This Punnet square shows us that female:female breeding schemes produce only female (XX) offspring.
Some growers intentionally use the pollen from intersex plants to fertilize females. They have found that the seeds and subsequent offspring produced from this union will be predominately female. The major problem with this technique is that these plants will have intersex tendencies. By selecting parent plants that have intersex tendencies, we ensure that some of the progeny will also have intersex tendencies. Using pollen from an intersex or hermaphrodite plant is an intentional selection for intersexuali-ty—like begets like.
Some seed companies market "feminized seeds," which are produced by collecting pollen from carefully selected, latent, stress-induced hermaphrodites, and use it to pollinate female plants. This process is time consuming and arduous, but yields mostly female plants when grown without stress. However, under the stresses that resulted in the intersexuality for the pollen parent, the progeny will often show some degree of intersexuality as well. Again, like begets like.
So how do we get true females (that do not show any degree of intersexuality under normal conditions) to produce pollen? Can we gel pollen from female plants that do not show a degree of intersexuality?
There are hormone treatments, which, when applied to cannabis, result in the formation of staniinate flowers on otherwise pistillate plants. To select against the intersex condition, we take our chosen female breeding candidates and grow them under stressful conditions that may lead to the formation of male flowers-irregular light cycle, high heat, etc. Only plants that resist intersexuality tinder these conditions should be considered as potential breeding parents for the creation of all-female seed lines. We call these intersex-resistant plants "true females." Intentional selection against intersex plants is the only way to ensure intersex-free offspring.
Clone copies of these pistillate intersex-resistant plants are then sprayed with our hormone treatment and placed into the flowering cycle and allowed to develop stamens. It typically takes three to five weeks for the plants to enter dehiscence and shed pollen. True female candidates that also resist intersexuality under typical stresses, are pollinated by pollen obtained by our hormone-treated, gender-reversed, stamen-bearing female plants. The result is a true gynoecrous population, consisting entirely of female plants.
An American company, Hybritech, was the first to introduce an effective ready-to-use hormone treatment-eliteXelite. This product is no longer available for public purchase. Another plant research firm, PG-Solutions, has since developed and released a ready-to-use hormone therapy spray, Stamen-It!. Stamen-It! is extremely effective in causing gender reversal of pistillate individuals. Some hormone sprays are able to induce staminate flower formation, but fail to produce viable pollen in any significant quantities. PG-Solutions has developed a formulation that causes significant pollen production, even in the most reversal-resistant genotypes. If you are interested in this technology, check their website, www.PGSolulions.com.
Continue reading here: Breeding schemes for crosspollinated crops
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