Leaf macro-and micro-morphological altitudinal variability of Carpinus betulus in the Hyrcanian forest (Iran)

We investigated the altitudinal variation of Carpinus betulus L. in the Hyrcanian forest using leaf macro-morphological and micro-morphological traits. We collected a total of 1600 leaves from two locations. In each location, we sampled six populations along an altitudinal gradient ranging from 100 m to 1,150 m. We found that trees in the higher elevations have smaller leaf lamina than those in the lower elevations. In contrast, leaf mass per area was high at low altitudes and increased newly at the higher ones. Stomatal dimension was negatively correlated with elevation, while stomatal density was positively correlated with elevation. We also found that two transects showed the same plasticity trend. Leaf area showed the highest plasticity, while the number of veins showed the lowest plasticity. This study shows that altitude, and related temperature and rainfall, represents an important driving force in Carpinus betulus leaf morphological variation. Moreover, our results suggest that leaf area, leaf mass per area and stomatal density could influence the species responses to different ecological conditions.

Contamination of microgreens by Salmonella enterica and Escherichia coli is influenced by selection breeding in chicory(Cichorium intybus L.)

The aim of this study was to assess whether selection breeding in chicory(Cichorium intybus L.)led changes in the susceptibility to Salmonella enterica and Escherichia coli contamination and whether the anatomical traits of the leaves are involved in the possible changes.Five chicory genotypes subjected to different intensities of selection were compared at the microgreen stage.Bacterial retention was evaluated after leaf incubation for 1.5 h on the surface of the bacterial suspension,followed by rinsing,grinding,plating on selective media,and colony forming unit(CFU)counting.The density of stomata and trichomes,total stomatal length and width,stomatal pit width,surface roughness and sharpness were evaluated.The intensively selected genotype(Witloof)was significantly more prone to contamination(2.9±0.3 lg CFU/cm^(2))as the average of the two bacterial types than the wild accession(Wild;2.3±0.4 lg CFU/cm^(2))and the moderately selected genotypes(two leaf chicories,Catalogna type,and root chicory'Magdeburg';on average,1.9±0.3 lg CFU/cm^(2)).Witloof microgreens also showed larger stomata(on average+34%for stoma width and+44%for pit width),which could justify,at least in part,the higher susceptibility to enterobacterial contamination.In fact,when contamination was performed in the dark(closed stomata),the bacterial retention in Witloof was significantly reduced in comparison with the opened stomata(-44%)and in Wild(-26%).Differences in retention between Witloof and Wild were still observed after UV treatment.The hierarchical clustering performed by grouping the leaf anatomical features was consistent with the chicory genetic groups.Our results suggest that the domestication process can affect the safety of produce and that the micromorphological traits of the leaves may be involved.