Postnatal development of the oviduct of intact and ovariectomized rabbits

The length of the oviduct, the thickness of its wall, and the height of its mucosal epithelium and cilia were measured in (a) 0-, 2-, 4- and six-month-old rabbits, (b) rabbits ovariectomized at birth and (c) ovariectomized, estrogen-treated rabbits. The length and external diameter of the oviduct increased progressively until four months of age, after which their rates of increase declined. The thickness of the oviductal wall at the uterotubal junction was twice as large as that of the isthmus at two months of age and six times as large at four and six months of age. The height of the mucosal epithelium in the fimbriae was less than that in other oviductal segments at birth, but exceeded that in other segments at six months of age. Ciliated cells and motile cilia were absent 24 hours after birth; they were first observed two months after birth. The cilia of fimbriae were shorter than cilia elsewhere in the oviduct. Neonatal ovariectomy retarded the development of the oviduct and the mesotubarium and caused pyknosis of ciliated and non-ciliated cells of the oviductal mucosa. Cells with scarcely motile cilia were present five and one-half months after neonatal ovariectomy.     

Incorporation of D-[U-14C]Glucose in the Cell Wall of Linum Plantlets during the First Steps of Growth

Flax plantlets, cultivated from day 3 in liquid medium and undercontinuous light showed linear growth. Electron microscopy observationsshowed that treatment of the cell walls with cdta-Na₂ clearedout the middle lamella and the cell junctions, whereas boilingwater extracted pectic polysaccharides from the primary cellwall in each tissue (epidermis, cortical parenchyma and phloem). Pulse-chase experiments showed that there was during the growthof flax plantlets a continuous redistribution of radioactivityin all parts of the cell walls: 1) from pectins to hemicellulosesand even to the cellulosic residues. 2) from oligomers to polymers.3) from neutral to acidic polymers in the core of the middlelamella. 4) from acidic to neutral pectins in the primary cellwalls. The elongation zone which was restricted to a small zoneback from the tip, involved strong synthesis of neutral pectinsin all the cell walls. Conversely, the redistribution of radioactivitywas related mainly to the plant cell maturation, and especiallyto the acidification of the cell wall. Demethylation of someneutral pectins occurred in the middle lamella whereas stronglyacidic pectins were synthetized in the primary cell wall. (Received October 1, 1990; Accepted April 9, 1991)     

The side-effects of plant extracts and metabolites of Reynoutria sachalinensis (F. Schmidt) Nakai and conventional fungicides on the beneficial organism Trichogramma cacoeciae Marchal (Hym., Trichogrammatidae)

The aim of this study was to investigate the side-effects of plant extracts (plant strengthener with resistance inducing properties) and conventional fungicides on the egg parasitoid Trichogramma cacoeciae Marchal. Two plant extracts and one metabolite from Reynoutria sachalinensis (F. Schmidt) Nakai (crude water extract (Rey-crude^®), which is used for the control of powdery mildew and other diseases, a methanolic fraction of this extract (Rey-meth^®) and the anthraquinone plant constituent (Physcion^®), as well as four fungicides (Thiram^®, Dithane^® M45, Euparen M^® and Kumulus^®) were tested. Adults of T. cacoeciae of uniform age were exposed to fresh dry film of the compounds and the percentage reduction in parasitism compared with water-treated controls was calculated. The results of experiments using the highest recommended concentrations sprayed on glass plates showed that the preparations greatly differed in their effect on the parasitoid. All of the conventional fungicides tested were found to be harmful. In contrast, Rey-crude and Physcion were harmless to T. cacoeciae , whereas the fraction Rey-meth was slightly harmful. In further experiments the side-effects of the plant protection agents on T. cacoeciae were compared when sprayed at different concentrations either on glass plates or on vine leaves. The results confirmed the findings of the first trials but showed that side-effects of the compounds Dithane M45 and Euparen M were less toxic when applied to vine leaves.