Basic Cannabis Breeding

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We know that the cannabis plant is a dioecious organism, meaning that it has separate male and female plants.

However, there are times when the male and female sex organs do exist on the same plant. The process by which this happens is referred to as ‘herming’.  When the female plant is stressed due to lack of water, light, or nutrients, the female flower can produce male reproductive organs aka stamen. 

These stamen are yellow sack-like structures that hold pollen. Because of their color and shape, they are often referred to as banana leaves. These banana leaves can compromise the female flower if left untreated. If not removed immediately, the stamen can burst, sending pollen everywhere. Any pollen that happens upon a pistil can potentially fertilize the flowers causing rampant seed development. As you might imagine, this compromises the marketable product as no one wants to smoke a bunch of seeds.

There are times, however, when you do want to expose pistils to pollen. Breeders, for example, carefully select certain plants to fertilize for seed production. They may want to breed two cultivars because of their desirable traits. Desirable traits can include mold resistance, or a certain favorable smell, taste, THC/CBD concentration.  The process by which female flowers are fertilized is very specific. Breeders will keep female and male plants in separate rooms so as not to accidentally or unintentionally cross- contaminate. Breeders will harvest the pollen from the male plants and use a paintbrush to painstakingly paint the pollen on to the pistils of the female flowers selected for fertilization. This way the pollen is not going anywhere it shouldn’t be.