Undesired Self-Pollination of the Parent Plant Decreases Dry Matter Yield of Silage Maize

A proportion of the maize seed sold in the Netherlands is genetically impure. The most common form of genetic impurity in hybrid seed production is the accidental self-pollination of the female parent. Varying quantities of selfed seeds were added to certified seedlots of three-way cross hybrids. These mixtures were tested in nine field experiments, in 1985 and 1986.
Whole plant dry matter yield decreased by 40 to 45 kg/ha per percent of selfed seed added. The effect of selfed seed on dry matter yield did not differ significantly in the hybrids studied.     

The causal organism of purple blotch disease on Sedum

Samenvatting Onderzoek van de kenmerken en synoniemen van dePhoma-soort die de paarsevlekkenziekte bijSedum telephium en andereSedum-soorten veroorzaakt, heeft geleid tot de nieuwe naamcombinatiePhoma telephii (Vestergr.) v. Kest. Voor het pycnidestadium vanLeptosphaeria doliolum (Pers. ex Fr.) Ces. & DNot. is de nieuwe naamPhoma hoehnelii v. Kest. geïntroduceerd.     

The occurrence of hypotaurine in ovarian follicle walls in sheep and in the Fallopian tube of sheep and other animals

Inhalt: In den Ovarien von Schafen kommen während des Brunstzyklus in den Folli-kelwandungen Hypotaurin und Inositol in Konzentrationen von 0–7 mg % bzw. 40 mg % vor. Hypotaurin wurde auβerdem in den Eileitern von Schaf, Pferd, Rind, Schwein und Kaninchen gefunden; in zwei Fällen gelang auch der Nachweis von Hypotaurin in der Fimbrienplatte der Hündin. Es wird die Hypothese aufgestellt, daβ bei mit Progesteron bebandelten Tieren das Fehlen von Hypotaurin möglicherweise die Entwicklung und den Transport der Eier ungünstig beeinfluβt.     

Comparison of four methods for early detection of experimental Trichinella spiralis infections in pigs

Four methods employed in the diagnosis of experimental porcine trichinellosis (trichinoscopy, digestion method, immunofluorescence and enzyme linked immunosorbent assay (ELISA)) were compared by eleven laboratories in the countries of the European Economic Community and Sweden. The aim of this study was to test the reliability of ELISA during the onset of T. spiralis infection. Material from conventionally raised pigs infected with 1500 or 10000 larvae was compared to uninfected controls at Day 17 and Day 21 post infection.The serological techniques gave higher percentages of positive results than the direct techniques. Specific antobodies could be demonstrated with ELISA at an earlier stage and at higher percentages than with the other methods. ELISA micro-assay was the most sensitive procedure.     

An ultrastructural study of the development of Babesia occultans in the salivary glands of adult Hyalomma marginatum rufipes

The development of Babesia occultans in the salivary glands of adult Hyalomma marginatum rufipes was studied with the electron microscope. Sporogony involved a process of multiple fission in which sporozoites formed from the periphery of a polymorphous sporont. Different stages of development were found concurrently in individual acini as well as within individual acinar cells. Mature sporozoites were found on Day 3 post-tick attachment and measures 3.0-3.5 X 1.5 micron. The apical complex consisted of a polar ring and 4-6 rhoptries. Micronemes were concentrated anteriorly and 1 or 2 spherical bodies were identified in each sporozoite. The general pattern of development was similar to that described in several other Babesia spp. but distinct morphologic differences were noted.     

Een waarneming over het voorkomen van fysiologische rassen van het aardappel cystenaaltje,welke zich sterk kunnen vermeerderen in resistente nakomelingen vanSolanum tuberosum subsp.andigena

Ohne Zusammenfassung

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With a summary: A record of the existence of physiologic races of the potato root eelworm, which multiply vigorously in resistant progy, of Solanum tuberosum subsp. andigenum