High-throughput phenotyping (HTP) identifies seedling root traits linked to variation in seed yield and nutrient capture in field-grown oilseed rape (Brassica napus L.).

Background and Aims Root traits can be selected for crop improvement. Techniques such as soil excavations can be used to screen root traits in the field, but are limited to genotypes that are well-adapted to field conditions. The aim of this study was to compare a low-cost, high-throughput root phenotyping (HTP) technique in a controlled environment with field performance, using oilseed rape (OSR; Brassica napus) varieties. Methods Primary root length (PRL), lateral root length and lateral root density (LRD) were measured on 14-d-old seedlings of elite OSR varieties (n = 32) using a 'pouch and wick' HTP system (∼40 replicates). Six field experiments were conducted using the same varieties at two UK sites each year for 3 years. Plants were excavated at the 6- to 8-leaf stage for general vigour assessments of roots and shoots in all six experiments, and final seed yield was determined. Leaves were sampled for mineral composition from one of the field experiments. Key Results Seedling PRL in the HTP system correlated with seed yield in four out of six (r = 0·50, 0·50, 0·33, 0·49; P < 0·05) and with emergence in three out of five (r = 0·59, 0·22, 0·49; P < 0·05) field experiments. Seedling LRD correlated positively with leaf concentrations of some minerals, e.g. calcium (r = 0·46; P < 0·01) and zinc (r = 0·58; P < 0·001), but did not correlate with emergence, general early vigour or yield in the field. Conclusions Associations between PRL and field performance are generally related to early vigour. These root traits might therefore be of limited additional selection value, given that vigour can be measured easily on shoots/canopies. In contrast, LRD cannot be assessed easily in the field and, if LRD can improve nutrient uptake, then it may be possible to use HTP systems to screen this trait in both elite and more genetically diverse, non-field-adapted OSR.

Inter-cultivar variation in soil-to-plant transfer of radiocaesium and radiostrontium in Brassica oleracea.

Radiocaesium and radiostrontium enter the human food chain primarily via soil-plant transfer. However, uptake of these radionuclides can differ significantly within species (between cultivars). The aim of this study was to assess inter-cultivar variation in soil-to-plant transfer of radiocaesium and radiostrontium in a leafy crop species, Brassica oleracea. This study comprised four independent experiments: two pot experiments in a controlled environment artificially contaminated with radiocaesium, and two field experiments in an area contaminated with radiocaesium and radiostrontium in the Chernobyl Exclusion Zone. Radiocaesium concentration ratios varied 35-fold among 27 cultivars grown in pots in a controlled environment. These 27 cultivars were then grown with a further 44 and 43 other cultivars in the Chernobyl Exclusion Zone in 2003 and 2004, respectively. In the field-grown cultivars radiocaesium concentration ratios varied by up to 35-fold and radiostrontium concentration ratios varied by up to 23-fold. In three of these experiments (one pot experiment, two field experiments) one out of the 27 cultivars was found to have a consistently lower radiocaesium concentration ratio than the other cultivars. The two field experiments showed that, five out of the 66 cultivars common to both experiments had consistently lower radiocaesium concentration ratios, and two cultivars had consistently lower radiostrontium concentration ratios. One cultivar had consistently lower radiocaesium and radiostrontium concentration ratios. The identification of cultivars that have consistently lower radiocaesium and/or radiostrontium concentration ratios suggests that cultivar selection or substitution may be an effective remediation strategy in radiologically contaminated areas. Future research should focus on plant species that are known to be the largest contributors to human dose.

The effectiveness of compulsory drug treatment: A systematic review.

BACKGROUND: Despite widespread implementation of compulsory treatment modalities for drug dependence, there has been no systematic evaluation of the scientific evidence on the effectiveness of compulsory drug treatment. METHODS: We conducted a systematic review of studies assessing the outcomes of compulsory treatment. We conducted a search in duplicate of all relevant peer-reviewed scientific literature evaluating compulsory treatment modalities. The following academic databases were searched: PubMed, PAIS International, Proquest, PsycINFO, Web of Science, Soc Abstracts, JSTOR, EBSCO/Academic Search Complete, REDALYC, SciELO Brazil. We also searched the Internet, and article reference lists, from database inception to July 15th, 2015. Eligibility criteria are as follows: peer-reviewed scientific studies presenting original data. Primary outcome of interest was post-treatment drug use. Secondary outcome of interest was post-treatment criminal recidivism. RESULTS: Of an initial 430 potential studies identified, nine quantitative studies met the inclusion criteria. Studies evaluated compulsory treatment options including drug detention facilities, short (i.e., 21-day) and long-term (i.e., 6 months) inpatient treatment, community-based treatment, group-based outpatient treatment, and prison-based treatment. Three studies (33%) reported no significant impacts of compulsory treatment compared with control interventions. Two studies (22%) found equivocal results but did not compare against a control condition. Two studies (22%) observed negative impacts of compulsory treatment on criminal recidivism. Two studies (22%) observed positive impacts of compulsory inpatient treatment on criminal recidivism and drug use. CONCLUSION: There is limited scientific literature evaluating compulsory drug treatment. Evidence does not, on the whole, suggest improved outcomes related to compulsory treatment approaches, with some studies suggesting potential harms. Given the potential for human rights abuses within compulsory treatment settings, non-compulsory treatment modalities should be prioritized by policymakers seeking to reduce drug-related harms.

Genetic analysis of potassium use efficiency in Brassica oleracea.

BACKGROUND AND AIMS: Potassium (K) fertilizers are used in intensive and extensive agricultural systems to maximize production. However, there are both financial and environmental costs to K-fertilization. It is therefore important to optimize the efficiency with which K-fertilizers are used. Cultivating crops that acquire and/or utilize K more effectively can reduce the use of K-fertilizers. The aim of the present study was to determine the genetic factors affecting K utilization efficiency (KUtE), defined as the reciprocal of shoot K concentration (1/[K](shoot)), and K acquisition efficiency (KUpE), defined as shoot K content, in Brassica oleracea. METHODS: Genetic variation in [K](shoot) was estimated using a structured diversity foundation set (DFS) of 376 accessions and in 74 commercial genotypes grown in glasshouse and field experiments that included phosphorus (P) supply as a treatment factor. Chromosomal quantitative trait loci (QTL) associated with [K](shoot) and KUpE were identified using a genetic mapping population grown in the glasshouse and field. Putative QTL were tested using recurrent backcross substitution lines in the glasshouse. KEY RESULTS: More than two-fold variation in [K](shoot) was observed among DFS accessions grown in the glasshouse, a significant proportion of which could be attributed to genetic factors. Several QTL associated with [K](shoot) were identified, which, despite a significant correlation in [K](shoot) among genotypes grown in the glasshouse and field, differed between these two environments. A QTL associated with [K](shoot) in glasshouse-grown plants (chromosome C7 at 62.2 cM) was confirmed using substitution lines. This QTL corresponds to a segment of arabidopsis chromosome 4 containing genes encoding the K+ transporters AtKUP9, AtAKT2, AtKAT2 and AtTPK3. CONCLUSIONS: There is sufficient genetic variation in B. oleracea to breed for both KUtE and KUpE. However, as QTL associated with these traits differ between glasshouse and field environments, marker-assisted breeding programmes must consider carefully the conditions under which the crop will be grown.

Interactions between selenium and sulphur nutrition in Arabidopsis thaliana.

Selenium (Se) is an essential plant micronutrient, but is toxic at high tissue concentrations. It is chemically similar to sulphur (S), an essential plant macronutrient. The interactions between Se and S nutrition were investigated in the model plant Arabidopsis thaliana (L.) Heynh. Arabidopsis plants were grown on agar containing a complete mineral complement and various concentrations of selenate and sulphate. The Se/S concentration ratio in the shoot ([Se](shoot)/[S](shoot)) showed a complex dependence on the ratio of selenate to sulphate concentration in the agar ([Se](agar)/[S](agar)). Increasing [S](agar) increased shoot fresh weight (FW) and [S](shoot), but decreased [Se](shoot). Increasing [Se](agar) increased both [Se](shoot) and [S](shoot), but reduced shoot FW. The reduction in shoot FW in the presence of Se was linearly related to the shoot Se/S concentration ratio. These data suggest (i) that Se and S enter Arabidopsis through multiple transport pathways with contrasting sulphate/selenate selectivities, whose activities vary between plants of contrasting nutritional status, (ii) that rhizosphere sulphate inhibits selenate uptake, (iii) that rhizosphere selenate promotes sulphate uptake, possibly by preventing the reduction in the abundance and/or activity of sulphate transporters by sulphate and/or its metabolites, and (iv) that Se toxicity occurs because Se and S compete for a biochemical process, such as assimilation into amino acids of essential proteins.