Genetic characterization of a red colour morph of Euphorbia esula subsp. esula (Euphorbiaceae) in the floodplains of the Saône (Eastern France)

Abstract

A new morph of leafy spurge, Euphorbia esula L., was discovered in the floodplains of the Val de Saône (VDS), France. In this region, this emerging weed shows two different morph colours: the common “green” variant and a rarer “red” variant. We compared the sequence data for the plastid trnT–trnF region among individuals of both morphs from the VDS, as well as other populations from Europe and North America, where this plant is invasive. In addition, we analysed the ploidy found among VDS individuals for both colours. Results showed that both morphs share two of the three chloroplast DNA (cpDNA) haplotypes found in the VDS and are both hexaploids (2n = 6x = 60). These results suggest that the red morph is only an environmental variant of E. esula subsp. esula. Our results indicate that leafy spurge infestations in this region form a genetically diverse structuring composed of three cpDNA haplotypes, two of which are shared by the two morphs.

Using karyotyping and achene morphology to accurately identifySonchus oleraceus(Asteraceae) in the context of its biological control

“…for optimum metaphase is around noon. Similar observations were made for different plant taxa grown under different conditions (Ekanem and Osuji 2006;Augé et al 2016). The duration of enzymatic digestion did not have any significant effect on the quality of the observation (mean of 4.5 cells in division after 45min, 0 after 50min, 1 after 55 min, 0.5 after 60min, 0 after 65min and 4.5 after 70min; F(1, 10) = 0.001, p-value = 0.972), hence one hour was the duration used for all the cytological experiments.…”

“…Two key parameters were herein tested: (i) the period of the day at which the root tips are harvested and (ii) the duration of the immersion of the root tips into the enzymatic solution for cell wall digestion. Harvest time of root tips should correspond to the peak of the metaphase, that might vary over the day, as observed in other taxa as Euphorbia esula (Augé et al 2016) and edible cocoyams (Ekanem and Osuji 2006). The harvest times of root tips tested were 8h00, 10h00 and 12h00.…”