Zoned potato varieties reaction on tuberization media in vitro
The conception of potato genotype specificity response to in vitro conditions forces us to optimize the cultivation conditions for each variety for microtuberization (MTB) method seed production. Zoned varieties, based on the similarity of field conditions requirements, could be cultivated on standardized media with the achievement of a sufficient average MTB efficiency. The morphometric parameters dynamics (7-62 days) of microplants from the collection of cultivars, widely cultivated in the Krasnoyarsk Territory, were studied on Murashige-Skoog media, containing MTB inductors: sucrose (80 g/L) (M0) and phytohormones in addition: kinetin (1 mg/L) (M1) or a combination of kinetin (2 mg/L), adenine, IAA (1.5 mg/L each) (M2). Hormone- free medium with 30 g/L sucrose was used as control. No inducing effect was detected of phytohormones on MTB frequency and process dynamic of investigated cultivars, except Red Scarlett, under sucrose concentration, had been used in the present study. The determining factor inducing MTB was a high level of sucrose (80 g/L). The phytohormones influence was manifested in the differences in the varietie`s growth parameters. Root systems of domestic cultivars Antonina, Charoit, Hozjajushka were completely developed by 28 days on all media. Close values of the shoot height and the internodes number on M0-M2 media during most of the cultivation period were detected. Meteor, Rosara, and especially Red Scarlett cultivars were distinguished by a decrease in growth parameters in the line of conditions Control> M0> M1> M2. Cultivars groups, marked in vitro, differ by the habitus of plants formed by cultivars under the field conditions. The first three cultivars are tall plants with large leaves, the second group consists of intermediate type plants. However, we can already speak, based on data on growth inhibition, about the advantage of media with phytohormones for cultivars with the same habit as the second group has. Such reaction may be indirect evidence of the redistribution of assimilates in favor of MTB.