In order to improve the quality and have some control over such things as color pattern etc. in our Show Kings we must be familiar with some basic knowledge of genetics and how to put them to use in our breeding programs. The scientific study of genetics can be very complicated and time consuming, as well as difficult to understand. I do not grasp the more technical aspects of it and am a very slow learner, so at this point in time can only relate some basics that as I understand them. However, these basics should be more than enough to accomplish what is needed to successfully breed Show Kings.
This first article will introduce you to some basic terminology and makeup of the pigeon. Future articles will deal with color, pattern, mutations etc. Understand that all these discussions on genetics apply to ALL pigeons and not just Show Kings. The only difference between the King and other breeds or variety of pigeons is the lack of genes that set the blue-print for that breed, such as a crest, feathered feet, toy stencil, pattern, fanned tail, very long or very short legs, etc. We could introduce any of these genes into our King, but of course this would change the King from our designated standard and this is not our purpose.
I will start with some terminology of genetics and try to give a simple definition of some of these, however, in some cases the definitions themselves seem hard to understand fully and require some repeating. The more you see in some of these terms used in writing, the more clear their meaning will become.

CELL : The Basic unit of life, the building component of all living things.

NUCLEUS : Regulates growth and development of the cell, the center of genetic potential.

CHROMOSOME : Located within the nucleus and composed of DNA thread-like fibers, they carry the genes.

GENE : Transmitted from parents to progeny, the gene determines heredity and occupies a fixed locus on the chromosome.

LOCUS : The position, location, that a gene occupies on a chromosome. More than one gene may occupy a chromosome and it is in a fixed position.

GENOTYPE : The gene make-up of an individual. What the bird actually is, rather than what it looks like.

PHENOTYPE : The actual appearance of the bird, what we see, determined by genotype.

ALLELE : Any of a series of possible genes which occur at the same locus on the same chromosome.

HOMOZYGOUS : Identical alleles at a gene location. A blue bar cock carries two chromosomes which contain the color genes, if both color genes are blue/black, then he is homozygous for that color.

HETEROZYGOUS : Two different alleles at one or more loci (locus). A blue bar cock that carries one color gene for blue/black and the other for brown would be heterozygous.

HEMIZYGOUS : Only one pair of alleles is present. An ash red hen carries only one sex chromosome which carries the gene for color, so she is only ash red and can supply no other color to a mating. She is hemizygous for ash red.

LINKAGE : There are many chromosomes in pigeons, a few have more than one gene. Where there are two or more genes on the same chromosome, they are linked.

SEX LINKAGE : One type of chromosome in pigeons determines the sex of the bird. There are four different types of genes located on this sex chromosome. These genes are sex linked, that is, any of these genes can play a role in determining the sex of a bird.

WILD TYPE : The most frequently observed phenotype, this type is used as the standard for comparison. The original ancestor to all domestic pigeons, the rock dove, is a blue bar patterned bird. The basic standard blue bar homing type pigeon is considered wild type.

There are lots more genetic terms, and a few may pop up in future articles, but these should help to start. Some of them will be easier to understand as they are used more in association with other terms and explanations.
In the next article I will start with some discussion on chromosomes and sex linkage. As most of you who have bred pigeons for a while know, the cock carries two sex chromosomes and the hen carries only one. These sex chromosomes are used to determine the sex of the offspring. There are also many other types of chromosomes carried by the pigeon, most with a single gene but a few with more than one gene contained within. However, the big difference between these chromosomes and the sex chromosomes is that most these other types the hen carries two just like the cock. For example, the color indigo is actually a modifier gene located on a separate chromosome from the one (sex chromosome) that carries one of the three basic colors that all pigeons have. An indigo hen actually can carry one or two of these chromosomes, which would determine whether she was homozygous or heterozygous for indigo ! I will discuss indigo and other modifiers in later articles. Good luck with your breeding program.