Soybean is an important oil- and protein-producing crop and over the last few decades soybean genetic transformation has made rapid strides. The probability of occurrence of transgene flow should be assessed, although the discrimination of conventional and transgenic soybean seeds and their hybrid descendants is difficult in fields. The feasibility of non-destructive discrimination of conventional and glyphosate-resistant soybean seeds and their hybrid descendants was examined by a multispectral imaging system combined with chemometric methods. Principal component analysis (PCA), partial least squares discriminant analysis (PLSDA), least squares-support vector machines (LS-SVM) and back propagation neural network (BPNN) methods were applied to classify soybean seeds. The current results demonstrated that clear differences among conventional and glyphosate-resistant soybean seeds and their hybrid descendants could be easily visualized and an excellent classification (98% with BPNN model) could be achieved. It was concluded that multispectral imaging together with chemometric methods would be a promising technique to identify transgenic soybean seeds with high efficiency.

Grain yield in bread wheat is often tightly associated with grain number/m2. In turn, spike fertility (SF), i.e., the quotient between grain number and spike chaff dry weight, accounts for a great proportion of the variation in grain number among cultivars. In order to examine the potential use of SF as a breeding target, (1) variation for the trait was assessed in six datasets combining commercial cultivars under different environmental conditions, (2) trait heritability was estimated in a set of F1 hybrids derived from controlled crosses between cultivars with contrasting SF and (3) SF distribution pattern was analysed in two F2 segregating populations. Analysis of commercial cultivars revealed considerable variation for SF, under both optimal and sub-optimal conditions. In addition, genotypic variation was consistently larger than genotype × environment interaction variation in all datasets. Narrow sense heritability, estimated by the mid-parent-offspring regression of 20 F1 hybrids and their respective parents, was 0·63. Data from two F2 populations exhibited bell-shaped and symmetric frequency distributions of SF, with a SF mean intermediate between the parental values. Substantial transgressive segregation was detected in both F2 populations. In conclusion, SF appears to be a heritable trait with predominantly additive effects. This warrants further investigation on the feasibility of using SF as an early selection criterion in wheat breeding programs aimed at increasing grain yield.

Many studies have highlighted the continuously increasing need for genetic diversity in the field; nonetheless, plant breeding is still predominantly generating uniform cultivars. Evolutionary plant breeding offers the possibility of reconciling agro-biodiversity, high yields and adaptation to climate change. However, the diversity that can be conserved in heterogeneous populations, its evolution and the potential of ‘evolutionary breeding’ in the actual scenario of climate change is still a matter of debate. In the present study, a total of 147 barley individuals, 56 from seven parental populations (PPs) and 91 from the composite cross-derived population (CCP) resulting from their inter-crossing were genotyped at 22 Simple Sequence Repeat (SSR) loci with the objective of obtaining insights into how genetic diversity evolved in the field during 13 years of multiplication. A total of 92 different alleles were detected in the PP and 100 in the CCP. Results showed that the composite individuals are grouped into five major clusters differing for both the number of individuals and the relative level of genetic diversity. The mean values of the most common descriptors of genetic diversity were not significantly different between the parental and the composite populations. However, analysis of molecular variance showed some degree of differentiation between the two populations suggesting that evolution occurred during the years of multiplication and selection effects were detected for some loci. The SSR loci detected as putatively under selection in the present study have already been reported as co-localized with quantitative trait loci for adaptedness traits or tagging genes related to abiotic stress response. According to the current results, evolving crop populations, which have the capability of adapting to the conditions under which they are grown, can be useful in conserving genetic diversity and as sources of genes for breeding purposes in particular in the actual scenario of climate change.

The present study was designed to estimate the effects of the mutant su1 on the genetic regulation of fitness-related traits when introgressed into field maize backgrounds. Estimated genetic effects of agronomic traits in Su1 v. su1 plants were monitored in two separate mean generation designs. The first involved unrelated inbred lines EP42 and A631, while two Corn Belt inbred lines, A619 and A632, were used for the second design. Parents, F1s, F2s and backcrosses were crossed to the su1 inbred P39 as the donor of su1 and the 12 crosses were successively self-pollinated for 5 years. For each cross, Su1 and su1 kernels were evaluated separately in a growth chamber under controlled environmental conditions following a randomized complete block design. In addition, the genotypes were evaluated in field trials in 10 × 10 triple lattice designs during 2010 and 2011 at Pontevedra in north-western Spain; and in 2010 at Algiers, located in the sub-humid North of Algeria. The performance of su1 plants was lower when compared to the Su1 plants for all traits evaluated in both designs and across environments. The estimates of genetic effects of Su1 v. su1 plants were strongly affected by genotype and environment. The results suggest that, depending on specific sweet × field maize interaction, seedling vigour and, particularly, chlorophyll content (CCM) were the most critical traits in determining su1 viability. However, the complexity of the genetic regulation of emergence and the great heterogeneity of environmental conditions in the field evaluation prevent the estimation of the genetic regulation on sugary1 fitness.

The objectives of the present study were to quantify the effects of contrasting methods for storing solid cattle manure on: (i) total carbon (C) and nitrogen (N) balances during storage, and (ii) crop apparent N recovery (ANR) following manure application to arable land, with maize as a test crop. Portions of 10 t of fresh solid cattle manure were stored for 5 months during 2009/10 in three replicates as: (i) stockpiled heaps, (ii) roofed heaps, (iii) covered heaps and (iv) turned heaps at Wageningen University, the Netherlands. Surface emissions of ammonia (NH3), nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) were measured regularly using a static flux chamber connected to a photo-acoustic gas monitor. Total C and N losses during storage were determined through the mass balance method. After storage, the manures were surface-applied and incorporated into a sandy soil, and maize ANR was measured as a proportion of both N applied to the field (ANRF) and N collected from the barn (ANRB).

During the storage period, the average losses of initial total N (Ntotal) were 6% from the covered, 12% from the roofed, 21% from the stockpiled and 33% from the turned heaps. Of the total N losses, 2–9% was lost as NH3-N, 1–4% as N2O-N and 16–32% through leaching. However, the greatest part of the total N loss from the four storage methods was unaccounted for and constituted in all probability of harmless dinitrogen gas. Of the initial C content, c. 13, 14, 17 and 22% was lost from the covered, stockpiled, roofed and turned heaps, respectively. Maize ANRF was highest from covered (39% of the applied N) followed by roofed (31%), stockpiled (29%) and turned manure (20%). The respective values in case of maize ANRB were 37, 27, 23 and 13%. It is concluded that from a viewpoint of on-farm N recycling the storage of solid cattle manure under an impermeable plastic cover is much better than traditional stockpiling or turning heaps in the open air.

Forage sorghum is an important component of the fodder supply chain in the arid and semi-arid regions of the world because of its high productivity, ability to utilize water efficiently and adaptability to a wide range of climatic conditions. Identification of high-yielding stable genotypes (G) across environments (E) is challenging because of the complex G × E interactions (GEI). In the present study, the performance of 16 forage sorghum genotypes over seven locations across the rainy seasons of 2010 and 2011 was investigated using GGE biplot analysis. Analysis of variance revealed the existence of significant GEI for fodder yield and all eight associated phenotypic traits. Location accounted for a higher proportion of the variation (0·72–0·91), while genotype contributed only 0·06–0·21 of total variation in different traits. Genotype-by-location interactions contributed 0·02–0·13 of total variation. Promising genotypes for fodder yield and each of the associated traits could be identified effectively using a graphical biplot approach. The majority of test locations were highly correlated. A ‘Which-won-where’ study partitioned the test locations into two mega-environments (MEs): ME1 was represented by five locations with COFS 29 as the best genotype, while ME2 had two locations with S 541 as the best genotype. The existence of two MEs suggested a need for location-specific breeding. Genotype-by-trait biplots indicated that improvement for forage yield could be achieved through indirect selection for plant height, leaf number and early vigour.

Land use and management, together with soil properties, determine soil organic carbon (SOC) concentration and its stabilization mechanisms. Four soils (0–30 cm depth) were studied in a semi-arid region with different uses and management regimes: two soils with olive cultivation, both under a non-tillage regime and one with a cover crop (OCC) and the other without (ONT); a fluvial terrace soil (FT) with cereal–sunflower–fallow rotation; and an unaltered soil under natural vegetation (oak trees; OT). The OT soil had a higher SOC concentration than the agricultural soils (OCC, ONT and FT), followed by the FT soil without significant differences. The olive grove soils had a lower SOC concentration but the two types of management differed significantly, with higher concentrations due to the cover crop. Hydrofluoric acid (HF)-soluble, hydrochloric acid (HCl)-resistant, and non-oxidizable (sodium peroxodisulphate; Na2S2O8) SOC fractions were determined at different depths (0–5, 5–10, 10–20 and 20–30 cm). The relative HCl-resistant and non-oxidizable SOC fractions increased with depth, whereas the relative HF-soluble SOC fraction varied slightly among the four soils considered. Differences in the SOC-stabilization mechanism were found according to the chemical SOC fractionation. In the FT and OT soils, where HF-soluble SOC and soil respiration rates were higher, the intense biological activity rapidly degraded the plant debris, being partially fixed and stabilized by the fine mineral-soil fraction as the principal stabilization mechanism of SOC. The olive grove soils had lower biological activity but higher SOC resistance to oxidation with Na2S2O8, thus suggesting that chemical recalcitrance of soil organic matter was a relevant stabilization mechanism in these soils.

To cope with phosphorus (P) deficiency, plants adapt root morphology to enhance inorganic P (Pi) acquisition from soil by allocating more biomass to roots, but whether the responses can be modified across gradients of P supply is not fully understood. The present study examined changes in root-length density (RLD), root-hair density (RHD) and root-hair length (RHL) of wheat (Triticum aestivum L.) in two contrasting soils, the Rough and Barnfield soils. Wheat plants were grown for 3 weeks in thin-plate rhizotrons in two soils with additions of 0, 10, 25, 50, 100 and 200 mg P/kg soil. Contrary to published literature, as P additions increased it was observed that a concomitant increase in RHL (250 to 1054 µm in the Rough soil and 303–1075 µm in the Barnfield soil) and RHD (57 to 122/mm in the Rough soil and 56–120/mm in the Barnfield soil), while RLD generally decreased (2480–1130 cm/cm3 in the Rough soil and 1716–865 cm/cm3 in the Barnfield soil). The levels of added P that resulted in critical P concentrations in the soils enabling maximum shoot biomass production were 50 mg/kg P in the Rough soil and 100 mg/kg P in the Barnfield soil, and these additions influenced root morphological changes. Under severe P deficiency, P supply increased RHL and RHD, but RLD was decreased. Improvement in lateral root and root-hair responses in wheat at extreme P deficiency may be a worthy target for breeding more sustainable genotypes for future agroecosystems.

Genetically modified (GM) plants expressing Bt toxin provide protection against lepidopteran pests. The only GM crop in Pakistan is Bt cotton, which was illegally imported and adopted rapidly by cotton producers. Farmers gained access to the seed of many unapproved Bt genotypes before the matter was picked up and formal approval granted by the relevant governmental agencies. The present study was conducted to evaluate the samples of Bt cotton, collected from farmers and seed dealer, for transgene integration and expression. Seeds of 52 cotton genotypes, labelled as Bt, were collected from various farmers and seed dealers. An immunoblot strip test was carried out, which showed that only 0·86 of the samples collected were synthesizing Cry1Ac toxin. According to multiplexed polymerase chain reaction (PCR) results, 0·86 of the genotypes tested were positive for the Mon531 event (an ‘event’ is a specific genetic modification in a specific species) and 0·14 were negative for any transgene. Transcript analysis of transgenes in positive genotypes by real-time Rt-PCR confirmed the synthesis of mRNA in all genotypes but with significant variation. The concentration of Bt toxin revealed by enzyme linked immunosorbent assay (ELISA) showed that only 0·02 genotypes had the reported optimum level. The real-time PCR and ELISA results further confirmed the attenuation of transgene expression at transcriptional and translational level by various internal and external factors. The same type of event was found in all genotypes, with significant variation in toxin level, revealing the impact of genetic background on transgene expression. The findings support the recommendation to improve the existing quality criteria for transgenic cotton variety approval and certification in Pakistan, with the inclusion of toxin concentration in the list of parameters to be considered.

The incursion of Bluetongue disease into the UK and elsewhere in Northern Europe in 2008 raised concerns about maintaining an appropriate level of preparedness for the encroachment of exotic diseases as circumstances and risks change. Consequently the Scottish government commissioned the present study to inform policy on the specific threat of Bluetongue virus 8 (BTV8) incursion into Scotland. An interdisciplinary expert panel, including BTV and midge experts, agreed a range of feasible BTV incursion scenarios, patterns of disease spread and specific control strategies. The study was primarily desk-based, applying quantitative methodologies with existing models, where possible, and utilizing data already held by different members of the project team. The most likely distribution of the disease was explored given Scotland's agricultural systems, unique landscape and climate. Epidemiological and economic models are integrated in an ex-ante cost-benefit appraisal of successful prevention of hypothetical BTV8 incursion into Scotland under various feasible incursion scenarios identified by the interdisciplinary panel. The costs of current public and private surveillance efforts are compared to the benefits of the avoided losses of potential disease outbreaks. These avoided losses included the direct costs of alternative vaccination, protection zone (PZ) strategies and their influence on other costs arising from an outbreak as predicted by the epidemiological model. Benefit-cost ratios were ranked within each incursion scenario to evaluate alternative strategies. In all incursion scenarios, the ranking indicated that a strategy, including 100% vaccination within a PZ set at Scottish counties along the England–Scotland border yielded the least benefit in terms of the extent of avoided outbreak losses (per unit cost). The economically optimal vaccination strategy was the scenario that employed 50% vaccination and all Scotland as a PZ. The results provide an indicator of how resources can best be targeted for an efficient ex-ante control strategy.

The objectives of the current study were to compare and model feed intake responses to ambient temperature across species and to assess opportunities to use cross-species (CS) data to parameterize models when species-specific (SS) data were limited. Literature searches were conducted to identify studies reporting intake during thermal stress compared with thermoneutral (TN) conditions. The resulting data set comprised 614 treatment means from 108 studies on livestock responses to thermal stress. An analysis of variance was conducted with the CS data set to identify the effects of species, temperature and species by temperature interactions on intake as (fractional feed intake; FFI). Four models were derived from the CS data set and root mean squared prediction error (RMSPE) and concordance correlation coefficients (CCC) of these models were compared with models of the same form derived from SS data sets. Models used explanatory variables for (1) duration of exposure; (2) mean temperature; (3) minimum and maximum temperatures; or (4) difference between minimum and maximum temperatures. An additional model accounting for temperature and stage of production was derived from the SS data. Analysis of variance demonstrated that the species by temperature interaction did not have a significant effect on FFI. Across species, intake decreased with temperature. Notably, all species demonstrated a constant decrease in intake across the TN zone indicating the previous assumption of constant intake during thermoneutrality may be not fully valid. When compared on a SS basis, SS-derived models had marginally lower RMSPE and higher CCC when compared with models derived from the CS data sets. The model fit with production data had the lowest RMSPE and highest CCC within the study. When compared over temperature ranges with minimal data available in some species (e.g., cold stress), using CS models often resulted in decreased RMSPE and improved CCC when compared with SS models. Although fitting models based on SS data allows for incorporating unique covariates, like level of production, fitting responses based on CS data can help to improve model estimates when knowledge gaps exist.

A completely randomized experiment for planting highland barley in 36 field plots of the Lhasa Agricultural Experiment Station was applied to investigate the effect of urea nitrogen (N) fertilization levels of 0 (control), 156, 258, 363, 465 and 570 kg/ha on nutrient accumulation, in vitro rumen gas production and fermentation characteristics of highland barley straw (HBS). Each urea application was divided into three portions of 0.4, 0.3 and 0.3 and sequentially fertilized at seeding (growth stage (GS) 0), stem elongation (GS 32) and heading (GS 49), respectively. The maturity stage lasted 5–13 days longer in response to the urea N fertilization compared with the control. After removing grains, HBS biomass was harvested at maturity. The biomass yields of leaf, stem, straw and grain were increased quadratically with increasing urea N fertilization, and HBS and grain yields peaked at the estimated urea N fertilization levels of 385 and 428 kg/ha, respectively. The increase of urea N fertilization increased the accumulation of crude protein, cellulose and lignin, and decreased the content of ash and hemicellulose in HBS, resulting in a decrease of the energy content available to be metabolized. After incubating HBS for 72 h with rumen fluids from lactating cows, the urea N fertilization decreased in vitro dry matter disappearance and cumulative gas production, and slightly altered fermentation end-gas composition. Urea N fertilization decreased microbial volatile fatty acid production, but did not alter the ratio of lipogenic acetate and butyrate to glucogenic propionate. In a brief, the current urea N fertilization strategy promoted the growth of the highland barley and increased biomass yield, protein and cellulose accumulation of HBS. A urea N fertilization level ⩽385 kg/ha could be sufficient for growth of highland barley in Tibet without a consequent nutritive reduction in ruminal digestion.

Pearl millet (Pennisetum glaucum (L.) R.) could play an important role as a feed source for ruminants in arid and semi-arid zones of the world owing to its high yield and drought tolerance. The current paper assessed the agronomic characteristics, ensilability, intake and digestibility of five Brazilian pearl millet cultivars (IPA Bulk1BF, BRS 1501, CMS-03, CMS-01 and BN-2) in a typical Brazilian northeastern semi-arid climate. Forage was harvested at the dough stage of grain maturity (growth stage 86 according to the BBCH scale) and ensiled under laboratory and farm conditions. Apparent digestibility of the silages was determined using 25 Santa Inês male lambs. The cultivars CMS-01, CMS-03 and BN-2 out-performed the others in terms of dry matter (DM) and digestible DM yield/ha. At DM partitioning among plant tissues, the cultivar IPA Bulk1BF had a greater DM associated with panicles and one of the greatest concentrations of organic matter, lactic acid and in vitro dry matter digestibility among the five cultivars. The cultivar BRS 1501 had greater butyric acid concentration as well as one of the highest pH values. Silage produced from BN-2 not only contained greater acetic acid concentration, but also showed one of the greatest total volatile fatty acid concentrations. There were no differences in feed intake and digestibility of nutrients and fibre fractions across all cultivars. Silage made from BN-2 resulted in greater urinary excretion of nitrogen than those produced from BRS 1501. Under the conditions of the present study, the results obtained for production of DM and digestible dry matter, and the ratio of plant fractions, indicates the possible use of these cultivars for silage production in the Brazilian semi-arid region.