Molecular characterisation of resistance against potato wart races 1, 2, 6 and 18 in a tetraploid population of potato (Solanum tuberosum subsp. tuberosum)

Potato wart is caused by the obligate biotrophic fungus Synchytrium endobioticum, which is subject to quarantine regulations due to the production of long persisting spores in the soil and the lack of effective fungicides. The objective of this study was to identify quantitative trait loci (QTL) for resistance against potato wart races (R) 1, 2, 6 and 18 in a tetraploid potato population developed by crossing cv. Saturna (resistant to R1) with cv. Panda (resistant to R1, R2, R6, R18). A total of 92 progenies were used for phenotyping and genotyping. Resistance tests were performed for races 1 and 18 in 2 years and for races 2 and 6 in 1 year on 10 to 20 eyepieces per genotype. Based on amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers, linkage maps were established for the female and male parent, respectively. Single marker analysis followed by a multiple regression analysis revealed initial marker–trait associations. The interval mapping routine of TetraploidMap was applied for QTL analysis. A major QTL for resistance against race 1 explaining between 46 % and 56 % of the phenotypic variation was identified near Sen1, a known resistance locus for potato wart race 1 on chromosome XI. Other resistance QTL were detected on chromosomes I (to R2), II (to R6, 18), VI (to R1, 2, 6, 18), VII (to R2, 6, 18), VIII (to R1, 2, 6, 18), X (to R2, 6, 18), XI (to R2, 6, 18) and on an unknown linkage group (to R18) explaining minor to moderate effects of the phenotypic variation. Resistance QTL against different potato wart races often overlapped, particularly concerning races 2, 6 and 18. Overall, this study gives a valuable insight into the complex inheritance of resistance against potato wart.     

Triglochinin in Araceen

Five species of four subfamilies of the Araceae contain triglochinin as the only cyanogenic glucoside. The compound was identified by TLC, PC, IR, NMR and hydrolysis with a triglochinin-specific β-glucosidase.     

Cultur der Cacteen

Ohne Zusammenfassung     

Cyanoglucoside storing cuticle of Zygaena Larvae (Insecta,Lepidoptera)

Summary As a deterrent against predators, larvae of Zygaena trifolii release droplets of fluid containing cyanoglucosides from segmentally arranged cuticular cavities. Histological examinations show that during the moulting period, the old cuticle, including the cavities and the secretion within them, is degraded, with the exception of a thin mesocuticular layer forming the exuviae. When the endocuticular layer of the new cuticle is deposited, the cuticle detaches from the underlying epidermis in specific areas, which leads to the formation of the cuticular cavities. During a moult-intermoult sequence the concentration of cyanoglucosides in both the haemolymph and the defensive secretion shows specific changes. These changes seem to be related to the formation and degradation of the cavities. We suggest that during the moult the cyanoglucosides are transported through the epidermis into the haemolymph to prevent them from being wasted with the exuviae and, after ecdysis, are retranslocated into the newly formed cavities.     

Zytologische Untersuchungen an Rhipidium europaeum (Cornu) v. Minden

Ohne ZusammenfassungMit 33 Textabbildungen.     

Über die Zoosporenreproduktion beiStigeoclonium

Ohne Zusammenfassung     

Die Verwendung von Chloralhydrat oder Phenol zur Aufhellung und von Phenol-Balsam als Einschlußmittel für Essigkarminpräparate

Zusammenfassung Es wird gezeigt, daß Karminessigsäurefärbungen in vielen Fällen mit Vorteil in neutralisiertem Chroralhydrat oder in verflüssigtem Phenol aufgehellt werden können. Die in Phenol liegenden Präparate lassen sich durch Umrandung mit Phenol-Harz-Mischungen in einfacher Weise dauerhaft machen.Mit 6 Textabbildungen