INTERSPECIFIC HYBRIDIZATION IN LAVANDIN (Lavandula × intermedia Emeric ex Loisel.) BREEDING FOR ESSENTIAL OIL QUALITY

Abstract

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 ...