Individual and geographic variability of Picea obovata cones in the Russian part of its area in relation to the seeds quantity in them

The cone length of Picea obovata Ledeb. is closely related to the seeds quantity that causes the importance of full-scale study of this indicator. Studies were carried out in the entire Russian part of the P. obovata range from Murmansk region to Transbaikalia and Yakutia. It was found that geographical variability of cone length is relatively small (44–77 mm) and significantly inferior to individual variability (45–110 mm). The coefficient of a variation is 10 and 14%, respectively. We found that in the total population of Picea abies (L.) H. Karst. and P. obovata determined by their strong introgressive hybridization, cones of P. obovata is the category small and average. It is reasonable to distinguish an additional category of very small cones. The established categories of cones are characterized by the following length: very small 50 (54 mm and less), small 60 (55–64 mm) and medium 70 (65 mm and more). The approximate number of full seeds in them at good yields is 76 (less in extreme conditions of the Far North), 78–92 and 94–108 pieces, respectively. These figures are important for assessing the processes of spruce forest regeneration. Geographical distribution of average cone length in the studied territory it is not clearly expressed. The smallest cones are characteristic of spruce populations along Arctic Circle and in the Polar Regions, while in populations of the southern part of the range they are much larger. The majority of the Russian populations of P. obovata (about 2/3) have cones 65–70 mm long. The content of full seeds in cones is rather small.