There is archaeological evidence for the existence of cotton in various shades of yellow, brown, green, and red. The pre-Columbian Peruvian textile at left is supposedly made from colored cotton without the processing of additional dyes. There are also reports of a naturally colored blue cotton, but the internet has provided minimal evidence for this.
The majority of commercially grown cotton belongs to the species Gossypium hirsutum. Varieties of this cotton species can be found in light brown and green, but the other colors are generally nowhere to be found.
|2. Inheritance of different fiber colors in cotton.|
These more interesting colors are seen in relatively wild varieties of a second cotton species, G. barbadense. G. hirsutem and G. barbadense don't naturally cross in the wild due to different timing of pollen maturation and other mechanisms. These are all easily circumvented by directed hybridization efforts. The resulting F1 hybrids grow well and are fertile, though fertility issues do arise in some F2 generation plants. These issues wouldn't interfere greatly with the intentional recombination of pigment alleles from both species, which I think has interesting potential to create new interesting colored varieties.
After I've done some further experiments with growing the cotton lines I already have in Minnesota, I might request some of the interesting colored forms from the collections.
|3. Cotton and I.|
A few years ago, on a whim, I planted some cotton seeds I had come across in south Texas. Cotton is typically described as needing a long and hot growing season to mature. I don't know how the production of my plants compared to similar plants in the South, but their production was dramatically higher than I expected up here in the North. After the first hard freeze of winter, I broke the plants off at their base and hung them to dry in the garage. A few weeks later, the cotton fibers had completed drying and were easy to collect. This process might not be something that can be scaled up to a proper crop, but it might. Further research is needed.