FLORAL PIGMENTATION STUDIES IN THE GENUS GOSSYPIUM. IV. EFFECTS OF DIFFERENT GROWING ENVIRONMENTS ON FLAVONOID PIGMENTATION

Petal extracts of Gossypium were analyzed chromatographically to determine if flavonoid constituents are modified by different environments. In the initial phase, fourteen inbred stocks from four species were grown in a plot that was replicated in five different localities ranging from the Mojave Desert to Raleigh, North Carolina. Petal samples were collected from each stock at each site, and chromatograms developed from these samples looked highly similar regardless of the locality of the growing site. In the second phase, two stocks were phytotron grown under a series of regimes in which daylength, temperature, and mineral nutrition were varied. Each stock showed very little floral flavonoid variation despite the growing conditions. A chromatographic survey of leaf extracts from these same phytotrongrown plants showed them to be much more variable. In cotton, flower petal constituents appear to be less variable than leaf constituents. The chemotaxonomic significance of these results are discussed.