Long-term storage of Scots pine (Pinus sylvestris L.) seeds as a basis for energy plantation establishment on marginal lands in Ukraine

Abstract

Purpose. To establish possibilities and conditions of long-term storage of Scots pine seed of different initial quality without losing its quality characteristics.Methods. Field, laboratory, statistical.Results. After 1, 2 and 3 years after the seeds were laid for storage in hermetic foil bags placed for permanent storage in chambers with a constant temperature of +4 °C and -20 °C, it was found that after the first year of storage, the seeds quality indicators fall significantly more when stored in chambers at -20 °C than at +4 °C. When stored for three years at +4 °C and -20 °C, there was no significant difference in the quality of fresh seeds. Aged seeds had high germination rate and seed vigor when stored in chambers at -20 °C. After three years of storage at a temperature of -20 °C, the highest quality seeds had seed vigor of 72%, and germination rate of 81.5%. The least qualitative, respectively: 44.5 and 53.0%. Analysis of the quality of samples of pine seeds, conducted after 10 years, showed that seed vigor of various samples during storage at +4 °C varied from 52.0 to 80.2%, and germination rate from 73.0 to 93.7%. At a temperature of -20 °C, the seed vigor of samples of different origin was from 70.5 to 96.2%, and the germination rate was 76–97.5%. Seed vigor in all samples is much better preserved at -20 °C. Over a 10-year period at -20 °C, it decreased from 0 to 16.0%, at a temperature of +4 °C by 13.8–34.3%. The germination rate of four of the six samples was also higher when stored at -20 °C. Over a 10-year period at -20 °C, germination rate decreased from 0 to 19.0%, and at a temperature of +4 °C – by 2.8–22.0%.Conclusions. An effective way for the long-term storage of Scots pine seeds is to place it in hermetic foiled bags in chambers with a constant temperature of + 4 °C and -20 °C. Sowing qualities of seeds at -20 °С are better preserved. The higher quality seeds were deposited, the better they were preserved over a 10-year period. The highest quality after long-term storage was pine seeds from clonal seed plantations of the first and second orders of the ‘Gutianske Forestry’. This indicates that their indicators are influenced not only by climatic and environmental conditions, but also by genotype.