Evaluation of productivity at the leaf level of juvenile poplars

Abstract

The purpose of this research was the comparative study of the morphological traits of the poplars assimilation apparatus and their possible use in the selection process. Leaf area, not leaf length, was taken as a unit of the plastochronic index for the first time in this work. Analysis of the sigmoidal curve of the growth of the fifth leaf of the apical shoot of poplar showed that 80% of the maximum leaf surface is reached through an interval of 2.2 plastochrons and corresponds to the 20-day calendar age of the leaf. It is noted that the raw biomass of the cross-section poplar 'Hybrid e.s.-38' was significantly higher than in other compared varieties. Two groups of genotypes with a high and a low specific surface leaf density were identified. Average size of the leaf area, as well as the total amount of the assimilating surface of the apical shoot of the poplar 'Hybrid e.s.-38', 2 and more times exceeded the similar parameters of the poplars studied. Such changes in the current increment and age dynamics of the photosynthetic apparatus of the cross-section 'Hybrid e.s.-38' allow to recommend it in breeding as a parent material for creating promising varieties of poplars.