The Potential of Low Phytic Acid1-1 Mutant in Maize (Zea mays L.): A Sustainable Solution to Non-Renewable Phosphorus.

BACKGROUND: Phosphorus is an essential component of fertilizers and feed and in recent decades has become one of the main sustainability issues as a non-renewable resource. In plant seeds, the main reserve of phosphorus is phytic acid, a strong anti-nutritional factor for monogastrics and a pollutant of cultivated lands. The reduction of phytic acid in cereal seeds has become a major challenge in breeding programs to increase the nutritional quality of foods and feeds and to improve the environmental phosphorus sustainability in agriculture. In maize (Zea mays L.), four low phytic acid (lpa) mutations have been isolated and lpa1-1 is the most promising. However, the reduction of phytic acid in lpa1-1 leads to many adverse pleiotropic effects on the seed and in general on plant performance. A seed weight reduction and a consequent yield loss were previously described in this mutant. METHOD: In this work, a field experiment to study seed weight and yield was conducted for two years in two different genetic backgrounds (B73 and B73/Mo17). Furthermore, the greater susceptibility of lpa1-1 to drought stress was also investigated: a dedicated field experiment was set up and measurements were carried out under optimal water conditions and moderate drought stress. RESULTS: From the first experiment it emerges that under high-input conditions, lpa1-1 seems to have comparable or even better yield than the relative control. The main problem of this mutant remains the reduced field emergence (~40%). In the study of drought stress it was found that the increased sensitivity in the mutant is mainly caused by an altered stomatal regulation, but not by a less developed root system, as previously reported. When the stress occurred, the parameters measured did not significantly change in the wild-type, while they dropped in the mutant: the net photosynthesis decreased by 58%, the transpiration rate by 63% and the stomatal conductance by 67%. CONCLUSIONS: Some possible solutions have been proposed, with the aim of developing a commercial variety, which remains the main goal to exploit the nutritional benefits of low phytic acid mutants.

Effect of homeopathy on soybean germination through soil and seed treatment

Homeopathy is a technique approved by the MAPA for organic production systems. Experiments demonstrating the effectiveness of homeopathy in agriculture are essential. Aims: To evaluate the effects of homeopathic treatment on soybean seed germination. Methodology: The experiment was performed in MS-Brazil. An area of 70 m² was used, divided into two comparison plots of 30 m² each. The soil of plot 1 (treated group) was treated with 5.25 kg of powdered Lithothamniummixed with 250 ml of 30% hydroalcoholic solution (HS) containing homeopathic ingredients. The soil of plot 2 (control group) was treated with thesame preparationbutwithout homeopathic ingredients. Additionally, the 400 seeds assigned toplot 1 were treated with 0,3 ml of a solution made up of 10 ml of 30% HS with homeopathic ingredients dilutedin 300 ml of water. The 400 seeds assigned toplot 2 were treated with 0.3 ml of a solutionmade up of 10 ml of HS without homeopathic ingredients diluted in 300 ml of water. The homeopathic ingredients Sulph 9C, Mag-c12C, and Calc-p 9C were used on soil and seed treatment. The selection and prescription of those ingredients followed Materia Medica instructions. The experiment was conducted using randomized design and 400 seeds per group were sown. Results and discussion: In plot 1, anaverage of 11 seeds per m² germinated, adding up to 330 germinated seeds at a percentage of 82.5%. In plot 2, an average of 7 seeds per m² germinated, adding up to 210 germinated seeds at a percentage of 52.5%. The frequency of seed germinationin both groups was assessed by the Chi-square test to check for significant differences(p<0.05). There was a statistical difference (p<0.05) in the seed germination in the treated group (n=330) compared to the control group (n=210). Conclusion:Homeopathic compounds can be used as a viable treatment for soybean germination.

Transcriptomics View over the Germination Landscape in Biofortified Rice.

Hidden hunger, or micronutrient deficiency, is a worldwide problem. Several approaches are employed to alleviate its effects (e.g., promoting diet diversity, use of dietary supplements, chemical fortification of processed food), and among these, biofortification is considered as one of the most cost-effective and highly sustainable. Rice is one of the best targets for biofortification since it is a staple food for almost half of the world's population as a high-energy source but with low nutritional value. Multiple biofortified rice lines have been produced during the past decades, while few studies also reported modifications in germination behavior (in terms of enhanced or decreased germination percentage or speed). It is important to underline that rapid, uniform germination, and seedling establishment are essential prerequisites for crop productivity. Combining the two traits, biofortified, highly-nutritious seeds with improved germination behavior can be envisaged as a highly-desired target for rice breeding. To this purpose, information gathered from transcriptomics studies can reveal useful insights to unveil the molecular players governing both traits. The present review aims to provide an overview of transcriptomics studies applied at the crossroad between biofortification and seed germination, pointing out potential candidates for trait pyramiding.

Transcriptome analysis in osmo-primed tomato seeds with enhanced longevity by heat shock treatment.

Seed priming is widely used in commercial seeds and its main function is to accelerate and synchronize seed germination. Undesirably, primed seeds show reduced longevity and treatments like heat shock have been shown to improve longevity in primed seeds. Nonetheless, the effect of heat shock treatment on primed seeds at the mRNA level is not known. Thus, the aim of this work was to investigate the effect of heat shock treatment on the longevity of primed tomato (Solanum lycopersicum) seeds at the physiological and transcriptome levels. Tomato seeds were primed and dried (control). Alternatively, primed seeds were subjected to heat shock treatment (38 °C/32 % relative humidity) before drying. Germination, vigor and longevity were evaluated. Transcriptome analysis was performed by RNA sequencing (RNA-seq) from biological samples collected immediately after priming and another samples collected from primed seeds followed by the heat shock treatments. The gene expression was validated by quantitative real time PCR (RT-qPCR). We showed that applying heat shock treatment after priming increased germination speed, enhanced seed longevity and preserved the vigor during storage of primed tomato seeds. Through transcriptome analysis, 368 differentially expressed genes were identified, from which 298 genes were up-regulated and 70 were down-regulated. We showed the increase of mRNA levels of HEAT SHOCK FACTOR-like and HEAT SHOCK PROTEIN-like chaperone genes, suggesting the involvement of the proteins coded by these transcripts in the enhancement of longevity in primed tomato seeds. The heat shock treatment after priming enhances and preserves the vigor of tomato primed seeds during storage. In addition, improves seed longevity through the increase in the expression of transcripts related to protection by response to stress.

Seed-specific down-regulation of Arabidopsis CELLULOSE SYNTHASE 1 or 9 reduces seed cellulose content and differentially affects carbon partitioning.

KEY MESSAGE: Seed-specific down-regulation of AtCESA1 and AtCESA9, which encode cellulose synthase subunits, differentially affects seed storage compound accumulation in Arabidopsis. High amounts of cellulose can negatively affect crop seed quality, and, therefore, diverting carbon partitioning from cellulose to oil, protein and/or starch via molecular breeding may improve seed quality. To determine the effect of seed cellulose content reduction on levels of storage compounds, Arabidopsis thaliana CELLULOSE SYNTHASE1 (AtCESA1) and AtCESA9 genes, which both encode cellulose synthase subunits, were individually down-regulated using seed-specific intron-spliced hairpin RNA (hpRNAi) constructs. The selected seed-specific AtCESA1 and AtCESA9 Arabidopsis RNAi lines displayed reduced cellulose contents in seeds, and exhibited no obvious visual phenotypic growth defects with the exception of a minor effect on early root development in AtCESA1 RNAi seedlings and early hypocotyl elongation in the dark in both types of RNAi line. The seed-specific down-regulation of AtCESA9 resulted in a reduction in seed weight compared to empty vector controls, which was not observed in AtCESA1 RNAi lines. In terms of effects on carbon partitioning, AtCESA1 and AtCESA9 RNAi lines exhibited distinct effects. The down-regulation of AtCESA1 led to a ~ 3% relative increase in seed protein content (P = 0.04) and a ~ 3% relative decrease in oil content (P = 0.02), but caused no alteration in soluble glucose levels. On the contrary, AtCESA9 RNAi lines did not display a significant reduction in seed oil, protein or soluble glucose content. Taken together, our results indicate that the seed-specific down-regulation of AtCESA1 causes alterations in seed storage compound accumulation, while the effect of AtCESA9 on carbon partitioning is absent or minor in Arabidopsis.

A practical genome-enabled legitimacy assay for oil palm breeding and seed production.

BACKGROUND: Legitimacy in breeding and commercial crop production depends on optimised protocols to ensure purity of crosses and correct field planting of material. In oil palm, the presence of three fruit forms permits these assumptions to be tested, although only after field planting. The presence of incorrect fruit forms in a cross is a clear sign of illegitimacy. Given that tenera forms produce 30% more oil for the same weight of fruit as dura, the presence of low levels of dura contamination can have major effect during the economic lifespan of an oil palm, which is around 25 years. We evaluated two methods for legitimacy test 1) The use of SHELL markers to the gene that determines the shell-thickness trait 2) The use of SNP markers, to determine the legitimacy of the cross. RESULTS: Our results indicate that the SHELL markers can theoretically reduce the major losses due to dura contamination of tenera planting material. However, these markers cannot distinguish illegitimate tenera, which reduces the value of having bred elite tenera for commercial planting and in the breeding programme, where fruit form is of limited utility, and incorrect identity could lead to significant problems. We propose an optimised approach using SNPs for routine quality control. CONCLUSIONS: Both dura and tenera contamination can be identified and removed at or before the nursery stage. An optimised legitimacy assay using SNP markers coupled with a suitable sampling scheme is now ready to be deployed as a standard control for seed production and breeding in oil palm. The same approach will also be an effective solution for other perennial crops, such as coconut and date palm.

Classification of Processing Damage in Sugar Beet (Beta vulgaris) Seeds by Multispectral Image Analysis.

The pericarp of monogerm sugar beet seed is rubbed off during processing in order to produce uniformly sized seeds ready for pelleting. This process can lead to mechanical damage, which may cause quality deterioration of the processed seeds. Identification of the mechanical damage and classification of the severity of the injury is important and currently time consuming, as visual inspections by trained analysts are used. This study aimed to find alternative seed quality assessment methods by evaluating a machine vision technique for the classification of five damage types in monogerm sugar beet seeds. Multispectral imaging (MSI) was employed using the VideometerLab3 instrument and instrument software. Statistical analysis of MSI-derived data produced a model, which had an average of 82% accuracy in classification of 200 seeds in the five damage classes. The first class contained seeds with the potential to produce good seedlings and the model was designed to put more limitations on seeds to be classified in this group. The classification accuracy of class one to five was 59, 100, 77, 77 and 89%, respectively. Based on the results we conclude that MSI-based classification of mechanical damage in sugar beet seeds is a potential tool for future seed quality assessment.

Fatty Acid Composition, Phytochemistry, Antioxidant Activity on Seed Coat and Kernel of Paeonia ostii from Main Geographic Production Areas.

Paeonia ostii is an important woody oil plant cultivated in China on a large scale. Its seed oil is enriched with unsaturated fatty acids and a high content of alpha-linolenic acid (ALA), which are beneficial to human health. The aim of this research is to determine the qualitative traits characteristic of P. ostii seed from various production areas in China. In this study, seed quality traits were evaluated on the basis of proximate composition, content of fatty acids, tocopherol, secondary metabolites, and the antioxidant activity of seed coat (PSC) and kernel (PSK). A high content of total fatty acids (298.89-399.34 mg g-1), crude protein (16.91%-22.73%), and total tocopherols (167.83-276.70 µg g-1) were obtained from PSK. Significant differences were found in the content of palmitic acids (11.31-14.27 mg g-1), stearic acids (2.42-4.24 mg g-1), oleic acids (111.25-157.63 mg g-1), linoleic acids (54.39-83.59 mg g-1), and ALA (99.85-144.71 mg g-1) in the 11 main production areas. Eight and seventeen compounds were detected in PSC and PSK, respectively. A significantly higher content of total phenols was observed in PSC (139.49 mg g-1) compared with PSK (3.04 mg g-1), which was positively related to antioxidant activity. This study indicates that seeds of P. ostii would be a good source of valuable oil and provides a basis for seed quality evaluation for the production of edible oil and potential ALA supplements from the promising woody oil plant.

Dissection of the genetic architecture of three seed-quality traits and consequences for breeding in Brassica napus.

Genome-wide association studies (GWASs) combining high-throughput genome resequencing and phenotyping can accelerate the dissection of genetic architecture and identification of genes for plant complex traits. In this study, we developed a rapeseed genomic variation map consisting of 4 542 011 SNPs and 628 666 INDELs. GWAS was performed for three seed-quality traits, including erucic acid content (EAC), glucosinolate content (GSC) and seed oil content (SOC) using 3.82 million polymorphisms in an association panel. Six, 49 and 17 loci were detected to be associated with EAC, GSC and SOC in multiple environments, respectively. The mean total contribution of these loci in each environment was 94.1% for EAC and 87.9% for GSC, notably higher than that for SOC (40.1%). A high correlation was observed between phenotypic variance and number of favourable alleles for associated loci, which will contribute to breeding improvement by pyramiding these loci. Furthermore, candidate genes were detected underlying associated loci, based on functional polymorphisms in gene regions where sequence variation was found to correlate with phenotypic variation. Our approach was validated by detection of well-characterized FAE1 genes at each of two major loci for EAC on chromosomes A8 and C3, along with MYB28 genes at each of three major loci for GSC on chromosomes A9, C2 and C9. Four novel candidate genes were detected by correlation between GSC and SOC and observed sequence variation, respectively. This study provides insights into the genetic architecture of three seed-quality traits, which would be useful for genetic improvement of B. napus.

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Field experiments, including four levels of N application 0, 18, 24, 30 g N·m-2, were carried out to clarify the effects of nitrogen fertilization on N accumulation and translocation in lea-ves as well as the seed quality of oil peony (Paeonia ostii 'Fengdan Group'). The results showed that the nitrogen application significantly increased the height, canopy, flower diameter and flower dry mass. The heights under the treatments 24 and 30 g N·m-2 increased by 14.7% and 15.2% compared with CK, respectively. Moreover, the nitrogen application improved seed yield. The highest seed yields were acquired under the treatments 24 and 30 g N·m-2, which were 15.2% and 15.4% higher than that of CK, respectively. The N accumulation and translocation in leaves and the N accumulation in seeds all increased with the nitrogen application level. The greatest leaf contribution proportion was acquired under the treatment 24 g N·m-2. The nitrogen application significantly increased the contents of protein N, total amino acid, and some saturated and unsaturated fatty acids in seeds. In this experiment, the N input of 24 g N·m-2 was optimal to obtain the higher N translocation amount, N translocation efficiency and N contribution proportion from leaves to seeds, seed yield as well as the contents of protein N, amino acid and unsaturated fatty acids.

Tetrazolium test to evaluate the viability of oil radish seeds / Teste de tetrazólio para avaliação da viabilidade de sementes de nabo forrageiro

The use of tetrazolium test is important in the evaluation of seeds lot quality and it has been adopted for vigor and viability identification for several species. The interest on the production of oil radish is increasing since the seeds were considered a good source of oil for biofuel production. The development of the tetrazolium test methodology for seeds of this species can improve the seed quality control process, and additionally will provide information for the characterization of remaining seeds (dead or dormant) in the germination tests. To verify the ideal conditions to tetrazolium test was conducted two experiments. At the first, oil radish seeds cultivar CATI AL-1000, lots from 2001 and 2006 were submitted to imbibition between paper in water for 6 hours. After the longitudinal cut in the longest direction, the seeds were immersed in the tetrazolium solution at the concentrations of 0,075%, 0,5% and 1% at 25°C for 3h, 12h and 18h. In the second experiment, oil radish seeds cultivar CATI AL-1000 lot from 2005 and IPR 116 cultivar, lots from 2004 and 2005 were immersed in the concentrations of ,1%; 0,2%; 0,3% and 0,4% of tetrazolium solution for 12 hours at a 25°C, 30°C, 35°C and 40°C. At the first experiment was observed the necessity of test intermediate concentrations between 0,075% and 0,5%, since with 0,075% the seeds stained weakly and with 0,5% the test results, were overestimated. In the second experiment was observed that the 0,3% concentration at 30°C can be recommended for the utilization of tetrazolium test to evaluation of oil radish seeds viability.

A utilização do teste de tetrazólio é importante na avaliação da qualidade de lotes de sementes e vem sendo adotado para várias espécies na identificação do vigor e viabilidade. A adequação da metodologia do teste de tetrazólio para sementes de nabo forrageiro, espécie que vem se destacando como fonte de óleo para produção de biocombustíveis, poderia melhorar o processo de controle de qualidade. Além disso, a utilização do teste poderá fornecer subsídios para identificação de sementes remanescentes (mortas e dormentes) nos testes de germinação. Para verificar as condições ideais para a realização do teste de tetrazólio, em um 1º experimento as sementes de nabo forrageiro da cultivar CATI AL-1000, lotes de 2001 e 2006, foram submetidas à embebição entre papel em água por 6 horas. Após corte longitudinal no maior sentido as sementes foram imersas nas concentrações de 0,075%; 0,5% e 1,0% de solução de tetrazólio a 25ºC por 3 h, 12 h e 18 horas. Em um 2º experimento sementes de nabo forrageiro da cultivar CATI AL-1000, lote de 2005 e cultivar IPR 116 lotes de 2004 e 2005, foram imersas nas concentrações de 0,1%; 0,2%; 0,3% e 0,4% de solução de tetrazólio a 25°C, 30°C, 35°C e 40°C por 12 horas. Pelo 1º experimento foram observados a necessidade de testar concentrações intermediárias entre 0,075% e 0,5%, visto que, com 0,075% as sementes coloriram fracamente e com 0,5% os resultados do teste foram superestimados. No 2º experimento observou-se que a concentração 0,3% a 30°C pode ser recomendada para utilização no teste de tetrazólio para avaliação da viabilidade de sementes de nabo forrageiro.

Genome-wide association study dissects the genetic architecture of seed weight and seed quality in rapeseed (Brassica napus L.).

Association mapping can quickly and efficiently dissect complex agronomic traits. Rapeseed is one of the most economically important polyploid oil crops, although its genome sequence is not yet published. In this study, a recently developed 60K Brassica Infinium(®) SNP array was used to analyse an association panel with 472 accessions. The single-nucleotide polymorphisms (SNPs) of the array were in silico mapped using 'pseudomolecules' representative of the genome of rapeseed to establish their hypothetical order and to perform association mapping of seed weight and seed quality. As a result, two significant associations on A8 and C3 of Brassica napus were detected for erucic acid content, and the peak SNPs were found to be only 233 and 128 kb away from the key genes BnaA.FAE1 and BnaC.FAE1. BnaA.FAE1 was also identified to be significantly associated with the oil content. Orthologues of Arabidopsis thaliana HAG1 were identified close to four clusters of SNPs associated with glucosinolate content on A9, C2, C7 and C9. For seed weight, we detected two association signals on A7 and A9, which were consistent with previous studies of quantitative trait loci mapping. The results indicate that our association mapping approach is suitable for fine mapping of the complex traits in rapeseed.

Armazenamento de sementes de Alfavaca-cravo (Ocimum gratissimum L. ) / Storage of Clove Basil (Ocimum gratissimum L. ) seeds

A espécie Ocimum gratissimum L. é um subarbusto aromático, pertencente à família Lamiaceae, considerado como importante produtor de óleo essencial e largamente utilizado na medicina popular. Devido à escassez de informações sobre a conservação das sementes dessa espécie o presente estudo objetivou analisar a longevidade das sementes submetidas a diferentes condições de armazenamento, por 12 meses, através de avaliações do potencial germinativo e da capacidade de formação de plântulas normais. As sementes foram armazenadas em três tipos de embalagens: sacos de papel, sacos de papel aluminizado, e frascos de vidro, e nas seguintes condições ambientais: balcão de laboratório, geladeira, e câmara fria. Aos 6, 8, 10 e 12 meses de armazenamento foram avaliados os seguintes parâmetros: umidade, porcentagem de germinação, índice de velocidade de germinação e porcentagem de plântulas normais. Durante o período de armazenamento a manutenção da umidade nas sementes foi mantida, bem como a porcentagem de germinação e de plântulas normais em todos os tratamentos avaliados. As sementes armazenadas apresentaram maiores valores de IVG quando comparadas com as recém-colhidas.

The Ocimum gratissimum L. species is an aromatic subshrub that belongs to the Lamiaceae family and is considered as an important producer of essential oil, widely used in folk medicine. Because of the lack of information about the conservation of O. gratissimum seeds, we aimed to evaluate the longevity of the seeds on different storage conditions for 12 months through the germination and seedling formation percentage in this study. The seeds were stored in three types of packages: paper bags (permeable), aluminized paper bags (semipermeable) and glass flasks (impermeable), in the settings of laboratory bench, refrigerator and cold room over the 12 month period. The germination tests were performed on the 6th, 8th, 10th and 12th month, when moisture, germinability, germination velocity index and percentage of normal seedlings were evaluated. During the storage period, moisture, germinability and percentage of normal seedling were kept in each storage condition. The stored seeds showed increased values of GSI compared to the newly- harvested ones.