Morphological and anatomical characteristics of needles in seedlings and vegetative progeny of different ages from mutational witches’ brooms of Pinus sibirica Du Tour

The study was carried out using three objects: 1) clones of the mutational witches’ brooms and the normal crown grafted together on the same rootstock; 2) mutant seedlings of the witches’ brooms; 3) clones of the witches’ brooms mutant seedlings. It was shown that the morphological and anatomical needle characteristics are affected as by the presence and the expression of the mutation, as well as the age of the maternal tree and the presence of a rootstock. Each factor and the interaction of some factors makes a significant contribution to the differences between the groups in the main needle characteristics. The mutant seedlings and their clones formed the shortest needles; they also had smaller areas of the central cylinder, resin ducts, mesophyll and vascular cylinder. Morphological and anatomical needle traits varied between the families, the needle length was a rather conservative trait in the families. Some differences between the groups from different families of witches’ brooms were due to the natural diversity of the maternal witches’ brooms.