CREATION OF CEDAR GARDENS ON GENETIC AND BREEDING BASIS

Titov E.V.

Voronezh state timber college,

Russia lesovod@vglta.vrn.ru

In Russia last 20-30 years preparation of pine nuts has sharply decreased at unlimited demand for this high-calorific, non-polluting product of high biological activity.

Revival of their mass manufacture contacts creation of highly productive cedar gardens on a genetic and breeding basis. Preconditions are individual variability of trees in populations on parameters семеношения (to size, dynamics (changes), structural attributes of a crop, pollen efficiency), high heritability of these properties in vegetative posterity маточных trees. The great value in formation of high crops has sexual types variability.

There are two ways of creation of high-yielding cedar gardens: 1 – cleaning cutting in cedar young stands and 2 - a bookmark clone seed orchards.

The first way went spontaneous national selection at formation “near village” Pinus sibirica seed stands. The effect of increase of crops in them is connected to duly clarification of perspective genotypes on seed efficiency. Above it in a zone of an ecological optimum of a kind. In low mountain Northeast Altai in 60-70-years stands, generated from such trees, it is possible to receive 230-740 kg/ha of seeds.

More significant (in 1,5-2 times it is more) crops of pine nuts give clone seed orchards. The cloning of plus trees allows already on 20-25-years orchards to receive industrial crops of nuts (500-600 kg / ha), i.e. on three - four decades earlier, than in “near village” seed stands.

Formation of high crops on a plantation is promoted mainly by effective pollination of high-yielding clones. In natural populations reliability of cross-pollination with them is provided with genotypes of the mixed and man's sexual types. For reception of high crops clone orchads, at absence of other reliable sources of natural pollination, it is necessary to create in view of sexual differentiation of trees. On them it is necessary to place clones of various (opposite) sexual type and productivity: high-yielding and mean-yielding. At the limited set of genotypes on a plantation it allows high-yielding individuals to realize the potential seed efficiency maximum. At cross-pollination of high-yielding genotypes the crop of seeds is reduced on the average on 27 %.

The optimum parity (ratio) high-yielding and mean-yielding clones - 3 : 1, accommodation of them is ordinary, mixture of numbers (lines) - regular. Because of weak pollen efficiency accommodation of high-yielding clones to the neighbourhood is supposed. Mean-yielding clones should be isolated reliably by them from each other since them cross-breeding does not lead to increase in a crop.

For stabilization of crops it is necessary to have a mixture of clones with different rhythmic of seed yielding - both rather constantly fructifying, and high-yielding in low-yielding years.