Lavandula angustifolia Mill. and lavandin (Lavandula  intermedia Emeric ex Loisel) are promising fragrant plants with medicinal, aromatic and ornamental properties. To obtain high quality healthy planting material, in vitro cultures of valuable cultivars Belyanka, Record (lavender) and Rabat, Snezhnyi Bars (lavandin) were derived. Obtained regenerants were cultured for 4-5 months on Murashige and Skoog medium with 0.3 mg/l kinetin, 0.025 mg/l NAA и 0.25 mg/l GA 3 in growth chamber at 25±1 C under 16-h photoperiod and light intensity of 37.5 μMŁm  2 Łs  1. Intact plants were studied during the growing season. In order to reveal plant morphogenetic capacity, biochemical stress indicators, indexes of photosynthetic activity, maximum fluorescence (F m), stationary level of fluorescence (F st) and water regime were determined. The proline content of lavender and lavandin plants grown ex situ was rather high (6.67-21.59 μg/g). In in vitro micro-plants, although there was considerable hydration of the plant tissues, the proline concentration was higher than that in the intact plants (8.24-35.72 μg/g). Intact lavender and lavendin plants accumulated high amounts of phenolic compounds (1033-1492 mg/100 g) and ascorbic acid (14.96-20.06 mg/100 g). In plants under controlled conditions, the concentration of phenolic compounds and ascorbic acid was lower (490-777 and 4.95-5.98 mg/100 g, respectively), which is caused by significant waterlogging of tissues and lack of stress. Regardless of the growing condition, the level of phenolic compounds was higher in the lavandin cultivars compared to lavandula plants. Open field cultivated plants were distinguished by high activity of catalase (18.13-36.97 g O 2 Łg  1 Łmin  1) and superoxide dismutase (12.55-14.82 a.u./g). Under the hydrothermal stress effect ex situ, relative photosynthetic activity and viability index indicated minor decrease in assimilation processes in lavender cultivars but was within vital limits. In in vitro culture, the catalase activity of lavender cultivars was higher than that of lavandin. At the same time, SOD and PPO activity of lavender micro-plants in vitro was lower than that of lavandin micro-plants. In open field cultivation, leaf tissue hydration of tested plants was 56-62 %, with greater part of bound water. In plants cultured in vitro, the rate of hydration was high (70-77 %), with the same trend of water fractional composition. Under the controlled conditions and nominal heterotrophic nutrition type, photosynthetic activity was 0.28-0.55 a.u. with the maximum in the Rabat cultivar. Values of chlorophyll fluorescence induction and vitality index indicated no photoinhibition. It was found out the lavandin cultivars had better capacity for a wide use under various conditions.

Lavandula angustifolia Mill. and (LavandulaxintermediaEmericexLoisel) are promising fragrant plants with medicinal, aromatic and ornamental properties. Since the collection plantations of these crops are very damaged with viral pathogens and there is lack of seed propagation in valuable cultivars 'Belyanka', 'Record' (lavender) and 'Rabat', 'Snezhnyi Bars' (lavandin), were introduced in vitro. Chemotherapy was used for cleaning up. Regenerants were cultured (4-5 months) on MS medium with 0. 3 mg L -Kinetin, 0. 025 mg L -NAA and 0. 25 mg L -GA 3 at 25±1°C under 16-h photoperiod. Intact plants were studied during the growing season. In order to reveal plants` biotechnological and genetic capacity some biochemical stress indicators, indexes of photosynthetic activity and water regime were identified. Under the open field cultivation, tested plants were rich in ascorbic acid, phenolic compounds, and redox enzymes (catalase, polyphenol oxidase, superoxide dismutase) were active. Leaf tissue hydration was 56-62%, with greater part of bound water. Photosynthetic activity was reduced only in the samples with visible damages with viral pathogens. In plants cultured in vitro, amount of ascorbic acid and phenolic compounds were lower, so as enzymatic activity and proline concentration were higher than in intact plants. The rate of hydration was high (70-77%), with the same trend of water fractional composition. Photosynthetic activity and vitality index indicated no photoinhibition. It was found out the lavandin cultivars had better capacity for a wide use under various culture conditions.

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A b s t r a c tLavandin cultivars (Lavandula ½ intermedia Emeric ex Loisel.) are sterile interspecies hybrids Lavandula angustifolia Mill. ½ L. latifolia Medic. They are of great interest for the essential oil industry. Lavandin cultivars express 1.5-2-fold higher yields of raw biomass and essential oil production, as well as 4-fold higher essential oil yield per area unit as compared to the used lavender cultivars. World production of lavandin essential oil is 1200 thousand tons, and lavender oil production is only 200 thousand tons. However, the quality of lavandin essential oil is lower compared to lavender one because of camphor, 1,8-cineole and borneol significant amounts. Besides, it is impossible to use lavandin cultivars in further breeding works, as they are sterile. The main trend in lavandin breeding is to improve the essential oil quality by reducing unwanted components to a minimum. In order to create lavandin hybrids characterized by high essential oil quality we had first synthesized tetraploid forms of L. angustifolia and L. latifolia and then crossed these forms with each other. As the result, their sterility was overcome and amphidiploid hybrids were obtained. Those hybrids were further used to create new highly effective cultivars. Crossing between amphidiploid hybrid ¹ 48 and lavender cultivars (Belyanka, Record, Prima) let us to select cross combinations and create lavandin cultivars with minimum amount of camphor, borneol and 1,8-cineol. It was revealed that obtained plants often demonstrated intermediate when compared to their parental forms. Thus, initial forms with high content of linalool and linalyl acetate and lower content of unwanted compounds should be used in breeding works. In cross combinations Amphidiploid 48 ½ Belyanka, Lavandin hybrids with high content of linalool (up to 68.8 %) were derived. Some hybrids had the content of borneol (up to 0.5 %), camphor (1.9 %) and 1,8-cineole (1.8 %) similar to that of parental forms. In cross combination Amphidiploid 48 ½ Prima hybrids were obtained with high content of linalool (up to 57.9 %) and linalyl acetate (up to 32.8 %) and low content of camphor (0.2 %), borneol (1.6 %) and 1,8-cineole (up to 0.9 %). The results of our investigations demonstrated that it is possible to create Lavandin hybrids with borneol amount lower than in the original forms. Camphor and 1,8-cineole content depression was not beyond the intermediate type of inheritance. We suppose that the extremely low content of 1,8-cineole and camphor in the lavender chemotypes selected for breeding corresponds to their lower biological limit of these metabolites. Hybrid plants (L. ½ intermedia) can only approximate these characteristics of L. angustifolia. Lavandin hybrids with the best essential oil composition have been obtained by crossings between the most closely related, from a biological point of view, chemotypes with dominant alleles of linalool and linalyl acetate and recessive alleles of camphor and 1,8-cineole in L. angustifolia, which is possible under creating ...

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