Physiological Quality Of Maize Seeds Research Articles

Yield and physiological quality of corn seeds after application of detasseling techniques in two cropping seasons

Detasseling is an essential practice in maize seed production to obtain hybrids. Due the difficulty in carrying out the detasseling in a standardized way, the objective of this study was to evaluate the yield and physiological quality of maize seeds after using detasseling techniques in two cropping seasons. The experiment was carried out in Pitangueiras - PR, using corn progenitors of the commercial hybrid Balu 761. The experimental design was randomized blocks with 4 replications. The factorial scheme was 6 × 2, with 6 detasseling techniques: removal of the tassel only (D0); tassel removal + 1 sheet (D1); tassel removal + 2 leaves (D2); tassel removal + 3 leaves (D3); tassel removal + 4 leaves (D4); and tassel removal + 5 leaves (D5), and 2 cropping seasons: cropping season 1 (2014) and cropping season 2 (2015). The variables analyzed were: seed yield (kg ha-1), germination (%) and seed vigor from the accelerated aging (%) and cold test (%). The results showed that detasseling of maize progenitors of the Balu 761 hybrid must be carried out with the removal of the tassel only, considering that the removal of leaves during this practice is capable of reducing seed yield by up to 25%. The removal of the tassel with up to five leaves does not affect the physiological quality of the maize seeds. The cropping season influenced the seed yield, as well as seed germination and vigor from the cold test

Responses of seed vigour and germination of maize to plasma-activated water priming, silver-nanopriming and green silver-nanopriming

The application of atmospheric non-thermal plasmas and nanomaterials for seed technology is relatively new compared to their use in industrial and agricultural sectors. This study aimed to investigate the potential of plasma-activated water (PAW) priming, silver-nanopriming and green silver-nanopriming for seed performance enhancement in maize. The experiment was carried out using two lots of maize seeds with a one-year difference in age. Seed treatment procedures were priming with PAW formular 1 (PAW1), with silver nanoparticles (AgNPs) using PAW formular 1 (PAW1SNP), with green-AgNPs using PAW formular 1 (PAW1GSNP), with PAW formular 2 (PAW2), with AgNPs using PAW formular 2 (PAW2SNP), with green-AgNPs using PAW formular 2 (PAW2GSNP) and hydropriming with deionised water; untreated seeds were used as the control. Results showed that the best protocol for enhancing seed vigour and germination performance of maize was PAW2. Priming with PAWs, PAW1 or PAW2, has the potential to enhance the physiological quality of maize seeds, particularly new seeds. The limitations of PAW1SNP, PAW1GSNP, PAW2SNP and PAW2GSNP in seed enhancement and storability after priming treatments are discussed.

Physiological quality in maize seeds using conventional methods and NIR spectroscopy

Maize is one of the most important cereals, and stands out for its wide genetic diversity, adaptation to the most diverse climate conditions, and being, both directly and indirectly, the most basic food source of man. Globally, production is dependent on seed quality. Known methodologies for evaluating seed quality require improvement in developing technologies capable of achieving, in less time, results for the targets under evaluation. The aim of this study, therefore, was to compare conventional vigour testing with the ability of NIR technology to classify the physiological quality of maize seeds, cv. DKB-290-HS. For the experiment, which was conducted in a completely randomised design (CRD), six Batches of 200 seeds were used, with four replications. Conventional methods of evaluating seed vigour were used in the study. For the evaluation using the near-infrared (NIR) method, the seeds were placed with the embryo facing the source of electromagnetic waves. The resulting spectra were analysed by the Pirouette software using the PLS-DA method. The conventional methods for vigour, and the NIR technique both efficiently detected the levels of physiological quality. NIR also revealed the differences between Batches, classifying the physiological quality of maize seeds, cv. DKB-290-HS, into different levels quickly and efficiently.

Effect of production environments on storage and physiological quality of maize seed

Storage is a factor that can affect seed quality as a function of latent damages. The losses that most contribute to the reduction in germination and vigor during storage are those caused by humidity, mechanical and temperature-related, that may interfere with seed quality throughout storage. The aim of this study was evaluating the physiological quality of maize seeds produced in two environments and classified in different formats compared to storage periods. The experiment was carried out in the 2016 harvest in two cultivation environments: Entre-Ijuís, RS and Pelotas, RS. Seeds were stratified by thickness through sieves with oblong holes and stratified into small round, large round, small flat and large flat. Growing environments influence the physiological characteristics of maize seeds. The flat and large format seeds have superior physiological quality for the measured physiological characters. The small and round seeds present lower values for germination, first germination count, emergence speed index, shoot dry matter of emergence seedlings and shoot dry matter of germination seedlings. Corn seeds when stored under controlled conditions remain for long periods without causing decreases in physiological quality.

Phytochemical profile and antifungal action of Anadenanthera colubrina extract on the quality of maize seeds

ABSTRACT Maize (Zea mays L.) is among the most cultivated crops in the world and can be affected by several diseases, especially those transmitted by seeds. The study of alternatives to fungicides used for seed treatment has a promising field in essential oils. Thus, this study determined the phytochemical profile of the ethanolic extract from Anadenanthera colubrina (Vell.) Brenan and to evaluate its antifungal activity on the sanitary and physiological quality of maize seeds. The seeds used were of the Jaboatao cultivar, which were submitted to the following treatments: control (untreated seeds), commercial fungicide (dicarboximide) and A. colubrina extract at 200, 400, 600, 800, and 1,000 ppm. The seeds were subjected to sanitary and germination tests in a completely randomized experimental design. Phytochemical prospecting of A. colubrina extract indicated the presence of alkaloids, tannins, flavonoids and saponins, as well as the major compounds lupeol, gallic acid, ferulic acid, catechin and quercetin. The A. colubrina extract reduced the incidence of Aspergillus spp., including Aspergillus niger, Alternaria spp., Curvularia spp. and Fusarium spp. at all concentrations. The highest concentrations (800 and 1,000 ppm) of the A. colubrina extract reduced the incidence of Penicillium spp. and yielded an effective control of Rhizoctonia spp. The extract of A. colubrina did not present phytotoxic effect, guaranteeing the viability and vigor of maize seeds.

Physiological quality of maize seeds produced under soil water deficit conditions

ABSTRACT Crop strategies focused on the rational use of water are required in semiarid regions. Thus, the objective of this work was to evaluate the physiological quality of maize seeds produced under soil water deficit conditions. Five irrigation water depth were established, based on the field capacity (100, 85, 70, 55 and 40%), to control the available water for two maize hybrids (2B-587 and DKB-390). A randomized block design was used, with a split-plot arrangement and four repetitions. The plots consisted of irrigation water depths, and the subplots consisted of maize hybrids. The seed water concentration, germination, and vigor were determined after the harvest, using data from first germination counting, seedling emergence, germination speed index, seedling length, and accelerated aging, electrical conductivity, and modified cold tests. The maize hybrid DKB-390 showed better physiological potential under the soil water deficit conditions evaluated. The irrigation water depths lower than 70% of field capacity resulted in decreases in soil water contents and affected negatively the physiological quality of the maize seeds produced.

Biochemical profiling and its role in physiological quality of maize seeds

Abstract: Viability and vigor of seeds are physiological attributes influenced by a myriad of factors including the genotype. Biochemical profiling of maize seeds and its correlation with their physiological quality is of crucial importance in breeding programs that the aim is seeds of better quality. The main goal of this study was to analyze the genetic diversity among maize inbred lines and evaluate the biochemical components that have an important role in physiological quality of seeds. The seeds of the inbred lines and hybrids were submitted to viability test, vigor by the accelerated aging and cold tolerance, and biochemical profiling (total protein content, soluble proteins, total phosphorus, phytate, inorganic phosphorus, starch and soluble sugars). The genetic divergence between the inbred lines found, prompt us to conclude that genetic gains may exist in association with physiological quality of maize hybrids. Seeds with higher inorganic phosphorus and soluble sugars presented superior physiological quality than seeds with lower levels of those compounds.

Physiological Quality of Maize Seeds Harvested with Different Moisture Contents and Submitted to Drying Delay

Maize seeds harvested on ears with high moisture content must be dried quickly before the processing. However, the seeds pass for a drying delay due to an overload of the seed processing unit. In this period, seeds under bad storage present an increase on the deterioration speed, causing a decrease on germination and vigour. It was aimed to evaluate the physiological quality of seeds of the inbred line GNS25 submitted to a delay of drying. The seeds were harvested with 48.0, 40.5, 34.2, 29.4 and 23.5% moisture content and then submitted to a delay for 0, 6, 12, 24, 36 and 48 hours at 20, 40 and 60 °C. It was observed that there is no loss on germination of maize seeds when the drying delay happens at 20 and 40 °C with moisture content lower than 40.5% for up to 48 hours, but when harvested with 48% moisture content the changes are observed since the beginning of the delay; there are changes on maize seeds vigour after drying delay even in the milder temperatures (20 and 40 °C), mainly when the seeds are harvested in the most humid points (48, 40.5 and 34.2% moisture content); the drying delay at 60 °C causes decrease on viability and vigour of maize seeds in all the moisture contents and delay times; the amount of heat resistant protein is lower in the seeds harvested with 48%, intermediate in the seeds harvested with 34.2% and higher in the seeds harvested with 23.5% moisture content.

INDIRECT SELECTION FOR DROUGHT TOLERANCE IN MAIZE THROUGH AGRONOMIC TRAITS AND SEEDS

High prolificacy, stay green, and a reduced interval between male and female flowering are among the traits most used for indirect selection for drought tolerance. The objective of this research was to evaluate five maize lines from the maize breeding program of the company Geneseeds Recursos Genéticos Ltda, as drought tolerance, grown at four plant population, 40, 60, 80 and 100 thousand plants ha-1. In these conditions, the following characters evaluated indirectly related to drought tolerance: prolificacy, stay green and interval between female and male flowering, as related to drought tolerance. We also evaluated the physiological quality of seeds and expression of the enzymes alpha amylase, esterase, catalase, superoxide dismutase, alcohol dehydrogenase, malate dehydrogenase, and, heat resistant proteins. The experiment was conducted in a randomized block design in a split plot layout. There were differences between the lines for all traits analyzed. Lines 63, 64 and 91 showed the greatest yields and prolificacy, and lines 63, 64, 54 and 91 had the lowest intervals between male and female flowering. There was no influence of plant population on the physiological quality of maize seeds, and the highest values of germination and seed vigor were observed in lines 64, 44 and 91. Lines 63, 64 and 91 are considered as promising for drought tolerance.

Importance of amylases for physiological quality in maize seeds

A qualidade de sementes está associada à soma dos atributos genéticos, físicos, fisiológicos e sanitários que afetam sua capacidade para realizar as funções vitais, estando relacionada à germinação, ao vigor e à longevidade. A expressão de genes associados à qualidade fisiológica pode ser avaliada por meio de análises de germinação e vigor, e ainda pelas análises de transcritos e de proteínas em sementes. Objetivou-se com este trabalho fazer uma revisão sobre a relevância das enzimas do grupo das amilases relacionadas à qualidade fisiológica de sementes de milho. Dentro do grupo das amilases, a α-amilase (1,4-α-D-glucan-glucanohydrolase E.C 3.2.1.1) é uma enzima importante na hidrólise do amido, sendo responsável por 90% da atividade amilolítica em sementes de milho. Essa enzima, a exemplo da dextrose, causa a conversão de amido em açúcares que são utilizados no crescimento do embrião. Já a β-amilase (1,4-α-glucan maltohydrolase E.C 3.2.1.2) é uma α-1,4-D-glucano maltohidrolise que catalisa a liberação de maltose e dextrinas a partir das extremidades não redutoras do amido. Pesquisas comprovam que as enzimas amilases estão ligadas diretamente à qualidade fisiológica de sementes de milho. A α-amilase e a β-amilase estão envolvidas principalmente no processo de germinação e na heterose das sementes, podendo ser também utilizadas como marcadores moleculares relacionadas à tolerância de secagem das sementes.

Hydration curve and physiological quality of maize seeds subjected to water deficit

The hydration pattern associated with the physiological quality of seeds can be an early indicator for the evaluation of seed quality. The present study aimed to evaluate the hydration pattern of seeds subjected, or not, to water restriction, and to relate these patterns to their physiological quality. The physiological quality of seeds from five maize strains (L1, L2, L3, L4, and L5) and four hybrids (HT1, HT2, HS1, and HS2) was initially determined using seed germination and vigor tests (accelerated ageing and electric conductivity). A completely randomized experimental design was used with four repeats for the physiological analyses and a regression analysis was performed in order to assess the behavior of the seeds over time. The hydration curve was determined by imbibing the seeds in distilled water (0.0 control) and in a -0.9-MPa osmotic solution of polyethylene glycol 6000. Water uptake by the seeds was found to follow a triphasic pattern in the absence of water stress (0.0 MPa); however, when exposed to a -0.9- MPa osmotic potential, an extended phase II was observed. Diversity was observed between the strains in terms of the hydration pattern of the seeds, which can influence the physiological quality of the hybrid seeds. Regarding the hybrids, a positive relationship was observed between the shortest time to root protrusion and the quality of the seeds, both with or without water restriction, which allows us to conclude that hydration pattern can be used as a parameter for the early evaluation of physiological quality in hybrid maize seeds.

English

The study was conducted on dry maize seed and seed subjected to sub optimal germination temperature. Four lines of maize seeds were used, two were classified as susceptible to low temperature (44 and 54) and two tolerant to low temperature (64 and 91°C). Water content and germination tests were performed at different temperatures (10 and 25°C) to evaluate the physical and physiological quality of maize seeds. For molecular study, activity of heat-resistant proteins, esterase, superoxide dismutase, catalase and α-amylase enzymes were assessed. Study of AOX1, ZmMPK5, SOD, APX, SAD, ENR and LEA genes with real time polymerase chain reaction (PCR) were carried out. AOX, SAD and LEA genes that are related as tolerant to abiotic stress showed higher expression in line 64, which was classified as tolerant to low germination temperature. The ZmMPK5 gene is associated with increased production of abscisic acid and expressed more in line 54, which was considered as susceptible to low germination temperature.  Key words: Zea mays, seed vigor, abiotic stress.

Qualidade fisiológica de sementes de milho em função de tamanho, formato e tratamento

Corn seeds are classified according to shape and size in order to facilitate the sowing in the field. Also, they receive a chemical treatment in pre-seeding phase, in order to reduce or eliminate pest problems during the initial stage of development. Because of this, the objective of this study was to determine the physiological quality of maize seeds depending on the size, shape and chemical treatment. This work was conducted at the Multidisciplinar Laboratory of the Rio Grande do Sul State University - UERGS, Santa Cruz do Sul Unit, Brazil, to determine the physiological quality of maize seeds depending on size, shape and chemical treatment. It was used BG7049 hybrid corn seeds, provided by Pioneer Seeds Ltda. Following analysis were performed: germination test, modified cold (FM) test, germination speed index and fresh weight, and root and shoot length determinations. For BG7049 early hybrid corn, larger seeds, flat and round, showed less physiological quality compared to smaller seeds. Among the formats, the flat seeds presented higher physiological quality. It was not possible to conclude about the chemical treatment, because it depends on the pre-existence of pathogenic agents.

Qualidade Fisiológica de Sementes de Milho em Função de Tamanho, Formato e Tratamento

Corn seeds are classified according to shape and size in order to facilitate the sowing in the field. Also, they receive a chemical treatment in pre-seeding phase, in order to reduce or eliminate pest problems during the initial stage of development. Because of this, the objective of this study was to determine the physiological quality of maize seeds depending on the size, shape and chemical treatment. This work was conducted at the Multidisciplinar Laboratory of the Rio Grande do Sul State University - UERGS, Santa Cruz do Sul Unit, Brazil, to determine the physiological quality of maize seeds depending on size, shape and chemical treatment. It was used BG7049 hybrid corn seeds, provided by Pioneer Seeds Ltda. Following analysis were performed: germination test, modified cold (FM) test, germination speed index and fresh weight, and root and shoot length determinations. For BG7049 early hybrid corn, larger seeds, flat and round, showed less physiological quality compared to smaller seeds. Among the formats, the flat seeds presented higher physiological quality. It was not possible to conclude about the chemical treatment, because it depends on the pre-existence of pathogenic agents.

Effect of processing stages in the physiological quality of maize seeds

Seeds are the primary input in the maize production process, and monitoring seeds through the processing stages is an essential practice in the production chain, particularly when identifying critical points in the process that can interfere with the final seed quality. Therefore, the objective of this study was to evaluate the effect of processing stages in the physiological quality of Balu 761 maize hybrid seeds. Seeds from the Balu 761 maize hybrid obtained during processing (receipt, shelling, drying, threshing, grading and bagging) were used. The experimental design was completely randomized with four replications. Physiological seed quality was evaluated using germination, accelerated aging, cold testing, electrical conductivity and seedling length tests, with the latter used to determine the length and dry weight of the shoot and root. The data were subjected to a variance analysis, and the means were compared using the Scott-Knott test (p≤0.05). The physiological quality of Balu 761 maize hybrid seeds was enhanced during processing because the percentage of normal seedlings from cold test, as well as the root length, shoot length and shoot dry weight were optimized when considering the process as a whole, which contributed to the increased vigor of both seeds and seedlings. The germination and accelerated aging tests were not influenced by the processing stages.

Image analysis in the evaluation of the physiological potential of maize seeds

The Seed Analysis System (SAS) is used in the image analysis of seeds and seedlings, and has the potential for use in the control of seed quality. The aim of this research was to adapt the methodology of image analysis of maize seedlings by SAS, and to verify the potential use of this equipment in the evaluation of the physiological potential of maize seeds. Nine batches of two maize hybrids were characterised by means of the following tests and determinations: germination, first count, accelerated ageing, cold test, seedling emergence at 25 and 30ºC, and speed of emergence index. The image analysis experiment was carried out in a factorial scheme of 9 batches x 4 methods of analysis of the seedling images (with and without the use of NWF as substrate, and with and without manual correction of the images). Images of the seedlings were evaluated using the average lengths of the coleoptile, roots and seedlings; and by the automatic and manual indices of vigour, uniformity and growth produced by the SAS. Use of blue NWF afffects the initial development of maize seedlings. The physiological potential of maize seeds can be evaluated in seedlings which are seeded on white paper towels at a temperature of 25 °C and evaluated on the third day. Image analysis should be carried out with the SAS software using automatic calibration and with no correction of the seedling images. Use of SAS equipment for the analysis of seedling images is a potential tool in evaluating the physiological quality of maize seeds.

Relationship among physiological quality, heterosis, and amylase gene expression in maize seeds.

In this study, we analyzed heterosis, amylase enzyme gene expression, and the physiological quality of maize seeds with different genotypes and sizes, which were subjected to aging and not subjected to aging. We used seeds from 2 maize lines that differed with regard to physiological quality, the hybrid, and the reciprocal hybrid; they were classified into 2 sizes and were subjected to aging and not subjected to aging. Physiological quality was assessed by performing tests for germination, emergence, emergence speed index, and artificial aging. Expressions of the genes alpha amylase B73, alpha amylase (LOC542522), isoamylase mRNA clone 353244, and the endogenous controls ubiquitin and alcohol dehydrogenase in the seeds were studied using quantitative real-time-polymerase chain reaction. We observed heterosis for seed quality and for expression of amylase genes in the genotypes studied. We found no difference in seed quality between large and small seeds.

Physiological quality and amylase enzyme expression in maize seeds

The physiological quality of maize seeds is affected by the genotype. Thus, the study of expression of genes associated with this characteristic is important in the genotype selection process in breeding programs. The aim of this research was to study the expression of amylase enzymes associated with physiological quality of maize seeds with different genotypes and seed sizes. We further sought to assess the expression of these enzymes in dry and soaked seeds The experiment was conducted in the experimental area and the Central Seed Laboratory of the Department of Agriculture of the Universidade Federal de Lavras. Seeds of four maize inbred lines were used, classified in two sizes. The physiological quality of the seeds was evaluated by means of germination, seedling emergence, seedling emergence speed index and accelerated aging test. Expression of the alpha amylase enzyme was evaluated by the electrophoresis technique and expression of the alpha amylase B73, alpha amylase (LOC542522) and beta amylase 5 (amyb5) genes was studied by the qRT-PCR technique in dry and soaked seeds of the inbred lines. There is differentiated expression of amylase enzymes in maize seeds of inbred lines with different levels of physiological quality. higher expression of amylase enzymes is observed in soaked maize seeds. The expression of transcripts is higher in smaller as wellas in soaked maize seeds of inbred lines.

Influência do tipo de embalagem na qualidade fisiológica de sementes de milho crioulo

Objetivou-se com este trabalho avaliar a qualidade fisiológica de sementes de seis variedades de milho submetidas ao armazenamento em embalagens plásticas a vácuo e em sacos de pano. Para tanto, foram realizadas avaliações do teor de água, germinação, primeira contagem de germinação, emergência, índice de velocidade de emergência, comprimento de parte aérea e massa seca de plântulas. Utilizou-se o delineamento inteiramente casualizado, com os tratamentos arranjados em esquema 6x4x2 (variedades x tempos de armazenamento x embalagens). Durante os seis meses de armazenamento, o teor de água das sementes não ultrapassou os 13%. A germinação foi reduzida nas duas embalagens, sendo que na embalagem plástica, esta queda ocorreu devido à retirada do oxigênio de dentro da embalagem, enquanto, para as sementes armazenadas em sacos de pano, pela infestação dos insetos-praga e o aumento da incidência de fungos, ocasionado pelas condições ambientais durante o período de armazenamento. Na avaliação de emergência, a tendência foi semelhante. Para o comprimento de parte aérea e massa seca para as duas formas de armazenamento, ao final dos seis meses, observaram-se valores próximos ou superiores à condição inicial. A manutenção da qualidade fisiológica de sementes de milho, durante o armazenamento, depende da variedade e do tipo de embalagem.

Influência de sistemas de culturas, mucuna preta e adubação mineral sobre a qualidade fisiológica de sementes de milho

O cultivo do milho em consórcio e a utilização de leguminosas como forma de adubação é prática bastante utilizada pelo agricultor nordestino. Desta forma, o presente trabalho teve como objetivo avaliar a qualidade fisiológica das sementes de milho, cv. BR-106, produzidas em sistemas de culturas isolados e consorciados (milho, milho + feijão guandu e milho + fava), na ausência e presença de adubo químico e mucuna preta. O ensaio foi conduzido no Laboratório de Análise de Sementes da Universidade Federal da Paraíba - Campus II, Areia - PB. Independentemente dos sistemas de culturas, adubo mineral e mucuna preta, a germinação, a emergência de plântulas em areia e o índice de velocidade de emergência foram altos. De acordo com os resultados, observa-se que o adubo mineral favorece a viabilidade e o vigor das sementes de milho; a mucuna preta além de não competir com os sistemas de culturas favorece a qualidade fisiológica das sementes de milho provenientes do consórcio e o consórcio de milho + guandu favorece o vigor das sementes de milho.