EFFECT OF ROOTING CONDITIONS ON SURVIVAL AND GROWTH DURING ACCLIMATIZATION OF MICROPROPAGATED CHESTNUT PLANTS (CASTANEA SATIVA X C. CRENATA)

Castanea sativa x C. crenata shoots regenerated in vitro from material of mature origin were induced to root by leaving the shoots for 5 days in basal rooting medium supplemented with 3 mgl^-1 IBA. After the induction treatment, the shoots were transferred either to auxin-free agar medium (in vitro rooting) or to a peat:perlite substrate (ex vitro rooting). Rooted shoots were subsequently acclimatized under 250± 10 μmol m^-2 s^-1 as photosynthetic photon flux density (PPFD). The survival rate reached 100% for plantlets with ex vitro rooting and 50% for in vitro ones.
Rooting conditions also appears to be an important factor for growth during acclimatization stage.
In fact the ex vitro rooting was associated to a vigorous growth of the plants expressed by an increase on relative growth, total dry weight, leaf area, number of new leaves formed, relative growth rate (RGR) and net assimilation rate (NAR). Nevertheless, plants with in vitro rooting have a similar shoot/root ratio, leaf weight ratio (LWR), and a slight increase on leaf area ratio (LAR) and specific leaf area (SLA) when compared to ex vitro rooted plants.

II International Symposium on Chestnut

J.C. Gonçalves, G. Diogo, M.T. Coelho, S. Amâncio

acclimatization, growth analysis, in vitro and ex vitro rooting, survival

https://doi.org/10.17660/ActaHortic.1999.494.35