Influence of Colchicine-Induced Polyploidy on Capsaicin Concentration in Peppers

Colchicine is a chemical known for inhibiting mitosis during eukaryotic cellular reproduction by halting the tubulin formation necessary for the division of the chromosomes. The meristem is the primary source of mitosis in developing flowering plants, and it was the focus of our research to determine if the hindrance of mitosis would interfere with the production of capsaicinoids within pungent pepper plants. Moruga Scorpion peppers have one of the world's highest concentration of capsaicinoids with Scoville Heat Units (SHU) averaging 1.2 million SHU (Bannister, 2012). The highest concentration of these capsaicinoids are within the placental and endocarp regions of the fruit, which are the primary location for capsaicinoid biosynthesis (Aza-Gonzalez & Nunez-Palenius, 2010). Hindering mitosis from the earliest stage of development could lead to phenotypic abnormalities within those placental and endocarp regions, quite possibly through the mechanism of the induced polyploidy. In many cases, this polymerization interference is beneficial in cultivating plants with characterized polyploidy due to its desired increased size of fruits and leaves. Due to the lethal nature of colchicine, there is threshold of effectiveness where it may induce polyploidy or it may result in fatality. This first stage of this research sought to determine which lethal dose was required to elicit a polyploid response or lead to seed unviability. The second stage was analyzing capsaicin concentration within the fruit of the mature dosed plants to determine whether there was an effect on the capsaicinoids, and whether polyploidy played a role in those effects. The final inspection of this research was in germinating the seeds from the hottest F1 pepper that had developed the fruit the slowest of all the doses, and determining whether there were any effects on the germination or seedling development.