Preface to the Series
Genome sequencing has emerged as the leading discipline in the plant sciences coinciding with the start of the new century. For much of the twentieth
century, plant geneticists were only successful in delineating putative chromosomal location, function, and changes in genes indirectly through the use
of a number of “markers” physically linked to them. These included visible
or morphological, cytological, protein, and molecular or DNA markers.
Among them, the first DNA marker, the RFLPs, introduced a revolutionary
change in plant genetics and breeding in the mid-1980s, mainly because
of their infinite number and thus potential to cover maximum chromosomal
regions, phenotypic neutrality, absence of epistasis, and codominant nature.
An array of other hybridization-based markers, PCR-based markers, and
markers based on both facilitated construction of genetic linkage maps,
mapping of genes controlling simply inherited traits, and even gene clusters
(QTLs) controlling polygenic traits in a large number of model and crop
plants. During this period, a number of new mapping populations beyond F 2
were utilized and a number of computer programs were developed for map
construction, mapping of genes, and for mapping of polygenic clusters or
QTLs. Molecular markers were also used in the studies of evolution and
phylogenetic relationship, genetic diversity, DNA fingerprinting, and
map-based cloning. Markers tightly linked to the genes were used in crop
improvement employing the so-called marker-assisted selection. These
strategies of molecular genetic mapping and molecular breeding made a
spectacular impact during the last one and a half decades of the twentieth
century. But still they remained “indirect” approaches for elucidation and
utilization of plant genomes since much of the chromosomes remained
unknown and the complete chemical depiction of them was yet to be
unraveled.
Physical mapping of genomes was the obvious consequence that facilitated the development of the “genomic resources” including BAC and YAC
libraries to develop physical maps in some plant genomes. Subsequently,
integrated genetic–physical maps were also developed in many plants. This
led to the concept of structural genomics. Later on, emphasis was laid on
EST and transcriptome analysis to decipher the function of the active gene
sequences leading to another concept defined as functional genomics. The
advent of techniques of bacteriophage gene and DNA sequencing in the
1970s was extended to facilitate sequencing of these genomic resources in
the last decade of the twentieth century.
vii
Genome sequencing has emerged as the leading discipline in the plant sciences coinciding with the start of the new century. For much of the twentieth
century, plant geneticists were only successful in delineating putative chromosomal location, function, and changes in genes indirectly through the use
of a number of “markers” physically linked to them. These included visible
or morphological, cytological, protein, and molecular or DNA markers.
Among them, the first DNA marker, the RFLPs, introduced a revolutionary
change in plant genetics and breeding in the mid-1980s, mainly because
of their infinite number and thus potential to cover maximum chromosomal
regions, phenotypic neutrality, absence of epistasis, and codominant nature.
An array of other hybridization-based markers, PCR-based markers, and
markers based on both facilitated construction of genetic linkage maps,
mapping of genes controlling simply inherited traits, and even gene clusters
(QTLs) controlling polygenic traits in a large number of model and crop
plants. During this period, a number of new mapping populations beyond F 2
were utilized and a number of computer programs were developed for map
construction, mapping of genes, and for mapping of polygenic clusters or
QTLs. Molecular markers were also used in the studies of evolution and
phylogenetic relationship, genetic diversity, DNA fingerprinting, and
map-based cloning. Markers tightly linked to the genes were used in crop
improvement employing the so-called marker-assisted selection. These
strategies of molecular genetic mapping and molecular breeding made a
spectacular impact during the last one and a half decades of the twentieth
century. But still they remained “indirect” approaches for elucidation and
utilization of plant genomes since much of the chromosomes remained
unknown and the complete chemical depiction of them was yet to be
unraveled.
Physical mapping of genomes was the obvious consequence that facilitated the development of the “genomic resources” including BAC and YAC
libraries to develop physical maps in some plant genomes. Subsequently,
integrated genetic–physical maps were also developed in many plants. This
led to the concept of structural genomics. Later on, emphasis was laid on
EST and transcriptome analysis to decipher the function of the active gene
sequences leading to another concept defined as functional genomics. The
advent of techniques of bacteriophage gene and DNA sequencing in the
1970s was extended to facilitate sequencing of these genomic resources in
the last decade of the twentieth century.
vii