopurine (BAP), meta-topolin (MT) and zeatin (ZEA), on viability, regrowth and conversion of the propagules. Caper microcuttings were dissected and placed in different Murashige and Skoog-based artificial endosperms, enriched of either MT, ZEA or BAP. The synthetic seeds obtained were sown on a medium with full strength salts concentration, enriched with 0.4 mg L-1of naphtalene acetic acid and 0.7 mg L-1of gibbelleric acid. After 60 days, the following parameters were detected: viability, regrowth, number and length of the shoots and roots, conversion. The results confirm that encapsulation did not negatively affect the viability, which showed the highest percentage with BAP (100%) in 'Tracino' and with ZEA (100%) in 'Scauri'. Similar results were obtained in regrowth, with statistically significant differences among the three PGRs tested: 'Tracino' showed the best regrowth on capsuled enriched with BAP (100%), 'Scauri' with ZEA (100%). In addition, the synseed conversion was greatly affected by the PGR, and it was higher in artificial endosperm added with BAP in 'Tracino' (56.6%) and ZEA in 'Scauri' (23.3%) genotype.