Drying soybean seed using air ambient temperature at low relative humidity

Under subtropical and tropical environments soybean seed (Glycine max (L.) Merrill) are harvested early to avoid deterioration from weathering. Careful after-harvest drying is required and is an important step in maintaining the physiological quality of the seed. Soybean seed should be harvested when the moisture content is in a range of 16-20%. Traditional drying utilizes a high temperature air stream passed through the seed mass without dehumidification. The drying time is long because the system is inefficient and the high temperature increases the risk of thermal damage to the seed. New technology identified as heat pipe technology (HPT) is available and has the unique feature of removing the moisture from the air stream before it is passed through the seed mass at the same environmental temperature. Two studies were conducted to evaluate the performance of HPT for dry soybean seed. In the first study the seeds were dried from 17.5 to 11.1% in 2 hours and 29 minutes and in the second sudy the seeds were dried from 22.6 to 11.9% in 16 hours and 32 minutes. This drying process caused no reduction in seed quality as measured by the standard germination, tetrazolium-viability, accelerated aging and seedling vigor classification tests. The only parameter that indicated a slight seed quality reduction was tetrazolium vigor in the second study. It was concluded that the HPT system is a promising technology for drying soybean seed when efficiency and maintenance of physiological quality are desired.

Evaluation of lignin content of soybean seed coat stored in a controlled environment

Breeding soybean for high seed quality is an important approach for developing cultivars for tropical regions, and the lignin content in the seed coat is one of the screening parameters for this trait. Considering that many breeding lines are evaluated in each growing season using the presently recommended method for lignin determination, a long period is required for the evaluation of the whole breeding program. This time limitation may influence lignin content assessment, if lignin is degraded during storage. This research reported was designed to determine whether lignin was degraded in the seed coat of soybean seed cultivars stored for one year in a controlled environment (10°C temperature and 50% air relative humidity). Seeds of 12 selected soybean cultivars that had a range in seed coat lignin content were evaluated. Seeds were hand harvested just after physiological maturity and evaluated for seed coat lignin content at harvest and after one year of storage in a cold room (10°C and 50% RH). The lignin content in seed coats differed significantly among cultivars in both analyses, but for both results the sequence of cultivar classification and the lignin content values of each cultivar did not change. A regression analysis of lignin content at harvest and after one year of storage indicated a direct relationship between both lignin determinations suggesting no differences between the lignin content of each cultivar due to prolonged storage (r² = 0.98***). This indicates that the lignin determination in the soybean seed coat can be performed over a long time period without any bias due to change in its content.

Response of soybean genotypes to the expression of green seed under temperature and water stresses

Soybeans grown under water stress associated with high temperatures during seed maturation and pre-harvest may produce green seed (GS) with expressive reduction in seed quality. The objectives of this study were to evaluate the response of different soybean cultivars grown under these stressful conditions regarding their susceptibility to GS production and to determine the chlorophyll retention levels and the chlorophyllase activity in the seeds. Seeds of four soybean cultivars [BRS 133, CD 206, MG/BR 46 (Conquista) and BRSMG 251 (Robusta)] were grown under greenhouse conditions until R5.5. At R6, the plants were transferred to phytotrons under temperature stress (from 28ºC to 36ºC) and with water stresses of 10% gravimetric moisture, no water and normal supply. Seeds were harvested at R9 when the percentage of GS and weight of 100 seeds were determined. The contents of a, b and total chlorophylls and the chlorophyllase activity were also determined. The expression of GS production under these conditions varied among cultivars: Conquista and Robusta were considered more susceptible to the production of GS compared to 'BRS 133' and 'CD 206'. These cultivars produced lower GS levels, lower chlorophyll retention and higher chlorophyllase activity compared to Robusta and Conquista. Soybean plants submitted to water and temperature stresses produced high levels of GS, which were small, light and had high chlorophyll contents and low chlorophyllase activity. The contents of a, b and total chlorophylls in GS were inversely proportional to the chlorophyllase activity.

Physiological and enzymatic alterations in papaya seed during storage

This study was done to evaluate the physiological and enzymatic alterations in papaya (Carica papaya L.) seeds during storage period. Seeds were extracted from mature fruits of Formosa group papaya hybrid Tainung 01. The sarcotesta was removed by rubbing the seeds on a wire screen under running water and then dried to the moisture content (MC) of 5, 8 or 11% The seeds were packed in multilayer paper bags, polyethylene bags, aluminum foil pouch and metallic canisters and stored for 15 months under laboratory conditions. Seeds were evaluated, at three month interval, for MC, germination, and the activity of acid phosphotase (AP) and malate dehyrogenase (MDH) was evaluated with the use of amide gel (12%) electrophoresis. The fresh seeds had post-harvest dormancy, which was broken after six month storage. Independent of the package type, the seeds could be stored for 12 months with 8 or 11% MC under ambient conditions. There was no association between seed deterioration and alterations in AP and MDH activity.

Physiological maturity of fruits and seeds of Poincianella pyramidalis (Tul.) L.P. Queiroz

The Leguminosae family is one of the most representative botanical families of the Caatinga, with 80 endemic species, highlighting the catingueira (Poincianella pyramidalis). The objective of this research work was to study the maturation process of P. pyramidalis seeds based on the physiological maturity. Five harvest of fruits and seeds were carried out, with 15 days interval each, in a period from July to September 2010. The harvests began 75 days after anthesis (d.a.a.) and lasted until 135 d.a.a. Fruits and seeds were subjected to the following assessments: size, moisture content, and dry mass of fruits and seeds; and germination and vigor of seeds (first count of germination, germination speed index, length and dry mass of seedling). Under the environmental conditions of municipality of Soledade, State of Paraiba, Northeast Brazil, the point of physiological maturity of P. pyramidalis seeds occurs at 125 d.a.a., when the maximum accumulation of dry mass is 1.993 g and moisture content is 21%. The ideal point of harvest is between 130 d.a.a and 135 d.a.a., before natural dehiscence, when the moisture content of seeds is between 13.0% and 5.0%.

Survey, survival and control of Alternaria alternata in wheat seeds

The fungus Alternaria alternata was quantified in 75 wheat seed samples collected from three different regions of southern Brazil for Cropping and Use Value (CUV) I, II and III. Fungal presence was evaluated in two hundred disinfested seeds per sample before sowing in a potato-dextrose-agar medium + antibiotic (PDA+A). Fungus survival was evaluated every 45 days for 180 days for three seed batches from six wheat cultivars stored in propylene bags in a storehouse, with air temperature varying between 18 to 22 °C and relative air humidity around 60%. The efficacy of carboxin+thiram, difenoconazol, thiram, triadimenol, triticonazol and triticonazol + iprodione fungicides to control A. alternata was determined. A. alternata was detected in all the samples with an incidences of 39.6 %, 38.8% and 35.9% for the CUV I, CUV II and CUV III regions, respectively. The highest mean incidence of the fungus was found in the CUV I region, the coolest and most humid, and was significantly different from the other two regions. The average reduction in A. alternata viability in the wheat cultivar seeds was 49.5% during the 180 days of storage (inter-harvest period), demonstrating that infected seeds are the primary inoculum source for the fungus. The triticonazol + iprodione fungicide mixture efficiently controls A. alternata.

Physiological maturity of eggplant seeds

Determination of seed physiological maturity and ideal moment for harvesting fruits to extract their seeds are important aspects to produce seeds with high quality. To identify the best period for harvesting eggplant fruits, associated with ideal resting period of the fruit for extracting seeds, an eggplant production field was installed in municipality of Ijaci, in the State of Minas Gerais, Southwestern Brazil. The fruits were harvested at periods of 49, 56, 63, 70, and 77 days after pollination (DAP). The seeds of fruits harvested in each period were manually extracted immediately after harvest or after a post-harvest resting period of seven days, under a shed. The physiological quality of seeds was assessed by tests of: germination percentage; germination and emergence speed indexes; and electrical conductivity; which were carried out in the Central Seed Laboratory, Federal University of Lavras. Electrophoretic analyses of isoenzymes: catalase (CAT); esterase (EST); superoxide dismutase (SOD); and peroxidase (PO), were also therein performed. Results of germination and vigor of seeds have showed that the best period for harvesting the fruit is around 70 DAP; and that seeds should be extracted immediately after harvest. Electrophoretic analysis of enzymes has showed immaturity for eggplant seeds, harvested after 49 DAP.

The effect of pH and ethanol on the astringent sub-qualities of red wine, and the implications for optimum grape maturity /

The first objective of this study was to identify appropriate sensory descriptors to assess the astringent sub-qualities of red wine. The influence of pH and ethanol on the sensation of astringency in red wine was evaluated, using a de-alcoholized red wine. A portion of the wine was adjusted to the pH values of 3.2, 3.4, 3.6 and 3.8, and another portion was adjusted to ethanol concentrations of 0%, 6%, 12%, and 15%. In addition, the pH 3.4 and 3.6 treatments were adjusted to an ethanol concentration of 12% and 15% all wines were then assessed sensorially and seventeen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: velvet, aggressive, silk/satin, dry, fleshy, unripe, pucker viscosity, abrasive, heat, chewy, acidity, grippy/adhesive, bitter, balance, overall astringency, and mouth-coat. Descriptive analysis profiling techniques were used to train the panel and measure the intensity of these attributes. It was found that decreasing pH values (averaged across all ethanol concentrations) showed an increase in the overall astringency of the wine. The combined treatments of ethanol and pH, real wine parameters (pH 3.4 and 3.6; 12% and 15% ethanol) did not have an effect on the perception of the astringent sub-qualities of the wine. A time intensity study was also included using the pH and ethanol adjusted wines, which showed that as the ethanol level of the wines increased so did the time to maximum intensity. The second objective was to identify appropriate sensory descriptors to evaluate the influence of grape maturity and maceration technique (grape skin contact) on the astringency sub-qualities of red vinifera wines from Niagara. The grapes were harvested across two dates, representing an early harvest and a late harvest. A portion of the Cabernet Sauvignon grapes wine was divided into three maceration treatments of oneweek maceration, standard two-week maceration, three-week maceration, and MCM. Another portion of both the early and late harvest Cabernet Sauvignon grapes were chaptalized to yield a final ethanol concentration of 14.5%. The wines were assessed sensorially and thirteen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: carbon dioxide, pucker, acidity, silk/chamois, dusty/chalky/powdery, sandpaper, numbing, grippy/adhesive, dry, mouthcoat, bitter, balance and, overall astringency. Descriptive analysis techniques were used to train the panel and measure the intensity of these attributes. The data revealed few significant differences in the mouth-feel of the wines with respect to maturity; which included differences in overall astringency and balance. There were varietal differences between Cabernet Sauvignon, Cabernet Franc, and Pinot Noir and differences for Cabernet Sauvignon wines due to the length and manner of maceration and as a result of chaptalization. Statistical analysis revealed a more complex mouth-feel for the Pinot Noir wines; and an increase in the intensity of the astringent sub-qualities as a result of the addition of sugar to the wines. These findings have implications for how processing decisions, such as optimum grape maturity and vinification methods may affect red wine quality.

Development of techniques for testing the effect of the E1 region on adenovirus integration /

Adenoviral vectors are currently the most widely used gene therapeutic vectors, but their inability to integrate into host chromosomal DNA shortened their transgene expression and limited their use in clinical trials. In this project, we initially planned to develop a technique to test the effect of the early region 1 (E1) on adenovirus integration by comparing the integration efficiencies between an E1-deleted adenoviral vector (SubE1) and an Elcontaining vector (SubE3). However, we did not harvest any SubE3 virus, even if we repeated the transfection and successfully rescued the SubE1 virus (2/4 transfections generated viruses) and positive control virus (6/6). The failure of rescuing SubE3 could be caused by the instability of the genomic plasmid pFG173, as it had frequent intemal deletions when we were purifying It. Therefore, we developed techniques to test the effect of E1 on homologous recombination (HR) since literature suggested that adenovirus integration is initiated by HR. We attempted to silence the E1 in 293 cells by transfecting E1A/B-specific small interfering RNA (siRNA). However, no silenced phenotype was observed, even if we varied the concentrations of E1A/B siRNA (from 30 nM to 270 nM) and checked the silencing effects at different time points (48, 72, 96 h). One possible explanation would be that the E1A/B siRNA sequences are not potent enough to Induce the silenced phenotype. For evaluating HR efficiencies, an HR assay system based on bacterial transfonmatJon was designed. We constmcted two plasmids ( designated as pUC19-dl1 and pUC19-dl2) containing different defective lacZa cassettes (forming white colonies after transformation) that can generate a functional lacZa cassette (forming blue colonies) through HR after transfecting into 293 cells. The HR efficiencies would be expressed as the percentages of the blue colonies among all the colonies. Unfortunately, after transfonnation of plasmid isolated from 293 cells, no colony was found, even at a transformation efficiency of 1.8x10^ colonies/pg pUC19, suggesting the sensitivity of this system was low. To enhance the sensitivity, PCR was used. We designed a set of primers that can only amplify the recombinant plasmid fomied through HR. Therefore, the HR efficiencies among different treatments can be evaluated by the amplification results, and this system could be used to test the effect of E1 region on adenovirus integration. In addition, to our knowledge there was no previous studies using PCR/ Realtime PCR to evaluate HR efficiency, so this system also provides a PCR-based method to carry out the HR assays.

The Catharanthus roseus 16-hydroxytabersonine O-methyltransferase involved in vindoline biosynthesis /

Madagascar periwinkle (Catharanthus roseus) produces the well known and remarkably complex dimeric anticancer alkaloids vinblastine and vincristine that are derived by coupling vindoline and catharanthine monomers. This thesis describes the novel application of carborundum abrasion (CA) technique as a tool for large scale isolation of leaf epidermis enriched proteins. This technique was used to facilitate the purification to apparent homogeneity of 16-hydroxytabersonine-16-0-methyltransferse (l60MT) that catalyses the second step in the 6 step pathway that converts tabersonine into vindoline. This versatile tool was also used to harvest leaf epidermis enriched mRNAs that facilitated the molecular cloning of the 160MT. Functional expression and biochemical characterization of recombinant 160MT enzyme showed that it had a very narrow substrate specificity and high affinity for 16-hydroxytabersonine, since other closely related monoterpene indole alkaloids (MIAs) did not act as substrates. In addition to allowing the cloning of this gene, CA technique clearly showed that 160MT is predominantly expressed in Catharanthus leaf epidermis, in contrast to several other OMTs that appear to be expressed in other Catharanthus tissues. The results provide compelling evidence that most of the pathway for vindoline biosynthesis including the 0- methylation of 16-hydroxytabersonine occurs exclusively in leaf epidermis, with subsequent steps occurring in other leaf cell types. Small molecule O-methyltransferases (OMTs) (E.C. 2.1.1.6.x) catalyze the transfer of the reactive methyl group of S-adenosyl-L-methionine (SAM) to free hydroxyl groups of acceptor molecules. Plant OMTs, unlike their monomeric mammalian homologues, exist as functional homodimers. While the biological advantages for dimer fonnation with plant OMTs remain to be established, studies with OMTs from the benzylisoquinoline producing plant, Thalictrum tuberosum, showed that co-expression of 2 recombinant OMTs produced novel substrate specificities not found when each rOMT was expressed individually (Frick, Kutchan, 1999) . These results suggest that OMTs can fonn heterodimers that confer novel substrate specificities not possible with the homodimer alone. The present study describes a 160MT model based strategy attempting to modify the substrate specificity by site-specific mutagenesis. Our failure to generate altered substrate acceptance profiles in our 160MT mutants has lead us to study the biochemical properties ofhomodimers and heterodimers. Experimental evidence is provided to show that active sites found on OMT dimers function independently and that bifunctional heterodimeric OMTs may be fonned in vivo to produce a broader and more diverse range of natural products in plants.

Localization and functional characterization of iridoid biosynthetic genes in Catharanthus roseus /

Catharanthus roseus is the sole biological source of the medicinal compounds vinblastine and vincristine. These chemotherapeutic compounds are produced in the aerial organs of the plant, however they accumulate in small amounts constituting only about 0.0002% of the fresh weight of the leaf. Their limited biological supply and high economical value makes its biosynthesis important to study. Vinblastine and vincristine are dimeric monoterpene indole alkaloids, which consists of two monomers vindoline and catharanthine. The monoterpene indole alkaloids (MIA's) contain a monoterpene moiety which is derived from the iridoid secologanin and an indole moiety tryptamine derived from the amino acid tryptophan. The biosynthesis of the monoterpene indole alkaloids has been localized to at least three cell types namely, the epidermis, the laticifer and the internal phloem assisted parenchyma. Carborundum abrasion (CA) technique was developed to selectively harvest epidermis enriched plant material. This technique can be used to harvest metabolites, protein or RNA. Sequencing of an expressed sequence tagged (EST) library from epidermis enriched mRNA demonstrated that this cell type is active in synthesizing a variety of secondary metabolites namely, flavonoids, lipids, triterpenes and monoterpene indole alkaloids. Virtually all of the known genes involved in monterpene indole alkaloid biosynthesis were sequenced from this library.This EST library is a source for many candidate genes involved in MIA biosynthesis. A contig derived from 12 EST's had high similarity (E'^') to a salicylic acid methyltransferase. Cloning and functional characterization of this gene revealed that it was the carboxyl methyltransferase imethyltransferase (LAMT). In planta characterization of LAMT revealed that it has a 10- fold enrichment in the leaf epidermis as compared to the whole leaf specific activity. Characterization of the recombinant enzyme revealed that vLAMT has a narrow substate specificity as it only accepts loganic acid (100%) and secologanic acid (10%) as substrates. rLAMT has a high Km value for its substrate loganic acid (14.76 mM) and shows strong product inhibition for loganin (Kj 215 |iM). The strong product inhibition and low affinity for its substrate may suggest why the iridoid moiety is the limiting factor in monoterpene indole alkaloid biosynthesis. Metabolite profiling of C. roseus organs shows that secologanin accumulates within these organs and constitutues 0.07- 0.45% of the fresh weight; however loganin does not accumulate within these organs suggesting that the product inhibition of loganin with LAMT is not physiologically relevant. The limiting factor to iridoid and MIA biosynthesis seems to be related to the spatial separation of secologanin and the MIA pathway, although secologanin is synthesized in the epidermis, only 2-5% of the total secologanin is found in the epidermis while the remaining secologanin is found within the leaf body inaccessable to alkaloid biosynthesis. These studies emphasize the biochemical specialization of the epidermis for the production of secondary metabolites. The epidermal cells synthesize metabolites that are sequestered within the plant and metabolites that are secreted to the leaf surface. The secreted metabolites comprise the epidermome, a layer separating the plant from its environment.

Assessing the influence of irrigation and fertigation on fruit composition, vine performance and wine quality in a cool, humid climate /

A study was devised to evaluate influences of irrigation and fertigation practices on Vitis vinifera and Vitis labruscana grapes in the Niagara Peninsula. A modified FAO Penman- Monteith evapotranspiration formula was used to calculate water budgets and schedule irrigations. Five deficit irrigation treatments (non-irrigated control; deficits imposed postbloom, lag phase, and veraison; fiiU season irrigation) were employed in a Chardonnay vineyard. Transpiration rate (4-7 /xg H20/cmVs) and soil moisture data demonstrated that the control and early deficit treatments were under water stress throughout the season. The fiiU season irrigation treatment showed an 18% (2001) and 19% (2002) increase in yield over control due to increased berry weight. Soluble solids and wine quality were not compromised, and the fiiU season treatment showed similar or higher °Brix than all other treatments. Berry titratable acidity andpH also fell within acceptable levels for all five treatments. Irrigation/fertigation timing trials were conducted on Concord and Niagara vines in 2001- 02. The six Concord treatments consisted of a non-irrigated control, irrigation fi^om Eichhom and Lorenz (EL) stage 12 to harvest, and four fertigation treatments which applied 70 kg/ha urea. The nine Niagara treatments included a non-irrigated control, two irrigated treatments (ceasing at veraison and harvest, respectively) and six fertigation treatments of various durations. Slight yield increases (ca. 10% in Concord; 29% in Niagara) were accompanied by small decreases in soluble solids (1.5°Brix), and methyl anthranilate concentrations. Transpiration rate and soil moisture (1 1.9-16.3%) data suggested that severe water stress was present in these Toledo clay based vineyards.

The Terroir of Winter Hardiness: Investigation of Winter Hardiness, Water Metrics, and Yield of Riesling and Cabernet Franc in the Niagara Region Using Geomatic Technologies

Grapevine winter hardiness is a key factor in vineyard success in many cool climate wine regions. Winter hardiness may be governed by a myriad of factors in addition to extreme weather conditions – e.g. soil factors (texture, chemical composition, moisture, drainage), vine water status, and yield– that are unique to each site. It was hypothesized that winter hardiness would be influenced by certain terroir factors , specifically that vines with low water status [more negative leaf water potential (leaf ψ)] would be more winter hardy than vines with high water status (more positive leaf ψ). Twelve different vineyard blocks (six each of Riesling and Cabernet franc) throughout the Niagara Region in Ontario, Canada were chosen. Data were collected during the growing season (soil moisture, leaf ψ), at harvest (yield components, berry composition), and during the winter (bud LT50, bud survival). Interpolation and mapping of the variables was completed using ArcGIS 10.1 (ESRI, Redlands, CA) and statistical analyses (Pearson’s correlation, principal component analysis, multilinear regression) were performed using XLSTAT. Clear spatial trends were observed in each vineyard for soil moisture, leaf ψ, yield components, berry composition, and LT50. Both leaf ψ and berry weight could predict the LT50 value, with strong positive correlations being observed between LT50 and leaf ψ values in eight of the 12 vineyard blocks. In addition, vineyards in different appellations showed many similarities (Niagara Lakeshore, Lincoln Lakeshore, Four Mile Creek, Beamsville Bench). These results suggest that there is a spatial component to winter injury, as with other aspects of terroir, in the Niagara region.

IMPACT OF CROP LEVEL AND HANG TIME ON THE COMPOSITION OF FOUR WINE GRAPE CULTIVARS FROM THE NIAGARA REGION

This study analyzed the use of two viticultural practices: “crop level” (half crop; HC, and full crop; FC) and “hang times”, and their impact on the composition of four grape cultivars; Pinot gris, Riesling, Cabernet Franc and Cabernet Sauvignon from the Niagara Region and wine volatile composition by GC-MS. It was hypothesized that keeping a full crop with a longer hang time would have a greater impact on wine quality than reducing the crop level. In all cultivars, a reduction of crop level induced reductions in yield, clusters per vine and crop load, with increases in Brix. Extended hang time also increased Brix related to desiccation. The climatic conditions at harvest had an impact on hang time effects. The GC-MS analysis detected the presence of 30 volatile components in the wine, with different odour activity values. Harvest time had a positive impact than crop reduction in almost all compounds.

Planification de la récolte et allocation des produits aux usines

L’industrie forestière est un secteur qui, même s’il est en déclin, se trouve au cœur du débat sur la mondialisation et le développement durable. Pour de nombreux pays tels que le Canada, la Suède et le Chili, les objectifs sont de maintenir un secteur florissant sans nuire à l’environnement et en réalisant le caractère fini des ressources. Il devient important d’être compétitif et d’exploiter de manière efficace les territoires forestiers, de la récolte jusqu’à la fabrication des produits aux usines, en passant par le transport, dont les coûts augmentent rapidement. L’objectif de ce mémoire est de développer un modèle de planification tactique/opérationnelle qui permet d’ordonnancer les activités pour une année de récolte de façon à satisfaire les demandes des usines, sans perdre de vue le transport des quantités récoltées et la gestion des inventaires en usine. L’année se divise en 26 périodes de deux semaines. Nous cherchons à obtenir les horaires et l’affectation des équipes de récolte aux blocs de coupe pour une année. Le modèle mathématique développé est un problème linéaire mixte en nombres entiers dont la structure est basée sur chaque étape de la chaine d’approvisionnement forestière. Nous choisissons de le résoudre par une méthode exacte, le branch-and-bound. Nous avons pu évaluer combien la résolution directe de notre problème de planification était difficile pour les instances avec un grand nombre de périodes. Cependant l’approche des horizons roulants s’est avérée fructueuse. Grâce à elle en une journée, il est possible de planifier les activités de récolte des blocs pour l’année entière (26 périodes).