Data: Effects of yeast genotype and plant identity on sucrose concentration of Helleborus foetidus nectar

An experiment was conducted on the early-blooming perennial herb Helleborus foetidus L. (Ranunculaceae) and the dominant yeast inhabiting its floral nectar, Metschnikowia reukaufii Pitt & M. W. Mill. (Metschnikowiaceae, Saccharomycetales). Floral nectar for the experiment was obtained in the field (Sierra de Cazorla, SE Spain) from 20 widely spaced H. foetidus plants whose inflorescences had been previously bagged at the bud stage to exclude pollinators. Nectar from many flowers (mean ± SE = 23 ± 2 flowers sampled/plant, 5-10 µL of nectar per flower) was gathered into a single bulk sample for each individual plant, and stored at ‑20ºC until used. Ten M. reukaufii strains isolated from nectar of unbagged H. foetidus flowers from the same population were chosen for the experiment.The experimental layout consisted of a two-way factorial design, with M. reukaufii genotype (N = 10) and H. foetidus individual (N = 20) as main factors, and two replicates per each genotype x individual combination (N = 381 experimental units; some plants had not sufficient nectar for replication). Each experimental unit consisted of a 0.2 mL PCR tube containing 15 mL of virgin, sterile nectar plus 1 mL of M. reukaufii cell suspension taken from a fresh culture on standard liquid medium. To assess differences among genotypes in initial cell densities, two replicated control tubes were also set per yeast genotype at the time of inoculation, each consisting of 15 mL of 10% lactophenol cotton blue (LCB hereafter) solution plus 1 mL of M. reukaufii cell suspension. After inoculation, all experimental tubes were held at 25ºC without agitation. Two aliquots were taken from each experimental unit for chemical analyses at 24 h and 48 h after inoculation. Samples of virgin nectar from experimental plants (N = 40, two aliquots per plant) and all nectar samples taken in the course of the experiment (N = 762) were analyzed using ion-exchange high performance liquid chromatography.This data repository consists of the following two files:Sucrose.conc.csvDelimited text file containing results of the experiment. Variable names are in the first row of the file, as follows:"planta" = plant ID"cepa_name" = yeast strain ID"tanda" = length of exposure time (24h or 48 h)"area_sac_pre" = pre-exposure sucrose concentration"mean.dens" = initial yeast cell density"con_sac" = post-exposure sucrose concentration.Concentrations expressed on a weight-to-weight basis.R.script.txtR script to perform analyses of the data