MICROCLONAL PROPAGATION OF MELISSA OFFICINALIS L.

Abstract

Depending on the type of explant, appropriate conditions for sterilization were selected. On the first stage of the work, as explants, green ticks (stems with a single node) of the medicinal varieties 'Soborna', which were isolated from plants in situ, were used as explants. To obtain aseptic melanoma explants, sterilization was performed in two regimens using the commercial preparation "Lysine" and 0.1% solution of HgCl₂. Among them, the best scheme of sterilization of explants using 70% ethanol (1min), 0.1% HgCl₂ (7min) and 4-time flushing in distilled water for 10min was chosen. Under this scheme, the level of contamination by microorganisms was the lowest (5.5%).

When introduced into an in vitro culture, seeds of the 'Lemon Balsam' strain were sterilized for 1min in 70% ethanol, followed by transferring to a 15min 0.1% HgCl₂  and washed 3 times with distilled water (10min). This scheme provided the effectiveness of sterilization at 100%, but the amount of germinated seeds was 70%. This can be explained by the fact that with increasing sterilization duration it is possible to achieve absolute sterility, but the amount of germinated seeds can decrease due to necrosis of the embryos. The obtained aseptic cuttings and seeds were transferred to the non-hormonal nutrient medium of MS. Subsequently, in the explants derived from plants in situ, slow growth was observed. When transferring parts of stems with one sleeping kidney to a modified nutrient medium MS1 supplemented with IMC (0.1 mg/l), BAP (0.5 mg/l), glycine (0.5 mg/l) and adenine (0.1 mg/l), there was the launch of sleeping kidneys, but the growth of shoots thus reached less than 1cm.To improve the method of micropropagation of melissa plants, we studied the influence of MS2 medium supplemented by KIN (0.25 mg/l) on the development of explants. At day 14, they observed the formation of roots on the basal part of the shoots (2-3pcs), the height of the shoots reached at least 2cm, further formed 3-4 leaves. During the development of the plant, regenerators actively recruited their vegetative mass, they had a well developed root system, the height of the shoots was not less than 15cm. Such plants are suitable for adaptation to in vivo conditions. Subsequently, for the propagation of mulch, micro-humans with one node were already obtained from well-formed regeneration plants and transferred to a fresh medium MS2. We have found that in all explants, after two weeks of cultivation, the growth of shoots from the axillary buds began and roots were actively formed.

As a result of the conducted research, it was found that the MS2 medium supplemented with KIN(0.25 mg/l) contributed to the effective collection of vegetative mass and the formation of the root system, which allowed further adaptation of the regenerated plants to in vivo conditions.