Seed Germination Performance Research Articles

초분광 영상기술을 이용한 수박종자 발아여부 비파괴 선별기술 개발

Abstract Seed viability is one of the most important parameters that is directly related with seed germination performance and seedling emergence. In this study, a hyperspectral imaging (HSI) system having a range of 1000–2500 nm was used to classify viable watermelon seeds from nonviable seeds. In order to obtain nonviable watermelon seeds, a total of 96 seeds were artificially aged by immersing the seeds in hot water (25°C) for 15 days. Further, hyperspectral images for 192 seeds (96 normal and 96 aged) were acquired using the developed HSI system. A germination test was performed for all the 192 seeds in order to confirm their viability. Spectral data from the hyperspectral images of the seeds were extracted by selecting pixels from the region of interest. Each seed spectrum was averaged and preprocessed to develop a classification model of partial least square discriminant analysis (PLS-DA). The developed PLS-DA model showed a classification accuracy of 94.7% for the calibration set, and 84.2% for the validation set. The results demonstrate that the proposed technique can classify viable and nonviable watermelon seeds with a reasonable accuracy, and can be further converted into an online sorting system for rapid and nondestructive classification of watermelon seeds with regard to viability.

Durum Wheat Seed Germination Response to Hydrogel Coatings and Moisture under Drought Stress

Technologies that can increase crop production while maintaining low pollution are essential for sustainable agriculture. This study compares the germination performance of Durum wheat seeds (Triticum durum Desf.) which were coated with synthetic coatings [polyacrylamide (PA)] and novel natural coatings [mixtures of agar/ι-carrageenan (AC)] at different moisture levels. A number of germination performance indicators were measured for each of the categories of coatings. These included: (i) % germination, (ii) radicle emergence, (iii) speed of germination, (iv) seedling length, (v) fresh seed weight and (vi) seed vigour index. Results showed that both the synthetic and natural coatings improved germination performance in the Durum wheat seeds versus the untreated seeds when non-drought (80% moisture) conditions were used. However, when 40% moisture levels were used, the natural coated seeds showed a 6% improvement in germination performance over the synthetic PA coated seeds. This improved germination performance under drought stress along with the fact that these novel AC coatings used are completely natural and environmentally friendly suggests that these novel coatings have a big future in seed coatings, especially in countries which experience drought conditions and are dependent on natural irrigation.

Improvement of Seed Germination Performance of Stored Commercial Pepper Seed Lots with Chlorophyll Fluorescence Sorting Method

Improvement of Seed Germination Performance of Stored Commercial Pepper Seed Lots with Chlorophyll Fluorescence Sorting Method

Seed-germination responses of Calotropis procera (Asclepiadaceae) to temperature and water stress in northern Australia

Understanding the seed biology of the introduced weed rubber bush (Calotropis procera (Aiton, W.T.Aiton)) is critical to its management in northern Australia. We examined the numbers of seeds produced and the effects of environmental temperature and water stress on germination performance (germinability G; mean germination time MGT) of rubber bush seeds from across northern Australia. Germination trials were conducted using seeds from wild populations monitored for 3 years. Seed numbers per fruit did not vary significantly among the six populations studied (mean ± s.e. = 433.2 ± 19.0), but seed mass did (range from 8.32 ± 0.24 to 5.24 ± 0.06 mg), with no negative correlation between the measures. Maximum seed germination (68–100%) occurred at 30°C, associated with a mean germination time of 2.58 days. Under water stress, the proportion of germinated seeds declined significantly with increasing temperature from 92.5 ± 1.1% at 20°C and 0 MPa to 2.8 ± 1.7% at 40°C and –0.4 MPa respectively. Seeds were unable to germinate at ambient temperatures ≥40°C, but remained quiescent and hence viable. Planting depth influenced seedling emergence, with minimal germination of seeds on the surface (5.8%) but 88.5% germination at 3-cm depth. The effect of water stress was dependent on temperature, with water stress inducing a reduction in optimum germination temperature from 30°C to 20°C. Phenotypic plasticity in G and MGT did not show clear patterns among populations or years. Short MGTs increase seedling survival by rapid transition from endosperm resources to photosynthesis, whereas seed quiescence (cf. dormancy) optimises germination opportunities in a semiarid environment. Thus, the germination traits reported in the present study are likely to promote seedling survival and potential spread of rubber bush in semiarid Australia.

Sonication of seeds increase germination performance of sesame under low temperature stress

A laboratory experiment was conducted to determine the effect of ultrasound (US) exposure time on germination behavior of sesame seeds. All tests were carried out at 20 kHz in a water bath ultrasonic device varying two factors, treatment duration (10, 20 and 30 min) and germination temperature (15, 20 and 25 ºC). Parallel tests were run in which seeds were soaked in water without sonication in order to eliminate the effect of water from US test results. US treatments enhanced seeds water uptake. At mild exposure time it improved sesame seed germination performance and seedling growth at suboptimal temperatures as indicated by higher germination percentage and germination rate. US applying for 20 min had relatively high superoxide dismutase activity; however, had not significant differences with control and US duration for 10 min. The catalase activity was strongly increased by applying the US for a 10 and 20 min. Among the treatments, application of US vibration for 10 and 20 min reduced both of malondialdehyde and H2O2 contents, however high US duration (30 min) increased both of the traits. In general, ultrasonic priming technique can be useful for early planting the sesame seeds, and lead to higher yields.

Temperature-related effects on the germination capacity of black locust (Robinia pseudoacacia L., Fabaceae) seeds

Germination is a key trait promoting species invasiveness and has become a major goal in invasion ecology. In this study, the effects of different scarification methods and temperature regimes on seed germination performance of the invasive exotic tree Robinia pseudoacacia L. were investigated. Ripe seeds were gathered from six collection sites in Tuscany (central Italy). Mechanical, chemical and thermal scarifications and no pretreatment were applied; seeds were incubated in a range (9–21°C) of constant temperature regimes. The scarification treatments proved highly important for the germination performance of seeds in term of both final response and germination rate in time, with mechanical scarification being the most effective treatment. Temperature significantly affected the germination rate and the mean germination time of the mechanically scarified seeds. The cumulative germination rate significantly decreased with the reduction of the temperature, with the highest value in the 18–21°C regimes (ca 98%), and the lowest in the 9–12°C regimes (ca 60%). The mean germination time slightly decreased with increasing temperature, but was substantially similar between 18°C and 21°C. Our data indicate that the temperature affected the onset of seed germination and that the lowest temperature tested delayed germination. These plastic germination responses, as well as the high germination capacity at lower temperature, may result in the spread of the propagule germination over a large time interval, contributing to the invasiveness of this species.

Effect of Different Priming Methods on Germination and Seedling Establishment of Two Medicinal Plants under Salt Stress Conditions

Abstract Priming is one of the seed enhancement methods that might be resulted in increasing seed performance (germination and emergence) under stress conditions, such as salinity. Salinity is a major environmental stress which adversely affects germination and seedling establishment in a wide variety of crops. The experiment was arranged as a factorial in completely randomized design (CRD) at Seed Research Laboratory of College of Agriculture, University of Tehran, Iran. The objective of this research was to evaluate the effect of different priming methods on seed germination of two medicinal plants including lemon balm (Melissa officinalis L.) and cumin (Cuminum cyminum L.) under salinity stress. Treatments were combinations of two levels of salinity stress (0 and 10 dsm−1) and five levels of priming (control = non-priming), GA3, manitol, NaCl and distilled water) with three replications. Seeds of lemon balm and cumin were primed for 24 h at 25°C. Results revealed that different growth traits (including germination percentage, germination rate, seedling dry weight, plumule and radical length) significantly (p=0.05) decreased with applying salinity. However, priming of seeds with different materials particularly GA3 was useful for alleviating salt stress effects and improving germination and seedling establishment under salt stress. Under salinity condition, primed seeds possessed more germination and emergence than control. The result of this experiment is consistent with the hypothesis that under salinity stress, priming can prepare a suitable metabolic reaction in seeds and can improve seed germination performance and seedling establishment.

Enhanced expression of the proline synthesis gene P5CSA in relation to seed osmopriming improvement of Brassica napus germination under salinity stress

Osmopriming is a pre-sowing treatment that enhances germination performance and stress tolerance of germinating seeds. Brassica napus seeds showed osmopriming-improved germination and seedling growth under salinity stress. To understand the molecular and biochemical mechanisms of osmopriming-induced salinity tolerance, the accumulation of proline, gene expression and activity of enzymes involved in proline metabolism and the level of endogenous hydrogen peroxide were investigated in rape seeds during osmopriming and post-priming germination under control (H2O) and stress conditions (100mM NaCl). The relationship between gene expression and enzymatic activity of pyrroline-5-carboxylate synthetase (P5CS), ornithine-δ-aminotransferase (OAT) and proline dehydrogenase (PDH) was determined. The improved germination performance of osmoprimed seeds was accompanied by a significant increase in proline content. The accumulation of proline during priming and post-priming germination was associated with strong up-regulation of the P5CSA gene, down-regulation of the PDH gene and accumulation of hydrogen peroxide. The up-regulated transcript level of P5CSA was consistent with the increase in P5CS activity. This study shows, for the first time, the role of priming-induced modulation of activities of particular genes and enzymes of proline turnover, and its relationship with higher content of hydrogen peroxide, in improving seed germination under salinity stress. Following initial stress-exposure, the primed seeds acquired stronger salinity stress tolerance during post-priming germination, a feature likely linked to a ‘priming memory’.

The importance of safeguarding genome integrity in germination and seed longevity.

Seeds are important to agriculture and conservation of plant biodiversity. In agriculture, seed germination performance is an important determinant of crop yield, in particular under adverse climatic conditions. Deterioration in seed quality is associated with the accumulation of cellular damage to macromolecules including lipids, protein, and DNA. Mechanisms that mitigate the deleterious cellular damage incurred in the quiescent state and in cycles of desiccation-hydration are crucial for the maintenance of seed viability and germination vigour. In early-imbibing seeds, damage to the embryo genome must be repaired prior to initiation of cell division to minimize growth inhibition and mutation of genetic information. Here we review recent advances that have established molecular links between genome integrity and seed quality. These studies identified that maintenance of genome integrity is particularly important to the seed stage of the plant lifecycle, revealing new insight into the physiological roles of plant DNA repair and recombination mechanisms. The high conservation of DNA repair and recombination factors across plant species underlines their potential as promising targets for the improvement of crop performance and development of molecular markers for prediction of seed vigour.

Physiological and sanitary quality, and transmission of fungi associated with Brachiaria brizantha (Hochst. ex. A. Rich.) Stapf seeds submitted to thermal and chemical treatments

The Brazilian pastures establishment success depends on the use of seeds with high physiological and sanitary quality. The aim of this study was to evaluate the effect of thermal and chemical treatments on quality of Brachiaria brizantha, cv. BRS Piatã and pathogen transmission via seed. The treatments included the use of fungicides, detergent, sodium hypochlorite, sulfuric acid and alcohol, as well as thermal treatments. In addition to seeds without treatment, nine treatments were tested. The tests used to assess the physiological quality of the seeds were first and final count of germination test and root protrusion; germination and root protrusion speed index. A transmitting test and filter paper method had been performed for sanitary quality. Fungal lower incidence was observed in seeds treated with alcohol, however, this treatment reduced the physiological quality of the seeds and higher frequency of fungi transmission from seeds to seedlings was observed for Bipolaris sp., Fusarium sp. and Phoma sp. Treatment with sulfuric acid provided a better seed germination performance and reduced the incidence of fungi.

BIIDXI, the At4g32460 DUF642 gene, is involved in pectin methyl esterase regulation during Arabidopsis thaliana seed germination and plant development.

BackgroundDUF642 proteins constitute a highly conserved family of proteins that are associated with the cell wall and are specific to spermatophytes. Transcriptome studies have suggested that members of this family are involved in seed development and germination processes. Previous in vitro studies have revealed that At4g32460- and At5g11420-encoded proteins interact with the catalytic domain of pectin methyl esterase 3 (AtPME3, which is encoded by At3g14310). PMEs play an important role in plant development, including seed germination. The aim of this study was to evaluate the function of the DUF642 gene At4g32460 during seed germination and plant development and to determine its relation to PME activity regulation.ResultsOur results indicated that the DUF642 proteins encoded by At4g32460 and At5g11420 could be positive regulators of PME activity during several developmental processes. Transgenic lines overexpressing these proteins showed increased PME activity during seed germination, and improved seed germination performance. In plants expressing At4g32460 antisense RNA, PME activity was decreased in the leaves, and the siliques were very short and contained no seeds. This phenotype was also present in the SALK_142260 and SALK_054867 lines for At4g32460.ConclusionsOur results suggested that the DUF642 family contributes to the complexity of the methylesterification process by participating in the fine regulation of pectin status during plant development.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0338-8) contains supplementary material, which is available to authorized users.

Germination responses to temperature and water potential as affected by seed oil composition in sunflower

Sunflower genotypes with increased concentration of stearic and oleic acids have been developed to fulfil industrial specific requirements. Fatty acid composition of membranes has been widely described to affect seed germination, but the effect of composition of reserve lipids on germination is still unknown. Two experiments were conducted including: traditional (high linoleic), high stearic–high oleic, high stearic–high linoleic and high oleic genotypes. Thermal and hydrotime analyses were performed on germination data obtained from the incubation of seeds at different temperatures and water potentials. Fatty acid composition affected the parameters values of thermal time model. Base temperature was inversely related to linoleic acid concentration. Genotypes with high linoleic acid concentration germinated earlier at low temperatures, while no significant differences among genotypes at temperatures above 15°C were found. High stearic–high oleic genotypes showed lower thermal time requirement for 50% germination than traditional and high stearic–high linoleic genotypes. The parameters of hydrotime model were not affected by fatty acid composition, but at low water potentials and high temperatures thermo-dormancy was induced and strongly reduced final seed germination in all genotypes studied. In conclusion, breeding for higher oleic acid and lower linoleic acid concentration in sunflower oil may affect seed germination performance at low temperatures.

An enhanced drought-tolerant method using SA-loaded PAMPS polymer materials applied on tobacco pelleted seeds.

Drought is one of the most important stress factors limiting the seed industry and crop production. Present study was undertaken to create novel drought-resistant pelleted seeds using the combined materials with superabsorbent polymer, poly(2-acrylamide-2-methyl propane sulfonic acid) (PAMPS) hydrogel, and drought resistance agent, salicylic acid (SA). The optimized PAMPS hydrogel was obtained as the molar ratio of 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) to potassium peroxydisulfate (KPS) and N, N′-methylene-bis-acrylamide (MBA) was 1 : 0.00046 : 0.00134. The hydrogel weight after swelling in deionized water for 24 h reached 4306 times its own dry weight. The water retention ratio (RR) of PAMPS was significantly higher as compared with the control. It could keep as high as 85.3% of original weight after 30 min at 110°C; even at 25°C for 40 d, the PAMPS still kept RR at 33.67%. PAMPS disintegration ratio increased gradually and reached around 30% after embedding in soil or activated sludge for 60 d. In addition, there were better seed germination performance and seedling growth in the pelleted treatments with SA-loaded PAMPS hydrogel under drought stress than control. It suggested that SA-loaded PAMPS hydrogel, a nontoxic superabsorbent polymer, could be used as an effective drought resistance material applied to tobacco pelleted seeds.

HEAT SHOCK TREATMENT CAN IMPROVE SOME SEED GERMINATION INDEXES AND ENZYME ACTIVITY IN PRIMED SEEDS WITH GIBBERELLIN OF MOUNTAIN RYE (SECALE MONTANUM) UNDER ACCELERATED AGING CONDITIONS

ABSTRACT Seed priming with gibberellin (GA) enhances seed germination performance; but the quality of primed seeds in aging condition often reduces more than non-primed seeds. An experiment was conducted to evaluate the effect(s) of heat shock treatments on germination characteristics and enzyme activity of primed mountain rye (Secale montanum) seeds with gibberellin under accelerated aging. Heat shock treatments, can substantially decrease the speed of quality reduction of mountain rye (Secale montanum) primed seeds. In primed seeds with gibberellin, which has non-aged, the highest germination percentage (GP) and normal seedling percentage (NSP) was attained from heat shock treatment at 35°C for 3 h, also after 3 days aging, it was attained from heat shock treatment at 35°C for 3 h. After 3 days of aging the highest germination index (GI) was attained from unprimed seeds, but no significant difference with heat shock treatment at 35°C for 3 h. The minimum means time germination (MTG) was in heat shock treatment at 30°C for 3 h in non-aged seeds. After 3 days of aging, heat shock treatment reduce MTG as compared to the primed seeds. Heat shock treatment at 35°C for 3 h increased seed vigor index (SVI) as compared to the unprimed and primed seed in non-aged seeds and after 3 days aging. Seedling length (SL) increases with heat shock treatment at 30°C for 4 h in non-aged seeds as compared to the primed and unprimed seeds, but after 3 days of aging heat shock treatment except at 35°C for 3 h and 40°C for 4 h reduced SL as compared to the primed and unprimed seeds. Also, heat shock treatments increase some antioxidant enzymes [Catalase (CAT), Ascorbat peroxidase (APX)].

Hormone Priming Improves Germination Characteristics and Enzyme Activity of Sorghum Seeds (Sorghum Bicolor L.) Under Accelerated Aging

Abstract Maximum germination percentage achieves immediately after harvesting and gradually decreases with storage time. Aging is one of the key factors in plant yield loss especially in vegetables. Seed aging is the main problem of seed storage. Application of accelerated aging treatment is used to assess seed vigor and quality. Seed priming enhances seed germination performance after aging. An experiment was conduct in order to investigate the activity of catalase and ascorbate peroxidase during accelerated aging and repair during priming treatment of sorghum seeds. In order to improve germination characteristics in aged seeds with seed priming. Our result showed that seed priming treatments significantly (p≤ 0.01) affected, germination percentage, germination index and means time to germination after aging (0, 3 and 6 days). Increasing aging duration resulted higher reduction in germination characteristics. Priming with gibberelic acid (GA), salicylic acid (SA) and ascorbic acid (ASC) increased germination characteristics of seed aged. The highest germination percentage, germination index, normal seedling percentage and enzyme activity were achieved in control conditions (0 day of aging). Antioxidant activity of aged seeds increased after seed priming.

Proteomic analysis of the enhancement of seed vigour in osmoprimed alfalfa seeds germinated under salinity stress

AbstractAlfalfa (Medicago sativaL.) yield is severely compromised by soil salinity, especially at the level of seedling establishment. This question was addressed by proteomics to decipher whether specific changes in protein accumulation correlate with germination performance of alfalfa seeds submitted to a salinity stress as obtained by imbibing seeds in the presence of NaCl. This study used alfalfa seeds submitted to an osmopriming invigoration treatment that proved very efficient in counteracting the negative effect of salinity stress on germination performance. Comparative proteomic analyses disclosed 94 proteins commonly characterizing the response of both the untreated control and osmoprimed seeds to the experimental salinity stress. Remarkably, many of them, representing 84 proteins, showed contrasting accumulation patterns when comparing the untreated control and osmoprimed seeds submitted to the same salt stress. Thus numerous changes observed in the proteome of the untreated control seeds imbibed in the presence of salt, and presumably accounting for the loss in seed vigour associated with salinity stress, can be substantially reversed in osmoprimed seeds undergoing this stress. These data therefore provide a biochemical understanding of the increase in seed vigour generally observed with primed seeds.

At3g08030 transcript: a molecular marker of seed ageing

Prolonged storage generally reduces seed viability and vigour, although the rate of deterioration varies among species and environmental conditions. Here, we suggest a possible ageing molecular marker: At3g08030 mRNA. At3g08030 is a member of the DUF642 highly conserved family of cell-wall-associated proteins that is specific for spermatophytes. At3g08030 expression was performed by RT-PCR and qRT-PCR analysis in seed samples differing in their rate of germination and final germination following a matrix priming and/or controlled deterioration (rapid ageing) treatment. The At3g08030 gene transcript was present during the entire Arabidopsis thaliana plant life cycle and in seeds, during maturation, the ripening period and after germination. Matrix priming treatment increased the rate of germination of control seeds and seeds aged by controlled deterioration. Priming treatments also increased At3g08030 expression. To determine whether the orthologues of this gene are also age markers in other plant species, At3g08030 was cloned in two wild species, Ceiba aesculifolia and Wigandia urens. As in A. thaliana, the At3g08030 transcript was not present in aged seeds of the tested species but was present in recently shed seeds. A reduction in germination performance of the aged seeds under salt stress was determined by germination assays. At3g08030 mRNA detection in a dry seed lot has potential for use as a molecular marker for germination performance in a variety of plant species.

Combined effect of hormonal priming and salt treatments on germination percentage and antioxidant activities in lettuce seedlings

Hormonal priming is a pre-sowing treatment that improves seed germination performance and stress tolerance. To understand the physiology of hormonal priming and its association with post priming stress tolerance, we investigated the effect of hormonal priming with increasing gibberellic acid (GA 3 ) concentrations (0, 3, 4.5 and 6 mM) on seedling growth and antioxidant system in lettuce. Germination percentage was higher in lettuce seedlings derived from primed seeds. Radicle and hypocotyl length and dry weight were reduced by salt treatment to a greater extent in non-primed than in primed seeds. Hormonal priming with 4.5 mM GA 3 induced the most dramatic decreases in electrolyte leakage (EL) and malondialdehyde (MDA) levels. NaCl increased catalase (CAT) activity in primed and non-primed seeds. The total ascorbate level remained constant in both primed and non-primed seeds under NaCl constraint. These results suggest that hormonal priming might have increased the salt tolerance of lettuce seeds through enhancing the activities of antioxidant enzymes and reducing the membrane damage as estimated using EL and MDA biomarkers. Key words: Ascorbate, germination, hormonal priming, lettuce, salinity.

English

Germination is a key event in plant life cycle and imbibition temperature is an important factor for the major reorganization pro- cesses in the germinating seeds. Sub-physiological temperature at this stage affects virtually all aspects of cellular function including protein folding, kinetic parameters of membrane fluidity, protein assembly, and general metabolic processes. In this article we will review the re- search which has been carried out to decipher the basic mechanisms of low temperature (LT) stress with special emphasis on germination. With the better understanding of LT tolerance in some plant species we will also discuss how these attributes can be transferred in the im- portant food crops to attain better germination stamina at sub-physiological temperatures. At germination stage, the cellular machinery in the embryo is not at its proper place and is going through reorganisation and any environmental severity has devastating effects on the fragile plant. But LT resistant species have evolved the ability to acclimatise, with the remodelling of cell and tissue structures and the reprogram- ming of metabolism and gene expression. Metabolic networks are redirected towards the synthesis of cryoprotectant molecules, which in association with other proteins bring about physical and biochemical restructuring of cell membranes through changes in the lipid composi- tion and induction of other non-enzymatic proteins that alter the freezing point of water. Genetic engineering of crops for enhanced seed germination performance will certainly help to achieve optimum agricultural yields..

Effect of exogenous silicon on germination and seedling establishment in Borago officinalis L.

Borage (Borago officinalis L.) is a valuable medicinal plant with a high content of gamma linolenic acid. Seed germination and early seedling growth are critical stages for plant establishment and production. One of the major problems in the field of plant cultivation and production of this plant is low and uniform seed germination. Thus in this experiment, the influences of exogenous silicon concentration during germination and early seedling growth was evaluated. Treatments were 7 levels of silicon (0, 0.2, 0.5, 0.7, 1, 1.5, 2 mM Na2Sio3) in 4 replicates. The results showed that different treatments of silicon had considerable effect on the germination rate (GR), germination index (GI) and seedling growth of borage. The highest germination percentage was obtained at 1.5 mM silicon and the total dry and fresh weight of seedling was increased. Result of this experiment is consistent with the hypothesis that silicon has a priming effect and can prepare a suitable metabolic reaction in seeds and improve seed germination performance and seedling establishment. Key word: Boragoofficinalis L., seed germination and seedling growth.