Schlüsselwörter
(Englisch)
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Organic farming; organic breeding; winter wheat cultivars; arbuscular mycorrhizal fungi; nutrient acquisition potential
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Forschungsprogramme
(Englisch)
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COST-Action 860 - Sustainable low-input cereal production: required varietal characteristics and crop diversity
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Kurzbeschreibung
(Englisch)
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Cultivars adapted to low input conditions are a pre-requisite for sustainable production. One of the main topics of breeding for systems with limited access to nutrients is therefore the improvement of nutrient uptake. Phosphorus and nitrogen are the most limiting macro-elements under low input conditions such as organic farming.The symbiosis formed by arbuscular mycorrhizal fungi (AMF) and roots can improve plant growth and nutrient uptake. The formation and functioning of the mycorrhizal symbiosis depends on the AMF species/genotype and the crop cultivars. The selection of cultivars under high input conditions and for high resistance to fungal root pathogens could bear the risk of a negative response to AMF.In this study we compare old and new cultivars of winter wheat (Triticum aestivum, ssp. aestivum) with cultivars bred under organic conditions, regarding genotypic response to mycorrhizal association in low input organic farming systems (at three fertiliser levels) and in a high input conventional system. For this purpose, the cultivars will be tested in the glass house and in the long-term DOK field experiment. AMF colonisation of the roots, mycorrhizal growth response of the plants, nutrient uptake and seed quality of winter wheat will be measured.
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Weitere Hinweise und Angaben
(Englisch)
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Full name of research-institution/enterprise: Forschungsinstitut für biologischen Landbau FiBL
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Partner und Internationale Organisationen
(Englisch)
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AT, BE, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GR, HU, IE, IL, IS, IT, LT, LV, MK, NL, NO, PL, PT, RO, SE, SK, TR, UK
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Abstract
(Englisch)
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The testing of crop cultivars on organic and conventional farms is often confounded by site heterogeneity. We compared the performance of a set of old, conventionally and organically bred winter wheat (Triticum aestivum L.) cultivars within the DOK long term trial in CH-Therwil in 2007. In the DOK trial organic and conventional farming systems are compared since 1978 in a split-split plot design with four replicates on a haplic luvisol. Yield (dry matter yield, thousand kernel weight, harvest index and nitrogen harvest index) and quality parameters (grain protein content, Hagberg falling number, Zeleny value, wet gluten content and gluten index) of ten cultivars were assessed in four systems: unfertilized control (NOFERT), bio-dynamic (BIODYN 1 and 2) and one conventional farming system (CONMIN) with different levels of total nitrogen inputs (0, 33, 66 and 140 kg ha-1, respectively). Effects of cultivars and systems on yield and quality parameters were statistically significant, genotype x system interactions were generally not detected. Grain yield increased from 2.7 (NOFERT), 3.7 (BIODYN 1), 4.2 (BIODYN 2) up to 6.8 t ha-1 for the conventional system CONMIN with an average protein content of 10.8, 9.4, 9.0 and 11.7%, respectively. No significant differences between cultivars were detected for yield in the organic system BIODYN 2, whereas in the conventional system CONMIN, cultivars bred under conventional conditions yielded significantly more than old cultivars. However, the protein content of old cultivars was significantly higher than that of modern cultivars. The results imply that breeding for yield was successful during the last century but only under high input conditions (7.6 kg ha-1 yr-1 in the conventional system CONMIN), where the development was accompanied by rising inputs of external resources (e.g. mineral fertilizers). Under organic conditions, yield increase with the year of release of cultivars was only 1.8 kg ha-1 yr-1 (in the organic system BIODYN 2) and modern cultivars could not outperform the old cultivars, irrespective of their selection environment. A redundancy analysis showed that yield was mainly determined by systems or the input of fertilizers, while the influence of cultivars was only minor. The redundancy analysis for baking quality parameters in contrast revealed that the influence of cultivars was higher than the influence of the systems. It is suggested, that long term system comparisons can ideally serve to test crop cultivars under identical soil and climatic conditions. Root colonization with arbuscular mycorrhizal fungi (AMF) was higher under organic than under conventional farming conditions but there was no evidence that breeding conditions were influencing AMF-root colonization of the different cultivars. We observed a positive correlation for AMF root colonization and shoot P at tillering and flowering under organic but not under conventional conditions. On-farm trials conducted at three organically managed farms in different environments in Switzerland (Canton Schaffhausen, Zürich and Bern) showed significant effects of cultivars on grain yield, yield components and technological quality parameters. Furthermore, significant genotype x environment interactions were detected. Under low yielding conditions, there was a significant trend towards higher yields of organically bred cultivars when compared with the yield of old and conventionally bred cultivars. AMF-root colonization differed between environments but again no differences for AMF-root colonization between the winter wheat cultivars were observed. We can conclude from our data that arbuscular mycorrhizal fungi are important in low input wheat production, and that breeding under the target growth conditions is more effective for the selection of appropriate cultivars.
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Datenbankreferenzen
(Englisch)
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Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. +41 31 322 74 82 Swiss Project-Number: C05.0111
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