The Influence of Spruce Seeds Longevity on Their Practical Germinating Ability

Abstract

Introduction. In the Republic of Mari El, harvesting of a great many spruce seeds and laying them on long-term storage is first and foremost explained with a vast periodicity of seeding (up to 4 years). There are no many researches on dynamics of spruce germinating capacity on long storage. Germinating capacity of seeds for the last day of  germinating with no analysis of germinating capacity in the days of  intermediate accounting are considered in most of the existing researches. The goal of the research is to define the optimum storage period for the spruce seeds and to analyze the dynamics of their germinating capacity on long storage. Objects and methods. The seeds  were harvested in the Republic of Mari El in winter- 2007/2008 in the  middle-aged, ripening and mature stands. All the harvested seeds  fall under the category of   natural seeds. The germinating apparatus of forest plants PLUS.441352.001 RE was used to define the germinating capacity of seeds at a water temperature of  24 ºС (night mode) and 36 ºС (day mode).  One hundred seeds in four repetitions of each of 14 seed lots were used for the germinating purpose. The account of germinating capacity of seeds was conducted on  7, 10 (germinating power) and 15 day of germinating. The germinating capacity of fresh-harvested spruce seeds and the seeds harvested 1, 2, 4, 6, 7, 8, 9, and 10 years ago was analyzed. Results. Fresh-harvested seeds are of good sowing capacity. The germinating capacity of fresh-harvested spruce seeds  on 7 day of germinating varies 47 -86 % depending on a lot; 10 day − 70- 96 %,  15 day  −  76 -98 %.  The germinating capacity of  spruce seeds after 10 years of storage is significantly low: it is 1-48% on 7 day of germinating , 3 - 77 %  on 10 day of germinating, and  6-88 % on 15 day of germinating. Good germinating capacity of fresh-harvested seeds is not a guarantee to save the capacity  in case of long storage. Difference in germinating capacity of  the seeds on long storage  (taken of different lots) is higher in comparison with the same parameter of fresh-harvested seeds. Conclusion. Mean germinating capacity of seeds of middle-aged stands  was 84,1 %, which was fairly lower the germinating capacity of seeds  harvested in the ripening (93,3 %) and mature stands (94,7 %). When storage, the germinating capacity of spruce seeds is sharply decreased: on  7 day of germinating for one year old seeds, on 10 and 15 days of germinating  for four year old seeds. Fifty point nine percent  of fresh-harvested seeds  are attributed to I class quality,forty ine point percent - II class quality . In two years of storage, the share of  I class seeds is increased up to 87,6 %, but the share of II class seeds is decreased up to 12,4 %. In the following years, the share of  I class seeds is decreased,  the share of II class seeds is increased. In 7 years of storage,  III class seeds are found. In 10 years of storage, the share of  I class seeds is 2,8 %, II class seeds – 4,9 %, III class seeds – 77,3 %,  the share of nonconforming seeds is  15,0 %. The recommended term of spruce seeds storage in a building without an air-temperature control equipment is 6 years.