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On the stratification of viburnum seeds

Viburnum (Viburnum opulus) Viburnum ordinary (Viburnum opulus) - a tall shrub with beautiful three-lobed leaves, colored by autumn in yellow and purple tones, is used in ornamental gardening to create groups, alleys and single plantings. Recently, in connection with obtaining varieties with low-bitter and sweet fruits, it has gained great popularity among amateur gardeners as a new berry crop. In addition to its decorative and nutritional value, Viburnum vulgaris is also noted as a good honey plant.

But the widespread distribution of this berry shrub is hampered by the fact that it is propagated only by vegetative methods. Meanwhile, the experiments carried out on growing Viburnum vulgaris from seeds from sweet-fruited specimens in the absence of specimens with bitter fruits as pollinators showed that the plants grown from these seeds in mass have sweet fruits. Moreover, some forms have even sweeter fruits than the maternal or pollinator forms. In this way, if there are only sweet-fruited forms on the mother plant, amateur gardeners can simultaneously carry out breeding of viburnum with reproduction.

Viburnum vulgaris belongs to a group of plants with a long dormant period and a complex cycle of development of the embryo of seeds. With the usual methods of stratification of seeds and the timing of planting, shoots of viburnum appear only after a year and a half. To speed up the process of growing viburnum seedlings, as well as to create the prerequisites for the selection work of this berry crop, Z.P. Zholobova at one time carried out a lot of research work, and developed methods to ensure the emergence of seedlings in the year of sowing seeds. The study of stratification of seeds of Viburnum vulgaris was based on different temperature regimes at different stages of stratification in accordance with the stages of embryo growth.

As a result, the following technique was developed. For germination of the guelder-rose embryo root, it is necessary to perform stratification at high temperatures, + 20 ... + 30 ° С. Under these conditions, pecking of seeds begins after 40 days, but mass germination occurs only after 80-90 days from the beginning of stratification. A more friendly germination occurs under the influence of variable temperatures, from +10 to + 30 ° C. With the exit of the root tip from the seed cover, the growth of cotyledonous leaves and an embryonic bud begins, but in conditions of high positive temperatures, it quickly stops.

Viburnum (Viburnum opulus)

Treatment of seedlings with stimulating solutions (0.5% glucose, 0.01% gibberellin, or 0.005% BCI) can extend the growth period of the embryonic bud inside the seed by 10-12 days. To resume the growth of the aboveground organs of seedlings, it is necessary to keep them for a short 14-30 days at low positive temperatures, + 1.5 ... + 3 ° C (in a basement or refrigerator). The period of growth of the rudimentary bud and cotyledonous leaves until they emerge from the seed covers lasts up to five months and requires relatively high temperatures - over + 18 ° C. Wet sand, peat chips, sawdust can be used as a substrate for stratification. To reject rotten seeds and select seedlings, the seeds should be checked once every 10 days. After keeping the seedlings at low positive temperatures, they are planted in planting boxes or nurseries. The seedlings obtained in this way in the year of sowing by the end of the growing season manage to form two pairs of true leaves, and after a spring pick, by the fall of next year, standard seedlings grow from them.