Chemogenetic study of phenolic compounds extracted from loblolly pine (Pinus taeda L.) needles

Abstract

This study was carried out to examine the variation of phenolic constituents of pine needles among selfed progenies of loblolly pine and to determine the inheritance patterns of phenolic constituents in loblolly pine needles. One-year-old needles of the selfed progenies were examined for the presence of absence of individual compounds. Four phenolic compounds which occurred sporadically among the selfed progenies were examined for segregation ratios. One of these compounds, compound 53, was identified as dihydrokaempferol 7-0-glucoside. Segregation ratios of these compounds were tested by chi-square analysis. The observed segregation ratios of compound 53 fit a single gene hypothesis best. The inheritance patterns of other phenolic compounds are not clear from this study. One-year-old needles of parents and grafts, if still available, were examined to determine if they conformed to the expected phenotype. In a few cases, the phenotypes of the parents did not conform to the expected phenotypes. Differences in age of trees and in year of needle collection might be possible causes. The phenotypes of grafts generally conformed to the expected phenotypes. Compounds found in grafts of a particular family were found in S1 progenies of that family in high frequency of occurrence (75%-93%), whereas compounds not found in grafts were found in S1 in much lower frequency of occurrence (16%-44%). The variation observed among the selfed progenies were results of genetic differences Environmental factors were not a significant contributor to the variation in phenolic content observed among the selfed progenies in a family. The difference in needle constituents between current and 1-year-old needles was conspicuous. No difference in needle constituents between 1- and 2-year-old needles was observed; however, needle constituents of 1-year-old, and possibly 2-year-old, needles varied seasonally.