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EnglishThe objective of the following research was to investigate the physiological responses of two bahiagrass genotypes (Paspalum notatum Flugge) submitted to water restriction, induced by polyethylene glycol (PEG6000), during seed germination. Seeds of cv. Pensacola (diploid) and Bagual ecotype (tetraploid) were placed on paper moistened with osmotic solutions at potentials of 0.0; -0.1; -0.2 and -0.3 MPa. Composed of two subsamples of 100 seeds and four experimental units per treatment, the germination test was conducted in a germination chamber under alternating temperatures of 30 °C (8 hours) and 20 °C (16 hours), with presence of light during the higher temperature. Final germination percentage and germination speed index of the seeds, as well as early growth, activity and expression of antioxidant enzymes of seedlings were evaluated. The water restriction induced by PEG6000 reduced the percentage of germination in Pensacola (from 74% to 59%) and Bagual (34% to 10%). For the latter, the evaluation of seedlings showed higher dry mass in relation to cv. Pensacola (1.7 times higher in root and 1.6 times in shoot). In response to moderate water restriction, the genotypes showed increases in root growth (1.7 times higher in -0.1 compared to 0.0 MPa), both in expression and enzymatic activity (superoxide dismutase and catalase) portuguesO presente estudo objetivou avaliar as respostas fisiologicas de dois genotipos de grama forquilha (Paspalum notatum Flugge) sob restricao hidrica induzida por polietileno glicol (PEG6000) durante a germinacao de sementes. Sementes da cv. Pensacola (diploide) e do ecotipo Bagual (tetraploide) foram colocadas em papel umedecido com solucoes osmoticas nos potenciais de 0,0; -0,1; -0,2 e -0,3 MPa. Composto de duas subamostras de 100 sementes e quatro unidades experimentais por tratamento, o teste de germinacao foi conduzido em câmara de germinacao sob temperatura alternada de 30-20 oC, com presenca de luz durante a maior temperatura. Foram avaliados a porcentagem final e o indice de velocidade de germinacao das sementes, assim como o crescimento inicial, a atividade e a expressao de enzimas antioxidantes das plântulas. A restricao hidrica induzida por PEG6000 reduziu o percentual de germinacao em Pensacola (de 74 para 59%) e Bagual (34 para 10%). Este ultimo, na avaliacao de plântulas, apresentou massa seca superior em relacao a cv. Pensacola (1.7 vezes superior em raiz e 1.6 vezes superior em parte aerea). Em resposta a restricao hidrica moderada, os genotipos apresentaram aumentos tanto do crescimento radicular (1.7 vezes superior em -0.1 em comparacao com 0.0 MPa), quanto da expressao e da atividade enzimatica (superoxido dismutase e catalase)

In this paper, a fully automated CT-scanner is presented, which has been developed for testing of sugar beet seeds in industrial production environment. The system is simple to use, and no special training is needed for staff. The system has high throughput and the evaluation of volume images is performed automatically by dedicated image processing software. Quantitative measures of various characteristics of the parts of the seed (volume, thickness, weight) for each individual seed of a sample of 400 seeds are obtained. From these measurements, quality parameters can be derived to control seed processing.

Seed is the basic unit of crop production. An optimum plant count depends on seed for their next progeny. Issues related to seed should be handled very carefully, since sowing of a poor-quality seed leads to undesirable loss in plant stand and hence crop yield. Focus on seed quality and seed health has been a point of serious consideration since time immemorial. Seed-related aspects are puzzling the researchers since long back. Well-developed science of seed pathology has been in existence for more than 100 years. Seed pathology includes studies on the mechanism of seed transmission, pathogenesis, epidemiology of seed-borne diseases, and control measures adopted against these diseases, ranging from crop management through chemical control to legislative precautions, as well as the technology of microbiological seed testing by covering the total range of seed-borne pathogens, viz., fungi, bacteria, viruses, nematodes, and physiological defects which may affect any member of the plant kingdom. The various aspects, viz., seed health, management of seed-borne diseases, seed treatments, and their detection and diagnosis techniques, were developed with the time. The systematic application of these techniques leads to the significant availability of healthy and disease-free quality seed. The institutional and technological developments in the science of seed pathology are being discussed in the present chapter.

Potato blackleg is a seedborne disease that can cause significant economic losses for growers. Disease development depends mainly on two drivers, namely seed inoculum and local climatic conditions. To better establish the relationship between these two drivers, blackleg development was monitored in Swiss field trials at multiple locations from 2010 to 2013 involving three sets of naturally infected seed lots planted in each of three locations. The seed lot itself was thereby the most important factor explaining differences in disease development, rather than environmental factors. In a further on‐farm project conducted at various locations in Switzerland and southern Germany from 2013 to 2015, the implementation of a seed‐testing procedure was investigated. A total of 177 seed lots were tested for natural latent infection with soft rot Pectobacteriaceae and the corresponding blackleg incidence was tracked in 242 fields. The reliability of the relationship between latent infection and field incidence was found to be strongly linked to the bacterial species. Dickeya spp. field infection could be predicted with an acceptable reliability, whereas Pectobacterium carotovorum subsp. brasiliense, even when detected as latent tuber infection, was not consistently expressed as visual blackleg. Moreover, commonly found mixed latent infections with several bacterial species made it even harder to predict which bacteria would cause blackleg symptoms. Finally, variability in the reliability of seed testing may also be explained by differences in local farming practices. These trials over several years with naturally infected potato seed highlight the usefulness and limits of seed testing to manage blackleg.

Quality seed is a basic input for crop production in agriculture, and there is always high demand of quality seed in national and international seed trade. The seed health and thereby its quality is affected by various seed-borne pathogens including fungi, bacteria, viruses, nematodes, etc. and also by abiotic factors. The science of seed pathology is an integral part of seed science and technology, which deals with the study of seed-borne diseases, overall seed health status, and management of seed-borne diseases. This science has traveled a long journey of more than a century. Many important institutions have come into existence, and a number of technologies related to seed health testing, detection, and diagnosis of seed-borne microflora and management of the seed-borne pathogens have been developed. To investigate seed health, many tests were standardized by individual researchers and organizations. Paul Neergaard made great contribution in the development of seed pathology, and hence he is considered as the father of seed pathology. Three primary organizations publish standardized seed health testing methods, and these are the International Seed Testing Association (ISTA), the International Seed Health Initiative (ISHI), and the USDA’s National Seed Health System (NSHS). Among them, ISTA is key institution which provides internationally agreed set of rules for seed sampling and testing, gives authority to seed testing laboratories, and provides international seed analysis certificates to facilitate seed trading nationally and internationally. Keeping in the view above facts, the major contributions of different individuals and various organizations are being discussed in this chapter.

The aim of the research was to determinate the degree of variation in morphological (seed weight) and functional polymorphism (final germination, dormancy, seed mortality and germination dynamic) within two seed populations of Ambrosia artemisiifolia L. Seeds were collected separately from 20 plants/population in Jastebarsko (45°40'18˝N; 15°39'03˝E), population-J and Popovača (45°34´1˝N; 16°40´43˝E), population-P in 2014. Seed weight of J and P populations had weak variability (CV-J = 18.2%, CV-P= 29.8%) with an average of 4.05 g (J) and 4.54 g (P). Estimated variability was strong for amount of death seeds in the J (CV = 67.6%), but weak for geminated (CV = 4.9%) and moderate for dormant seeds (CV = 51.0%). Variability within P population was moderate for both germinated and dead seeds (CV = 34.5%; 34.1%), while variability within amount of dormant seeds was weak (CV = 14.2%). Variability in medium germination (T50) was relatively low for both experimental populations (CV – J = 12.0%; CV – P = 22.4%). Despite determined intrapopulation variation, degrees of variability between researched parameters (final germination, dormancy and medium germination – T50) were weak or moderate and therefore acceptable for further experiment base on seed testing., Cilj istraživanja bio je utvrditi stupanj morfološke (masa sjemena) i funkcionalne (klijavost, dormantnost, smrtnost sjemena i dinamika klijanja) varijabilnosti unutar dvije populacije sjemena korovne vrste Ambrosia artemisiifolia L. (ambrozija) sakupljene u sjeverozapadnom dijelu Hrvatske: Jastrebarsko (45 ° 40'18˝N; 15 ° 39'03˝E), populacija-J i Popovača (45 ° 34´1˝N; 16 ° 40´43˝E), populacija-P. Prikupljeno je sjeme s 20 biljaka/populaciji u listopadu 2014. Rezultati istraživanja ukazuju na slabu varijabilnost (CV-J = 18,2%, CV-P = 29,8%) mase 1 000 sjemenki s prosječnom masom od 4,05 g (J) i 4,54 g (P). Intrapopulacijska varijabilnost bila je relativno visoka za udio mrtvog sjemena u populaciji-J (CV = 67,6%), ali vrlo slaba za udio klijavog (CV = 4,9%) te umjerena za udio dormantnog sjemena (CV = 51,0%). Varijabilnost unutar populacije-P bila je umjerena za udio klijavog i mrtvog sjemena (CV = 34,5%; 34,1%), a relativno slaba za udio dormantnog sjemena (CV = 14,2%). Dinamika klijanja (T10, T50 i T90) obje populacije bila je slabo ili umjereno varijabilna. Sredina klijanja (T50) bila je relativno slabo varijabilna za obje istraživane populacije (CV - J = 12,0%; CV - P = 22,4%).

Kadar air (KA) benih merupakan salah satu faktor penting yang menentukan tingkat viabilitas selama penyimpanan maupun pengecambahan benih. Oleh karena itu, kemampuan untuk menduga KA benih dengan tepat merupakan kebutuhan dasar bagi produsen kecambah. Bagi benih-benih berukuran besar seperti benih kelapa sawit, International Seed Testing Association (ISTA) mensyaratkan penggunaan oven suhu tinggi dan suhu rendah serta penerapan pemecahan benih untuk penentuan KA yang lebih tepat, sedangkan produsen menggunakan benih utuh untuk proses penentuan parameter tersebut. Hasil percobaan memperlihatkan bahwa benih-benih yang diuji dengan oven suhu rendah konstan memberikan nilai KA yang lebih tinggi dibanding KA yang diperlihatkan oleh metode oven suhu tinggi. Selain itu, benih yang dianalisis secara utuh memberikan nilai KA yang tidak berbeda nyata dengan KA benih yang dianalisis dengan metode pemecahan benih. Berdasar komponen penyusun, inti benih memiliki KA yang secara nyata lebih tinggi dibanding KA pada cangkang, baik menggunakan metode oven suhu rendah ataupun suhu tinggi. Percobaan lebih lanjut dibutuhkan mengingat luasnya keragaman ketebalan cangkang benih kelapa sawit.

Brazil nut (Bertholletia excelsa Bonpl.; Lecythidaceae) seeds are large, and the oily embryo (edible part) is covered by a thick, woody seed coat. Difficulties in seed storage may be due to desiccation sensitivity of the seeds, and prior variable results may be related to procedures for seed moisture content (MC) determination. This study first compared 3 methods of preparation of whole seeds, prior to MC determination: (i) intact seeds; (ii) chopped (

Each taxon is characterized by a temperature range over which seed germination is possible and this may vary in space and time in relation to climate and ecological conditions. We used thermal modelling to test the hypothesis that thermal thresholds for seed germination can predict germination timing of Mediterranean species along an altitudinal and environmental gradient. Seeds of 18 species were collected in Sardinia from sea level to 1810 m above sea level, and germination tests were carried out at a range of constant (5 to 25°C) and alternating (25/10°C) temperatures. Different dormancy-breaking treatments [gibberellic acid (GA3), cold (C) and warm (W) stratifications and dry after ripening (DAR)] were applied. The annual pattern of soil temperatures was recorded using 24 data-loggers buried close to the study species. The logged soil temperatures distinguished ‘Mediterranean lowland’ from ‘Mediterranean mountain’ species. Although germination was >50% in untreated seeds of most species, GA3 had a positive effect in all species. C either inhibited or had a neutral effect on germination, W did not enhanced seed germination, while DAR had a positive effect only in species from coastal environments. The thermal time constant (S) for 50% germination ranged from 22 to 357°Cd (degree days) above base temperatures (Tb) of –9 to 9°C, depending on species and treatments. Mediterranean lowland species had lower Tb values compared with upland species. This study revealed significant differences in germination thresholds of Mediterranean lowland and mountain species in relation to Tb and S that probably have an impact on germination timing in the field and niche competitiveness.

Fresh seeds of oilseed rape (Brassica napus) are reported to be nondormant and nonphotoblastic. However, a portion of the seeds can be induced into a light‐requiring state (secondary dormancy) for germination and also exhibit dormancy cycling. Thus, if seeds become buried in the soil they can form a persistent seedbank and become a serious volunteer weed in succeeding crops. The capacity of nondormant seeds of B. napus to be induced into secondary dormancy is contrary to results of studies on fresh nondormant seeds of some other species. A reanalysis of published and unpublished data shows that fresh seeds of this species have some degree of primary dormancy and that there is a significant relationship between primary dormancy and the capacity to enter secondary dormancy. However, most germination tests on B. napus have not been done in enough detail to detect primary dormancy (or not) in fresh seeds of this species. The usefulness of information on the relationship between primary dormancy and the capacity of the seeds to enter secondary dormancy is discussed in relation to management of weedy volunteers of this species.

One of the main problems in pepper seed production is the uneven maturation of the fruits due to the continuous flowering period of the plant, making it difficult to harvest all the fruits at the same time. Thus, studies on fruit maturation stage and seed physiological potential are extremely important in order to identify the appropriate harvest time, avoiding seed deterioration. The aim of this study was to evaluate the physiological potential of five genotypes of “dedo de moça” pepper seeds (Capsicum baccatum var. pendulum) in three maturation stages (green, orange and red), with and without 10-day rest period after harvest date. Physiological potential and vigor of seeds were evaluated through germination tests (first count, accelerated aging and electrical conductivity). The observed results were submitted to variance analysis, comparing averages through Tukey test and principal components analysis. In general, red fruits reflected seed maturity since they provided maximum germination. On the other hand, even fruits harvested at a maturation stage prior to red (green and orange), showed the benefits of the rest periods on germination and vigor characteristics, being this result more evident in green fruits which, initially, had lower physiological potential. The evaluated genotypes showed lower physiological potential of fruits harvested at the green stage, without 10-day rest period.

“Orthodox” seeds are desiccation tolerant, enabling dry storage for agricultural and conservational purposes. Protocols of “controlled deterioration” (CD) using elevated temperatures and seed water contents (WCs) are frequently used to study mechanisms of seed ageing. However, the relevance of using CD to understand how seeds age at lower water contents and temperatures has been disputed. Here, comparisons in antioxidant changes are drawn between barley seed stored for up to 15 years in a seedbank with seeds aged using CD (45 °C, 75% RH; WC = 13% FW) under normoxia (21%) or elevated (75%) O2. Regardless of ageing method, glutathione (GSH) levels decreased concomitantly with an oxidative shift in the glutathione redox state (EGSSG/2GSH) as viability was lost. An earlier oxidative shift in EGSSG/2GSH and more rapid loss of seed vigour was found in seeds aged by CD under 75% O2, compared to 21% O2, but longevity was not shortened by elevated O2. Seedbank-aged seeds contained more glutathione disulphide (GSSG) levels, leaked more electrolytes upon imbibition and contained less tocochromanols than non-stored seeds. In contrast, in response to CD, levels of GSSG fell, electrolyte leakage did not increase and tocochromanol levels increased (21% O2), or remained stable (75% O2). In a further set of 24 barley genotypes stored for up to 15 years at 20 °C (WC = 11% FW) and 0 °C (WC = 8% FW), tocochromanol levels positively (r = 0.42) correlated with total germination, which ranged between 1-78% (20 °C) and 65-97% (0 °C). Of all tocochromanol species, α-tocopherol correlated most with total germination (r = 0.49) and γ-tocotrienol least (r = 0.08). It is concluded that CD is not a perfect model for understanding mechanisms of ageing that occur under seedbank conditions.

Despite the insufficient internal supply of popcorn kernel cultivars, the Brazilian production is continuously increasing. Therefore, searching for tests that offer fast results and reliable information on the physiological potential of the seeds is very important. The objective of this study was to assess the efficiency of the accelerated aging test, by using different times and exposure temperatures, for the evaluation of the physiological quality of popcorn seed lots. Popcorn seeds from three lots of the hybrid AP 8203 were used. For the initial characterization of the lots, the following tests were conducted: seed moisture content, first and final germination count, and field emergence. The accelerated aging test was performed in a 3x4x2 factorial scheme. After aging, the seeds were tested for moisture content, germination, and electrical conductivity. The experiment was carried out in a completely randomized design. The characteristic vigor was affected during aging, as evidenced by the increase in the amount of leachate detected by the electrical conductivity test. Seed lot 3 was most vigorous in the aging test conducted for 48 h at 45 °C. The accelerated aging test at 42 ºC for 48 h provides consistent information to differentiate seed lots of popcorn.

Seed quality is closely associated with internal substances during seed development. Tobacco seed varieties Honghua Dajinyuan (HD) and Yunyan97 (Y97) had higher viability and vigor when harvested from 31 to 33 days after pollination (DAP), subsequently decline slightly on 35 DAP. From 7 to 35 DAP, the moisture content of HD and Y97 decreased sharply from 90 to 30%, and abscisic acid declined more than 80% totally in seeds. Accumulation of oil and protein was accompanied with the consumption of soluble sugar and starch, especially from 7 to 23 DAP. In addition, crude fiber and arginine exhibited an increasing trend, while ash and lysine significantly decreased from 7 to 23 DAP. Generally, the germination percentage (seed viability) in HD and Y97 seed was related to oil, moisture, soluble sugar, protein, starch, ABA, lysine, arginine, seed weight and seed coat color; however, only moisture, oil and protein had a significant correlation with vigor index (seed vigor). Thus, seed viability could be applied to estimate the relationship between internal substances and seed quality, and predict the optimum seed harvest time of tobacco.

The present study was designed to study the effects of priming using 2.5 mM or 5 mM methyl jasmonate (MeJA) on the tolerance of rice (Oryza sativa, L) seedlings to osmotic stress that was simulated by 30 g/L of polyethylene glycol (PEG, 6000). The results showed that seed germination and seed vigor were improved by 2.5 mM MeJA priming as compared with unprimed control. However, the application of 5 mM MeJA reduced the germination and seed vigor. Similarly, the seedlings parameters that were decreased under PEG stress, including root length, shoot length, fresh weight and dry weight, were better improved by 2.5 mM MeJA priming than 5 mM MeJA priming. Priming with 2.5 mM MeJA also improved photosynthetic parameters that were decreased under PEG stress, such as net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr). In addition, under PEG stress, the chlorophyll content and the photochemical efficiency of PSII (Fv/Fm) were better improved by 2.5 mM MeJA than 5 mM MeJA. MeJA priming improved water potential, water use efficiency (WUE) and relative water content (RWC) under PEG stress condition but worsened electrical conductivity. The Gas Chromatography-Mass Spectrometry (GC–MS) analysis revealed that PEG stress induced changes in the concentration of many metabolites in the root and shoot tissues of both studied cultivars. The proline content was significantly increased under PEG stress indicating plant positively undergoing the PEG stress. Our data showed that priming with 2.5 mM MeJA alleviated the effects of PEG stress on seed germination and seedling growth in rice.

The marica ('Mimosa bimucronata' (DC) O. Kuntze) is a forest species, belonging to the family Fabaceae, considered endemic to the Atlantic Forest biome. The present work aimed to study the germinative behavior of 'M. bimucronata' seeds under different temperatures and light qualities, as well as to evaluate the effect of the amount of water (humidity) in the substrate and the osmoconditioning during germination. Thus, the experiment was performed using a completely randomized design. The treatments were distributed in a 4 x 4 factorial scheme (temperatures and light qualities), with 4 replicates of 25 seeds each. The means were compared by Tukey's test at 5% probability. The volume of water and osmoconditioning of substrate was evaluated and data were subjected to regression analysis. The following variables were analyzed: first count of germinated seeds, germination, germination speed index, and electrical conductivity. The results revealed that seeds are neutral photoblasts, needing a constant temperature of 30 degreesC along with a white light for appropriate germination and vigor. Seeding on two sheets of paper towel moistened with water volume (mL) from 2.62 to 2.70 times was more suitable for conducting the germination test. The osmotic conditioning was inefficient in maintaining germination of these seeds.

Cicuta virosa L. has significant medicinal, ecological, and research potential, however there is little research history about seed dormancy. We characterized morphological changes during the embryo maturation stages of C. virosa L. seeds to better understand its dormancy type and germination characteristics, which is necessary for optimizing seed propagation. In addition, water absorption measurements, germination tests, cold moist stratification, and GA3 or kinetin were used to determine dormancy and germination characteristics. C. virosa seed dormancy presents a morphophysiological dormancy (MPD) with an undeveloped embryo. Since cold moist stratification at 4 °C caused the embryo to develop and the radicle to break through seed coat, its dormancy was determined to be of a non-deep complex type. For dormancy-broken seeds, the optimal germination condition was incubation at 25 °C in the light, with a pretreatment of GA3 and kinetin. Indeed, GA3 improved the germination rate up to 90% regardless of its concentration, and kinetin at least doubled the germination rate of C. virosa seeds compared to that of the controls. Additionally, KNO3 improved germination rates by 50% with respect to that of the controls regardless of the concentration at which it was added. Our results indicate that C. virosa seeds have MPD and can be planted consistently en masse with cold stratification, GA3, kinetin, and KNO3 treatments. In particular, once the embryo has developed sufficiently, a combined administration of 500 mg L−1 GA3 and 20 mg L−1 kinetin was much more effective than either treatment alone; therefore, an appropriate method must be used based on the stage of embryo development.

Consumption and removal of buried seeds by granivorous rodents is one of the major problems when direct seeding is applied for restoration of oak (Quercus robur) and European beech (Fagus sylvatica) forests. In this laboratory study, the use of four seed treatments to potentially reduce bank vole (Myodes glareolus) consumption of beech nuts and acorns and a control was evaluated using a no-choice feeding set-up. The five seed treatments were: Chili (Capsicum chinense)/coconut fat, citronella (Cymbopogon winterianus)/rapeseed oils, mink (Mustela vision) excrement, sand coating as a physical barrier and a control. Seed germination tests were carried out with all the treatments. A total of 40 bank voles were individually given access to beech nuts or acorns at a rate of one treatment per day during two sessions. Mink excrement and chili/coconut fat treatments greatly reduced the consumption of beech nuts, and also reduced touching of beech nuts and acorns. In contrast, the sand coating treatment increased the consumption of both types of seeds. Germination of both beech nuts and acorns was reduced by the chilli/coconut fat and citronella/rapeseed oils treatments. Our results suggest that mink excrement has a potential as an effective repellent against bank voles when direct seeding is applied. However, further studies to determine the best method of application, as well as the efficiency under field conditions, are needed before definitive recommendations can be given to restoration managers.

A laboratory test was carried out to examine the influence of various storage containers and periods on the germination percentage of black gram seed. In this research, three seed containers, viz. sealed tin container, poly bag and gunny bag were used to store the seeds, as well as seeds were stored for three different storage periods, viz. 15, 30 and 45 days and thereby conducted germination tests. The results revealed that storage and storage periods considerably influenced the germination percentage (GP) of black gram seed. The highest GP of 87.73% was found in the seeds stored at sealed tin container, while the lowest GP (71.08%) was observed in the seeds stored in gunny bag. Among the three storage containers, the GP reduced rapidly in the seeds stored in gunny bags (6.52%), followed by poly bag (18.98%). The maximum values of GP (85.43%) of black gram seed were recorded when 15 days after storage (DAS), whereas the lowest GP (68.33%) was at 45 DAS, and the GP decreased noticeably with the increase of storage periods from 15 to 30 and to 45 DAS. In combination influence of storage containers and storage periods, the maximum GP (85.90%) was recorded at when seeds kept in sealed tin container with stored for the shortest duration (15 DAS), while the minimum (58.11%) was recorded in the seeds stored in gunny bag for the longest period with 45 DAS. Seeds stored in the sealed tin containers exhibited an excellent performance regarding GP with the shortest storage periods and, thereby, black gram should be kept in sealed tin containers or like this air tight containers for storage, as well as seeds should be sun dried after a short period for maintaining seed quality.

The tetrazolium (TZ) test is one of the main methods to estimate vitality or viability and seed vigor. The aim of this study was to improve the methodology and reduce the execution time of tetrazolium test on carrot seeds, considering two existing references on this subject. Eight lots of ‘Brasilia’ carrot seeds were used. The hydration, during the pre-conditioning of the seeds, was done in two ways: directly in water during 18 hours and in rolls of filter paper during 2 hours. Seed color was analyzed through combinations between cutting types, concentration, period and temperature used during contact with the TZ solution. Three types of longitudinal cutting were used, before immersion in the tetrazolium solution: a) lateral and as distant as possible from the embryo distal to the embryo; b) partial, in the distal region opposite to the embryo, on about 1/3 of seed length; c) lateral and near the embryo, without reaching it. The used TZ concentrations were 0.1; 0.5 and 1.0%; periods of contact of the seeds with TZ solution were 1, 2, 6 and 24 h and temperatures were 30 and 35°C. The experimental design was completely randomized, with 5 replicates of 20 seeds per lot, per procedure. The results obtained through TZ test were compared with the results obtained in germination and seedling emergence tests. We could make hydration period shorter, from 18 to 2 hours, and staining from 24 to 2 hours. The lateral cutting as close as possible to the embryo, without reaching it, used in preparing the staining, should be emphasized for making execution and interpretation easy. The combination of higher efficiency used for hydration rolls of filter paper during 2 hours and, for staining lateral cutting as close as possible to the embryo, without reaching it, with the development of staining during 2 hours in 0.1% TZ solution at 35ºC. Thus, the reduction of the maximum tetrazolium test time, considering hydration (18 hours) and staining (24 hours), was from 42 to 4 hours and showed to be a feasible and reliable alternative. RESUMO O teste de tetrazólio (TZ) é um dos principais métodos para estimar a vitalidade ou viabilidade e o vigor de sementes. O objetivo do presente estudo foi aperfeiçoar a metodologia e reduzir o tempo de execução do teste de TZ em sementes de cenoura, a partir de duas referências existentes sobre esse assunto. A pesquisa foi realizada com oito lotes de sementes de cenoura ‘Brasília’. A hidratação, durante o pré condicionamento das sementes, foi conduzida de duas maneiras: diretamente em água por 18 horas e em rolos de papel filtro por 2 horas. A coloração das sementes foi analisada por meio de combinações entre tipos de corte, concentração, período e temperatura utilizados durante o contato com a solução de TZ. Foram utilizados três tipos de corte longitudinal prévios à imersão na solução de TZ: a) lateral e mais distante possível do embrião; b) parcial, na região distal oposta ao embrião em cerca de 1/3 do comprimento da semente; c) lateral e próximo ao embrião, sem atingi-lo. As concentrações de TZ empregadas foram 0,1; 0,5 e 1,0%; os períodos de contato das sementes com a solução de TZ foram de 1, 2, 6 e 24 h e, as temperaturas foram de 30 e 35ºC. O delineamento experimental foi inteiramente casualizado, com 5 repetições de 20 sementes em cada lote, por procedimento. Os resultados obtidos com o teste de TZ foram comparados com os obtidos nos testes de germinação e emergência de plântulas. Foi possível abreviar o período de hidratação de 18 para 2 horas e o de coloração de 24 para 2 horas. O corte lateral e mais próximo possível do embrião sem atingi-lo, utilizado no preparo para coloração, merece ser enfatizado pela facilidade na execução e interpretação. A combinação de maior eficiência utilizou para hidratação rolos de papel filtro por 2 horas e, para coloração o corte lateral, o mais próximo possível do embrião, sem atingi-lo, com o desenvolvimento da coloração durante 2 horas na solução de TZ 0,1% sob 35ºC. Portanto, a redução do tempo máximo de realização do teste de tetrazólio, considerando hidratação (18 horas) e coloração (24 horas), foi de 42 para 4 horas e, demonstrou ser uma alternativa exequível e confiável.

Launaea nudicaulis (Asteraceae) produces two morphologically distinct types of achenes (whitish brown and black) in a single capitulum. All L. nudicaulis achenes have a pappus and pappi were removed artificially in this study for experimental purposes. The germination of achenes of both colours, with and without pappi, under various temperature regimes and illumination conditions was tested. Different coloured achenes showed differences in their mass and germination behavior. Whitish brown achenes (with and without pappi) displayed greater germination than black ones. Whitish brown achenes without pappi generally displayed greater germination than achenes with pappi. Continuous darkness enhanced germination, regardless of the presence of pappi, indicating that L. nudicaulis seeds are negatively photoblastic.

This study was carried out to develop an evaluation method to predict rice seedling establishment (SE) under low-temperature conditions. Two Korean-bred japonica cultivars, Shindongjin and Hopum were used in the experiment. Fresh seeds were treated with an accelerated aging (AA) at 40°C and 100% RH for 1-15 days. The SEs of the fresh and AA seeds were evaluated in nursery beds at 17°C, and their correlation coefficients with seed vigor values measured by 9 test methods including standard germination test (SGT), cool germination test (CLT), cold germination test (CDT), seedling growth rate test (SGRT), ascorbate peroxidase (APX), peroxidase (POX), superoxide dismutase (SOD), catalase (CAT), and α ‐amylase (AMY) activities. The percentage of SE decreased slowly from 75 to 0% with an increasing of AA period from 0 to 15 days. The result of nine vigor tests showed different correlations with the SE. SGT, CLT, SGRT, and POX were significantly correlated with the SE. In the correlation analysis with only short-term aging seeds (1-7 days), the SE was very highly correlated with SGT, CLT, CDT, SGRT, POX, and CAT. These results suggest that seed vigor values measured by several methods including SGT and POX could be used as a reference value to secure SE at low temperatures in nursery bed rice seedling culture.

Made available in DSpace on 2019-10-03T18:19:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01 USDA National Institute of Food and Agriculture, hatch project Rapid, non-destructive methods for measuring seed germination and vigour are valuable. Standard germination and seed vigour were determined using 81 soybean seed lots. From these data, seed lots were separated into high and low germinating seed lots as well as high, medium and low vigour seed lots. Near-infrared spectra (950-1650 nm) were collected for training and validation samples for each seed category and used to create partial least squares (PLS) prediction models. For both germination and vigour, qualitative models provided better discrimination of high and low performing seed lots compared with quantitative models. The qualitative germination prediction models correctly identified low and high germination seed lots with an accuracy between 85.7 and 89.7%. For seed vigour, qualitative predictions for the 3-category (low, medium and high vigour) models could not adequately separate high and medium vigour seeds. However, the 2-category (low, medium plus high vigour) prediction models could correctly identify low vigour seed lots between 80 and 100% and the medium plus high vigour seed lots between 96.3 and 96.6%. To our knowledge, the current study is the first to provide near-infrared spectroscopy (NIRS)-based predictive models using agronomically meaningful cut-offs for standard germination and vigour on a commercial scale using over 80 seed lots. Univ Baghdad, Coll Sci Women, Dept Biol, Baghdad, Iraq Univ Kentucky, Dept Hort, Lexington, KY 40546 USA Sao Paulo State Univ, Sch Agr & Veterinarian Sci, Jaboticabal, Brazil USDA ARS, Ctr Grain & Anim Hlth Res, Manhattan, KS 66502 USA Univ Kentucky, Dept Plant & Soil Sci, Lexington, KY 40546 USA Sao Paulo State Univ, Sch Agr & Veterinarian Sci, Jaboticabal, Brazil USDA National Institute of Food and Agriculture, hatch project: KY011042 USDA National Institute of Food and Agriculture, hatch project: KY006062

La germinación tardía y errática de semilla de papaya es afectada por la presencia de la sarcotesta, membrana que contiene compuestos fenólicos inductores de latencia, misma que inhibe el intercambio de líquidos y gases, prolongar el período de secado y facilitar la colonización de fitopatógenos. Las técnicas utilizadas en el benef icio de semilla de papaya para eliminar la sarcotesta son limitadas, por tanto, el objetivo del presente estudio fue obtener tecnología útil en éste aspecto, para lo cual se comparó tratamientos a base de hidróxido de sodio, ácido sulfúrico y clorhídrico, y evaluó su efecto en la calidad física,sanitariayfisiológicadelasemilla.Lainvestigaciónse realizó en el Laboratorio de Análisis de Semillas del Colegio de Postgraduados, Campus Montecillo, Estado de México, en 2011. El NaOH al 25% y 15 min de inmersión, eliminó 98% de sarcotesta, presentó sólo 2% de incidencia de micoflora, incremento y homogeneizó la germinación. El H2SO4 eliminó al 100% la sarcotesta, inhibió la colonización de hongos con sólo 6%, cuando se empleó en forma concentrada, pero afecto negativamente la germinación. El HCl fue ineficiente en eliminar la sarcotesta (9.6%), presentó la más alta colonización de hongos (97% de incidencia) y el menor porcentaje de germinación (7%). Los efectos positivos del uso de NaOH en el beneficio de semilla de papaya, simula la degradación natural de la sarcotesta y mejora la condición de la semilla por lo que resulta una alternativa viable para su empleo en el acondicionamiento de semilla.

The critical node (CN) is an important stage during seed aging, which is related to effective genebank conservation. Previous studies have demonstrated that proteins undergo carbonylated modification at the CN in rice, indicating oxidative damage. However, the levels of reactive carbonyl species (RCS) and the associated scavenging system at the CN are largely unknown. In this study, we optimized methods for the extraction and analysis of RCS from dry rice embryos. In order to acquire seeds at the CN, rice seeds were subjected to natural conditions for 7, 9, 11 and 13 months, and the seed germination rates were reduced to 90%, 82%, 71% and 57%, respectively. We chose the stage with seed germination rate of 82% as the CN according to the rice seed vigor loss curve. The levels of crotonaldehyde and 4-hydroxy-(E)-2-nonenal (HNE) were significantly increased at the CN. In addition, genes encoding carbonyl-scavenging enzyme, including OsALDHs and OsAKRs, were significantly down-regulated at the CN, and reductions in the expression of OsALDH2-2, OsALDH2-5, OsALDH3-4, OsALDH7, OsAKR1 and OsAKR2 in particular could be responsible for RCS accumulation. Thus, the accumulations of crotonaldehyde and HNE and down-regulation of genes encoding carbonyl-scavenging enzyme might be related to an accelerating loss of seed viability at the CN. Key words: carbonyl-scavenging system, reactive carbonyl species, seed aging, crotonaldehyde, critical node, rice storage

Salinity is the major environmental stress that affects the growth and productivity of plants. The present study was conducted to determine the effect of salinity on growth and ions uptake by moringa (Moringa oleifera L.) plant. The experiment was carried out in two phases. Initially, a germination test was conducted in the laboratory under the different salinity levels (control, 5, 10, 15, and 20 dS m⁻¹) and found that moringa seeds were germinated only at 5 and 10 dS m⁻¹ salinity levels, and no germination occurred at higher salinity levels (15 and 20 dS m⁻¹). The experiment was laid out in a completely randomized design (CRD) with five replications. In the second phase, three-week old nursery grown plants of moringa were shifted in pots under the five salinity levels (control, 5, 10, 15, and 20 dS m⁻¹). The experiment was laid out in CRD and replicated four times. In pot experiment, the root, shoot length, and dry weights were significantly affected by increasing the salinity levels. The uptake of K⁺ and Ca²⁺ was highly affected at different salinity levels as compared to control and Na⁺ ions accumulation was higher in roots rather than shoot. The results reveal that moringa plant can germinate, survive, and can be cultivated in areas with moderate saline condition.

High zinc (Zn) concentration of seeds has beneficial effects both on seed vigor and human nutrition. This study investigated the effect of Zn biofortification on growth of young durum wheat (Triticum durum cv. Yelken) seedlings under varied Zn and water supply. The seeds differing in Zn concentrations were obtained by spraying ZnSO4 to durum wheat plants at different rates under field conditions. Three groups of seeds were obtained with the following Zn concentrations: 9, 20, and 50 mg Zn kg(-1). The seeds differing in Zn were tested for germination rate, seedling height, shoot dry matter production, and shoot Zn concentration under limited and well irrigated conditions in a Zn-deficient soil with and without Zn application. In an additional experiment carried out in solution culture, root and shoot growth and superoxide dismutase activity (SOD) of seedlings were studied under low and adequate Zn supply. Low seed Zn concentration resulted in significant decreases in seedling height both in Zn-deficient and sufficient soil, but more clearly under water-limited soil condition. Decrease in seed germination due to low seed Zn was also more evident under limited water supply. Increasing seed Zn concentration significantly restored impairments in seedling development. Drought-induced decrease in seedling growth at a given seed Zn concentration was much higher when soil was Zn-deficient. Increasing seed Zn concentration also significantly improved SOD activity in seedlings grown under low Zn supply, but not under adequate Zn supply. The results suggest that using Zn-biofortified seeds assures better seed vigor and seedling growth, particularly when Zn and water are limited in the growth medium. The role of a higher antioxidative potential (i.e., higher SOD activity) is discussed as a possible major factor in better germination and development of seedlings resulting from Zn-biofortified seeds.

Salinity is one of the most important factors limiting agricultural production. Cotton, as an oil-fiber plant, is one of the most important industrial plants and is sensitive to salinity, especially at germination and seedling stages. Therefore, in this study, 14 allotetraploid varieties of commercial and local cotton were selected. The study was carried out as factorial with a completely randomized design and three three replications, using the sandwich method. Germination tests were performed at three salinity levels of 0, 8 and 16 ds.m-1. Afterwards, root and shoot length, fresh and dry weight of root and shoot, germination percentage, allometric coefficient, seedling water percentage and seed vigor index were measured and stress tolerance indices were calculated based on yield (seedling dry weight) in stress and non-stress conditions. Given these indices, all cultivars were aalyzed at two levels of 8 and 16ds.m-1, using principal component analysis and biplot diagrams were drawn. Finally, the dendrogram classification of genotypes was plotted based on STI indices (stress tolerance index), SSI (stress susceptibility index), and the performance (dry weight plantlet) in stress and non-stress conditions. The result of variance analysis for genotype, salinity and salinity×genotype demonstrated that dry weight root, dry weight shoot, fresh weight root, stem length, vigor index seedling, allometric coefficient, dry weight seedling, and length seedling were significant in p-value 0.01, and fresh weight shoot, length root were significant in p-value 0.05. Clustering and the biplot of the genotypes based on STI and SSI indices at salinity levels of 8 and 16 ds.m-1 indicated that the Sepid and Giza genotypes were tolerant and that the Kashmar genotype was sensitive to salt levels at germination stage. Highlights: The reaction of the cotton cultivars studied was different to levels of salinity stress. An increase in salt stress caused a significant reduction in the germination characteristics of cultivars of cotton studied. Bi-plot analysis and clustering based on STI and SSI indices turned out to be a suitable method for clustering cotton cultivars.

New switchgrass (Panicum virgatum L.) bioenergy cultivars are being bred through genetic engineering; however, baseline information is urgently needed to establish guidelines for small-scale field trials prior to commercialization. In this study, we documented the pattern of pollen-mediated gene flow and the extent of seed longevity in field experiments. To mimic crop-to-wild, pollen-mediated gene flow, we planted wild recipient switchgrass ramets at various distances away from cultivar donor ramets at two sites in Ohio. Percent hybridization at each distance was estimated from seed set on recipient ramets, which were self-incompatible clones. The pattern of gene flow was best described by negative exponential models, and the minimum isolation distance for a 0.01% gene flow threshold was predicted to be 69 m and 109 m away from the pollen source at the two sites. To investigate seed longevity, we buried seeds of six cultivars and ten wild biotypes in Ohio and Iowa in 2011. A subset of the seeds were exhumed, germinated, and tested for dormancy over three years. Cultivars lost seed viability and dormancy significantly sooner than wild biotypes at both locations in the first year, and most biotypes lost dormancy by the second year. Cultivar seeds buried in the cooler, drier Iowa site had an overall greater longevity than those buried in Ohio. Our findings suggest that substantial amounts of pollen-mediated gene flow could occur in the immediate vicinity of switchgrass pollen sources, and current switchgrass cultivars are unlikely to persist in the seed bank for more than three years.

In Seed Testing Laboratory (STL), test for other distinguishable variety (ODV) is carried out for the seed sample received from the seed producer after harvesting. This is done to obtain foundation/certified tag from the seed certification department before marketing the product. This is currently done manually by observing the morphological characteristics of the seeds through the naked eye. This is a time-consuming process for the STL and there is a chance for human error in identifying ODV. Hence, there is the need for the machine vision technique to automate the process of identifying ODV in the seed testing laboratory. Various techniques for varietal identification of sunflower seeds are explored in this paper. Experiments are performed on a dataset that contains ten varieties of sunflower seeds and the success rate achieved using various techniques is reported in this paper. In cascaded support vector machine (SVM), the order in which the classifier blocks are arranged plays an important role in improving the classification rate. The main contribution of this paper lies in the manipulation of ant colony optimization technique for obtaining the order of cascaded SVM by maximizing the total probability of correct decision. When the SVM is cascaded in optimum order, classification rate has been increased from $88.32\%$ (obtained using the actual order) to $98.82\%$ for kernel linear discriminant analysis based boundary descriptors. The closed form expression for computing the total probability of correct detection of the constructed cascaded SVM classifier is also reported in this paper.

Ecological restoration is predicated on our abilities to discern plant taxa. Taxonomic identification is a first step in ensuring that plants are appropriately adapted to the site. An example of the need to identify taxonomic differences comes from big sagebrush (Artemisia tridentata). This species is composed of three predominant subspecies occupying distinct environmental niches, but overlap and hybridization are common in ecotones. Restoration of A. tridentata largely occurs using wildland collected seed, but there is uncertainty in the identification of subspecies or mix of subspecies from seed collections. Laboratory techniques that can determine subspecies composition would be desirable to ensure that subspecies match the restoration site environment. In this study, we use spectrophotometry to quantify chemical differences in the water-soluble compound, coumarin. Ultraviolet (UV) absorbance of A. tridentata subsp. vaseyana showed distinct differences among A.t. tridentata and wyomingensis . No UV absorbance differences were detected between A.t. tridentata and wyomingensis . Analyses of samples from > 600 plants growing in two common gardens showed that UV absorbance was unaffected by environment. Moreover, plant tissues (leaves and seed chaff) explained only a small amount of the variance. UV fluorescence of water-eluted plant tissue has been used for many years to indicate A.t. vaseyana; however, interpretation has been subjective. Use of spectrophotometry to acquire UV absorbance provides empirical results that can be used in seed testing laboratories using the seed chaff present with the seed to certify A. tridentata subspecies composition. On the basis of our methods, UV absorbance values A.t. vaseyana and values > 3.1 would indicate either A.t. tridentata or wyomingensis . UV absorbance values between 2.7 and 3.1 would indicate a mixture of A.t. vaseyana and the other two subspecies.

Quinoa (Chenopodium quinoa Willd.) cultivated since more than 5000 BC. Because the gluten-free and high nutritious grains have been of commercial interest over last two decades, studies have focused on mainly adaptation and commercial production. In this study, seed vigor was tested after different storage periods (60, 120, 180, 240, 300 and 360 days) and temperatures (4-, 10- and 25 °C) for Mint Vanilla and Titicaca varieties at the temperature-humidity-controlled environments. Seed testing and growth parameters for the grains raised from each storage conditions were recorded after 7 days of seed incubation in each treatment. It was shown that the maintenance of seed vigor can vary significantly depending on genotype selection (i.e. seed vigor was the highest for Titicaca grains), as a result of kinetic modeling and constellation plot analysis. The most effective temperature that can be used in storage for the longer durability for quinoa seeds is 4 °C and 10 °C. Seed deterioration and vigor loss were a clear patent at 25 °C for both quinoa varieties. As a result, the storage temperature and duration show the change of germination parameters and may be used as a reference for quinoa quality and consumption safety.