Seed Germination Test Research Articles

Evaluating compost maturity with a newly proposed index based on a germination test using Komatsuna (Brassica rapa var. peruviridis) seeds

A new index for evaluating compost maturity was developed based on a germination test of Komatsuna seeds using water extract from compost. Several compost samples were collected from a kitchen-garbage composting plant to determine an index to evaluate compost maturity. Firstly, some extraction conditions for extracting compost ingredients with water were evaluated using the time course of total organic carbon concentration in water extract. The water temperature of 60 °C, periodic mixing, and extraction period >1 were selected. Secondly, applying these conditions, the germination test was performed using the water extract solutions at several dilution ratios. The relationship between the germination rate and the dilution ratio was expressed using a logistic regression curve. The dilution ratio to give a germination rate of 0.5, defined as DG50, was calculated with the parameters of the curve. Compared with other maturity indices, DG50 was the most effective. Moreover, it has a unique feature in that maturity is quantified even for the compost from which water extract results in a germination rate of 0. This feature can be used to compare the maturity of different kinds of composts and quantify the change in the levels of inhibitory substances in a composting process.

Evaluation of Alternaria alternata causing leaf spot of barnyardgrass grown in rice fields

Barnyardgrass (Echinochloa spp.) is considered one of the world worst weeds. Fungal pathogens can be exploited as biological agents for the management of agricultural weeds. In this research, Alternaria alternata was isolated from Echinochloa spp. and studied as a biocontrol agent against this weed in paddy fields. Pathogenicity test of isolates was done in desiccators, and revealed the pathogenicity of this fungus and its ability to cause leaf blight on Echinochloa spp. Inoculation was done using a spore suspension consisting of 105spore/ml distilled water and 1% Tween-20 at the 2-3 leaf stage. Also, seeds germination inhibition test was done. The results indicated that A. alternata was able to infectEchinochloa spp. in a higher rate compared with rice cultivar. Moreover, the results showed that seed germination of Echinochloa spp. was significantly affected by A. alternata in comparison with controls. Cluster analysis using unweighted pair group method with arithmetic mean (UPGMA) method gave two groups. The different isolates of A. alternatashowed different reactions in seeds germination test and pathogenicity test. Hence, A. alternata can be considered as a probable bioherbicide for the control of Echinochloa spp. at early stages of growth of weed. Key words: Echinochloa spp., Alternaria alternata, fungi, biological control.

Vermiculita como substrato para o teste de germinação de sementes de ipê-amarelo

Vermiculite is a substrate used in seedling production of forest species and can be an option for the germination test of ipe seeds. The objective of this research was to evaluate the use of vermiculite in the germination test of Tabebuia chrysotricha seeds and to stablish appropriate particle size and moisture for this substrate. Four replications of 20 seeds were sown in soil, sand, paper rolls, and vermiculite with different particle sizes: micron (0.15-0.20 mm), superthin (0.21-0.30 mm), thin (0.30-0.50 mm) and medium (0.50-1.19 mm) moistened with water equivalent to 0.5, 1.0, 1.5 and 2.0 times the weight of the dry subtrate. Germination test was carried out at 30°C. The percentage of normal seedlings was obtained seven days after sowing (first count) and then weekly until 28 days, when abnormal seedlings and dead seeds were also counted. It was concluded that the germination test of ipe seeds can be carried out with thin or medium vermiculite moistened with water equivalent to 1.5 times the dry weight of the substrate. These treatments resulted in higher and faster germination (21 days).

Efficacy of garlic extract and mancozeb against seed borne fungal pathogen of farmer saved sorghum (Sorghum bicolor) and groundnut (Arachis hypogaea) seeds {2010-2011}

An experiment was conducted in 2010-11 at Department of Plant Protection, Hamelmalo Agricultural College, Hamelmalo, Eritrea to determine the type of seed borne fungal pathogens associated with stored sorghum (Sorghum bicolor) and groundnut seeds (Arachis hypogaea). The sorghum and groundnut seeds were obtained from Hamelmalo farmers of Keren Sub-Zoba. Five fungal genera were identified to be growing on the seed samples. These were Alternaria alternata, Fusarium oxysporum, Aspergillus sp, Rhizopus sp and Colletotrichum graminicola. All the five fungi occurred in the control seed sub-samples, whereas only three (Alternaria alternata, Fusarium oxysporum and Rhizopus sp.) of the five occurred in the sub-samples that were treated with different treatments. On evaluation of fungicides and garlic extracts against seed borne fungal pathogen of sorghum and groundnut. All treatments were evaluated through inhibition of seed germination test and mycelia weight. Among different treatments combinations T2 (4 gm garlic/kg seed) was most effective which showed maximum seed germination in sorghum and groundnut i.e. 96.70% and 0.42 and 0.26 g mycelia weight respectively followed by T4 (2 g garlic+2 g mancozeb per kg seed) and T3 (2 g mancozeb per kg seed) and was effective than control.

Cereus jamacaru seed germination and initial seedling establishment as a function of light and temperature conditions

Cereus jamacaru is a widespread Cactaceae of northeast Brazil, largely used as cattle food, and as ornamental and medicinal plant. Despite its distinguished importance, until now, there has been little information about the physiological aspects involved on its germination. The objective of this study was to evaluate the effect of light and temperature interaction on the seed germination and seedling establishment of this plant. The evaluated variables were germination percentage at 7 (% G7) and at 14 days after imbibition (% G14), germination average time index (GSI), germination average time (GAT), germination accumulated frequency (GAF), seedling dry mass and height. The highest % G14 and GSI were at 25 ºC in white light, whereas the highest GAT values were in darkness for all evaluated temperatures. On the other hand, % G14, GSI and GAF had the lowest values in darkness. Seeds germinated even in darkness, being however stimulated by the presence of light. The combination of white light and temperature of 25 or 30 °C is the most appropriate condition for seed germination tests.

Validation of quality tests for forest seed species

The Brazilian literature on seed germination testing of tropical forest species, although still insufficient, is extensive for species with economical potential. However, this information is still fragmented and often reported in scientific communications of modest circulation. In this summary, we present the results of a validation process for germination tests on Brazilian forest species, which had as a starting point the ample reviewing of current methods, besides exhaustive pre-testing in certified laboratories. Specific protocols were created for each species, including substrate, temperature, seed disinfection, breaking of dormancy, seedling classification and other information. These protocols were sent to research laboratories and accredited by the Ministry of Agriculture, together with seed lots of three distinct qualities. The presuppositions of normality of the residuals and homoscedasticity of the variations were previously tested and the completely randomized factorial design statistical model was applied to the normal seedlings of each species. After this analysis, germination test methods for seeds of Astronium fraxinifolium, Ceiba speciosa, Cybistax antisyphilitica, Enterolobium contortisiliquum, Guazuma ulmifolia, Lafoensia pacari, Mimosa caesalpiniaefolia, Peltophorum dubium, Pseudobombax tomentosum and Pterogyne nitens, all forest species of different Brazilian biomes, were considered to be validated.

Bovine serum albumin mediated decrease in silver nanoparticle phytotoxicity: root elongation and seed germination assay

In this study the environmental toxicity of procured silver (Ag) nanoparticles (NPs) and its equivalent Ag ion concentrations were determined using seed germination tests with Lycopersicum esculentum and Zea mays. Our results showed that AgNP exhibited more toxicity than its equivalent ion concentration by inhibiting root length and germination in a concentration-dependent manner. Interestingly, AgNP supplemented with bovine serum albumin was able to reduce the adverse effects induced by the particles. Lycopersicum esculentum was found to be more sensitive to the treatments than Z. mays. Thus, understanding of the transformations that NP undergo after interaction with environmental biomolecules is necessary to predict adverse consequences within ecosystems.

采用本土蔬菜种子替代水堇评价污泥有机肥腐熟度

旨在筛选出对城市污泥毒性物质敏感、与国际通用的水堇种子相似、可用于评价处理后的城市污泥有机肥的植物毒性的本土植物种子。试验采用我国常见的5个科的17种蔬菜种子,检测了不同腐熟度的城市污泥堆肥以及经植物处理的城市污泥产品的种子发芽系数,同时以水堇(<em>Lepidium sativum </em>L.)种子发芽系数为标准作比较分析。结果表明,对于未腐熟的污泥堆肥,油青四九菜心(<em>Brassica parachinensis </em>Bailey)、青江白菜(<em>Brassica campestris </em>Pekinensis<em>)</em>、京丰一号甘蓝(<em>Brassica oleracea </em>L.)等种子对污泥植物毒性较敏感,与水堇种子较相似。对于植物处理后的污泥产品,青江白菜和京丰一号甘蓝与水堇种子又有明显差异,只有油青四九菜心与进口水堇种子对污泥腐熟度的响应未表现出明显差异。而且油青四九菜心种子发芽系数与水堇之间的直线相关系数<em>R</em>²达到0.7465,水堇种子发芽系数0.5时对应于的该菜心种子发芽系数为0.53,因此较适合代替目前广泛用于检测污泥有机肥腐熟度的进口水堇种子。;Cress (<em>Lepidium sativum </em>L.) seed germination test is an internationally recognized method for evaluating the maturity of biosolids. However the cress seed is not available in China and needs import from foreign countries. In order to screen out vegetable seeds native in China and sensitive to the phyto-toxicity of treated municipal sewage sludge, 17 species of vegetable seeds from 5 families were used to test the germination index of composted or phyto-treated sewage sludge in comparison with the cress seed. The preliminary tests with non-matured sludge composts, which were co-composted with wood chips for 12, 26 and 40 days, showed that there were significant difference between the seeds of 6 species and the cress seed towards to the sludge composts according to the paired T-test, while the seeds of <em>Brassica parachinensis </em>Bailey (Cultivar: Youqing Sijiu)<em>, Brassica campestris </em>Pekinensis and <em>Brassica oleracea </em>L<em>.</em> (Cultivar: Jingfeng-1) were rather sensitive to the phyto-toxicity, rather similar to the cress seed and classified in a same group according to the cluster analysis of the germination indexes. Further tests with phyto-treated sludges including matured and non-matured samples showed that <em>B. campestris </em>and <em>B. oleracea </em>were significantly different to the cress, only <em>B. parachinensis </em>did not exhibit significant difference to the cress seed. The germination indexes of <em>B. parachinensis </em>were significantly correlated (<em>R</em>²=0.7465) with those of the cress. When the cress seed germination index is 0.50, which signifies fairly matured of the compost sample, the corresponding value of <em>B. parachinensis </em>was 0.53, the two values were rather similar. Therefore, this native vegetable seed can replace the cress seed for evaluating the maturity of the biosolids.

Germinação, biometria de sementes e morfologia de plântulas de Guizotia abyssinica Cass

O niger (Guizotia abyssinica Cass.) é uma herbácea anual com potencial para produção de biodiesel, porém com poucas informações referentes à qualidade de suas sementes. Com isso, objetivou-se determinar as temperaturas e substratos para a germinação e desenvolvimento inicial de plântulas, além de caracterizar morfologicamente as sementes e plântulas. Foram determinados o peso de mil sementes, grau de umidade, massa, comprimento, largura e espessura das sementes. No teste de germinação foram utilizadas quatro temperaturas constantes sob luz branca constante (15 °C, 20 °C, 25 °C e 30 °C) e uma temperatura alternada (20-30 °C) sob regime de 10 horas de escuro e 14 horas de luz branca para a temperatura mais elevada e dois substratos (entre papel e sobre papel). Foram determinadas as curvas de embebição das sementes, a germinação, o índice de velocidade de germinação, o tempo médio de germinação e o comprimento e massa seca de plântulas. As sementes de niger possuem dimensões semelhantes entre si, média de 4,54 mm de comprimento, 1,39 mm de largura, 1,15 mm de espessura e 0,0043 g de peso. As temperaturas 20-30 °C e 25 °C e ambos os substratos testados são eficientes para a condução do teste de germinação em sementes de niger.

Germinação de Sementes de Anadenanthera peregrina (L.) Speg. com Diferentes Substratos em Condições Laboratoriais

In seeds of forest species, usually there is a great variation in the seed germination performance in relation to the substrate in laboratory, so it is necessary to determine the type of substrate which allows a better germination for each forest species. This study aimed at evaluating the behavior of seed germination (percentage of germination and index of germination speed - IVG) of the legume forest species Anadenanthera peregrina (L.) Speg. (Fabaceae - Mimosoideae), submitted to different substrates (sand, filter paper and vermiculite). The substrates that demonstrated higher values of IVG were vermiculite and filter paper, and vermiculite also allowed higher percentage of germination, indicating that this substrate is the most adequate for germination tests of seeds of A. peregrina.

El efecto de la normativa de protección en la mejora de la conservación ex situ de especies amenazadas: germinación de plantas catalogadas en la Comunidad Valenciana (España)

The positive effect of new legal rules improving the ex situ conservation actions on protected plants is analysed in the Valencian Community (Spain), comparing the data of seed germination tests made by the Valencian Wildlife Service (Servicio de Espacios Naturales y Biodiversidad) on the species strictly protected by a new regional Decree, entering in force in 2009. The amount of tested species after the enforcement of this Decree (years 2009-2011, x=35,000 ± 9,644 species/year) is significantly different (F13,2=0,132 ; p=0,013) than the pre-Decree period (1995-2008, x=6,500 ± 3,503 species/year). If only new species tested are compared -so not considering the data on formerly tested species- the difference between the pre-Decree time (2,286 ± 1,978 new species/year) and the post-Decree period (14,333 ±7,767 new species/year) is also significant (F13,2=0,065 ; p=0,001).

Impact of Fe and Ag nanoparticles on seed germination and differences in bioavailability during exposure in aqueous suspension and soil

The potential environmental toxicity of zero-valent iron nanoparticles (nZVI) and three types of nanosilver differing in average particle size from 1 to 20 nm was evaluated using seed germination tests with ryegrass, barley, and flax exposed to 0-5000 mg L(-1) nZVI or 0-100 mg L(-1) Ag. For nZVI, germination tests were conducted both in water and in two contrasting soils to test the impact of assumed differences in bioavailability of nanoparticles. Inhibitory effects were observed in aqueous suspensions at 250 mg L(-1) for nZVI and 10 mg L(-1) for Ag. Reduction in shoot growth was a more sensitive endpoint than germination percentage. Complete inhibition of germination was observed at 1000-2000 mg L(-1) for nZVI. For Ag, complete inhibition was not achieved. The presence of soil had a modest influence on toxicity, and inhibitory effects were observed at 300 mg nZVI L(-1) water in soil (equivalent to 1000 mg nZVI kg(-1) soil). Complete inhibition was observed at 750 and 1500 mg L(-1) in sandy soil for flax and ryegrass, respectively, while for barley 13% germination still occurred at 1500 mg L(-1) . In clay soil, inhibition was less pronounced. Our results indicate that nZVI at low concentrations can be used without detrimental effects on plants and thus be suitable for combined remediation where plants are involved. Silver nanoparticles inhibited seed germination at lower concentrations, but showed no clear size-dependent effects, and never completely impeded germination. Thus, seed germination tests seem less suited for estimation of environmental impact of

Tipos de substratos para germinação de sementes de palmeira- real-australiana (Archontophoenix alexandrae H. Wendl. & Drude)

Os objetivos deste trabalho foram avaliar o desempenho germinativo de sementes de palmeira-australiana em diferentes substratos e estabelecer a granulometria e intensidade de umedecimento adequado. A semeadura foi realizada com quatro repetições de 25 sementes em solo, areia, rolo de papel e em vermiculita de diferentes granulometrias: mícron (0,15-0,20 mm), superfina (0,21-0,30 mm), fina (0,30-0,50 mm) e média (1,19-0,50 mm), umedecidas com 0,5; 1,0; 1,5; e 2,0 vezes o seu peso em água. O teste de germinação foi conduzido a 20-30 °C, avaliando-se a primeira contagem do teste aos sete dias após a semeadura e, semanalmente, a germinação (plântulas normais) até os 35 dias, quando foram contabilizadas, também, as plântulas anormais e as sementes mortas. Calcularam-se o tempo médio e frequência relativa de germinação. A vermiculita mícron umedecida com uma vez o seu peso em água apresentou o melhor desempenho como substrato para o teste de germinação de sementes de palmeira-real-australiana, por possibilitar a máxima germinação das sementes (90%) e velocidade de germinação, demandando tempo médio de 15,3 dias nesse processo.

Mechanical Test Methods for Compost Maturity

Manure-based composts can have detrimental effects on the agricultural lands and crops if they are applied without proper stabilization process. Composting is well-known method for the stabilization of manure-based composts and the extent of composting could be examined by maturity test. Among various methods to examine compost maturity, the performances of two mechanical methods (Solvita and CoMMe-100) were examined and the test results were compared with seed germination test. The mechanical methods are considered to be simple and relatively objective. Also they are cost- and time-efficient. Ten commercially available composts collected in Korea were used for this study. Basically, the maturity determined with these mechanical methods was in good agreement with the seed germination test. However, it appeared that the index levels of compost maturity indicated more maturity by CoMMe-100 than Solvita for the same compost. The differences between maturity index levels determined by both methods were able to be minimized through extending the reaction time for CoMMe-100 and adjusting index level for maturity determination in the standard color chart.

A folate independent role for cytosolic HPPK/DHPS upon stress in Arabidopsis thaliana

Cytosolic HPPK/DHPS (cytHPPK/DHPS) in Arabidopsis is a functional enzyme with activity similar to its mitochondrial isoform. Genomic complementation of the cytHPPK/DHPS knockout mutant with the wild type gene led to a complete rescue of the stress sensitive mutant phenotype in seed germination tests under abiotic stress conditions. Moreover, over-expression of the gene resulted in higher germination rate under stress as compared to the wild-type, confirming its role in stress resistance. Analysis of folates in seedlings, inflorescence and dry seeds showed unchanged levels in the wild-type, mutant and over-expressor line, upon stress and normal conditions, suggesting a role for cytHPPK/DHPS distinct from folate biosynthesis and a folate-independent stress resistance mechanism. This apparently folate-independent mechanism of stress resistance points towards a possible role of pterins, since the product of HPPK/DHPS is dihydropteroate.

Adequação da metodologia para o teste de germinação de sementes de pitaia vermelha

Hylocereus undatus (Haw.), popularmente conhecida como pitaia vermelha é uma cactácea para a qual se tem registrado um aumento de consumo nos últimos anos e, por ser ainda pouco explorada, vários aspectos referentes à sua propagação ainda são desconhecidos. Até o momento, não existem critérios para a execução de testes de germinação para sementes dessa espécie, publicados nas Regras para Análise de Sementes. Nesse sentido, objetivou-se com este trabalho adequar a metodologia quanto ao substrato, temperatura e tempo de contagem inicial e final para o teste de germinação. Foram testados quatro substratos (rolo de papel, areia, vermiculita e solo) e quatro temperaturas (20, 25, 30 e 20-30°C). O efeito dos substratos no desempenho germinativo das sementes foi avaliado pelo teste de germinação e de primeira contagem instalado com quatro subamostras de 50 sementes. Foram feitas contagens diárias do número de plântulas emergidas até atingirem a estabilidade e, no final do experimento, foram avaliados a porcentagem de germinação das sementes, considerando as plântulas normais, anormais e sementes mortas. Concluiu-se que o teste de germinação de sementes de pitaia vermelha deve ser realizado à temperatura constante de 25°C em rolo de papel, com contagens inicial e final aos cinco e dez dias após a semeadura, respectivamente.

Salinity Tolerance of 12 Turfgrasses in Three Germination Media

Salinity tolerance of 12 turfgrasses in four groups, creeping bentgrass (Agrostis stolonifera L.), fescues (Festuca spp.), kentucky bluegrass (Poa pratesis L.), and alkaligrass [Puccinellia distans (Jacq.) Parl.], was evaluated using three germination methods. Seeds were germinated on 1% agar medium, on germination paper, or in a hydroponic system under salinity levels of 0, 5, 10, 15, or 20 g·L−1 NaCl. Germination rate and seedling growth of each grass were determined. Salinity reduced the final germination rate (FGR), daily germination rate (DGR), and seedling leaf area (LA) in all tests. On agar medium, no significant difference in salinity tolerance was observed among the four turf groups; however, ‘Turf Blue’ kentucky bluegrass with a corn starch-based coating (coated ‘Turf Blue’) showed a significant higher salinity tolerance than the uncoated one. Using germination paper, creeping bentgrass required the highest salinity level to cause 50% reduction in FGR followed by alkaligrass, fescues, and kentucky bluegrass. Kentucky bluegrass required the lowest salinity level (9.5 g·L−1) to reduce DGR by 50%. With the hydroponic system, alkaligrass required a salinity level of 26.3 g·L−1 to reduce FGR by 50%, the highest among the four groups. Alkaligrass showed again the highest salinity tolerance with an average of 12.7 g·L−1 needed to reduce LA by 50%. Among the grasses, coated ‘Turf Blue’ kentucky bluegrass, ‘Declaration’ creeping bentgrass, and ‘Fults’ alkaligrass showed the highest salinity tolerance when evaluated on agar medium, on germination paper, or in the hydroponic system, respectively. The present study determined the salinity tolerance of 12 turfgrasses at seed germination and early seedling growth stages and showed that the germination method was a factor affecting the evaluation result and it should be considered in a seed germination test of turfgrass for salinity tolerance.

Bacterial decolorization and detoxification of black liquor from rayon grade pulp manufacturing paper industry and detection of their metabolic products

This study deals with the decolorization of black liquor (BL) by isolated potential bacterial consortium comprising Serratia marcescens (GU193982), Citrobacter sp. (HQ873619) and Klebsiella pneumoniae (GU193983). The decolorization of BL was studied by using the different nutritional as well as environmental parameters. In this study, result revealed that the ligninolytic activities were found to be growth associated and the developed bacterial consortium was efficient for the reduction of COD, BOD and color up to 83%, 74% and 85%, respectively. The HPLC analysis of degraded samples of BL has shown the reduction in peak area compared to control. Further, the GC–MS analysis showed that, most of the compounds detected in control were diminished after bacterial treatment while, formic acid hydrazide, 4-cyclohexane-1,2-dicarboxylic acid, carbamic acid, 1,2-benzenedicarboxylic acid and erythropentanoic acid were found as new metabolites. Further, the seed germination test using Phaseolus aureus has supported the detoxification of bacterial decolorized BL.

돼지풀의 페놀화합물 동정 및 이들 화합물이 잡초의 유식물 생장에 미치는 영향

Phenolic compounds, which are products of secondary metabolism, have been demonstrated to be widespread growth substances in plants. The objectives of this study were to identify the phenolic compounds in common ragweed (Ambrosia artemisiifolia var. elatior) by HPLC and to evaluate their effects on germination and seedling growth of three weed species. Under controlled conditions in Petri dishes at 25℃, 10 -3 and 10 -4 M solutions of phenolic compounds were evaluated in seed germination tests. Four phenolic compounds (caffeic acid, ο-coumaric acid, ρ -coumaric acid and ferulic acid) in common ragweed plant were identified and their concentration was increased from the stage before flowering through full flowering stage. Treatment of ο- and ρ-coumaric acids delayed the seed germination of Digitalia ciliaris, while the treatment of caffeic acid delayed the seed germination of Echinochloa crus-galli. In time to 50% germination (T50), phenolic compounds at 10 -4 M promoted in Cyperus microiria and E. crus-galli but the level of 10 -3 M delayed the T50 of those weeds. The ο-coumaric acid inhibited seed germination and seedling growth of the tested weeds and especially it perfectly inhibited the root growth of E. crus-galli.

Influence of physico‐chemical parameters of the aquatic medium on germination of Eichhornia crassipes seeds

The germination of seeds of Eichhornia crassipes in locations distant from the foci of infestation may be a means of dispersal of this invasive plant. Nonetheless, no modern studies have examined the influence of single components on germination, although the influence of temperature, oxygen and redox potential was examined in earlier studies. The effects of pH, conductivity, nitrate, phosphate, potassium, calcium, iron and boron on germination of E. crassipes were determined in seed germination tests. The results showed that external input of nutrients influences germination, since neither pH nor conductivity alone had any effect, but there was a significant increase in germination in growth media containing phosphorus at 3.95 mg·l(-1) (P/L; 95.5%) and boron at 10 mg·l(-1) (B/L; 97.5%); at higher concentrations, the latter was toxic. These findings contribute to knowledge of factors controlling the germination of E. crassipes seeds. Consequently, E. crassipes seeds would find very good conditions for germination in water classified as hypereutrophic, which may play a decisive role in expansion of this plant.