Iris lutescens on serpentine soil: volatile emission profiles in different organs of its two colour morphs

Iris lutescens is a rhizomatous species of the Iridaceae family, generally found in the dry areas of the Mediterranean basin. It is characterised by large flowers, exhibiting a colour polymorphism in two varieties (yellow and purple). Even though it can grow on calcareous soils, it is reported as a serpentine-preferential taxon. In this work, the volatile emission in the headspaces of flowers, leaves and rhizomes of specimens of both the colour morphs growing on an ultramafic garigue have been analysed. The flower and rhizome headspaces had greater overall similarities compared to the leaves; flowers were the organs for which the volatile emission differed the most between the two colour morphs. Moreover, a comparison with a published headspace composition ofI. lutescens yellow and purple flowers growing on calcareous soil evidenced quali-quantitative differences, as well as a greater differentiation of the volatile organic compounds emitted by the two colour morphs growing in a serpentine environment. To the best of our knowledge, this is the first report on the volatile emission of different organs of I. lutescens specimens growing on serpentine soil.