◎ I know this is boring with all the explanations, please bear with me.... But this is the most important part.

"the essence of life is to reproduce itself (to procreate)."
This definition is controversial, but it is the prevailing view in biology.
When I consider the F1 species according to this definition, the question arises, "Isn't this out of the nature of life?"

In my previous post (2), I wrote that the rudimentary method to produce F1 is to pull out all the stamens and leave only the pistil, so that the pistil will not self-pollinate with the pistil of the same flower. This is a method called "dehiscence".

It is an incredibly time-consuming and labor-intensive process to manually pull out a large number of stamens one by one. Is there a more efficient way to produce F1 seeds? After some trial and error, we came up with the "male sterility" method of F1 production.

Male sterility is an unfamiliar term. What does it mean?

A "normal" individual flower has a stamen and a stamen plug. Pollen is contained in the stamen. When the stamen is split or punctured, pollen is released. Once the pollen reaches the pistil and pollinates it, the cotton ball begins to grow and expand as a fruit.

Male sterility is a condition in which there is some abnormality in the "stamen" or "yaku" that causes dysfunction or no pollen. In the case of laboratory mice, the male mouse's reproductive organs are dysfunctional or azoospermia occurs even if sperm is available. In other words, the male mouse is unable to mate with a female mouse, or even if it does mate, the egg is not fertilized and no offspring are produced.
(I apologize if anyone is offended by this analogy.)

A certain percentage of individual flowers are found to be male sterile due to a genetic abnormality. The cause is believed to be a malfunction in the expression of a genetic switch.

In other words, male sterility is an individual with no stamens and only pistils.

Recall the example in my previous post (2).

○ Cotton A is characterized by small cotton balls but strong fibers.
○ Cotton B is characterized by large cotton balls but weak fiber strength.

In both Cotton A and Cotton B, a certain percentage of individuals are found to be male-sterile due to a genetic malfunction. Once we find male sterility in Cotton A or B, we can eliminate the process of manually pulling out the stamens and, according to the genetic law of "hybrid vigor," create a large number of F1 seed with the new trait, AB.

Male sterility is transmitted from mother to offspring. If the mother is male-sterile, all her offspring will be male-sterile. The grandchildren will also be male sterile. All offspring will be male-sterile, which, in the mouse analogy, means that the azoospermia trait will spread from the mother to all of her offspring. By replicating large numbers of male-sterile individuals, large numbers of F1 strains can be produced and placed on the market.

Cotton F1 varieties have a wide variety of complex traits such as white color, long fiber, strength, fineness, luster, resistance to certain insects, resistance to certain diseases, resistance to heat, resistance to cold, etc., which are being developed by seed producers on a daily basis to provide a wide range of traits that are beyond our grasp.

The development of F1 varieties brings great benefits to midstream industries, such as cotton ginners and spinners, and downstream industries, such as designers and marketers. This is because raw cotton (raw cotton balls) of uniform size, quality, and harvest time are delivered from the fields. It is also good for the end consumer to be able to purchase cotton products of improved quality.

On the other hand, the introduction of the F1 variety in the 1960s placed an increased economic burden on cotton farmers. Cotton farmers, who had previously collected their own seed from harvested cotton balls to sow the following year, now had to buy cotton seed from seed dealers every year because of the introduction of F1 seed. Other serious problems began to arise.

( to be continued )