Revisiting the use of Iprodione and Trichoderma in the integrated management of onion white rot

The biocontrol properties of Trichoderma species are well documented, but their effectiveness in antagonism of the problematic Sclerotium cepivorum, the causal agent of white rot in Allium species, appears limited with reports of significant control only relating to deliberately-mutated strains of Trichoderma. Our previous studies have indicated the possibility of using selected naturally-occurring strains of the antagonist in the suppression of other diseases; now in vitro and controlled environment in vivo studies have indicated that a degree of control of Onion White Rot is possible, and that the selected antagonist strains can be used in integrated treatments with Iprodione to good effect. The possible value of such treatments is considered in light of other approaches to the suppression of this continuing problem.     

Documenting ancient DNA quality via alpha satellite amplification and assessment of clone sequence diversity

C/G-->T/A nucleotide alterations have been shown to hamper the straightforward interpretation of mitochondrial DNA sequence data derived from ancient tissues. Attempting to characterise this finding with respect to nuclear DNA, we contrasted two established protocols: (i) an enzymatic repair of damaged DNA, thereby translating and closing nicks in the DNA, and (ii) the application of N-phenacylthiazolium bromide, which cleaves glucose-derived protein crosslinks, presumably derived from Maillard reactions. We used medieval human bones that were refractory to standard PCR procedures. Due to negligible presence of short tandem repeat loci and also mitochondrial sequences, the extracted ancient DNA needed a higher copy PCR system to yield amplification products. The chosen PCR target was specific alphoid repetitive DNA with an experimentally determined minimum of 1000 copies per haploid genome. Alphoid repeat segments were generated from both contemporary DNA and DNA extracts of two human skeletons dating from 450-600 AD (omitting uracil N-glycosylase pre-treatment of the extracted samples), and were subsequently cloned and sequenced. The sequences were evaluated for the number and type of nucleotide alterations noted after the different pre-treatments, and were compared to our alphoid consensus sequence generated from modern DNA. Both methods failed to reflect the expected 32% variability among single alphoid repeats (accounting for locus-specific differences and polymerase errors) as well as to display the actual 2.88 ratio of transitions to transversions. Our data obtained from high-copy-number nuclear DNA mirror the phenomenon of sequence deviations observed in mitochondrial DNA extracted from old specimens.     

Radiocarbon dating the appearance of modern humans and timing of cultural innovations in Europe: new results and new challenges

New radiocarbon dates from the sites of Bockstein-T?rle, Geissenkl?sterle, Hohle Fels, Hohlenstein-Stadel, Sirgenstein, and Vogelherd in the Swabian Jura of southwestern Germany indicate that the Aurignacian of the region spans the period from ca. 40-30ka BP. If the situation at Vogelherd, in which skeletal remains from modern humans underlie an entire Aurignacian sequence, is viewed as representative for the region, the dates from the Swabian Jura support the hypothesis that populations of modern humans entered the region by way of the "Danube Corridor." The lithic technology from the lower Aurignacian of Geissenkl?sterle III is fully developed, and classic Aurignacian forms are well represented. During the course of the Aurignacian, numerous assemblages rich in art works, jewelry, and musical instruments are documented. By no later than 29ka BP the Gravettian was well established in the region. These dates are consistent with the "Kulturpumpe" hypothesis that important cultural innovations of the Aurignacian and Gravettian in Swabia predate similar developments in other regions of Europe. The radiocarbon dates from Geissenkl?sterle corroborate observations from other non-archaeological data sets indicating large global fluctuations in the atmospheric concentrations of radiocarbon between 30 and 50ka calendar years ago. These fluctuations lead to complications in building reliable chronologies during this period and cause the "Middle Paleolithic Dating Anomaly" and the "Coexistence Effect," which tend to exaggerate the temporal overlap between Neanderthals and modern humans.     

A web server to locate periodicities in a sequence

Summary : FT is a tool written in C++, which implements the Fourier analysis method to locate periodicities in aminoacid or DNA sequences. It is provided for free public use on a WWW server with a Java interface. Availability : The server address is http://o2.db. uoa.gr/FT Contact : shamodr@atlas.uoa.gr      

Plant use in three Pre-Pottery Neolithic sites of the northern and eastern Fertile Crescent: a preliminary report

The beginnings of agriculture throughout the Fertile Crescent are still not completely understood, particularly at the eastern end of the Fertile Crescent in the area of modern Iran. Archaeobotanical samples from Epipalaeolithic/PPNA Körtik Tepe in southeastern Turkey and from the Pre-Pottery Neolithic sites of Chogha Golan and East Chia Sabz in south western Iran were studied in order to define the status of cultivation at these sites. Preliminary results show the presence of abundant wild progenitor species of crops at the Iranian sites before 10600 cal. b.p., and very few wild progenitor species at Körtik Tepe dated to 11700–11250 cal. b.p. The Iranian sites also indicate size increase of wild barley grain across a sequence of 400 years through either cultivation or changing moisture conditions.     

Τesting models for the beginnings of the Aurignacian and the advent of figurative art and music: the radiocarbon chronology of Geißenklösterle

The German site of Geißenklösterle is crucial to debates concerning the European Middle to Upper Palaeolithic transition and the origins of the Aurignacian in Europe. Previous dates from the site are central to an important hypothesis, the Kulturpumpe model, which posits that the Swabian Jura was an area where crucial behavioural developments took place and then spread to other parts of Europe. The previous chronology (critical to the model), is based mainly on radiocarbon dating, but remains poorly constrained due to the dating resolution and the variability of dates. The cause of these problems is disputed, but two principal explanations have been proposed: a) larger than expected variations in the production of atmospheric radiocarbon, and b) taphonomic influences in the site mixing the bones that were dated into different parts of the site. We reinvestigate the chronology using a new series of radiocarbon determinations obtained from the Mousterian, Aurignacian and Gravettian levels. The results strongly imply that the previous dates were affected by insufficient decontamination of the bone collagen prior to dating. Using an ultrafiltration protocol the chronometric picture becomes much clearer. Comparison of the results against other recently dated sites in other parts of Europe suggests the Early Aurignacian levels are earlier than other sites in the south of France and Italy, but not as early as recently dated sites which suggest a pre-Aurignacian dispersal of modern humans to Italy by ∼45000 cal BP. They are consistent with the importance of the Danube Corridor as a key route for the movement of people and ideas. The new dates fail to refute the Kulturpumpe model and suggest that Swabian Jura is a region that contributed significantly to the evolution of symbolic behaviour as indicated by early evidence for figurative art, music and mythical imagery.