A lot of people have been asking around about Sour Diesel with a high CBD content. I’ve heard from a few growers it’s possible to get as high as 15% CBD in the harvest, but it’s highly unlikely.
A plant that is used for breeding needs extreme stability because it will be reproduced extensively. For this reason, cannabis plants are heavily selected against mutations and deviations from the norm in order to avoid any surprises in the offspring. The bigger the population you start with, the bigger your chances are of creating stable genetics that will breed true over several generations.
If you want to combine two different phenotypes into one variety (artificial hybridization), then you need to make absolutely sure their offspring won’t show potentially unwanted variations. THC and diesel cbd hemp flower production is very closely related to each other. A mutation in the gene controlling one will impact the other and vice versa: if a plant produces more THC it usually has less CBD and vice versa.
This is why we try to keep different chemical varieties as true-breeding as possible because when they are crossed with themselves, or crossed with another variety that was also stabilized, you get an offspring that will be just like its parents (and grand-, great-grandparents). This stability is vital for large-scale breeding projects such as Big Bud, Skunk #1, and Haze, not to mention countless others.
Hybrids between chemotypes are interesting but only from a limited perspective because the resulting offspring cannot be reproduced reliably year after year.
Now, with that in mind, let’s go back to the original question. Why is it impossible for a plant to produce 15% CBD? It must be related to stability and selective breeding… Right? That’s exactly what it is! We can study marijuana genetics on a molecular level thanks to the work of dedicated scientists who have been using advanced techniques such as DNA sequencing and spectroscopy to map various sour diesel CBDgenes. Whether this information has any value beyond academic interest remains to be seen but at least we know more about our favorite plant than ever before.
In order for a female plant to make seeds, she needs pollen from another variety. This means her evolved chemical defenses against pests will be passed on as well because those defense mechanisms are genetically encoded in the plant’s DNA. If a female plant with a high THC/low CBD content is crossed with a male of the same variety, her offspring will express these traits too.
