| Plant latin name | Paeonia suffruticosa Andrews |
| Literature code | Paeonia_suffruticosa-Ref-1 |
| Reference | Margherita Beruto et al, Plant Cell, Tissue and Organ Culture 79: 249–255 (2004) |
| Summary | We investigated the in vitro propagation by axillary budding of different cultivars of tree peonies, selected
for cut flower production under Mediterranean conditions. Buds with expanded leaves were better to
initiate cultures than just emerged ones (64% compared to 43%). The aptitude for micropropagation was
genotype-dependent, and the propagation ratio ranged between 2 and 5 per cycle. Tendency to necrosis
and/or hyperhydricity were also genotype dependent. Indole-3-butyric acid improved rooting but was not
really necessary provided the shoots were pre-treated at 2 ℃ for 7 days. Plantlets were successfully
acclimatized under in vivo conditions. Adventitious propagation was achieved using filaments and petals as
explants. They first developed callus, able to regenerate shoots after 8 weeks on media supplemented with
thidiazuron. |
| Objectives | Micropropagation of tree peony |
| Materials | Seventeen Chinese cultivars (‘Bai Yu’, ‘Feng Dan
Bai’, ‘Shi Yuang Bai’, ‘White Pearl’, ‘Xue Lian’,
‘Yao Huang’, ‘Huang Yu’, ‘Orange Yellow’,
‘Golden Palace’, ‘Hu Hong’, ‘Da Jin Fen’, ‘Fish
Scale Pink’, ‘Zhuang Yuan Hong’, ‘Zi Zy Qiao’,
‘First Red’, ‘Red Diamond’ and ‘Zhu Sha Lei’),
two Japanese cultivars (‘Orange’ and ‘Red’) and
an old traditional cultivar from our region (‘Old
Pink’) were used in our experiments. |
| Explant | Axillary buds, Filaments, petals |
| Initial culture | Axillary propagation was performed in 25×150 mm test tubes, containing 10 ml of agargelled medium and closed by a plastic cap (Bellco Kaputs ). Flower parts were cultured in Petri dishes (35 mm diameter) containing 5 ml of medium during the initiation phase; larger Petri dishes (60 mm diameter) filled with 15 ml of medium were used subsequently. The pH of all media was adjusted to 5.85 ±0.01 while the media were liquid (T=76 ℃ ± 1) and before autoclaving at 120 ℃, 101 kPa,15 min. Culture room conditions: photoperiod 12 h/day; PAR 50 lmol m 2 s 1 (fluorescent tubes: TLD 36W/33 Philips) and room temperature of 19 ± 1℃. For rooting, cultures were first kept in the dark for 14 days, and subsequently returned to the light conditions. |
| Shoot multiplication | The WPM medium (Lloyd and McCown, 1980) containing a doubled concentration of Ca2+ (6 mM) and supplemented with citric acid (0.36 mM), ascorbic acid (0.28 mM), BA (4.44 μM) and 0.8% agar (BV cd S-1000) was used. Flower buds harvested 15–20 days before flower opening and maturity were excised; petals of 1–2 cm2 surface and 1 cm long filaments were removed and cultured on gelled (0.8% BV agar S-1000) MS (Murashige and Skoog, 1962) medium supplemented with sucrose 3% and different hormonal formulations (NOA 0.49 μM; 2iP 24.60 μM and PIC 4.14 μM; TDZ 2.27 μM; TDZ 2.27 μM and 2,4-D 9.05 μM). |
| Rooting | The WPM medium (Lloyd and McCown, 1980) containing a doubled concentration of Ca2+ (6 mM) and supplemented with citric acid (0.36 mM), ascorbic acid (0.28 mM), IBA (0; 1.23; 2.46; 4.92 or 49.21 μM) and 0.8% agar (BV cd S-1000) was used for the complete rooting period (Treatments A).Rooting took also place without IBA (±10%), but it increased to 50% with IBA 49.20 μM. As an alternative, the aforementioned treatments were used for 2 weeks before transfer to hormone free medium supplemented with 0.3% of charcoal (Treatments B). A third rooting approach was to culture the plants on hormone free medium and give them a cold treatment (2℃) for 7 days, in the dark, before transfer to the aforementioned IBA treatments for 2 weeks (Treatments C).Chilling microcuttings before transfer to root induction medium, had a beneficial effect on rooting percentage when no hormones were supplied. |
| Acclimation | Gradual acclimatization of rooted plantlets to in vivo conditions was performed by transferring the in vitro plants to glass vessels (500 ml) filled with sterilized milled peat (Rekiva, cd 1A) and perlite (Perlite Italiana, nr 3) (1:1), maintained under the same conditions as the culture room, for 4 weeks. |
| Planting | the plantlets were transferred to greenhouse conditions (unheated greenhouse) and received standard cultural practices regarding nutrition, irrigation and pest control (Rogers, 1996; Lianying, 1998). Gradual acclimatization of plantlets in closed containers placed in the culture room resulted in plantlets of good quality which could be transferred to greenhouse conditions, with a survival rate of 80 ± 10%. |
| Cultivation conditions | |
| Traints of regenerants | |
| Ingredients analyzed | |
| Extraction | |
| Analitical methods | |
| Notes | |