Full Text Available Orthodox seeds are living organisms that survive anhydrobiosis and may display dormancy, an inability to germinate at harvest. Seed germination potential can be acquired during a prolonged period of dry storage called after-ripening. The aim of this work was to determine if gene transcription is an underlying regulatory mechanism for dormancy alleviation during after-ripening. To identify changes in gene transcription strictly associated with the acquisition of germination potential but not with storage, we used seed storage at low relative humidity that maintains dormancy as control. Transcriptome profiling was performed using DNA microarray to compare change in gene transcript abundance between dormant (D, after-ripened non-dormant (ND and after-ripened dormant seeds (control, C. Quantitative real-time polymerase chain reaction (qPCR was used to confirm gene expression. Comparison between D and ND showed the differential expression of 115 probesets at cut-off values of two-fold change (p<0.05. Comparisons between both D and C with ND in transcript abundance showed that only 13 transcripts, among 115, could be specific to dormancy alleviation. qPCR confirms the expression pattern of these transcripts but without significant variation between conditions. Here we show that sunflower seed dormancy alleviation in the dry state is not related to regulated changes in gene expression.
Du, W; Cheng, J; Cheng, Y; Wang, L; He, Y; Wang, Z; Zhang, H
After-ripening is a common method used for dormancy release in rice. In this study, the rice variety Jiucaiqing (Oryza sativa L. subsp. japonica) was used to determine dormancy release following different after-ripening times (1, 2 and 3 months). Germination speed, germination percentage and seedling emergence increased with after-ripening; more than 95% germination and 85% seedling emergence were observed following 1 month of after-ripening within 10 days of imbibition, compared with germination and 20% seedling emergence in freshly harvested seed. Hence, 3 months of after-ripening could be considered a suitable treatment period for rice dormancy release. Dormancy release by after-ripening is mainly correlated with a rapid decline in ABA content and increase in IAA content during imbibition. Subsequently, GA(1)/ABA, GA(7)/ABA, GA(12)/ABA, GA(20)/ABA and IAA/ABA ratios significantly increased, while GA(3)/ABA, GA(4)/ABA and GAs/IAA ratio significantly decreased in imbibed seeds following 3 months of after-ripening, thereby altering α-amylase activity during seed germination. Peak α-amylase activity occurred at an earlier germination stage in after-ripened seeds than in freshly harvested seeds. Expression of ABA, GA and IAA metabolism genes and dormancy-related genes was regulated by after-ripening time upon imbibition. Expression of OsCYP707A5, OsGA2ox1, OsGA2ox2, OsGA2ox3, OsILR1, OsGH3-2, qLTG3-1 and OsVP1 increased, while expression of Sdr4 decreased in imbibed seeds following 3 months of after-ripening. Dormancy release through after-ripening might be involved in weakening tissues covering the embryo via qLTG3-1 and decreased ABA signalling and sensitivity via Sdr4 and OsVP1. PMID:26205956
The direct effect of X-rays on freshly picked, sweet red pepper at dose levels of between 0 and 800 krad, and on the after-ripening of red pepper at dose levels of between 0 and 100 krad, was investigated. As an effect of the irradiation of between 400 and 800 krad, the pericarps softened; the carotenoid content, however, was not substantially reduced, even at a dose of 800 krad. During the nine weeks' storage period at room temperature, subsequent to irradiation, an increase of about 90% of the total pigment content, expressed as capsanthin, was observed in the samples not treated. The formation of the carotenoid pigments was accelerated, to some extent, by 80 rad, and substantially accelerated by treatment of 2 krad. The samples treated at the 2-krad level reached the same pigment content in three weeks as the control samples in eight weeks. In the radiation-treated samples, however, the pigment content decreased after the fourth to fifth week of storage. Dose levels above 10 krad slowed down or inhibited the formation of carotenoids during storage (after ripening). The reducing sugar content and the rate of drying were not affected by 0 to 100-krad doses. Since the several hundred kilorad irradiation doses needed to destroy, or substantially inhibit, the growth of moulds causing the deterioration of red pepper of high moisture content have a deleterious effect, the application of irradiation to decrease storage losses in fresh, picked red pepper does not seem to be advisable. The application, however, of the very low doses stimulating carotenoid formation does seem to be promising in view of shortening the after-ripening period and increasing the pigment content. Further investigations are needed to establish the most suitable storage conditions for the after-ripening of red peppers and the causes responsible for decrease in the carotenoid content of irradiated fruits in the second half of the storage period. (author)
Irradiated Camembert can easily be identified by the detection of radiation-induced hydrocarbons (HC) in the lipid fraction. The investigations included the quantification of HC in cheese irradiated before ripening as well as in cheese after ripening. The doses applied were 0.25, 0.5, 1 and 2 kGy. The volatiles were separated from the lipid by Florisil column chromatography and identified by gaschromatographic/mass-spectrometric detection. (author)
Vijaya R Chitnis
Full Text Available Maintenance and release of seed dormancy is regulated by plant hormones; their levels and seed sensitivity being the critical factors. This study reports transcriptional regulation of brassinosteroids (BR, ethylene (ET, cytokinin (CK and salicylic acid (SA related wheat genes by after-ripening, a period of dry storage that decays dormancy. Changes in the expression of hormonal genes due to seed after-ripening did not occur in the anhydrobiotic state but rather in the hydrated state. After-ripening induced dormancy decay appears to be associated with imbibition mediated increase in the synthesis and signalling of BR, via transcriptional activation of de-etiolated2, dwarf4 and brassinosteroid signaling kinase, and repression of brassinosteroid insensitive 2. Our analysis is also suggestive of the significance of increased ET production, as reflected by enhanced transcription of 1-aminocyclopropane-1-carboxylic acid oxidase in after-ripened seeds, and tight regulation of seed response to ET in regulating dormancy decay. Differential transcriptions of lonely guy, zeatin O-glucosyltransferases and cytokinin oxidases, and pseudo-response regulator between dormant and after-ripened seeds implicate CK in the regulation of seed dormancy in wheat. Our analysis also reflects the association of dormancy decay in wheat with seed SA level and NPR independent SA signaling that appear to be regulated transcriptionally by phenylalanine ammonia lyase, and whirly and suppressor of npr1 inducible1 genes, respectively. Co-expression clustering of the hormonal genes implies the significance of synergistic and antagonistic interaction between the different plant hormones in regulating wheat seed dormancy. These results contribute to further our understanding of the molecular features controlling seed dormancy in wheat.
Full Text Available Treatments that promote dormancy release are often correlated with changes in seed hormone content and/or sensitivity. To understand the molecular mechanisms underlying the role of after-ripening (seed dry storage in triggering hormone related changes and dormancy decay in wheat (Triticum aestivum, temporal expression patterns of genes related to abscisic acid (ABA, gibberellin (GA, jasmonate and indole acetic acid (IAA metabolism and signaling, and levels of the respective hormones were examined in dormant and after-ripened seeds in both dry and imbibed states. After-ripening mediated developmental switch from dormancy to germination appears to be associated with declines in seed sensitivity to ABA and IAA, which are mediated by transcriptional repressions of PROTEIN PHOSPHATASE 2C, SNF1-RELATED PROTEIN KINASE2, ABA INSENSITIVE5 and LIPID PHOSPHATE PHOSPHTASE2, and AUXIN RESPONSE FACTOR and RELATED TO UBIQUITIN1 genes. Transcriptomic analysis of wheat seed responsiveness to ABA suggests that ABA inhibits the germination of wheat seeds partly by repressing the transcription of genes related to chromatin assembly and cell wall modification, and activating that of GA catabolic genes. After-ripening induced seed dormancy decay in wheat is also associated with the modulation of seed IAA and jasmonate contents. Transcriptional control of members of the ALLENE OXIDE SYNTHASE, 3-KETOACYL COENZYME A THIOLASE, LIPOXYGENASE and 12-OXOPHYTODIENOATE REDUCTASE gene families appears to regulate seed jasmonate levels. Changes in the expression of GA biosynthesis genes, GA 20-OXIDASE and GA 3-OXIDASE, in response to after-ripening implicate this hormone in enhancing dormancy release and germination. These findings have important implications in the dissection of molecular mechanisms underlying regulation of seed dormancy in cereals.
Liu, Aihua; Gao, Feng; Kanno, Yuri; Jordan, Mark C; Kamiya, Yuji; Seo, Mitsunori; Ayele, Belay T
Treatments that promote dormancy release are often correlated with changes in seed hormone content and/or sensitivity. To understand the molecular mechanisms underlying the role of after-ripening (seed dry storage) in triggering hormone related changes and dormancy decay in wheat (Triticum aestivum), temporal expression patterns of genes related to abscisic acid (ABA), gibberellin (GA), jasmonate and indole acetic acid (IAA) metabolism and signaling, and levels of the respective hormones were examined in dormant and after-ripened seeds in both dry and imbibed states. After-ripening mediated developmental switch from dormancy to germination appears to be associated with declines in seed sensitivity to ABA and IAA, which are mediated by transcriptional repressions of PROTEIN PHOSPHATASE 2C, SNF1-RELATED PROTEIN KINASE2, ABA INSENSITIVE5 and LIPID PHOSPHATE PHOSPHTASE2, and AUXIN RESPONSE FACTOR and RELATED TO UBIQUITIN1 genes. Transcriptomic analysis of wheat seed responsiveness to ABA suggests that ABA inhibits the germination of wheat seeds partly by repressing the transcription of genes related to chromatin assembly and cell wall modification, and activating that of GA catabolic genes. After-ripening induced seed dormancy decay in wheat is also associated with the modulation of seed IAA and jasmonate contents. Transcriptional control of members of the ALLENE OXIDE SYNTHASE, 3-KETOACYL COENZYME A THIOLASE, LIPOXYGENASE and 12-OXOPHYTODIENOATE REDUCTASE gene families appears to regulate seed jasmonate levels. Changes in the expression of GA biosynthesis genes, GA 20-OXIDASE and GA 3-OXIDASE, in response to after-ripening implicate this hormone in enhancing dormancy release and germination. These findings have important implications in the dissection of molecular mechanisms underlying regulation of seed dormancy in cereals. PMID:23437172
Liu, Aihua; Gao, Feng; Kanno, Yuri; Jordan, Mark C.; Kamiya, Yuji; Seo, Mitsunori; Ayele, Belay T.
Treatments that promote dormancy release are often correlated with changes in seed hormone content and/or sensitivity. To understand the molecular mechanisms underlying the role of after-ripening (seed dry storage) in triggering hormone related changes and dormancy decay in wheat (Triticum aestivum), temporal expression patterns of genes related to abscisic acid (ABA), gibberellin (GA), jasmonate and indole acetic acid (IAA) metabolism and signaling, and levels of the respective hormones were...
Full Text Available O objetivo deste trabalho foi avaliar os teores de lignina e celulose em plantas de cana-de-açúcar após a aplicação de dois maturadores para a colheita. O experimento foi conduzido em uma área de cana-soca, cultivar SP 803280, no município de Igaraçu do Tietê/SP. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições. Os tratamentos constituíram-se da aplicação de dois maturadores: sulfometuron-methyl (Curavial e glyphosate (Roundup original. As doses utilizadas foram: glyphosate a 72 g e.a. ha-1; glyphosate a 144 g e.a. ha-1 ; glyphosate a 72 g e.a. ha-1 + sulfometuron methyl a 10 g p.c. ha-1; glyphosate a 108 g e.a. ha-1 + sulfometuron-methyl a 12 g p.c. ha-1; sulfometuron-methyl a 20 g p.c. ha-1; e a testemunha sem aplicação de maturadores. As análises de lignina e celulose foram realizadas pelo método lignina em detergente ácido modificado. O glyphosate e o sulfometuron-methyl alteraram os níveis de lignina no momento da colheita, e esse efeito foi observado também durante o crescimento da cana-de-açúcar (meses após a aplicação desses produtos. O glyphosate a 72 g e.a. ha-1 promoveu reduções nos teores de lignina, na colheita e durante o crescimento da cana-de-açúcar, quando comparados com os da testemunha, enquanto o sulfometuron-methyl isolado na menor dose (10 g ha-1 promoveu aumento nos teores desse biopolímero na soqueira da cana-de-açúcar.The aim of this study was to evaluate the content of lignin and cellulose in sugarcane after application of ripeners. The experiment was carried out in a sugarcane ratoon area, variety SP803280 in Igaraçu Tietê, São Paulo, Brazil. The experimental design was a randomized complete block with four replications. The treatments consisted of application of two ripeners: sulfometuron methyl (Curavial and glyphosate (Roundup Original. The doses used were: glyphosate 200 mL pc ha-1; glyphosate at 400 mL p.c. ha-1, glyphosate at 200 mL p.c. ha-1 plus sulfometuron methyl at 10 g p.c. ha-1; glyphosate at 150 mL p.c. ha-1 plus sulfometuron methyl at 12 g p.c. ha-1; sulfometuron methyl at 20 g p.c. ha-1 and the untreated control without ripener application. Lignin and cellulose analyses were made using acid detergent lignin modified. Glyphosate and sulfometuron methyl altered lignin levels at harvest and during sugarcane growth (months after application of the products. In general, glyphosate at 200 mL ha-1 promoted reductions in lignin compared to the control, while sulfometuron methyl isolated at a dose of 10 g ha-1 promoted an increase in the levels of this compound in sugarcane.
Antonione Araujo Coelho
Full Text Available Conduziu- se este trabalho, com o objetivo de avaliar a qualidade do suco de maracujá-amarelo (Passiflora edulis Sims. f. flavicarpa Degener com diferentes pontos de colheita e, após o completo amadurecimento em câmara de armazenamento, visando à comercialização in natura ou a industrialização. Foram determinados os teores de acidez titulável, ácido ascórbico, sólidos solúveis, açúcares redutores e não-redutores e o valor de pH. As médias foram comparadas quanto ao intervalo de confiança com 5 % de significância e 10 % de desvio em torno da média amostral de população infinita. Os resultados mostraram que o ponto adequado para a colheita dos maracujás-amarelos da safra de inverno foi identificado quando pelo menos 30,7 % da superfície da casca estavam amareladas. Nesse ponto, eles apresentaram características químicas adequadas para o consumo in natura ou para sustentar o processo fisiológico de amadurecimento do fruto durante o armazenamento.This work had as an objective to evaluate the quality of yellow passion fruit juice (Passiflora edulis Sims. f. flavicarpa Degener in different harvest points and after complete ripening in a storage chamber, intended for natural consumption or sales of derived products. We determined the levels of titratable acidity, ascorbic acidy, soluble solids, reducer and non-reducer sugars and pH value. The averages were compared regarding confidence intervals with a 5% significance and 10 % deviation around the sampling average of infinite population. The results showed that an adequate harvest point of the yellow passion fruits from the winter season was identified when at least 30.7% of the peel surface was yellowish. At this point they presented appropriated chemical characteristics for consumption in natura or to support the physiological ripening process during storage.
Chilling exposure of tomato fruit to 5 °C for less than 5 days at mature green stage does not cause visual symptom of chilling injury (CI), however, it is unknown whether such conditions would impact flavor quality (internal CI) after ripening, and if a pre-chilling heat treatment could alleviate in...
SONG Bing-yan; SHI Jin-xiao; SONG Song-quan
Echinochloa crus-gal i, one of the world’s most serious weeds, inlfuences seriously the yield and quality of cereal crop plant. It is wel known that E. crus-gal i grain is dormant, but its dormant type, as wel as its dormancy release and germination in relation to galactomannan-hydrolysing enzyme activity were poorly understood. The cooperation of endo-β-mannanase (EC 18.104.22.168),β-mannosidase (EC 22.214.171.124) andα-galactosidase (EC 126.96.36.199) can hydrolyze the cel wal s rich in mannan-based polymers. In the present paper, the mature grains are used as experimental materials, we investigated the water uptake of grains, the effect of removing partial endosperm, after-ripening, stratiifcation and phytohormone on grain germination, and the change in endo-β-mannanase,β-mannosidase andα-galactosidase activities of grains during after-ripening and germination. The results showed that the freshly-col ected grains were water-permeable and had only phase I and II of water uptake, while the grains after-ripened for 150 d had an obvious phase III of water uptake. In alternating photoperiod, the germination of grains freshly-col ected was zero at 10–35°C, and that of half grains was 11%at 20°C only. The grain germination was notably promoted by after-ripening and stratiifcation, but not by gibberel ic acid and 6-benzyladenine at 0.0001–1 mmol L–1. β-Mannosidase activity increased during 0 to 300 d of after-ripening and then decreased. The activity of endo-β-mannanase andα-galactosidase of grains decreased with after-ripening. During grain germination, endo-β-man-nanase andβ-mannosidase activities obviously increased, whileα-galactosidase activity decreased. Our data showed that E. crus-gal i grain was a deep physiological dormant, the dormancy release by after-ripening was related to an increasingβ-mannosidase activity, and its germination was closely associated with an increasing endo-β-mannanase andβ-mannosi-dase activity;which have provided new knowledge
Magwa, Risper Auma; Zhao, Hu; Xing, Yongzhong
Background Seed dormancy is an adaptive trait employed by flowering plants to avoid harsh environmental conditions for the continuity of their next generations. In cereal crops, moderate seed dormancy could help prevent pre-harvest sprouting and improve grain yield and quality. We performed a genome wide association study (GWAS) for dormancy, based on seed germination percentage (GP) in freshly harvested seeds (FHS) and after-ripened seeds (ARS) in 350 worldwide accessions that were character...
Topuz, Muhamet; Nemli, Yildiz; Fatima, Tahira; Mattoo, Autar
Biotypes of the broad-leaved wild mustard (Sinapis arvensis L.) found in wheat fields of Aegean and Marmara region of Turkey were characterized and shown to have developed resistance to sulfonylurea (chlorsulfuron), an inhibitor of acetolactate synthase (ALS). DNA sequence analysis of the ALS genes from two such resistant (‘R’) biotypes, KNF-R1 and KNF-R2, revealed point mutations, CCT (Pro 197) to TCT (Ser 197) in KNF-R1 and CCT (Pro 197) to ACT (Thr 197) in KNF-R2; these substitutions are consistent with the presence of chlorsulfuron-insensitive ALS enzyme activity in the ‘R’ S. arvensis biotypes. An additional phenotype of chlorsulfuron resistance in the Turkish S. arvensis ‘R’ biotypes was revealed in the form of an altered seed dormancy behavior over 4 to 48 months of dry storage (after-ripening) compared to the susceptible (‘S’) biotypes. Seeds of the ‘S’ biotypes dry stored for 4 months had a higher initial germination, which sharply decreased with storage time, while the seeds of the ‘R’ biotypes had lower germination after 4-months storage, rising sharply and peaking thereafter by 24 months’ of dry storage. The ‘R’ biotype seeds continued to maintain a higher germination percentage even after 48 months of after-ripening. The seed weight of ‘R’ and ‘S’ biotypes after-ripened for 4 months was similar but those after-ripened for 48 months differed, ‘R’ seeds were significantly heavier than those of the ‘S’ seeds. Differential seed germinability between ‘S’ and ‘R’ biotypes was found not a case of differential viability, temperature regimen or non-response to pro-germination hormone GA3. These studies are of relevance to ecological fitness of herbicide-resistant biotypes in terms of seed viability and germination.
Martinez, Shantel A.; Schramm, Elizabeth C.; Harris, Tracy J.; Kidwell, Kimberlee K.; Garland-Campbell, Kimberly; Steber, Camille M.
Zak ERA8 (ENHANCED RESPONSE to ABA8) (Reg. No. GP-966, PI 669443) is a unique line derived from soft white spring wheat (Triticum aestivum L.) cultivar Zak that has increased seed dormancy but after-ripens within 10 to 16 wk. The goal in developing this germplasm was to use increased seed dormancy to improve tolerance to preharvest sprouting, a problem that can cause severe economic losses. This germplasm was developed by USDA–ARS, Pullman, WA, in collaboration with Washington State Universit...
Eduardo Seibert; Michel Elias Casali; Marcos Laux de Leão; Ernani Pezzi; Adriana Regina Corrent; Renar João Bender
Over three years the postharvest quality of 'Marli' peaches harvested from the integrated (IFP) and conventional production (CFP) systems was evaluated. The peaches were harvested from commercial orchards of Prunus persica at two locations close to the city of São Jerônimo, RS, Brazil, and stored at 0.5°C for 10, 20 or 30 days. The peaches were evaluated at harvest, at retrieval from storage and after ripening periods at 20°C. No differences in fruit weight losses were determined. Decay incid...
Magrinyà Navarro, Núria; Bou Novensà, Ricard; Tres Oliver, Alba; Rius Bofill, Núria; Codony Salcedo, Rafael; Guardiola Ibarz, Francesc
The effects of the addition to sausage mix of tocopherols (200 mg/kg), a conventional starter culture with or without Staphylococcus carnosus, celery concentrate (CP) (0.23% and 0.46%), and two doses of nitrate (70 and 140 mg/kg expressed as NaNO(3)) on residual nitrate and nitrite amounts, instrumental CIE Lab color, tocol content, oxidative stability, and overall acceptability were studied in fermented dry-cured sausages after ripening and after storage. Nitrate doses were provided by nitra...
Full Text Available The Sirac is traditional cheese of Bosnia and Herzegovina, produced in the area of Tomislavgrad town. The taste is mild and moderately salty. It is consumed fresh, immediately upon production, or matured, after ripening. The technology is specific and according to that the Sirac can be classified as acid coagulated cheese. Milk proteins are coagulated by use of high temperature and acidity without adding of rennet. The aim of the work was to investigate traditional technology of the Sirac in small village households and to establish an optimal technology in order to apply it to industrial production. For this purpose, a ten tries in laboratory condition were done. The chemical composition of cheese milk, whey, fresh and ripened cheese was determined. During experiments all steps in technological process were followed. Special attention was paid to temperature and acidity of milk coagulation, draining of whey and pressing. Cheese was sensory evaluated after ripening period. The sensorial quality was good. Average score for all ten cheeses was 18.3 points and 5 samples were classified as extra and 5 as 1st class. The yield ranged from 12.25 to 17.76 % and showed that distribution of components to cheese was high. The analyses of whey confirmed this finding.
Full Text Available The ecophysiological regulation of seed dormancy in perennial species and those with a varied life cycle has not been studied in detail yet. That is why an attempt has been made to determine the Cirsium arvense seed water relations during stratification and afterripening at different temperatures and germination at constant or fluctuating temperatures on the basis of the hydrotime model. The obtained results showed that breaking of the primary dormancy of achenes took place only during the first stratification month at moderate temperatures, mainly due to an increase in the average water-stress tolerance in a seed population. The induction of secondary seed dormancy during after-ripening at all temperatures resulted mostly from a substantial loss of the seeds' ability to tolerate water stress. Fluctuating temperatures affected neither seed germination nor the hydrotime model parameters. The analysis of the variations of hydrotime model parameters allows a better understanding of the physiological basis of seed dormancy relief and induction.
The effect of 4 kGy ionisation irradiation, combined with ripening temperatures at 8 deg. C and 16 deg. C on the ripening of Cheddar cheese was investigated. Changes in cheeses were monitored by sensory, microbiological, and chemical analyses. Sensorically, no cheese was preferred above the other. At 16 deg. C ripening, irradiation affected the bacterial groups, but not the psychrotrophs. The free fatty acid content of the cheeses was not affected by irradiation, but higher thiobarbituric acid-values were observed after ripening at 16 deg. C, as well as higher water-soluble nitrogen/total nitrogen. Differences in proteolysis products were detected by urea-page and RP-HPLC
Jacobsen, John V; Barrero, Jose M; Hughes, Trijntje; Julkowska, Magdalena; Taylor, Jennifer M; Xu, Qian; Gubler, Frank
Abscisic acid (ABA) plays a central role in seed dormancy and transcriptional regulation of genes coding for ABA biosynthetic and degradation enzymes is responsible for control of ABA content. However, little is known about signalling both before and after ABA regulation, in particular, how environmental signals are perceived and transduced. We are interested in these processes in cereal grains, particularly in relation to the development of strategies for controlling pre-harvest sprouting in barley and wheat. Our previous studies have indicated possible components of dormancy control and here we present evidence that blue light, nitric oxide (NO) and jasmonate are major controlling elements in wheat grain. Using microarray and pharmacological studies, we have found that blue light inhibits germination in dormant grain and that methyl jasmonate (MJ) and NO counteract this effect by reducing dormancy. We also present evidence that NO and jasmonate play roles in dormancy control in vivo. ABA was reduced by MJ and this was accompanied by reduced levels of expression of TaNCED1 and increased expression of TaABA8'OH-1 compared with dormant grain. Similar changes were caused by after-ripening. Analysis of global gene expression showed that although jasmonate and after-ripening caused important changes in gene expression, the changes were very different. While breaking dormancy, MJ had only a small number of target genes including gene(s) encoding beta-glucosidase. Our evidence indicates that NO and MJ act interdependently in controlling reduction of ABA and thus the demise of dormancy. PMID:23588419
Miranda, Adelaide; Malheiro, Eliana; Skiba, Elżbieta; Quaresma, Pedro; Carvalho, Patrícia A.; Eaton, Peter; de Castro, Baltazar; Shelnutt, John A.; Pereira, Eulália
A photocatalytic approach was used to synthesize triangular nanoplates in aqueous solution. The synthesis is based on the reduction of a gold salt using a tin(iv) porphyrin as photocatalyst, cetyltrimethylammonium bromide (CTAB) as a stabilizing agent, and triethanolamine (TEA) as the final electron donor. The average edge length of the triangular nanoplates can be easily changed in the range 45-250 nm by varying the concentration of photocatalyst, and fine-tuning of the average edge length is achieved by varying the concentration of CTAB. Study of the mechanism of formation of the nanoplates by UV-vis and by transmission electron microscopy (TEM) shows that there is a first stage where formation of 5 nm seeds takes place, further growth is probably by fusion and by direct reduction of gold onto the preformed nanoparticles. The nanoparticles formed during the photocatalytic reduction of the gold precursor show an irregular shape that evolves to regular triangular nanoplates after ripening in solution for 24 h.A photocatalytic approach was used to synthesize triangular nanoplates in aqueous solution. The synthesis is based on the reduction of a gold salt using a tin(iv) porphyrin as photocatalyst, cetyltrimethylammonium bromide (CTAB) as a stabilizing agent, and triethanolamine (TEA) as the final electron donor. The average edge length of the triangular nanoplates can be easily changed in the range 45-250 nm by varying the concentration of photocatalyst, and fine-tuning of the average edge length is achieved by varying the concentration of CTAB. Study of the mechanism of formation of the nanoplates by UV-vis and by transmission electron microscopy (TEM) shows that there is a first stage where formation of 5 nm seeds takes place, further growth is probably by fusion and by direct reduction of gold onto the preformed nanoparticles. The nanoparticles formed during the photocatalytic reduction of the gold precursor show an irregular shape that evolves to regular
Full Text Available Papaya is generally harvested at condition of hard green mature. The maturity level depends on the market destination. Understanding the maturity level and its postharvest quality changes of papaya during storage is important in order to determine the market destination. The objective of this study was to investigate the effect of different picking date on the postharvest quality and shelf life of papaya cv. IPB9 during storage period. Sample of papaya fruits were harvested at 135, 131, 128, 121 and 114 days after anthesis. After harvesting, papaya fruits were ripened artificially by injecting 50ppm of ethylene during 24 hand then were placed in the room temperature. The results showed that picking date of 128 has the highest starch content. After ripening, this papaya fruit has soluble solid content (SSC of 6.7oBrix. For those papaya fruits with picking date of 135 and 131 have SSC of 8.3oBrix dan 7.5oBrix at four days storage. Papaya fruit with picking days of 128 has the longest shelf life until six days. The shortest shelf life was papaya fruits with picking date of 131 and 135 until four days. These picking date of 114 and 121 showed the lowest SSC. It could be concluded that for papaya fruit cv IPB9, the picking date of 128 was the most suitable for long distance market.
Workneh, T S; Osthoff, Gary; Steyn, M
The major objective of this study was to explore the significance of an integrated agro technology in maintenance of postharvest quality of tomato. Preharvest ComCat® treated tomatoes and untreated controls were evaluated for changes in physiological, chemical, and microbiological quality during storage at 13 °C and room temperature (16.9-25.2 °C) and a relative humidity of 34-76%. Effects of disinfection coupled with packaging were evaluated. Physiological weight loss, total soluble solids, peroxidase activity and marketability were maintained better in anolyte disinfected tomatoes. At harvest, ComCat® treated tomatoes had lower pH, glucose and microbial populations, and higher total soluble solids, total titratable acids, sucrose, peroxidase activity than controls. The total soluble solids were better retained in ComCat® treated tomatoes than in control, while the sucrose and glucose contents remained lower after ripening. Peroxidase activities were lower in ripening ComCat® treated tomatoes, and difference in polygalactronase activity was only visible after 30 days. The microbial populations were lower in ComCat® treated fruit. Marketability of ComCat® treated tomatoes was better than that of the control. Integrated technology covering preharvest ComCat® application, disinfection with anolyte water and packaging combined with cold storage at 13 °C maintained the superior quality of tomato. PMID:24293687
Full Text Available The aim 0f this study was undertaken to evaluate the effect of the bacteria strain (Klebsiella spp., silver nitrate, cobalt chloride and ACC in germination of Striga seeds. Striga seeds required after- ripening, pretreatment (conditioning in moist warm environment for 2-14 days and subsequently exposure to an exogenous stimulant. In the present study, an inhibitor of ethylene biosynthesis, AgNO3 and CoCl2, was found to inhibit germination. Germination was found to be inhibited by higher concentrations of AgNO3 and CoCl2. Combination of ACC with AgNO3 and CoCl2 increased Striga seeds suppression as compared with control. Also this study investigates the effect of microorganism in Striga germination. Klebsiella spp. strains known to produce large amounts of ethylene w ere tested for efficacy in germinating seeds of Striga hermonthica (Del. Benth. Incubation of conditioned S. hermonthica seeds over a medium inoculated with a Klebsiella sp. resulted in considerable germination (34-49% this indicates an involvement of a volatile substance. Unconditioned S. hermonthica seeds were not stimulated.
Walnut syrup, milk, sugar as the main raw material, walnut yogurt can be made into nutritionol yogurt products through the deployment, sterilization, inoculation and fermentation process. Results showed that by adding 25% of the walnut paste and 8% sucrose in the milk, after heat sterilization at 95℃ for zomin, access to 4% of the lactic acid bacteria, culture for 4h at 42. 5℃, after-ripening for 12h at 4℃, high-quality walnut yogurt products could be get.%核桃酸奶是以核桃浆、牛奶、蔗糖为主要原料,通过调配、杀菌、接种及发酵等工艺制成的一种风味优良、营养丰富的酸奶制品。试验表明,在牛奶中加入25%的核桃浆、8%的蔗糖,经95℃、20min保温杀菌后,接入4%的乳酸菌,42.5℃培养4h,在4℃条件下后熟12h,即可得到优质的核桃酸奶制品。
Full Text Available The effects of cold stratification and gibberellic acid (GA3 on dormancy breaking for seeds of the annual halophyte species Juncus ranarius were tested. Germination percentage and recovery responses of salt stressed seeds were also tested. Freshly collected seeds germinated slowly under all incubation conditions. Thus, the seeds of J. ranarius have physiological dormancy, e.g. they are water permeable, have a fully developed embryo and require cold stratification to come out of dormancy. Furthermore, promotion of germination by GA3 after-ripening in dry storage also indicated that these seeds have non-deep physiological dormancy. In general, the higher the GA3 concentration, the more germination occurred within the studied range. Juncus ranarius demonstrated a germination preference for light. The highest germination percentage and rate of germination were recorded under constant light conditions at 22 °C after 24 weeks of cold stratification. In saline solutions, the highest percentage of germination was obtained at 25 mM L-1 NaCl, and further increase in salinity resulted in a gradual decrease in germination. However, ungerminated seeds were not damaged by salt, showing a high level of recovery. The greater the reduction in salinity, the better the germination rate became. It was concluded that dormancy could be completely broken by cold stratification, indicating spring germination. Juncus ranarius can grow well at lower NaCl concentrations under constant light conditions at 22 °C.
Effects of combined treatment of hot water dip (50 deg. C for 5 min.) and irradiation (0.65 kGy) on technological and sensory qualities of Carabao mangoes were investigated. Mangoes that ripen to the yellow green stage during transport may be subjected to irradiation of combined hot water dip at 50 deg. C for 5 minutes and irradiation at 0.65 kGy. When stored at the low temperature of 12-15 deg. C, shelf life is extended further. Time interval between hot water dip and irradiation must be as short as possible and fruits must be stored at ambient temperature prior to irradiation to prevent discoloration. Shelf life studies show that green fruits subjected to combined treatment and stored at ambient temperature extended shelf life by 6 days, 50% of yellow green mangoes subjected to combined treatment exhibited shelf life extension by four days. Mangoes stored at cold temperature, whether immediately after irradiation or after ripening showed considerable reduction in bacterial decay, regardless of fruit maturity, thus extending their shelf life considerably. Results of sensory evaluation showed no marked differences in color, aroma, appearance, and acceptability were observed by the taste panelists and although controls were always rated higher than the treated samples, scores higher than 5 given to the treated samples showed that they were also generally acceptable
Barrero, Jose M; Downie, A Bruce; Xu, Qian; Gubler, Frank
It is well known that abscisic acid (ABA) plays a central role in the regulation of seed dormancy and that transcriptional regulation of genes encoding ABA biosynthetic and degradation enzymes is responsible for determining ABA content. However, little is known about the upstream signaling pathways impinging on transcription to ultimately regulate ABA content or how environmental signals (e.g., light and cold) might direct such expression in grains. Our previous studies indicated that light is a key environmental signal inhibiting germination in dormant grains of barley (Hordeum vulgare), wheat (Triticum aestivum), and Brachypodium distachyon and that this effect attenuates as after-ripening progresses further. We found that the blue component of the light spectrum inhibits completion of germination in barley by inducing the expression of the ABA biosynthetic gene 9-cis-epoxycarotenoid dioxygenase and dampening expression of ABA 8'-hydroxylase, thus increasing ABA content in the grain. We have now created barley transgenic lines downregulating the genes encoding the blue light receptors CRYTOCHROME (CRY1) and CRY2. Our results demonstrate that CRY1 is the key receptor perceiving and transducing the blue light signal in dormant grains. PMID:24642944
Atkinson Ross G
Full Text Available Abstract Background While there is now a significant body of research correlating apple (Malus x domestica fruit softening with the cell wall hydrolase ENDO-POLYGALACTURONASE1 (PG1, there is currently little knowledge of its physiological effects in planta. This study examined the effect of down regulation of PG1 expression in ‘Royal Gala’ apples, a cultivar that typically has high levels of PG1, and softens during fruit ripening. Results PG1-suppressed ‘Royal Gala’ apples harvested from multiple seasons were firmer than controls after ripening, and intercellular adhesion was higher. Cell wall analyses indicated changes in yield and composition of pectin, and a higher molecular weight distribution of CDTA-soluble pectin. Structural analyses revealed more ruptured cells and free juice in pulled apart sections, suggesting improved integrity of intercellular connections and consequent cell rupture due to failure of the primary cell walls under stress. PG1-suppressed lines also had reduced expansion of cells in the hypodermis of ripe apples, resulting in more densely packed cells in this layer. This change in morphology appears to be linked with reduced transpirational water loss in the fruit. Conclusions These findings confirm PG1’s role in apple fruit softening and suggests that this is achieved in part by reducing cellular adhesion. This is consistent with previous studies carried out in strawberry but not with those performed in tomato. In apple PG1 also appears to influence other fruit texture characters such as juiciness and water loss.
The use of ionizing radiation as a food preservation technique has been recognized for many years as a means to reduce food losses, improve food safety, and extend shelf life. Furthermore, irradiation can be an effective way of reducing the incidence of food borne disease and treating a variety of potential problems in food supplies. The treatment of food with ionizing radiation is one of the most thoroughly researched techniques available to the food processing industry. In view of the afore mentioned the objective of this study were to study the effect of irradiation time and dose on Ras cheese quality, investigate the effect of irradiation after ripening on cheese quality and possibility of prolonging the shelf-life of Ras cheese, study the effect of irradiation dose on Kareish cheese quality and its shelf- life and to monitor the chemical, microbiological and sensory changes during ripening and storage of Ras and Kareish cheeses .The results of this study will be presented in three parts: Part I: Effect of irradiation dose and time on some properties of Ras cheese:Part II: Effect of irradiation on some properties during storage of ripened Ras cheese.Part III: Effect of irradiation on the quality and shelf-life of Kareish cheese: It could be concluded that irradiation caused a significant reduction of cheese ripening indices, and count of total viable,proteolytic, lipolytic bacteria and mould and yeast. Using irradiation doses of 3 and 4 kGy were able to stop the ripening factors and these safety dose were used to prevent the ripened Ras cheese irradiation of ripened Ras cheese has been prolonged the shelf-life of Ras cheese to about 32 months compared with control cheese, which showed only 18 months. The obtained results revealed that the best irradiation treatment was at the end of ripening period. Also safety irradiation of Kareish cheese has been prolonged the shelf-life of Kareish cheese to about 54 days compared with 12 days only control cheese.
Dorria, M. Ahmed
Full Text Available The beneficial effects of using Modified Atmosphere Packaging (MAP of persimmon fruits to extend its availability for export purpose to perform the consumers and markets demands were investigated during two successive seasons of 2007 and 2008. Hachia and Triumph persimmon fruits were harvested at three quarter color stage and enclosed in different packaging materials of Low Density Polyethylene (LDPE bags at the thickness of 2, 4 and 7 :m LDPE. 100% Nitrogen gas was flushed into the bags for complete replacing of normal air while control fruits were packed with aerobic atmosphere for each thickness. Fruit quality characteristics i.e. fruit firmness, respiration rate, fruit color, Softening as days to eat soft, soluble solid content, total acidity, ascorbic acid content, total phenols and total tannins were assessed periodically after storage periods at 0ºC and after 7 days at 20ºC and 80-85% RH. Packaging fruits at 7 μm Low Density Polyethylene film (LDPE with N2 (100% can be more effective in keeping fruits firm with the least respiration rate during storage and after ripening at 20ºC than 4 and 2 μm LDPE films and control fruits for the two cultivars respectively. Lightness (L* and Chroma (C* color parameters had the significant highest values in fruits received (N2 application and packaged with7 μm LDPE after 90 d storage at 0ºC and 7d ripe. SSC had slight insignificant decrease throughout the storage period at 20ºC due to different polyethylene packaging films and 100% N2 exposure, also untreated fruits showed the same direction. LDPE film at 7 μm thickness recorded the highest content of ascorbic acid but with the least level of acidity and phenols content followed by 4 and 2 μm films throughout storage and ripening periods.Total tannins as indicator of removing fruit astringency were as storage period extend and the thickness of LDPE films increase in packed persimmon fruits in the two cultivars respectively. Moreover, Triumph
To understand germination timing in an ecological context, the response to environmental events that effect seed dormancy is central and has to be combined with knowledge of germination responses to different ecological factors. In this study, seed dormancy, germination and seedling survival of annual short-lived clasping pepper weed Lepidium perfoliatum L. (Brassicaceae) were investigated. Three types of pre-treatments viz., various temperature dry storage, light and water stress were tested as possible dormancy and survival-affecting environmental events. Fresh mature seeds were greatly dormant. Warm (30 deg. C) dry storage more facilitated breaking dormancy, they germinated well under apt conditions (e.g. 20 deg. C and 10/20 deg. C plus periodic light, 14 h/d). For those seeds which underwent after-ripening, they could germinate at a range of constant temperatures (4, 10, 15, 20, 25, and 30 deg. C) and one alternating temperature (10/20 deg. C). Under alternating temperature regimes, the final percent germination of L. perfoliatum seeds increased from 37 deg. C to 93% when temperature altered from 4/10 deg. C to 10/20 deg. C in light, then decreased with increasing temperature. The germination pattern under constant temperature conditions was similar to that under alternating temperature and significant differences in final percent germinations and rates of germination were observed among different temperatures. Under different light treatments, final germination of showed significant differences, only with 35% of germination percentage in dark, much lower than those in red and white light (i.e. 93% and 91%, respectively). GA3 could promote the germination of non-dormant seeds in dark. When water potentials were reduced, final percent germination decreased dramatically, and few seeds germinated at -0.98 MPa (generated by PEG-8000). The changes of proline content in resultant seedlings were reverse to that of final percent germination with changing water
Full text: Oils of the so called lauric acid group plants are very interesting for industries commercially because of their relatively high content of saturated medium chain triglycerides (MCT), in particular lauric acid (C12:0). Steep melting point curves and low melting points make these oils particularly suitable as fats for synthetic creams, hard butters and similar products; sodium soaps of MCT's are hard, stable to oxidation, and free lathering. Palm kernel oil from Elaeis guineensis Jacq. and coconut oil from Cocos nucifera L. are the two most important commercial source of MCT's for the chemical industry. However, because of large variation in production and price, industries became interested in a continuous supply of MCT's from other species. The genus Cuphea (Lythraceae) contains a large number of herbaceous annuals adapted to temperate climate whose seed oil contains high levels of MCT's. Unfortunately, a common characteristic of the wild species is seed shattering during ripening. Seed shattering could be due to floral zygomorphy which causes the placenta to rupture the ovary wall during development, exposing the seeds; exposed seeds dry and are quickly shed. Seed dormancy is another major deterrent to the agronomic use of Cuphea. It appears to result from hard seed coats as well as from physiological factors and can be effectively broken only by prolonged after-ripening (up to a year). Natural genetic variation in Cuphea does not appear to be suitable for the development of non-shattering types. Therefore, the potential of broadening genetic variation through mutagenesis (using EMS) was investigated, first in the autogamous species C. aperta and in the allogamous species C. lanceolata, and C. procumbens. Mutants having somewhat improved seed retention were selected from all three species, however, expressivity was complete only in C. aperta. According to HIRSINGER and ROEBBELEN, the autogamous species C. tolucana Peyr. (n=12) and C. wrightii A. Gray
Germinação e emergência de plântulas para três espécies de gramíneas invasoras de cultura do gênero Digitaria Heister ex Haller Germination and seedling emergence for three weed grasses of the genus Digitaria Heister ex Haller
José Marcos Barbosa
also realized to verify the effect of depth of seed planting on seedling emergence. Results of percentage and rate of seed germination showed strong inhibition of germination caused by the bracts on the caryopsis. However, in the treatments with naked caryopsis the inhibition yet persist on germination process, indicating that these seeds may require a period of after ripening. Results of seedling emergence showed that the seeds which were planted on the surface and at 2cm depht gave best seedling emergence percentages. The interpretation of the results of germination and seedling emergence shows important aspects of the germination behaviour of these species and permits their rational control in cultivated areas.
Full Text Available Para avaliar o efeito do atraso na armazenagem como tratamento para evitar danos por frio, pêssegos Maciel foram colhidos nos estádios de vez e maduros e armazenados imediatamente em refrigeração ou condicionados a 20°C por dois dias (maduros ou três dias (de vez antes da armazenagem refrigerada a 0°C. Análise dos frutos ocorreu após 7, 14, 21 ou 28 dias a 0°C e após mais três dias a 20°C. Pêssegos de vez condicionados (VCD apresentaram maiores perdas de massa fresca no armazenamento e menores perdas após o amadurecimento que pêssegos não-condicionados. Pêssegos colhidos maduros não apresentaram diferenças entre tratamentos. Pêssegos VCD apresentaram menor firmeza que os de vez não-condicionados no amadurecimento a 20°C. Os pêssegos maduros condicionados (MCD foram mais firmes que osdo tratamento maduro sem condicionamento. Sintomas de lanosidade não foram observados. Escurecimento da polpa foi observado nos pêssegos que receberam tratamento de condicionamento após 21 ou 28 dias a 0°C. O distúrbio retenção de firmeza ocorreu em todos os tratamentos no amadurecimento a 20°C após 21 ou 28 dias a 0°C. O condicionamento nãoevitou a manifestação de danos por frio em pêssegos Maciel e, portanto, não é recomendado para aplicação nesta cultivar.Delayed cooling (conditioning was evaluated for effectiveness in avoiding chilling injuries of Maciel peaches harvested at two ripeness stages, mature-green or tree-ripe, and immediately thereafterplaced in cold rooms at 0°C (controls or maintained for 2 days (tree-ripe or 3 days (mature-green at 20°C before transfer to cold storage at 0°C. After 7, 14, 21 or 28 days, samples were retrieved from storage and kept for 3 more days to complete ripening at 20°C.Delayed cooling mature-green (DCMG peaches had higher weight losses compared to control mature-green fruit at retrieval from storage and more reduced fresh weight losses after ripening. Peaches harvested at the tree
葛枝; 刘东红; 丁甜; 徐玉亭; 钟建军
during storage. Slightly acidic electrolyzed water (SAEW) is regarded as a novel and promising alternative method of disinfection in fresh products. It is hoped that ultrasound and SAEW could play a role in the preservation of the strawberry. This study was performed to investigate the effect of ultrasound and SAEW on the quality of an immature strawberry. The impact of SAEW and ultrasound, separately or in combination, on total aerobic bacteria and yeast and mold was studied. Quality attributes including firmness, total soluble solids (TSS), total titratable acidity (TA), vitamin C (VC), and anthocyanin content were also investigated. Results showed that ultrasound and SAEW alone or combined significantly removed about 0.52, 1.07, 1.29 lg CFU/g for total aerobic bacteria and 0.30, 0.93, 1.18 lg CFU/g for yeast and mold, respectively. And the treated samples also maintained relatively low microbial loads during storage. It was observed that the three treatments changed the respiratory characteristic of strawberries and a respiratory peak appeared during storage. The TSS, TA, VC, and anthocyanin content appeared to be 10.93, 0.52%, 65.7 mg/100g, and 3.20 mg/100g immediately after harvest. In 14 storage days, anthocyanin content was gradually increased as 4.16 mg/100g, while TSS, TA, and VC content changed little for the control group. All the treatments increased the content of TSS, VC, and anthocyanin during storage. The TSS, VC, and anthocyanin levels in fruit treated by ultrasound and SAEW were 7.72%, 10.53%, and 19.28%higher, respectively, than that in the control fruit after 14 days of cold storage. It was also found that ultrasound inhibited the decrease of firmness, while SAEW had no impact on the firmness of strawberries. Overall, it was found that ultrasound and SAEW treatment could promote strawberry after-ripening during storage. Results showed that both ultrasound and SAEW have the potential to ensure the microbial safety and improve the quality of an immature