In vitro propagation and conservation of wild bilberry (Vaccinium myrtillus L.) genotypes collected in the Tuscan Apennines (Italy)

Abstract

BACKGROUND: Vaccinium myrtillus L. is a valuable wild fruit species of conservation concern in the Tuscan Apennines (Italy). OBJECTIVE:The development of a micropropagation protocol for the conservation of this species in in vitro-banks for the year-round mass production of specific selected superior bilberry genotypes, maintaining the genetic variability of natural populations, avoiding genetic erosion. METHODS: Nodal segments from seedlings were cultured on mMS medium with zeatin or 2iP for multiplication and elongation stage, afterwards shoots were rooting in vitro and in vivo. The RAPD analysis was applied to lines obtained and slow growth storage (4 • C -darkness) was evaluated for the conservation. RESULTS: Zeatin concentration 9.1 M was the most favorable for shoot proliferation. The activated charcoal was essential for in vitro rooting. Both in vitro and ex vitro methods were successfully used to root and acclimatize bilberry shoots. The RAPD analysis indicated a large genetic diversity among the micropropagated genotypes. Shoots were successfully in vitro preserved for up to 6 months with no apparent deterioration effect. CONCLUSIONS: In vitro propagation and conservation are fundamental tools for exploiting the whole potential of this wild crop species for breeding and genetic improvement purposes.

Optimizing factors influencing micropropagation of ‘Bluecrop’ and ‘Biloxi’ blueberries and evaluation of their morpho-physiological characteristics during ex vitro acclimatization

“…Regarding rooting, the results show that the rhizogenic capacity improved when the culture medium contained activated charcoal (in addition to the use of auxins and sucrose), while its exclusion increased the rate of callus formation (between 86.67 ± 11.55 to 100 %). Cüce & Sökmen [25], Nin et al [36] and Mohamed et al [37] reported similar results, and when they incorporated activated charcoal (1 g L -l ) it was observed that roots of Vaccinium species were more elongated and shoots and leaves developed more vigorously. Similarly, Mohamed et al [38] reported that the addition of this element (activated charcoal) increased the rooting rate and allowed better acclimatization of seedlings.…”

In Vitro Conservation through Slow Growth Storage Technique of Fruit Species: An Overview of the Last 10 Years

“…Vaccinium myrtillus shoots showed the highest survival rate (90%) and recovery rate (80%) after cold storage at 4 °C in darkness for up to 6 months [ 32 ]. Arbeloa et al [ 18 ] conducted the same cold storage protocol (4 °C and darkness) for 18 fruit species ( Crataegus , Cydonia , Eriobotrya , Ficus , Malus , Prunus , Punica and Pyrus ).…”

“…In the same study, the storage on media with 3% sucrose without PGRs reduced the conservation period to only 12 months while adding mannitol at different concentrations, as well as its combination with sucrose, shortened the duration to 3 months with no good quality of preserved plants. Hormone-free MS medium was efficient to maintain Vaccinium myrtillus under slow growth storage for 6 months, recording high survival (90%) and the shoots were of good quality showing no browning symptoms [ 32 ]. In addition, SGS of Ribes nigrum was prolonged up to 18 months when the shoot cultures were conserved on MS medium, supplemented with PGRs (BA and IBA), 2% sucrose and 2% mannitol compared to only 12 months on the same medium but without the addition of PGRs [ 20 ].…”

“…The performance of in vitro shoots is strongly affected by the genotype. In the literature, there are different examples where the results obtained with micropropagation varied from one plant variety to another [ 32 , 57 ]. For this reason, efforts should not only focus on developing appropriate genotype-specific protocols for tissue culture and micropropagation of plants, but also for SGS [ 54 , 58 ] to be applied on a wide range of accessions.…”