Lösungsansätze für Nachbauprobleme durch bodenbürtige Pathogene im biologischen Erdbeeranbau

Soil-borne pathogens, above all Verticillium sp. cause plant losses and yield decreases in many Austrian strawberry fields, also in organic farming systems; in a research project possibilities to resolve this problem were examined. In a field trial, which was started 1998, organically managed and differently fertilized plots (green compost, manure, hornchips) were compared to an unfertilised control plot and to two mineral fertilized and conventionally treated plots; the differences in field characteristics of strawberries in 2004 and 2005 were low, but differences in storage and biochemical characteristics could be seen in 2005. Some new cultivars tested as alternative to the very sensitive 'Elsanta' planted in 2005 on several farms showed a higher tolerance to diseases and good yield and fruit quality characteristics. Brassica sp. planted as an intercrop before strawberries reduced the amount of microsclerotia of Verticillium dahliae in highly infested soils, nevertheless the system has to be optimised and adapted to our climatic and husbandry conditions in further trials

Possible solutions for replant problems caused by soil-borne pathogens in organic strawberry production

Soil-borne pathogens, above all Verticillium sp. cause plant losses and yield decreases in many Austrian strawberry fields, also in organic farming systems; in a research project possibilities to resolve this problem were examined. In a field trial, which was started 1998, organically managed and differently fertilized plots (green compost, manure, hornchips) were compared to an unfertilised control plot and to two mineral fertilized and conventionally treated plots; the differences in field characteristics of strawberries in 2004 and 2005 were low, but differences in storage and biochemical characteristics could be seen in 2005. Some new cultivars tested as alternative to the very sensitive 'Elsanta' planted in 2005 on several farms showed a higher tolerance to diseases and good yield and fruit quality characteristics. Brassica sp. planted as an intercrop before strawberries reduced the amount of microsclerotia of Verticillium dahliae in highly infested soils, nevertheless the system has to be optimised and adapted to our climatic and husbandry conditions in further trials

Unravelling legacy: a triadic actor-network theory approach to understanding the outcomes of mega events

Mega events have recently attracted the attention of social scientists due to their important role for festival capitalism, urban regeneration and political propaganda. Their planning stage often produces elaborate strategies for maximising the benefits before, during and after the actual event, which has given rise to interdisciplinary studies of event legacy and leveraging. This paper aims to advance ongoing debates on the outcomes of sports mega events by bringing together the literatures on mega event legacy, leveraging and actor-network theory. Drawing on a case study on the usage of the Queen Elizabeth Olympic Park, the main legacy of the London 2012 Olympic Games, the paper develops a novel conceptual framework for researching the multi-scalar outcomes of mega events and locating respective studies within the resulting wider research agenda. The proposed concept extends Preuss’ (2007) legacy cube in two ways by visualising its five research dimensions in the legacy rings and using three rather than two sub-dimensions per ring, thereby replacing the restrictive dyads of dualistic thinking through more comprehensive but still manageable triads of triadic thought (Jöns, 2006)

Stone formation in peach fruit exhibits spatial coordination of the lignin and flavonoid pathways and similarity to Arabidopsis dehiscence

<p>Abstract</p> <p>Background</p> <p>Lignification of the fruit endocarp layer occurs in many angiosperms and plays a critical role in seed protection and dispersal. This process has been extensively studied with relationship to pod shatter or dehiscence in <it>Arabidopsis</it>. Dehiscence is controlled by a set of transcription factors that define the fruit tissue layers and whether or not they lignify. In contrast, relatively little is known about similar processes in other plants such as stone fruits which contain an extremely hard lignified endocarp or stone surrounding a single seed.</p> <p>Results</p> <p>Here we show that lignin deposition in peach initiates near the blossom end within the endocarp layer and proceeds in a distinct spatial-temporal pattern. Microarray studies using a developmental series from young fruits identified a sharp and transient induction of phenylpropanoid, lignin and flavonoid pathway genes concurrent with lignification and subsequent stone hardening. Quantitative polymerase chain reaction studies revealed that specific phenylpropanoid (phenylalanine ammonia-lyase and cinnamate 4-hydroxylase) and lignin (caffeoyl-CoA O-methyltransferase, peroxidase and laccase) pathway genes were induced in the endocarp layer over a 10 day time period, while two lignin genes (<it>p-</it>coumarate 3-hydroxylase and cinnamoyl CoA reductase) were co-regulated with flavonoid pathway genes (chalcone synthase, dihydroflavanol 4-reductase, leucoanthocyanidin dioxygen-ase and flavanone-3-hydrosylase) which were mesocarp and exocarp specific. Analysis of other fruit development expression studies revealed that flavonoid pathway induction is conserved in the related Rosaceae species apple while lignin pathway induction is not. The transcription factor expression of peach genes homologous to known endocarp determinant genes in <it>Arabidopsis </it>including <it>SHATTERPROOF</it>, <it>SEEDSTCK </it>and <it>NAC SECONDARY WALL THICENING PROMOTING FACTOR 1 </it>were found to be specifically expressed in the endocarp while the negative regulator <it>FRUITFU</it>L predominated in exocarp and mesocarp.</p> <p>Conclusions</p> <p>Collectively, the data suggests, first, that the process of endocarp determination and differentiation in peach and <it>Arabidopsis </it>share common regulators and, secondly, reveals a previously unknown coordination of competing lignin and flavonoid biosynthetic pathways during early fruit development.</p

Transgenic apple plants overexpressing the chalcone 3-hydroxylase gene of Cosmos sulphureus show increased levels of 3-hydroxyphloridzin and reduced susceptibility to apple scab and fire blight

Main conclusionOverexpression of chalcone-3-hydroxylase provokes increased accumulation of 3-hydroxyphloridzin inMalus. Decreased flavonoid concentrations but unchanged flavonoid class composition were observed. The increased 3-hydroxyphlorizin contents correlate well with reduced susceptibility to fire blight and scab.The involvement of dihydrochalcones in the apple defence mechanism against pathogens is discussed but unknown biosynthetic steps in their formation hamper studies on their physiological relevance. The formation of 3-hydroxyphloretin is one of the gaps in the pathway. Polyphenol oxidases and cytochrome P450 dependent enzymes could be involved. Hydroxylation of phloretin in position 3 has high similarity to the B-ring hydroxylation of flavonoids catalysed by the well-known flavonoid 3′-hydroxylase (F3′H). Using recombinant F3′H and chalcone 3-hydroxylase (CH3H) from Cosmos sulphureus we show that F3′H and CH3H accept phloretin to some extent but higher conversion rates are obtained with CH3H. To test whether CH3H catalyzes the hydroxylation of dihydrochalcones in planta and if this could be of physiological relevance, we created transgenic apple trees harbouring CH3H from C. sulphureus. The three transgenic lines obtained showed lower polyphenol concentrations but no shift between the main polyphenol classes dihydrochalcones, flavonols, hydroxycinnamic acids and flavan 3-ols. Increase of 3-hydroxyphloridzin within the dihydrochalcones and of epicatechin/catechin within soluble flavan 3-ols were observed. Decreased activity of dihydroflavonol 4-reductase and chalcone synthase/chalcone isomerase could partially explain the lower polyphenol concentrations. In comparison to the parent line, the transgenic CH3H-lines showed a lower disease susceptibility to fire blight and apple scab that correlated with the increased 3-hydroxyphlorizin contents.Austrian Sci-ence Fund (FWF