Initial Germination Percentage Research Articles

Global warming could shorten the seed lifespan of pioneer tree species and thus natural regeneration window of damaged areas

Prolonged periods without precipitation in spring prevent timely and rapid germination of pioneer tree seeds and could lead to an accelerated loss of germination capacity (reduced lifespan). To get knowledge about the shortening of seed lifespan and, thus, the shortening of natural regeneration windows under climate change, an experiment was conducted. Seeds of Alnus glutinosa, Betula pendula, Populus tremula, Salix caprea, Larix decidua, Pinus sylvestris, and Picea abies were exposed to temperatures of 15 °C, 25 °C (past or present climate), and 40 °C (future climate) with low or high humidity for a period of 3 months. Regardless of air humidity, the initial germination percentage of Alnus glutinosa, Betula pendula, Larix decidua, and Pinus sylvestris seeds decreased only slightly by 5–15% over the 91-day period when stored at 15 °C and 25 °C. For Populus tremula and Salix caprea, time windows of maximum 14–49 days and 42–91 days were identified, respectively.However, as climate change progresses with rising temperatures and increasing absolute air humidity values, the window of opportunity for successful germination will shorten for all studied tree species. In the moist air humidity variant of 40 °C, the germination percentage dropped to 0% after 42 days for Alnus glutinosa, Betula pendula, and Larix decidua. The natural regeneration window will be reduced by half from more than three months to about three weeks under climate change. The lifespan of Populus tremula and Salix caprea seeds will be shortened to 1 week. For Picea abies, the time window will shorten to a maximum of 28 days.

Influence of storage conditions on viability and vigour of Sunflower (Helianthus annuus L.) seeds

The storage experiment examined the effects of storage temperatures, seed moisture contents (SMC), and storage durations (SD) on the viability and vigour of sunflower seeds. Certified sunflower seeds were evaluated for seed germination, seedling vigour, and fungal infection. A 3x3x6 factorial experiment in Completely Randomized Design was set out in four replicates. The three factors were temperature (5, 20, 35 ºC), SMC (6,8,10%), and SD (15, 30, 45, 60, 75, 90Days After Storage, DAS). Before storage (0 DAS), the initial germination percentage (GP=94%), Germination index (GI=322), Seedling vigour index (SVI=2118), and fungal infection incidence (FII=52%) were determined and used as control. The lowest GP of 67%, GI (269.2), SVI (1295), and FII (78.0%), was found in seeds stored at a temperature of 35 ºC and SMC of 10% at 90DAS. Upon the interaction effect at the end of 90DAS, the temperature of 5 ºC with SMC of 6% followed by the temperature of 20 ºC with SMC of 6% recorded the greatest GP of 87.5 and 87.0%, GI of 304.3 and 296.8 SVI of 1910 and 1877 and fewer fungi incidence (%) of 61.5 and 63 respectively. The germination percentage was above the minimum certification standards of 85%, as per the Tanzania Official Seed Certification Institute. Conclusively, our results discovered that the optimum storage conditions-Temperature of 5 and 20 ºC with SMC of 6 and 8% could be suitable for maintaining the viability and vigour of sunflower seeds throughout the storage duration (90 DAS).

Ultrafine Bubbles Water priming to improve viability and vigor of bean (Phaseolus vulgaris) seeds

Priming is a physiological technique of hydration of seed to improve metabolic processes before germination to accelerate germination and seedling growth under normal and stress conditions. This research is aimed to study the pretreatment using ultra-fine bubble (UFB) water to increase viability and vigor of seeds before planting (pre-planting) and during storage (pre-storage). This research was conducted at the Laboratory of Seed Quality Testing, IPB University, Indonesia. The research consisted of two experiments, i.e., UFB water priming to increase viability and vigor of bean seeds and its storability after priming. The first experiment was arranged using a completely randomized design with a combination of seed lot treatments (L1: initial germination percentage (GP) about 80%, L2: initial GP around 70%, and L3: initial GP around 60%) with priming (P0: no priming/control, P1: soaked in distilled water for 60 minutes, P2: distilled water for 120 minutes, P3: 8 ppm UFB water for 60 minutes, P4: 8 ppm UFB water for 120 minutes, P5: 20 ppm UFB water for 60 minutes, P6: UFB water 20 ppm for 120 minutes). The second experiment was arranged using a nested design with the main factor being the condition of the storage room and priming as the second factor nested in the main factor. The storage room condition factors consisted of KM: room conditions (temperature 28±5˚C, RH 73±7%) and AC: air-conditioned room (18±2 ̊C, RH 61±7%). The priming factor consisted of two levels, namely P0: without priming and P1: priming with 20 ppm UFB water soaked for 120 minutes. The results showed that priming treatment with UFB water 20 ppm for 120 minutes as a pre-planting treatment can increase the viability of bean seeds, particularly for seeds with low initial viability, and primed bean seeds with an initial viability of approximately 80% were able to retain their viability for 16 weeks of storage in an air-conditioned room.

Multi-trait selection of tomato introgression lines under drought-induced conditions at germination and seedling stages

To be considered drought-tolerant, a tomato cultivar is required to present some level of tolerance at all developmental stages of plant growth. Since drought tolerance is a stage-specific phenomenon, genotype assessment must be performed separately at all developmental stages. In this study, we used a multi-trait index based on factor analysis and genotype-ideotype distance (FAI-BLUP index) to properly rank 49 tomato genotypes according to their tolerance to drought stress conditions at germination and seedling stages. Seeds of 47 introgression lines, which cultivar M82 is considered drought-sensitive, and the Solanum pennellii wild accession LA 716, which is considered drought-tolerant, were subjected to a control condition, where seeds were soaked in distilled water, and a drought condition, where seeds were soaked in a polyethylene glycol (PEG) solution (-0.3 MPa). Drought stress, induced by PEG, had a significant impact on all nine germination and growth performance-related traits; there was a reduction in shoot length (SL), total length (TL), initial germination percentage (IGP), final germination percentage (FGP), germination velocity index (GVI), and germination rate (GR). In contrast, the root-to-shoot ratio (R/S) and time to reach 50% germination (T50) increased under drought stress. Root length (RL) was less affected by drought, and in some genotypes, it was even increased. As expected, LA 716 ranked closest to the drought tolerance ideotype. IL 1-4-18, IL 2-3, IL 1-2, IL 9-2, and IL 10-1 were the most drought-tolerant at the germination stage. These results will serve as guidance for breeders who are aiming at developing drought-resistant tomato cultivars.

Physiological Quality of Corn Seeds Treated with Gaseous Ozone

ABSTRACT The objective of this study was to evaluate the effect of gaseous ozone on the physiological quality of corn seeds with different initial germination percentages. Seeds with initial germination percentages of 54.0% (low physiological quality) and 86.0% (high physiological quality) were used. Samples of 0.12 kg of seeds were exposed to different combinations of inlet ozone concentrations (10 and 30 mg L−1) and exposure times (0, 30, 60, 90, and 120 min). A flow rate of 1.0 L min−1 was used at a temperature of 25 °C. The percentage of germination, shoot, root, and seedling lengths, germination velocity index, and electrical conductivity were analyzed. Univariate and multivariate analysis were used for data analysis. Seeds with low initial germination percentage showed increase of 1.6 to 1.8 times in germination percentage and approximately 1.2 times in length of the seedlings when the inlet ozone concentration was 10 mg L−1 and the exposure times were 30 and 120 min. Regarding seeds of high physiological quality, there was an increase in the germination velocity index of 1.1 to 1.2 times in ozonated seeds at 10 mg L−1, compared to the non-ozonated seeds. According to the multivariate analysis, the inlet ozone concentration of 10 mg L−1 associated with exposure times of 30 and 120 min showed similar results for seeds with low initial germination percentage. Based on the obtained results, we concluded that regardless the initial corn seeds quality, the recommended treatment is made by the combination of inlet ozone concentration of 10 mg L−1 and exposure time of 30 min. Also, greater benefits are obtained from the application of ozone gas in corn seeds of low initial physiological quality. The ozonation proved to be a promising technique for seed treatment since it increased germination percentage and shoot and seedling lengths.

Determination of tobacco (Nicotiana tabacum) seed vigour using controlled deterioration followed by a conductivity test

Seeds of eight lots of four tobacco varieties differing in vigour were studied. The initial germination percentage (GPUT) was 81-100% and the controlled greenhouse emergence percentage (CEP) was 55-91%. All seeds were treated by controlled deterioration (CD) at 20% moisture content and 45°C for 24 hours, then some seeds were subjected to a standard germination test and the rest of the seeds were subjected to a conductivity test. The electrical conductivity (EC) of seed soak water was measured every six hours up to 54 hours. The results showed that relative conductivity after CD (RCCD) was highly significantly correlated with GPCD after 30 to 48 hours soaking (r = -0.9324 to -0.9409, P < 0.001). After 36 and 42 hours, RCCD was significantly correlated (P < 0.01) with CEP (correlation coefficients of -0.9120 and -0.9137, respectively). Therefore, it is suggested that measuring relative conductivity after CD could be used to rank tobacco seed lots for vigour. In addition, the best seed soaking time for EC measurement is 36 to 42 hours, with respect to both efficiency and accuracy.

Effect Of Seed Hydration-Dehydration Integrated With Rhizobacteria On Viability And Vigor Of Deteriorated Soybean Seed

Soybeans undergo rapid deterioration due to its chemical composition and unfavourable storage conditions. The objective of the research was to determine the length period of seed hidration and dehydration which is integrated with rhizobateri to viability and vigor of deteriorated soybean seed. A completely randomized design with four replicates were used in this experiment. Seeds were treated with varied combination of hydration period in a rhizobacteria suspension and followed by dehydration time. Data were analysed using the F-test and significant differences were further tested with Least Significant Difference at the 5% level. Results showed that the hydration and dehydration period of seeds in a rhizobacteria suspension improved viability and vigor of seed which have 59.5% initial germination percentage. The improvement was 12.28%, 0.56, 25.4% and 1.4 days for standard germination test, vigor index, first count test percentage and T50, respectively. The hydration for 60 minutes followed by dehydration for 60 minutes gave the best results on seed viability and vigor.

Optimization of Hydropriming of Okra (Abelmoschus esculentus) Seeds Using Response Surface Methodology

This research study was envisaged to evaluate the effect of parameters, viz. initial germination percentage (IGP), soaking duration (SD), temperature, rotation speed (rpm) and air flow rate (AFR) for hydropriming of Okra (Abelmoschus esculentus L.) seeds. Three different seed lots based on their moisture content and germination percentage were chosen in this study. Moisture content and germination percentage of the selected lots varied from 11.33 to 16.89% (d.b.) and 50 to 80%, respectively. Accelerated ageing was performed at 40 ± 1 °C, 100% relative humidity to obtain required lots from available seed sample. Response surface methodology was adopted using a five factor three-level Box–Behnken design with soaking duration (4, 5 and 6 h), temperature (20, 25, 30 °C), rotation speed, (320, 340, 360 rpm), air flow rate, (2.192, 2.740, 3.288 m3/min) as the main process parameters. The effect of process affecting parameters was observed on responses, viz. moisture content, germination percentage, seedling length, seedling dry weight, vigour index-I, vigour index-II, electrical conductivity and radiography. Models were found to be significant for all the process responses with the optimal solution as 73% (IGP), 6 h (SD), 23 °C temperature, 330 (rpm) and 2.50 m3/min (AFR).

Métodos de escarificación en semillas de Guaiacum coulteri , especie amenazada del bosque tropical caducifolio del norte de Sinaloa, México

This investigation documented the effect of methods of physical and chemical scarifi cation in seeds of Guaiacum coulteri, a species of tropical deciduous forest from Sinaloa protected by national and international laws, in order to contribute to the germinative knowledge of the species. For this, six pregerminative treatments were evaluated on the initial germination time (IGT), initial germination percentage (IGP), mean germination time (t50) and fi nal germination percentage (FGP) with a randomized completely design under laboratory conditions. Scarifi cation methods infl uenced signifi cantly (p<0.05) in the four variables. The seeds subjected to the treatments H2SO4 for 5 and 10 min started to germinate one day after sowing, whereas in the control occurred until the third day. The initial germination percentage increased to 73.3% with the treatment of sandpaper against the control that was just 10%. The scarifi cation with H2SO4 for 5 and 10 min advanced the mean germination time to 1.8 d, in relation with the control that was 5.2 d. The higher fi nal germination percentage was obtained with the sanding of the seeds (86.7%), unlike 51.1% achieved in hot water (60 °C) for 10 min. The knowledge derived from this essay demonstrated that the methods of scarifi cation with sandpaper and sulfuric acid were the best pregerminative treatments, due to they fragmented or weakened the seed coat and allowed obtaining high germination rates, what will have relevance for the production of seedlings.

Optimization of pea (Pisum sativum) seeds hydropriming by application of response surface methodology

Evaluation of selected parameters viz. initial germination percentage (IGP), soaking duration (SD), process temperature, rotation speed (rpm) and air flow rate (AFR) was performed in this research investigation for hydropriming of Pea (Pisum sativum) seeds. Three seed lots having difference in their moisture content (14.94–28.04 % d.b) and germination percentage (60–80 %) were selected in this study. Procured seed lots were subjected to variable duration of accelerated aging (40 ± 1 °C, 100 % RH) to attain necessary seed lots for experimental run. Response surface methodology (Box–Behnken design) with five factors and three-level combination was adopted, and the independent variables are germination percentage (80, 70, 60), soaking duration (45, 60, 75 min), temperature (20, 25, 30 °C), rotation speed (320, 340, 360 rpm) and air flow rate (0.411, 0.548, 0.685 m3/min). Second order polynomial equation was fitted for analyzing the experimental data and data was also subjected to analysis of variance as a part of regression analysis. Process responses which were selected to evaluate the effect of hydropriming were moisture content after hydropriming, final germination percentage, seedling length, seedling dry weight, vigor indices (VI–I and VI–II) and electrical conductivity. Regression analysis suggested that models were significant for all process responses and using numerical optimization technique, the optimal solution found was 75 % IGP, 55 min SD, 20 °C temperature, 320 rpm and 0.50 m3/min AFR. Values predicted by model were found to be at par with the results of a confirmation experiment carried out at optimum conditions.

Effects of cold stratification and dry storage at room temperature on seed germination of eight desert species from the Hexi Corridor of China

Aims We investigated seed germination of eight desert plant species of the Hexi Corridor of China following cold-wet stratification and dry storage at room temperature to better understand seed germination and dormancy characteristics and how these species are adapted to their habitat. Methods Seed viability and initial germination percentage of Glycyrrhiza uralensis, Sphaerophysa salsula, Peganum multisectum, Zygophyllum fabago, Nitraria tangutorum, Lycium ruthenicum, Salsola ruthenica and Asterothamnus centrali-asiaticus were determined. Then seeds of these species were divided into four groups (I, II, III and IV) and stored in a refrigerator ((4 ± 1) °C, moist), cold room in winter ((–5 ± 1) °C, moist), outdoor in winter ((–26 – 10) °C, moist) and room temperature ((20 ± 1) °C, dry) for 60 d. Germination was determined under a constant (20 °C) and an alternating temperature regime (25 °C / 10 °C) with 12 h photoperiod (light/dark) for 30 d. Two main germination indices including germination percentage and T50 (half germination time) were recorded. Data were analyzed by one-way ANOVA and the least significant difference test (LSD) at 5% level. Important findings There were three types of seed responses to cold-wet stratification: germination percentage increased, no change, or decreased. Germination percentage of seeds of P. multisectum and Z. fabago significantly increased following cold-wet stratification of 4 °C and –5 °C, and partially increased following –26 – 10 °C. Germination percentage of seeds of L. ruthenicum significantly increased following 4 °C, –5 °C, –26–10 °C and dry storage at room temperature, with germination of 90%–100%. Seeds of P. multisectum, Z. fabago and L. ruthenicum have slight physiological dormancy. Germination of seeds of N. tangutorum, G. uralensis and Sphaerophysa salsula slightly changed following three cold-wet stratification. Seeds of Salsola ruthenica with non-dormancy (germinated to 84% before storage) decreased their germination following cold-wet stratification of 4 °C, whereas no change occurred at –5 °C, –26 – 10 °C. In addition, the response of germination to incubation temperature varied with species.

Desidratação de sementes de quatro lotes de pupunheira: efeitos sobre a germinação e o vigor

Com o objetivo de verificar o efeito da desidratação sobre a germinação e o vigor de sementes de pupunheira inerme (Bactris gasipaes Kunth), quatro lotes de sementes, colhidos nas localidades de Yurimaguas, Peru; Camamu e Piraí do Norte, BA e Pindorama, SP, foram submetidos à secagem em câmara seca a partir das testemunhas não desidratadas, retirando-se amostras a cada 24 horas. O efeito da desidratação sobre a qualidade das sementes foi avaliado por meio de teste de germinação (184 dias da semeadura, em vermiculita, 20-30ºC), primeira contagem de germinação (36 dias), velocidade de germinação e teor de água das sementes. Comprovou-se que sementes dessa espécie são sensíveis à desidratação, com germinação inicial alta (59 a 84%) quando não desidratadas (47 a 38% de umidade inicial). Teores de água abaixo da faixa de 28 a 23% reduziram significativamente a germinação e o vigor. Todas as sementes com teores de umidade abaixo de 15% (lotes 2 e 4) e 13% (lotes 1 e 3) morreram.

Efeito do retardamento da secagem na qualidade fisiológica de sementes armazenadas de azevém anual

O objetivo deste trabalho foi avaliar os efeitos do retardamento da secagem e do armazenamento aberto na qualidade fisiológica de sementes de azevém anual (Lolium multiflorum Lam.), cultivar Comum-RS. Compararam-se períodos de retardamento da secagem (0, 2, 4, 6, 8, 12, 18, 24, 36 e 48 horas) e períodos de armazenamento (0, 4 e 8 meses). Enquanto submetidas aos períodos de retardamento da secagem, 24 kg de sementes ficaram acondicionadas em 18 caixas de poliestireno. A secagem foi realizada sobre piso de concreto, à sombra, por 12 horas, sendo completada em estufa a 35ºC com circulação forçada de ar. As sementes mantiveram o nível inicial de germinação durante os oito meses de armazenamento, mesmo com até 12 horas de retardamento da secagem; entretanto, com seis horas de retardamento, o vigor das sementes foi reduzido aos oito meses de armazenamento, mas se manteve praticamente inalterado aos quatro meses, com até 11 horas de retardamento. Sementes com germinação acima de 70% mantiveram este valor até oito meses de armazenamento, independentemente do período de retardamento da secagem.

Dormancy, ABA content and sensitivity of a barley mutant to ABA application during seed development and after ripening.

Assessment of dormancy inception, maintenance and release was studied for artificially dried immature seeds harvested throughout seed development in the barley cv. Triumph and its mutant line TL43. Each was grown in Spain and Scotland under low and high dormancy inducing conditions, respectively. Both TL43 and Triumph followed a similar pattern of release from dormancy across the seasons, although seeds of TL43 were able to germinate at an earlier seed development stage. Abscisic acid (ABA) content was also studied in immature grains throughout the seed development period. Total amount of ABA in seeds of Triumph and TL43 was higher in plants grown in Scotland than in Spain. However, no clear genotypic differences in ABA pattern in the course of grain development could be detected whilst significant genotypic differences were observed for germination percentage (GP). Endogenous ABA content alone throughout grain development did not explain genetic differences in GP within environments. Environmental and genetic differences in dormancy were also observed on mature seeds throughout the after-ripening period. The initial germination (GP(0)) played a key role in the sensitivity to ABA of post-harvest mature seeds. For the same after-ripening stage, TL43 was more insensitive to exogenous ABA than Triumph. However, ABA responses in seeds of the two genotypes with similar GP(0) at different after-ripening stages were comparable. Therefore, differences in exogenous ABA sensitivity of post-harvest mature grain of these two genotypes seemed to be determined by, or coincident with, the initial germination percentage.

Effect of seed storage on germplasm integrity of meadow fescue (Festuca pratensis Huds.)

Qualitative and quantitative changes in populations of meadow fescue (Festuca pratensis Huds.) after seed storage under different conditions were estimated. Phenotypic characters of plants grown from seeds stored for 54 months under two different storage conditions were compared. The germination of most of the seed accessions stored under favourable conditions remained at the initial level while storage under unfavourable conditions resulted in a decrease of the initial germination percentage as well as in an increase in the number of plants showing chlorophyll aberrations. There is great variability among the accessions resulting from storage under unfavourable conditions. In case of a few accessions a decrease in germination below 35% resulted in chlorophyll aberrations, faster flowering, shorter inflorescence and reduced viability of pollen grains.

Mechanical scarification ofstylosanthes guianensis cv. Oxley seed

Abstract In a series of experiments, in‐pod seed of Stylosanthes guianemis cv. Oxley from various sources, containing high proportions of hard seed, was mechanically scarified either by abrasion or impact treatments, involving different machine speeds and numbers of passes through the machinery. The effects on the resultant proportions of naked seed, in‐pod seed and waste, as well as germination capacity were estimated. Combine harvested seed had higher initial germination percentage than seed harvested with a smaller suction harvester, and needed less scarification to attain a given germination capacity. Modification of a commercial scarifying machine by replacing the carborundum lining with rubber, satisfactorily increased germination capacity, and little seed was damaged with the correct procedure. A hammer‐mill operation at reduced speed damaged the seed without effective scarification. The experiments provided a guide to the optimum number of passes for various machines.