Cytogenetic and Biochemical Characteristics of Callus <i>Pinus sylvestris</i> L.

Abstract

A comprehensive assessment was carried out of the changes occurring during the darkening of the callus obtained from vegetative buds of 40-year-old Scots pine treesPinus sylvestrisL. Based on biometric assessment of callus (intensity of callus formation, proportion of light callus, callus mass) from 32 analyzed trees (16 genotypes represented by two clones), two genotypes with high callus-forming ability were singled out. Analysis of mitosis showed that, although the proportion of aberrant cells in the callus does not exceed the rate of spontaneous mutation forP. sylvestris, the range of violations at the stage of meta-, ana-, and telophase in the callus culture was wider compared to that in the seed progeny of the same pine trees. Darkening of the callus was accompanied by a decrease in sucrose metabolism in the cell (decrease in cytoplasmic, vacuolar invertase and sucrose synthase) and a significant decrease in peroxidase activity. At the same time, the activity of apoplast invertase was maintained at a constant level. The activity of superoxide dismutase, catalase, polyphenol oxidase, and phenylalanine ammonia lyase, on the contrary, was higher in dark callus. The possible use of the studied enzymes as biochemical markers of the transition to darkening callus pine crops is discussed.