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Foulkes M.J.,University of Nottingham | Slafer G.A.,University of Lleida | Davies W.J.,Lancaster University | Berry P.M.,ADAS High Mowthorpe | And 6 more authors.
Journal of Experimental Botany | Year: 2011

A substantial increase in grain yield potential is required, along with better use of water and fertilizer, to ensure food security and environmental protection in future decades. For improvements in photosynthetic capacity to result in additional wheat yield, extra assimilates must be partitioned to developing spikes and grains and/or potential grain weight increased to accommodate the extra assimilates. At the same time, improvement in dry matter partitioning to spikes should ensure that it does not increase stem or root lodging. It is therefore crucial that improvements in structural and reproductive aspects of growth accompany increases in photosynthesis to enhance the net agronomic benefits of genetic modifications. In this article, six complementary approaches are proposed, namely: (i) optimizing developmental pattern to maximize spike fertility and grain number, (ii) optimizing spike growth to maximize grain number and dry matter harvest index, (iii) improving spike fertility through desensitizing floret abortion to environmental cues, (iv) improving potential grain size and grain filling, and (v) improving lodging resistance. Since many of the traits tackled in these approaches interact strongly, an integrative modelling approach is also proposed, to (vi) identify any trade-offs between key traits, hence to define target ideotypes in quantitative terms. The potential for genetic dissection of key traits via quantitative trait loci analysis is discussed for the efficient deployment of existing variation in breeding programmes. These proposals should maximize returns in food production from investments in increased crop biomass by increasing spike fertility, grain number per unit area and harvest index whilst optimizing the trade-offs with potential grain weight and lodging resistance. © 2010 The Author(s). Source

Berry P.M.,ADAS High Mowthorpe | Spink J.,Teagasc | Foulkes M.J.,University of Nottingham | White P.J.,Scottish Crop Research Institute
Field Crops Research | Year: 2010

Four field experiments were performed in the UK in harvest seasons 2007 and 2008. Each experiment consisted of 10 winter oilseed rape varieties grown at a low level of available nitrogen (N) and at a high level of available N intended to replicate commercial practice. A combined analysis of three of the experiments with significant yield differences between the N treatments showed a significant interaction between N availability and variety for yield. Across these three experiments the proportion of yield lost when crops were grown at low N compared with high N ranged from 0.23 to 0.35 among varieties. The proportion of yield lost at low N was negatively associated with crop N uptake. There was also an interaction between N supply and variety for N use efficiency (kg of seed dry matter/kg available N) within these three experiments. Varietal differences in yield at low N correlated most closely, and positively, with crop N uptake, final crop dry matter and seeds/m2, but not N utilisation (kg seed/kg N uptake). Every additional kilogram of N taken up by the crop increased yield at low N by 0.020t/ha. The amount of N taken up after flowering was the most important phase of N uptake for determining yield differences between the varieties, with every additional kilogram of N taken up after flowering associated with a yield increase of 0.016t/ha. Each additional 1000seeds/m2 was associated with an additional 1.4kgN/ha taken up after flowering. There was no correlation between yield at low N or late N uptake and individual seed size. © 2010 Elsevier B.V. Source

Berry P.M.,ADAS High Mowthorpe | Berry S.T.,Limagrain UK Ltd
Euphytica | Year: 2015

A genetic analysis of plant characters associated with lodging resistance, yield and other agronomic traits was made on two doubled haploid winter wheat populations grown at two UK locations in the 2004/2005, 2005/2006 and 2006/2007 seasons. Wide genetic variation was found for traits that affect lodging, including plant height, components of stem strength (stem diameter, wall width and material strength), components of anchorage strength (spread and depth of the root plate), ear area and shoot number per plant. Heritabilities were estimated for each of the key lodging traits, with plant height having the highest heritability and anchorage traits the lowest values. Six quantitative trait loci (QTL) controlling plant height had individual height effects (2 × the additive effect) of 3–9 cm and taken together, could potentially increase plant height by up to 34 cm. Three of the height QTL were also associated with greater yield or greater thousand grain weight, and three were associated with components of stem strength or anchorage strength. QTL were also identified for each of the measured lodging traits, which were unrelated to height. Individual QTL with the largest estimated effects on lodging resistance were for height, stem diameter, stem material strength, stem failure moment, root plate spread and root plate depth. Diagnostic genetic markers for the most important QTL regions are now required to enable breeders to efficiently combine multiple traits together in a single variety that will increase lodging resistance and yield simultaneously. © 2015, Springer Science+Business Media Dordrecht. Source

Berry P.M.,ADAS High Mowthorpe | Spink J.,Teagasc
Field Crops Research | Year: 2012

Lodging is a major limiting factor for wheat (Triticum aestivum L.) production, yet few studies have investigated the mechanism by which it reduces yield. This paper tests the hypothesis that lodging-induced yield losses in wheat can be predicted by calculating the reduction in canopy photosynthesis that results from lodging-induced changes to the architecture of the canopy. An existing model of canopy photosynthesis has been further developed to account for the effect of lodging-induced changes to the canopy architecture on photosynthesis and grain yield. The model predicted that lodging at 90° from the vertical will reduce yield by approximately 61%. The ability of the model to predict lodging-induced yield losses was tested against observations made in three separate field experiments. The model predicted 71% of the variation in the proportion of yield lost due to lodging (Y LOSS) and the best-fit line was not significantly different from the 1:1 relationship. Sensitivity analysis showed that the proportion of yield lost was relatively insensitive to the model parameters. As a result it was shown that a simplified model could be employed without losing predictive accuracy. YLOSS=∑if(L90×0.7+L65×0.3+L25×0.1)/n In this equation i and f are the 1st and last days of grain filling, L 90 is the proportion of crop area lodged at 85-90° from the vertical, L 65 is the proportion of crop area lodged between 46° and 84°, L 25 is the proportion of crop area lodged between 5° and 45° and n is the number of days of grain filling. © 2012 Elsevier B.V. Source

Lo Iacono G.,University of Cambridge | van den Bosch F.,Rothamsted Research | Paveley N.,ADAS High Mowthorpe
Journal of Theoretical Biology | Year: 2012

Disease resistance genes are valuable natural resources which should be deployed in a way which maximises the gain to crop productivity before they lose efficacy. Here we present a general epidemiological model for plant diseases, formulated to study the evolution of phenotypic traits of plant pathogens in response to host resistance. The model was used to analyse how the characteristics of the disease resistance, and the method of deployment, affect the size and duration of the gain. The gain obtained from growing a resistant cultivar, compared to a susceptible cultivar, was quantified as the increase in green canopy area resulting from control of foliar disease, integrated over many years-termed 'Healthy Area Duration (HAD) Gain'. Previous work has suggested that the effect of crop ratio (the proportion of land area occupied by the resistant crop) on the gain from qualitative (gene-for-gene) resistance is negligible. Increasing the crop ratio increases the area of uninfected host, but the resistance is more rapidly broken; these two effects counteract each other. We tested the hypothesis that similar counteracting effects would occur for quantitative, multi-genic resistance, but found that the HAD Gain increased at higher crop ratios. Then we tested the hypothesis that the gain from quantitative host resistance could differ depending on the life-cycle component (sporulation rate or infection efficiency) constrained by the resistance. For the patho-system considered, a quantitative resistant cultivar that reduced the infection efficiency gave a greater HAD Gain than a cultivar that reduced sporulation rate, despite having equivalent transmission rates. © 2012 Elsevier Ltd. Source

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