Dead Seeds Research Articles

Métodos para superação da dormência tegumentar em sementes de Caesalpinia ferrea Mart. ex Tul.

O presente trabalho teve por objetivo avaliar a eficiência de métodos para superação de dormência tegumentar em sementes de <em>Caesalpinia ferrea</em>. O delineamento experimental utilizado foi o inteiramente casualizado, com doze tratamentos e quatro repetições de 25 sementes por unidade experimental. Os tratamentos pré-germinativos utilizados foram: testemunha (T1); imersão em água a 100, 80 e 65 °C por 5 minutos (T2, T3 e T4, respectivamente); imersão em ácido sulfúrico (98%) por 5 e 10 minutos (T5 e T6, respectivamente); escarificação em lixa n° 120 (T7); desponte na região oposta ao hilo e na extremidade do ponto de inserção da vagem (T8 e T9, respectivamente); imersão em vinagre de álcool, de vinho tinto e vinho branco, por 15 minutos (T10, T11 e T12, respectivamente). As características avaliadas foram: percentagem de emergência, índice de velocidade de emergência, percentagem de sementes duras e mortas, comprimento de raiz, altura de plântulas e número de folhas. Os tratamentos com a imersão em ácido sulfúrico por 5 ou 10 minutos, escarificação com lixa n° 120 e o desponte do tegumento, tanto na região oposta ao hilo quanto na extremidade do ponto de inserção da vagem, são os mais adequados para a superação de dormência tegumentar nas sementes de <em>Caesalpinia ferrea</em>.

Relações entre as variáveis das análises de sementes de espécies agrícolas

The aim of this study was to evaluate the direct and indirect relationships between normal seedling germination and other crop seed analysis variables, to identify the relative contributions of seed variables and combine analyses for each crop species. The study was based on the results of 1.332 seed analyses carried out between 2007 and 2014 obtained from the seed laboratory archives of the Universidade Federal de Santa Maria. Path analysis confirmed the true association and influence of dead seeds on the reduction of the germination of Oryza sativa, Avena strigosa, Lolium multiflorum e Triticum aestivum. There was no casual relationship and direct effects of percentage of inert material, other seeds and dormant seed on germination. Germination is more representative in explaining the variability in Lolium multiflorum and Triticum aestivum. The cluster analysis of seed analysis discriminated against regarding your quality of seed lots. The groups differed significantly by germination, percentage of dead seeds and other seeds in Oryza sativa, Glycine max and Lolium multiflorum, respectively.

Origin and temperature on the germination of beggartick seeds

ABSTRACT The invasive behavior of beggarticks (Bidens pilosa L.) in cropped areas is due to its ecological adaptation and aggressive regeneration, which is dependent on seed germination. The objective of this research was to verify the effects of B. pilosa seed origin and temperature on seed germination. The seeds were collected in Entre Rios do Oeste, PR, Botucatu, SP, Capão Bonito, SP, São Joaquim da Barra, SP, Sertãozinho, SP, Selvíria, MS, Barra do Garças, MT, Areia, PB and Manaus, AM. The seeds were evaluated regarding moisture content, 1000-seed weight, germination speed index and germination at 60 days (normal seedlings, dormant seeds and dead seeds) at the temperatures of 10, 15, 20, 25, 30, 35, 40, and 45 ºC. The replicates were distributed according to a completely randomized design in a 9 x 8 factorial arrangement (seed origin x temperature) with four replicates. The means were compared by the Scott-Knott test. B. pilosa seeds germination depends on seed origin. Temperatures higher than 35 ºC are lethal to the seeds. The temperature of 15 ºC allows maximum germination in the shortest time whichever the seed origin.

A Spectrophotometric Assay for Robust Viability Testing of Seed Batches Using 2,3,5-Triphenyl Tetrazolium Chloride: Using Hordeum vulgare L. as a Model.

A comparative analysis was carried out of published methods to assess seed viability using 2,3,5-triphenyltetrazolium chloride (TTC) based assays of seed batches. The tests were carried out on seeds of barley (Hordeum vulgare cv. Optic) as a model. We established that 10% [w/v] trichloroacetic acid (TCA)/methanol is superior to the acetone and methanol-only based methods: allowing the highest recovery of formazan and the lowest background optical density (OD) readings, across seed lots comprising different ratios of viable and dead seeds. The method allowed a linear-model to accurately capture the statistically significant relationship between the quantity of formazan that could be extracted using the method we developed and the seed temperature-response, and seed viability as a function of artificially aged seed lots. Other quality control steps are defined to help ensure the assay is robust and these are reported in a Standard Operating Procedure.

Seed health and quality of some selected rice varieties and their management

A study was conducted for assessing seed health status of four varieties of rice (Oryza sativa) viz. BR 11, BRRI Dhan 28, BRRI Dhan 29 and BRRI Dhan 40 and management of seed borne fungal pathogens by selected chemical namely Thiovit (4%) and a bio-control agent BAU-Biofungicide @ 2% (Trichoderma based preparation) at Seed Pathology Center (SPC) and M.S. Laboratory, Department of Plant Pathology, Bangladesh Agricultural University (BAU), Mymensingh. Seed health test by blotter method revealed that seven seed borne fungi belonging to six genera viz. Alternaria padwickii (0.5%-1%), Bipolaris oryzae (1%-6.5%), Curvularia lunata (1%-5.5%), Fusarium moniliforme (3%-8.5%), Fusarium oxysporum (2%-9%), Aspergillus flavus (0.5%-1.5%) and Penicillium spp (0.5%-1%) were associated with the seeds. Germination of seeds of the four selected rice varieties varied from 94% to 98.50% (blotter method). In treated seeds, germination ranged from 88-100%. The highest germination (100%) was found in BRRI Dhan 28 when seeds were treated with BAU-Biofungicide and the lowest was (88%) in BRRI Dhan 29. The tested samples produced healthy seedlings (77 to 98%), diseased seedlings (2 to 15%), diseased seeds (0 to 7%) and dead seeds (0 to 5%). Upto 18.18% higher formation of healthy seedlings over control was achieved by treating seeds with BAU-Biofungicide and it also significantly decreased (upto 81.82%) formation of diseased seedlings over the control treatment. The highest vigor index (1306%) was in BRRI Dhan 28 when seeds were treated with BAU-Biofungicide and the lowest was (2805%) in BRRI Dhan 29 under control (untreated). Moreover, BAU-Biofungicide increased up to 81.82% Vigor index over untreated control. Asian Australas. J. Biosci. Biotechnol. 2017, 2 (1), 75-80

Nondestructive classification of mung bean seeds by single kernel near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) in the range 900–1700 nm was performed to develop a classifying model for dead seeds of mung bean using single kernel measurements. The use of the combination of transmission-absorption spectra and reflection-absorption spectra was determined to yield a better classification performance (87.88%) than the use of only transmission-absorption spectra (81.31%). The effect of the orientation of the mung bean with respect to the light source on its absorbance was investigated. The results showed that hilum-down orientation exhibited the highest absorbance compared to the hilum-up and hilum-parallel-to-ground orientations. We subsequently examined the spectral information related to the seed orientation by developing a classifying model for seed orientation. The wavelengths associated with classification based on seed orientation were obtained. Finally, we determined that the re-developed classifying model excluding the wavelengths related to the seed orientation afforded better accuracy (89.39%) than that using the entire wavelength range (87.88%).

English

The objective of this research was to know the performance of the seeds from different species of the Leucaena genus (Leucaena leucocephala, Leucaena lanceolata, Leucaena diversifolia, Leucaena macrophylla and Leucaena esculenta), stored under ambient conditions and subject to an evaluation of their physical, physiological and sanitary quality. The material came from the harvests of the collection planted at the Pastures and Forages Research Station Indio Hatuey (Matanzas province, Cuba). Samples were taken from two seed lots, with 6 and 18 months of storage, in which the moisture content, germination and viability were determined. In addition, the hard, fresh and dead seeds were counted. A completely randomized design was used, and the data were processed through a variance analysis (ANOVA). The results indicated the variation, in terms of quality, of the stored seeds at 6 months with regards to those that had been stored for 18 months; however, both lots are considered adequate. The rotting increased (75%) with the months of storage; while the viability decreased as the storage time and physiological age increased (95 vs. 65,7% at 6 and 18 months, respectively). Fungi were the main microorganisms that caused seed rot, with higher effect on the seeds that had been stored for 18 months. Key words: Physical and physiological quality, Leucaena spp., seeds, storage

English

The standard germination tests have been commonly used on commercial grain crops, such as soybean, field beans, rice and maize. However, there are no standard tests for potential new crops; quinoa being one of them. This work is aimed at evaluating the effect of substrate, temperature and counting time in seed germination of quinoa. The following treatments were used in tests with seeds: on blotter paper, between blotter paper, on sand and within sand, all previously soaked with distilled water. These substrates were combined to the temperatures of 15, 20, 25, 30°C, and alternated between 20 to 30°C. The experiment was conducted on an entirely randomized factorial design 5 × 4 (temperature × substrate) with 4 repetitions. Normal seedlings, abnormal seedlings and dead seeds were counted until stabilized. The germination velocity index and mean time for germination were calculated.  From the results, it was concluded that germination test of quinoa seeds should be conducted at 20 to 30°C alternate temperatures, on or between blotter paper, with initial count at 2 days and final count at 4 days. Key words: Chenopodium quinoa willd., substrate temperature, counting time, seed viability.

Molecular marker analysis for differentiating viable seeds in maize

The objective of the present work was to establish a true cause and effect relationship under controlled ageing and to check genetic changes in surviving and dead seeds. Six different maize genotypes were evaluated through 30 SSR primers. During the investigation, six primers showed four different types of variability viz., Type I, II, III and IV, among live and dead seeds. The results suggested that at least part of the variability could actually be explained to the degradation of DNA under ageing. However, to identify the genes related to germination, more number of SSR primers should be employed so that the whole spectrum of genes covering all the 10 chromosomes can be obtained. Therefore, to identify the genes responsible for germination, expression profiles of genes which are upregulated or downregulated during germination need to be investigated.

Harvest Date Influence on Seed Germination of Some Nerica Rainfed Rice Varieties

The present study aims to determine the effect of harvest date on the germination of rice seeds. The experiment was carried out at Nkol bisson, a locality within the forest agro-ecological zone characterized by a bimodal rainfall pattern. Four varieties of NERICA: NERICA 3, NERICA 8, NERICA 9 and 13 NERICA widely grown in Cameroon were used and planted in a completely randomized block design. Rice seed was produced according to the standards of its production and were harvested at six different dates: 20, 25, 30, 35, 40 and 45 days after heading. The harvested seeds were dried at 13% moisture content. The results showed that the harvest dates have a significant effect on the latency, the time corresponding to 50% sprouted grains (T50), the number of sprouted grains, number of dead seed and the number of non-sprouted grains. There was significant difference between rice varieties evaluated and the different harvesting date. The germination rates 98.88%, 99.44%, 99.75% and 97.00% were obtained respectively for the harvest dates of 30, 35, 40 and 45 days after 50% heading. The harvest dates 20 and 25 days after 50% heading presented low germination rates. With these early harvesting dates, the mean percentages of dead seeds ranged between 18.25% and 55.25%. Too early harvest had a negative impact on rice seeds germination. To obtain good germination rate, it is recommend harvesting rice between the ranges of 30 to 40 days after 50% of heading.

Tratamentos pré-germinativos para sementes de Hymenaea stigonocarpa Mart. ex Hayne

http://dx.doi.org/10.5007/2175-7925.2016v29n4p1Hymenaea stigonocarpa, conhecida como jatobá-do-cerrado, pertence à família Fabaceae (Leguminosae) e está incluída na categoria de espécie “quase ameaçada de extinção”. Seus indivíduos ocorrem em áreas de cerrado e cerradão e suas sementes apresentam dormência física. Em razão dessa característica, este estudo teve por objetivo avaliar diferentes tratamentos pré-germinativos em sementes de H. stigonocarpa, sendo eles: imersão em fogo, ácido sulfúrico, ácido clorídrico, acetona, éter e água quente (100°C), além de escarificação mecânica com lixa e corte do tegumento com alicate de unha, lavagem em água corrente por 2 h. Os resultados obtidos pelos tratamentos foram comparados aos da testemunha, que não foi submetida a nenhum deles. Os parâmetros analisados foram: a porcentagem de germinação, o Índice de Velocidade de Germinação (IVG) e os percentuais de sementes duras e firmes e de sementes mortas. Os resultados obtidos foram: a) germinação: a água fervente e o ácido sulfúrico foram superiores aos da testemunha; b) IVG: a água fervente, o ácido sulfúrico, o fogo e a lixa foram superiores aos da testemunha; e c) não foram observadas diferenças estatísticas entre a testemunha e os demais tratamentos para o percentual de sementes mortas. Em vista disso, os tratamentos com a água fervente e o ácido sulfúrico se mostraram os melhores, considerando-se os parâmetros analisados.

The estimation of some wild flowers seed material from the natural-valuable meadow habitats

Abstract The restoration of the species composition of the meadow habitats is often linked to the introduction of the typical species’ seeds. The effectiveness of that treatment requires getting the acquired detailed knowledge of the germination biology of peculiar species. Eight typical plant species of four non-forest habitats of the river valleys, representing the following types: Cnidion dubii (6440), Molinion (6410), Arrhenatherion (6510) and Festuco-Brometea (6210) were investigated. The diasporas were collected in the years 2014–2015 on the meadows of PLH 140016 protection area near Mniszew (Kozienice county, Mazovian voivodeship). The ability of seeds’ germination in the laboratory conditions was studied. It was stated that Cnidion and Molinion meadows’ species require pre-chilling to break the seeds’ dormancy, while the Arrhenatherion meadows and xerotermophilous swards do not require such treatment. The Allium angulosum, Plantago lanceolata, Achillea millefolium and Eryngium planum were characterized by high vigour and germination capability as well as the low share of dead seeds. The extremely drought in 2015 caused the decreasing in germination capability and increasing in the dead seeds’ share. The preliminary studies, presented in this paper, show that Cnidion and Molinion meadows may be most difficult to restore because of the necessity of breaking the seeds’ dormancy and higher sensitiveness for the unfavourable weather conditions during the seed ripening stage. The studies have practical significance for the works connected with the floristic diversity’ increasing of threatened communities and the restoration of the destroyed meadow habitats.

Subversion or Subservience?

Postcolonial literature is supposed to be a battleground on which an active pursuit of decolonization should continue in every possible way. African literature written in the language of the Empire does not appear to be completely anticolonial. Ngugi wa Thiong’o feels a need for linguistic decolonization of African literature. According to him, African literature manifests the domination of the Empire by using their language. He classifies the works of Chinua Achebe and Wole Soyinka as Afro-European literature. But is taking up the language the same as accepting the standards of the colonizer? The language question has many implications, especially when it comes to African literature. We see that Achebe attempts to decentralize control over language by extensively modifying it. My paper examines how the Nigerian authors Chinua Achebe and Wole Soyinka have developed their own written English vernacular codes and the way they Nigerianize their texts using pidgin English in their dialogue—the English that is actually used by some Nigerians. My paper also shows that there are other manifestations of imperial domination apart from the linguistic hegemony in African literature. The English of the Empire has been domesticated by Achebe and it has effectively become the language of literary expression, but a preference for the White Man’s codes and customs is seen in sociocultural settings. There was cultural domination in the country, which is still at work in present day Nigeria. My paper shows that the domestication of the English language is able to carry the weight of the African culture, but these authors point out that internal indigenous structures are flawed and these deficiencies allow the apparently dead seeds of hegemony to germinate all over again in native soil. So, in Ngugi wa Thiong’o’s words, the decolonization of the mind has not yet taken place. In this paper I include my personal experiences of and interactions with the westernized Nigerian and their apparent Afro-European lifestyle. The years I have spent in Nigeria have brought me in contact with the westernized educated Igbos and Yorubas of the South, and my description of their day-to-day tendencies explicitly show that there is a serious imperial effect deeply rooted in the Nigerians.

Reliable Method for Assessing Seed Germination, Dormancy, and Mortality under Field Conditions.

We describe techniques for approximating seed bank dynamics over time using Helianthus annuus as an example study species. Strips of permeable polyester fabric and glue can be folded and glued to construct a strip of compartments that house seeds and identifying information, while allowing contact with soil leachate, water, microorganisms, and ambient temperature. Strips may be constructed with a wide range of compartment numbers and sizes and allow the researcher to house a variety of genotypes within a single species, different species, or seeds that have experienced different treatments. As opposed to individual seed packets, strips are more easily retrieved as a unit. While replicate packets can be included within a strip, different strips can act as blocks or can be retrieved at different times for observation of seed behavior over time. We used a high temperature glue gun to delineate compartments and sealed the strips once the seed and tags identifying block and removal times were inserted. The seed strips were then buried in the field at the desired depth, with the location marked for later removal. Burrowing animal predators were effectively excluded by use of a covering of metal mesh hardware cloth on the soil surface. After the selected time interval for burial, strips were dug up and seeds were assessed for germination, dormancy and mortality. While clearly dead seeds can often be distinguished from ungerminated living ones by eye, dormant seeds were conclusively identified using a standard Tetrazolium chloride colorimetric test for seed viability.

Reliable Method for Assessing Seed Germination, Dormancy, and Mortality under Field Conditions

We describe techniques for approximating seed bank dynamics over time using Helianthus annuus as an example study species. Strips of permeable polyester fabric and glue can be folded and glued to construct a strip of compartments that house seeds and identifying information, while allowing contact with soil leachate, water, microorganisms, and ambient temperature. Strips may be constructed with a wide range of compartment numbers and sizes and allow the researcher to house a variety of genotypes within a single species, different species, or seeds that have experienced different treatments. As opposed to individual seed packets, strips are more easily retrieved as a unit. While replicate packets can be included within a strip, different strips can act as blocks or can be retrieved at different times for observation of seed behavior over time. We used a high temperature glue gun to delineate compartments and sealed the strips once the seed and tags identifying block and removal times were inserted. The seed strips were then buried in the field at the desired depth, with the location marked for later removal. Burrowing animal predators were effectively excluded by use of a covering of metal mesh hardware cloth on the soil surface. After the selected time interval for burial, strips were dug up and seeds were assessed for germination, dormancy and mortality. While clearly dead seeds can often be distinguished from ungerminated living ones by eye, dormant seeds were conclusively identified using a standard Tetrazolium chloride colorimetric test for seed viability.

Methods for overcoming dormancy in Stryphnodendron pulcherrimum seeds

Seed dormancy is a phenomenon observed in several tropical species. This condition causes low and non-uniform germination. The present study was designed to identify an efficient method of breaking seed dormancy in Stryphnodendron pulcherrimum. Seeds of four mother plants were subjected to the following treatments: immersion in sulfuric acid for 2, 4, 6, 8, 10 and 12 min and scarification on 150-grit sandpaper. Seeds were sown on substrate containing sand and sawdust (1:1). It was evaluate the days to onset seedlings emergence, seedlings emergence (SE), emergence speed index (ESI), germination (G), hard seeds (HS), dead seeds (DS), dormant seeds (DMS), abnormal seedlings (AS) and dry mass of aerial part (DMAP) and roots (DMR). The experimental design was completely randomized with four replications of 25 seeds for each treatment. Data were subjected to analysis of variance and means compared by Tukey's test (p < 0.05). Significant differences among treatments were observed for ESI, SE, G, HS, DMAP and DMR. Highest HS was observed in control treatment (85%). Highest G was observed in seeds scarified with sulfuric acid for 10 min (82%) and 12 min (74%). These treatments also showed highest ESI, DMAP and DMR, indicating that these scarification treatments were the most efficient in overcoming dormancy.

Effectiveness of Seed Processing Machinery on Seed Quality Improvement in Paddy (Oryza sativa L.)

A series of seed-processing machines were used to evaluate seed quality improvement in paddy during the Kharif season 2013-14. The processing machines proved an efficient tool in producing quality seeds. The consistent and higher seed quality (germination 91.67% and physical purity 99.83%) could be achieved by efficient use of processing machines. The product and separate (reject) from individual machines were analysed to evaluate machine efficiency in separating the seed components as well as impurities from the harvested lot. The air-screen machines were found effective in removing dead seeds, whereas specific gravity separator removed abnormal seeds significantly. Gradual increase in seed quality was recorded with decrease in recovery in the processing line. Seed loss in reject port was always associated with handling of seed lots by each machine and observed only 1.30%. Specific gravity separator was found essential for the seed lot of medium-term storage or for the buffer stocking.

Flotation techniques to improve viability of Juniperus polycarpos seed lots

The germination of freshly collected Juniperus polycarpos (K. Koch) seeds is very low and attributed to the large proportion of nonviable seeds in the seed lots. Thus, the aim of this study was to improve seed lot quality by removing nonviable seeds using two flotation techniques: incubation-drying-separation (IDS) and modified specific gravity (MSG) separation. We examined different IDS conditions (the specific incubation time, subsequent drying time and sorting media) for effectively sorting out nonviable seeds; and tested the feasibility of modified SG separation, which involved soaking seeds in water for a certain period before sorting in different concentrations of sucrose solution. Viable seeds were expected to absorb and metabolically bind more water during soaking than dead seeds could, and hence be sorted effectively depending on the viscosity of the sucrose solution. The viability of the seeds that floated or sank was determined in a topographical tetrazolium chloride (TTC) test. For the IDS trial, 7 days incubation followed by 9 h of drying and sedimentation in pure water or 200 g·L−1 sucrose solution identified, respectively, 75 and 82 % of the seeds as viable (sunken) seeds. For the MSG trail, 77 % viable seeds were recovered in the sunken fraction when seeds were soaked for 48 h then immediately sorted in 600 g·L−1 sucrose solution. In both cases, the loss of viable seeds in the discarded floating fraction was only 4 %. The results demonstrate that both IDS and MSG separation techniques substantially improved seed lot viability, but MSG separation is simple and needs no modern seed handling facility, and its efficacy relies on seed mass (due to the initial soaking) and the specific density and viscosity of the flotation medium.

Effect of some Evaporation Matters on Storability of Sunflower ( Helianthus annuus L.) Seed.

This study focuses on finding compounds that are safe to humans and environment, such as propionic and acetic acids that may provide an alternative control of seed-borne pathogens and decrease seed deterioration during storage. The objectives of this study were to reduce sunflower seed deterioration and improve the viability of sunflower seed using environmentally safe organic acids. Propionic and acetic acids were applied on sunflower seed at different concentrations under laboratory conditions during different storage periods. After 6 months storage period, the viability of sunflower seed as well as morphological and physiological characteristics of seedlings were evaluated under greenhouse conditions. Laboratory experiment was conducted in a factorial completely randomized design and randomized complete block design for greenhouse experiment. Propionic and acetic acids at different concentrations showed inhibitory effects on the presence of different fungal genera in all storage periods. Propionic acid was most effective followed by acetic acid. Increasing storage periods from 0-6 months significantly decreased germination percentage, germination energy, seedling characters, survived healthy seedlings and seed oil and protein percentages but dead and rotted seeds, as well as rotted seedlings were increased. Treating sunflower seeds with propionic acid (100%) improved germination criteria, seedling characters and seed chemical characters as well as survival seedlings and minimized the dead seeds, rotted seeds and rotted seedlings as compared with the control under all storage periods. Under greenhouse conditions, the maximum growth parameter and physiological characters (chlorophylls a, b, carotenoids and total phenols) were recorded from seed treated with 100% propionic acid after 6 months of storage. It may be concluded that propionic and acetic acids vapors can have considerable fungicidal activity against sunflower pathogens and improve seed viability. Therefore, it is recommended using 100% propionic acid to reduce deterioration and seed-borne pathogens of sunflower under storage conditions.

High gamma irradiation doses and long storage times reduce soybean seed quality

High quality seeds are required for soybean production. This study evaluated the effect of gamma irradiation and storage time on seed quality in soybean lines VX04-6828 and VX04-5692. Seeds were gamma irradiated (60Co) with 0, 50, 150, and 250 Gy. After the first seed production cycle (M1), the harvested seeds were stored in the laboratory for 0, 2, 4, and 6 months. Moisture content, seed quality (germination rate, dead seeds, and normal and abnormal seedlings), and seed vigor (first germination count, germination index, and seedling length) were determined. Data were submitted to analysis of variance for each soybean line using a 4 x 4 factorial design (four storage times x four gamma irradiation doses). Response surfaces were constructed based on the F test significance (p ? 0.05). VX04-5692 seeds were more sensitive to gamma radiation than were VX04-6828 seeds. Soybean seed quality was highest in M2 seeds derived from seeds irradiated with less than 100 Gy and stored for up to two months. High gamma irradiation doses and long storage times reduced soybean seed quality.