Proceedings Volume 2010 (format .pdf) - SimpBTH

Acclimatization of plants under ex vitro conditions: The effect of differentmixture substrates on the survival rate of A. montana plants during ex vitroacclimatization was examined (Table 2).Table 2. Effect of different mixture substrates on survival rate of A. montana plants duringacclimatizationMix Differentpeat mixtureNumber oftransplanted plantsSurvival percentage ofplantletsM1 Peat: Perlite (2:1 v/v) 30 70M2 Peat: Coco (2:1 v/v) 20 65M3 Peat: Perlite: Coco(2:1:1 v/v/v)20 90It was observed that the tested mixtures had significantly beneficial effect on survivalrate and growth of the plants. The data in Table 2 show that the highest percentage ofplant survival was obtained after transplantation to peat, perlite and coco mixture(2:1:1 v/v/v). During adaptaion, plants with the greatest number of leaves wereobserved when M3 mixture was used, where the survival percentage was 90%(Figure 1d, 1e and 1f). The acclimatized plants were of proper growth anddevelopment, when M1 mixture of peat and perlite (2:1) was used. In order tomaximize the survival of in vitro derived plants, it is routine practice to acclimatizethem under high levels of relative humidity. In the present study in vitro grown plantswere acclimatized in humid environment. In the first and second weeks oftransplantation the plants were covered with a transparent polythene for providinghigh humidity and sufficient light. When new leaves developed the polythene wasremoved. The high humidity and moderate temperature enhanced the initial survivalof potted grown plants. A method adopted in this study has facilitated the successfultransfer of plants from in vitro to ex vitro conditions. The rate of successfullyacclimated rooted plants was influenced by both shoot and root size. At the time ofrooting, shoot height on ½ MS media supplemented with studied auxins rangedbetween 0.5 and 2.5 cm and root length varied between 0.5 and 2.0 cm for fourweeks. The rooted plants of 1.5-2.0 cm height and root length with 1.0 -1.5 cm gave85% successful survival (Table 3). These plants were more suitable for adaptation.Only 46.1% of the plants with 2.0-2.5 cm height and 1.5-2.0 cm root length survived.Acclimatizated plants were successfully transferred in garden soil conditions. Thefirst growing season is critical for in vitro obtained plants and they grew slowly.About 60% of the plants could tolerate and survive under soil conditions. The plantsgrow normally after overcoming the stress of change in growing conditions, and thesecond year of development they start to flowering (Fig. 1g).262