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Archaeobotanical analyses together with historical records can provide unique information about the cargoes and histories of sunken ships, which are found as wrecks at the bottom of the seas all over the world. An interdisciplinary research project was undertaken on the Vrouw Maria (Lady Mary), a Dutch wooden two-masted merchant ship that sank on October 9th in 1771 in the Finnish Baltic Sea. She rested at a depth of 41 m and was in good condition when discovered. Based on written sources and archaeological research, the ship was carrying a valuable cargo including, for example, sugar, dyes, cloth, porcelain, wood and goods that the Russian nobility had ordered. Among them were paintings that the Russian Empress Catherine the Great (1729–1796) had bought at an auction in Amsterdam. Samples from four wooden barrels and from one wooden packing crate among the ship’s cargo were investigated. Botanical analysis revealed products such as stimulants, dyes and fruits originating from the Mediterranean, India, Africa and South America. One of the most intriguing finds from the cargo was Indigofera tinctoria L. (true indigo), a valuable dye plant. Our paper presents the botanical data analysed from the barrels and summarizes the plants mentioned in the historical records on the cargo of the Vrouw Maria.

Symptomless contamination with the rot-inducing bacterium Erwinia carotovora was detectable by the tuber incubation method in 82% of the commercial seed potato stocks surveyed. E. carotovora subsp. atroseptica (Eca) was more common than E. carotovora subsp. carotovora (Ecc ) among the tuber contaminants. In a four-year survey of ten meristem-based seed stocks, recontamination with both Eca and Ecc occurred typically during the second field generation, but three stocks remained free of detectable contamination throughout the survey period. The first blackleg symptoms occurred typically during the third field generation. The serogroup distribution of Finnish Eca isolates was different from that reported from other countries. The predominant serogroup, I, constituted only 74% of all Eca isolates, since serogroups XXXV and XLI occurred relatively frequently. Serogroup I was more common among isolates from diseased stems than among those from latently contaminated tubers. The results also suggest that serogroup I is more dominant in the southern than in the northern parts of the country., Perunan tyvi- ja märkämätää aiheuttava bakteeri Erwinia carotovora esiintyi oireettomana 82 %:ssa perunateollisuuden ja Siemenperunakeskuksen varastoimista siemenperunaeristä vuosina 1981-83. Bakteerin alalajeista tyvimätäbakteeri (E. carotovora subsp. atroseptica, Eca) oli yleisempi kuin märkä- mätäbakteeri (E. carotovora subsp. carotovora, Ecc). Meristeemiviljeltyjen, terveiden siemenperunaerien saastumista tutkittiin määrittämällä tyvi- ja märkämätäbakteerin yleisyys kymmenessä siemenerässä neljänä kasvukautena. Ensimmäinen kasvukausi oli lisäys kasvihuoneessa. Bakteeri - saastunta havaittiin useimmissa erissä toisen peltolisäyksen jälkeen ja ensimmäiset tyvimätäoireet kolmannen peltolisäyksen aikana. Kuitenkin kolmessa siemenerässä ei esiintynyt oireetontakaan saastumaa koko seurannan aikana. Eca:n seroryhmien yleisyyttä tutkittiin, jotta saataisiin perustietoa siemenerien saastuntatasoa määrittävän serologisen testin kehittämiseen. Vuosina 1983-88 määritettiin seroryhmä yhteensä 2330 Eca-isolaatista. Seroryhmäjakauma osoittautui olevan Suomessa poikkeava monissa muissa maissa vallitsevasta. Seroryhmä I:een kuului vain 74 % kaikista Eca-isolaateista, kun taas muualla sen osuus on ollut yli 90 % isolaateista. Täten seroryhmä I:n antiseerumiin perustuvat kaupalliset tunnistussarjat eivät sovellu käyttöön Suomessa. Muita yleisesti esiintyviä seroryhmiä olivat XXXV ja XLI. Seroryhmien taudinaiheuttamiskyvyssä ei ole selviä eroja, mutta seroryhmä I oli kuitenkin yleisempi tyvimätäisestä varresta kuin oireettomasta mukulasta eristettyjenbakteerien joukossa. Alustavien tulosten mukaan seroryhmä 1 on myös yleisempi Etelä-Suomessa kuin siementuotantoalueella. Tuloksista voidaan päätellä, että E. carotovora esiintyy hyvin yleisesti perunassa ja perunan tuotantoympäristössä, mutta aiheuttaa tautioireita suhteellisen harvoin. Bakteerin täydellinen hävittäminen olisi erittäin vaikeaa tai mahdotonta. Diagnostisten menetelmien kehitys saattaa tulevaisuudessa mahdollistaa bakteerisaastunnan määrityksen kaikista siemeneristä, mutta siemenen muu kunto sekä viljely- ja varastointitekniikka säilyttävät tällöinkin merkityksensä tyvimädän ja märkämädän torjunnassa.

The effect of seven disinfectants on Clavibacter michiganensis subsp. sepedonicus and Erwinia carotovora subsp. atroseptica was tested on metal, plastic and wood surfaces in laboratory trials. lobac P was the most effective disinfectant in the control of E. carotovora on clean and dirty surfaces. Ipasept and Menno-Ter-forte were effective on plastic surfaces, but dirt reduced their efficacy. The least effective preparations were Deskem-1, Virkon S and Korsolin. lobac P, Korsolin and Virkon S were the most effective disinfectants against C. michiganensis. The efficacy of Ipasept and Menno-Ter-forte was reduced by dirt. The least effective preparation was Deskem-1.

Early stages of leaf development were studied in Schistochila appendiculata (Hook.) Dumort. ex Trevis., S. nobilis (Hook.) Trevis., Pachyschistochila subhyalina (R. M. Schust.) R. M. Schust. & J. J. Engel, and Gottschea conchophylla (E. A. Hodgs. & Allison) Grolle & Zijlstra, using transverse microtome sections. Like other groups of leafy liverworts, all four species have apical cells with three cutting faces and two primary leaf initials from which bilobed leaves are initiated. Apical cell geometry and early patterns of merophyte development are the same for all taxa studied, including those without underleaves. The wing of the leaf develops very early, shortly after the leaf lobes begin to form. The initial sign of wing development is the outward expansion and protrusion of a row of cells along the keel and the basiscopic or posterior margin of the ventral lobe. These cells undergo subsequent divisions so that transverse sections of the young leaves appear Y-shaped.

Bacterial lipopolysaccharide (LPS) has been implied in a variety of pathogenic and symbiotic plant-bacterium interactions. In order to study the role of LPS in pathogenecity of Erwinia carotovora, a broad host range phytopathogen, we isolated LPS defective mutants of two subspecies of Erwinia carotovora, subsp. carotovora (Ecc) and subsp. astroseptica (Eca). This was accomplished by using the Escherichia coli phage T4 as a selective agent. Screening of Erwinia isolates revealed that some of them were sensitive to T4 and thus T4 could be employed in mutant isolation. Fully T4 resistant mutants were all shown to be defective in their LPS structure. Preliminary pathogenicity tests on tobacco did not, however, reveal any decrease in the virulence of the LPS defective strains.