Genotypic and phenotypic distinctness of restored and indigenous populations of Pimpinella saxifraga L. 8 or more years after restoration.

The recovery of altered or damaged ecosystems demands large-scale reintroductions of seeds. In the past, ecological restoration in Germany was carried out with non-local seeds of naturally occurring species. We here analysed whether the genetic pattern of the introduced non-local seeds (R = restored) of Pimpinella saxifraga are still detectable several years after application and whether the phenotype differs from that of the regional gene pool (I = indigenous) of the species. We collected material from individuals of R and I sites, conducted a common garden experiment and tested for genetic, morphological and phenotypic differences. In a cutting experiment we investigate treatment effects on indigenous and restored populations. At all investigated sites we only found P. saxifraga individuals with comparatively similar genome sizes. The population genetic analysis revealed two large and quite distinct molecular clusters, separating indigenous and restored individuals along the first axis. None of the vegetative, but two of the reproductive fitness parameters differed between individuals of the R and I sites. Cutting always had a significant influence on all analysed vegetative and reproductive fitness parameters, regardless of the individuals' origin. The effects of mowing always mask origin-specific characteristics, which then disappear. Genotypic coexistence reduces the availability of niches for the local genotype and may eventually lead to genotypic competition or introgression. We therefore recommend not to use non-local genotypes of this species in the region. Instead, we recommend using the genetically diverse local genotypes of P. saxifraga for restoration purposes.

Molecular phylogeny and character evolution in terete-stemmed Andean opuntias (Cactaceae-Opuntioideae).

The cacti of tribe Tephrocacteae (Cactaceae-Opuntioideae) are adapted to diverse climatic conditions over a wide area of the southern Andes and adjacent lowlands. They exhibit a range of life forms from geophytes and cushion-plants to dwarf shrubs, shrubs or small trees. To confirm or challenge previous morphology-based classifications and molecular phylogenies, we sampled DNA sequences from the chloroplast trnK/matK region and the nuclear low copy gene phyC and compared the resulting phylogenies with previous data gathered from nuclear ribosomal DNA sequences. The here presented chloroplast and nuclear low copy gene phylogenies were mutually congruent and broadly coincident with the classification based on gross morphology and seed micro-morphology and anatomy. Reconstruction of hypothetical ancestral character states suggested that geophytes and cushion-forming species probably evolved several times from dwarf shrubby precursors. We also traced an increase of embryo size at the expense of the nucellus-derived storage tissue during the evolution of the Tephrocacteae, which is thought to be an evolutionary advantage because nutrients are then more rapidly accessible for the germinating embryo. In contrast to these highly concordant phylogenies, nuclear ribosomal DNA data sampled by a previous study yielded conflicting phylogenetic signals. Secondary structure predictions of ribosomal transcribed spacers suggested that this phylogeny is strongly influenced by the inclusion of paralogous sequence probably arisen by genome duplication during the evolution of this plant group.

[Root caries in patients in periodontal follow-up care. Prevalence and risk factors]. / Wortelcariës bij patiënten in parodontale nazorg. Prevalentie en risico-indicatoren.

The aim of this cross-sectional study was to investigate the prevalence and several risk indicators of root cariës in 45 periodontal maintenance patients, who had been actively treated for adult periodontitis 11-22 years ago. These patients were part of a routine 3-6 monthly maintenance schedule. Active and inactive root caries and root fillings were recorded, as well as coronal caries experience. Plaque and bleeding scores, number of exposed root surfaces, rate of saliva secretion, saliva buffer capacity, S. mutans counts and Lactobacilli were also scored. From the total of 45 subjects, 37 patients (82%) showed root lesions (root caries and/or fillings), while only 8 patients were free of any root lesions. On average, there were 4.3 lesions per patient (range 0-19) in the present study. Of all damaged root surfaces, 9% were active lesions, mostly located on mandibular teeth at lingual and vestibular sites; 40% were inactive lesions often detected at vestibular sites. The remaining damaged root surfaces (51%) were restored; they were equally divided over both jaws. A higher number of root lesions was observed in those patients with > 106 S. mutans/ml saliva. Although the actual number of lesions per patient was low in relation to the large number of sites with gingival recession, the results from this cross-sectional study in periodontal maintenance patients indicate that: root cariës can be regarded as a complication in periodontal maintenance patients, that the individual number of root lesions correlate with individual dental plaque score, that a high number of root lesions is associated with counts of salivary S. mutans, and that no relation between root cariës and coronal caries experience, salivary secretion rate or salivary buffering capacity seems present. Therefore, repeated oral hygiëne instructions and adjunctive preventive measures including diet counseling and fluoride rinses, as well as fluoride and chlorhexidine varnishes, should be advocated in high-risk patients.

A cross-sectional study into the prevalence of root caries in periodontal maintenance patients.

The aim of this cross-sectional study was to investigate cross-sectionally the prevalence and several risk indicators of root caries in 45 periodontal maintenance patients, who had been actively treated for adult periodontitis 11-22 years ago. These patients were part of a routine 3-6 monthly maintenance schedule. Active and inactive root caries and root fillings were recorded, as well as coronal caries experience. Plaque and bleeding scores, number of exposed root surfaces, rate of saliva secretion, saliva buffering capacity, mutans streptococci counts and Lactobacilli were also scored. From the total of 45 study subjects, 37 patients (82%) showed root lesions (root caries and/or root fillings), while only 8 patients were free of any root lesions. On average, there were 4.3 root lesions per patient (range 0-19) in the present study. 10 patients had active root caries lesions. Of all damaged root surfaces, 9% were active lesions, mostly located on mandibular teeth at lingual and vestibular sites: 40% were inactive lesions often detected at vestibular sites. The remaining damaged root surfaces (51%) were restored; they were equally divided over both jaws. A higher number of root lesions was observed in those patients with >106 mutans streptococci/ml saliva. Although the actual number of lesions per patient was low in relation to the large number of sites with gingival recession, the results from this cross-sectional study in periodontal maintenance patients indicate that: (1) root caries can be regarded as a complication in periodontal maintenance patients; (2) the individual number of root lesions correlate with individual dental plaque scores; (3) a high number of root lesions is associated with high counts of salivary mutans streptococci; (4) no relation between root caries and coronal caries experience, salivary secretion rate or salivary buffering capacity seems present. Therefore, repeated oral hygiene instructions and adjunctive preventive measures including diet counseling and fluoride rinses, as well as fluoride and chlorhexidine varnishes, should be advocated in high-risk patients.

Clinical evaluation of tine shape of 3 periodontal probes using 2 probing forces.

The objective of this study was to evaluate the effect of the tine shape of 3 different periodontal probes. One tapered, one parallel-sided and one WHO-probe tine, each with a diameter of 0.5 mm at the tip, were mounted in hinged handles exerting a constant probing force (Brodontic). The handles were adjusted to either 0.25 N (127 N/cm2) or 0.5 N (255 N/cm2). 12 patients with moderate to severe periodontitis were measured after supra- and subgingival debridement, using all 6 possible tine/force combinations in 3 sessions. In each session one tine/force combination was used in the 1st and 3rd quadrants, and another tine/force combination in the 2nd and 4th quadrant. The measurements in the same quadrants could therefore be used for comparisons within the same site. The selection for the 2 quadrants in which a given tine/force combination was to be used, was randomised. Calculations of differences (mean per patient) between probing measurements show that the WHO tine yields deeper recording than the parallel/sided and tapered tines, both at 127 N/cm2 and 255 N/cm2. We conclude that in addition to probing force, the tine shape of a periodontal probe is of significant importance for the recorded probing depth.