Genomes: Classical Era

Abstract

The study of conifer genomes began in 1933 with the publication by Sax and Sax (1933) of chromosome numbers found in several conifer species. From 1933 until the beginning of the application of recombinant DNA technologies in the 1970s, the study of conifer genomes was done using classical cytogenetic techniques. From the 1970s until the late 1990s, a suite of developing DNA technologies was applied to the study of conifer genomes. We have labeled the years between 1933 and the late 1990s as the classical era in the study of conifer genomes. Beginning in the late 1990s, high-throughput DNA sequencing began to be applied. We have labeled this period as the modern era which will be covered in Chap. 3. In conifers, like all higher plants, there are three genomes; the nuclear genome (nDNA), the chloroplast genome (cpDNA), and the mitochondrial genome (mtDNA). In this chapter we will discuss what was learned about chromosome number, ploidy, karyotypes, genome size, and basic genome content in all three genomes during the classical era.