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Wheat is an important crop for global food security and the key to its production is germination. The germination is a laborious and long process susceptible to be altered by biotic and abiotic factors therefore innovative technologies can be used to improve seeds' germination behavior. The objective of this study was to assess the germination of two varieties of durum wheat, Simeto and Chen's, subjected to two physical treatments: ultrasound (US) and pulsed electric field (PEF). The germination parameters studied were germination kinetic, precocity of germination (PG), final germination rate (FGR), germination speed (GS) and germ's length (LG). The seeds were exposed to ultrasound at frequencies of 20, 30 and 40 kHz for 20, 40 and 60 min, as well as to a pulsed electric field of intensity 350 V/cm, 700 V/cm, 2 kV/cm and 4 kV/cm with 10, 50 and 100 pulses (P). The results show that an optimal treatment with ultrasound is obtained at 40 kHz/20 min, giving an earliness of 80% and a final germination rate of 96.66% obtained at 30 kHz/20 min and 40 kHz/40 min for Simeo variety. For PEF, the final germination rate of 86.66% is obtained with treatment at 700 V/cm 50 pulses, while the best germination speed of 0.47 is obtained with 4 kV/cm 10 pulses for the Chen's variety. These results indicate that ultrasonic exposure of durum wheat affects germination precocity and speed, while PEF had a significant effect on germ's length. [ABSTRACT FROM AUTHOR]

Studies to improve the use of subsurface drippers in pasture formation are needed. Therefore, the objective of this study was to evaluate the germination and emergence of Sabia grass as a function of drippers installed at different depths. The study was conducted in pots in Viçosa, Minas Gerais State, Brazil. The experiment was conducted using a completely randomized design with four replicates. The experimental layout featured split plots over time, where the main plots consisted of three cultivation cycles and the subplots represented various dripper installation depths. The three sowing dates were 26 March, 12 April, and 29 April 2022. Drip tapes were installed at seven different depths: 0 (superficial), 5, 10, 15, 20, 25, and 30 cm. The results showed that the reduction in water potential, associated with increased temperature, resulted in lower performance of Sabia grass seeds. Seed germination and parameters related to germination speed were negatively impacted by the increase in dripper installation depth, with a 30–40% reduction in germination speed observed at depths greater than 15 cm. Drippers installed at 15–20 cm depth in clayey soil were ideal, providing a balance between reducing soil water evaporation and maintaining seedling emergence rates. Compared to surface installation, this depth improved seed performance by up to 25%, while enhancing operability and minimizing water loss. It is recommended to install drippers at a depth of 15–20 cm in subsurface drip irrigation systems in clayey soil areas to achieve benefits such as decreased soil water evaporation and improved operability compared to surface systems.

Studies to improve the use of subsurface drippers in pasture formation are needed. Therefore, the objective of this study was to evaluate the germination and emergence of Sabia grass as a function of drippers installed at different depths. The study was conducted in pots in Viçosa, Minas Gerais State, Brazil. The experiment was conducted using a completely randomized design with four replicates. The experimental layout featured split plots over time, where the main plots consisted of three cultivation cycles and the subplots represented various dripper installation depths. The three sowing dates were 26 March, 12 April, and 29 April 2022. Drip tapes were installed at seven different depths: 0 (superficial), 5, 10, 15, 20, 25, and 30 cm. The results showed that the reduction in water potential, associated with increased temperature, resulted in lower performance of Sabia grass seeds. Seed germination and parameters related to germination speed were negatively impacted by the increase in dripper installation depth, with a 30–40% reduction in germination speed observed at depths greater than 15 cm. Drippers installed at 15–20 cm depth in clayey soil were ideal, providing a balance between reducing soil water evaporation and maintaining seedling emergence rates. Compared to surface installation, this depth improved seed performance by up to 25%, while enhancing operability and minimizing water loss. It is recommended to install drippers at a depth of 15–20 cm in subsurface drip irrigation systems in clayey soil areas to achieve benefits such as decreased soil water evaporation and improved operability compared to surface systems. [ABSTRACT FROM AUTHOR]

Several ecological filters in deforested and degraded areas reduce seedling emergence and establishment and hinder ecological restoration by direct seeding. Understanding whether functional traits are related to a species' capacity to overcome these filters and predict their field performance might improve the success of direct seeding techniques for ecological restoration. We assessed eight seed functional traits of tropical tree species, seeking those that best explained their establishment success in direct seeding restoration projects. We analyzed a dataset from 52 studies that tested direct seeding techniques with tree species in Brazil. From each study, we collected the mean establishment percentage for all tree species. Seed mass, cotyledon function, and germination speed were the only functional traits that significantly affected the species establishment percentage in direct seeding restoration projects. Species with larger seeds, storage cotyledons, and faster germination had higher establishment percentages. Choosing species with these functional traits for seed mixes will provide higher establishment percentages and, consequently, improve restoration success by direct seeding techniques. [ABSTRACT FROM AUTHOR]

'New Red Fire' is one of most cultivated cultivars of leafy lettuce in Europe. Considering lettuce is a salt-sensitive crop, assessment of its responses to salt stress and applying efficient techniques to alleviate stress effects are highly important. Here, the influence of seed priming with different seaweed (Ascophyllum nodosum (Sc) and Sargassum angustifolium (Sa)) and microalgal (Chlorella vulgaris (Cv) and Arthrospira platensis (Sp)) extracts on germination indices of leafy lettuce under salt stress conditions (irrigation with saline water with EC levels of 1.37, 2.5, 4, 5.5 and 7 dS m-1) was investigated (with a modeling approach). Under control level of salinity, highest germination percentage was recorded in seeds primed with microalgae extracts. Based on Logistic model, the highest (a) parameter (predicted germination percentage) was for seeds primed with Cv (75.09). Also, the highest (x50) parameter (salt tolerance threshold) was recorded in Cv-primed seeds (15.76 dS m-1). According to liner regression model, (b) parameter (reduction rate of germination speed per unit increase in salinity level) of Cv-primed seeds was lower than that of Sp-, Sc- and Sa-primed seeds. In conclusion, it is recommended to apply C. vulgaris extract as seed priming solution to alleviate negative effects of salt stress on germination indices and seedling growth parameters of leafy lettuce. It is also recommended to quantify the germination responses of leafy lettuce to the other biotic and abiotic stresses for future studies. [ABSTRACT FROM AUTHOR]

Functional traits can have intraspecific and interspecific variations essential in the structure and dynamics of natural communities. These traits may have implications in the germination and seedling establishment phases in seeds. The objective of this study was to evaluate the effect of variations in mass, volume, and nutrient content (C, N, and P) on the germination of eight species representative of the tropical dry forest (TDF). Our results showed that seed size, both in terms of mass and volume, did not predict germination rates or percentages, nor were they related to nutrient content. In contrast, N content was the most important trait in the germination phase. Larger seeds did not germinate more or faster, but they could offer better resistance against desiccation, since they had higher C/N ratios in their tissues, a characteristic of orthodox seeds. The species A. guachapele, B. arborea, H. crepitans, and V. tortuosa presented a high biological potential in terms of their regeneration capacity, particularly, because the characteristics of their seeds, as well as the nutrient content, revealed consistent implications in their reproductive success, promoting high germination percentages in less time. In general, the results obtained in this study provide basic knowledge for future research, offering starting points for further exploration of species-specific adaptations and how they may be affected by the environment. [ABSTRACT FROM AUTHOR]

Antirrhinum majus L. has many applications in genetic studies and the medicinal and ornamental plant industries. However, its seeds have a low germination percentage and speed, and the growth of its seedlings is weak, which has caused many problems for researchers and flower growers. Plant germination, development, and flowering are affected by light quality. Recently, light-emitting diodes (LEDs) have been used for multiple purposes in plant production. Accordingly, the influence of light quality on the germination and growth of snapdragons was assessed in this study. Hence, different light treatments included natural daylight (C), white LED (W), blue LED (B), red LED (R), and a mix of 50% blue and 50% red (BR). Germination indices were investigated for up to 21 days. Morphological and biochemical indices were analyzed in seven-day and 30-day-old seedlings, respectively. According to the results, the positive effects of BR treatment were evident in all germination indices, particularly in the germination speed. Morphological indices such as fresh weight, dry weight, shoot height, and root length were the highest in R and BR. Also, growth indices such as the contents of photosynthesis pigments, total soluble carbohydrates, total soluble protein, and total phenolic increased remarkably under the BR treatment. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of different treatments on seed germination of the Mucuna flagillepes Hook. F (ukpo) species was carried out at the Teaching and Research Farm of the Faculty of Agriculture and Veterinary Medicine, Imo State University, Owerri. This experiment consisted of seven(7) treatment levels and was replicated three times, the treatment were O, 12, 24, 36, 48, 60, and 72hours, then untreated seeds serve as a control in a completely randomized design. During the germination stage, germination percentage, imbibitions period (IP), germination index(GI), germination speed (GS), and seed vigor index (SVI) were recorded. The result obtained from Plant extract, Piper guineense (uziza), and Xlopia aethiopica (Uda), results showed that uziza extract at 12 and 48hours priming gave the highest germination percentage (99.33%) while 72hours gave the fastest imbibitions period of 7days which was significantly different (P<0.05) from the controls. Also, Uziza extract compared with Uda extract in 72 hours priming duration significantly improved the Germination index (0.4066), germination speed (0.2300), and seed vigor index (5.277). The use of plant extracts at an increased soaking period of 60 hours and 72 hours respectively will enhance germination parameters and seedling growth treatment of the seed of Mucuna flagellipes. [ABSTRACT FROM AUTHOR]

Objective: Seed priming is the simplest and the best method to increase seed germination speed. Methods: To address this, in a study aimed at the effect of priming of different barley (Hordeum vulgare L.) cultivars on various germination characteristics, in the form of a factorial experiment was conducted using a completely randomized design with four replications in the research greenhouse of the Agricultural and Natural Resources Research Center of Hamadan province in 2022. Treatments including priming of seeds with fertilizers 1. Biozar, 2. Seafull amino zinc, 3. Sabzine, 4. Royesh, 5. Ecobooster, and 6. control (no fertilizer application), and different barley cultivars including Jolgeh, Bahman, Azaran, Abidar, Ghaflan, and Sahand. Results: The results indicated a significant effect of seed priming on the evaluated characteristics compared to the control treatment. The highest enzyme activities of catalase (0.117 Unit/ml) and peroxidase (85.08 Unit/ml) were obtained in seedlings obtained from seeds priming with Seafull amino zinc, which were 72 and 33% more than control treatments, respectively. The highest seedling vigor index was related to the seeds priming with seafull amino zinc fertilizer (26.55), which was significantly higher than the control treatment (22.84) and other treatments. Also, the germination percentage of seeds priming with seafull amino zinc fertilizer was significantly higher (3.5%) than the control. Conclusion: Considering that seed priming is a cost-effective and easy method and at the same time it is simple and does not require complex technical knowledge, it can be easily implemented by farmers. Therefore, this method is recommended to improve germination, seedling growth, and the quality and strength of barley seeds. [ABSTRACT FROM AUTHOR]

Abstract We investigated the associations of seasonality, dispersal modes and seed germination speeds with the fruiting of Clusia nemorosa, Pleroma fissinervium, and Vochysia pyramidalis in a gallery forest, Chapada Diamantina, Brazil. Observations of mature fruits with dispersing seeds were carried out from 2003 to 2006. Cross-correlation and circular statistics were performed to test the relationships among fruiting and abiotic factors, and phenological seasonality. Dispersion syndromes were defined and germination experiments were performed after seed collection (n =100/species), using four replicates. The species evidenced seasonal fruiting. Clusia nemorosa produced zoochoric seeds and V. pyramidalis anemochoric seeds, which were dispersed during the rainy season and positively correlated with precipitation; P. fissinervium produced autochoric seeds, released during the dry season to early rainy season, being positively correlated with insolation and negatively with humidity. The rotating wing seeds of V. pyramidalis were released in the rainy season and aided floating in watercourses, characterizing hydrochory. Clusia nemorosa and V. pyramidalis germinated (2-6 days) more rapidly than P. fissinervium (9 days). Seasonality, dispersal modes, and optimal germination conditions modulated the fruiting of the species examined, whose reproductive strategies responded to environmental drivers such as precipitation, favoring germination during the rainy season.

We investigated the associations of seasonality, dispersal modes and seed germination speeds with the fruiting of Clusia nemorosa, Pleroma fissinervium, and Vochysia pyramidalis in a gallery forest, Chapada Diamantina, Brazil. Observations of mature fruits with dispersing seeds were carried out from 2003 to 2006. Cross-correlation and circular statistics were performed to test the relationships among fruiting and abiotic factors, and phenological seasonality. Dispersion syndromes were defined and germination experiments were performed after seed collection (n =100/species), using four replicates. The species evidenced seasonal fruiting. Clusia nemorosa produced zoochoric seeds and V. pyramidalis anemochoric seeds, which were dispersed during the rainy season and positively correlated with precipitation; P. fissinervium produced autochoric seeds, released during the dry season to early rainy season, being positively correlated with insolation and negatively with humidity. The rotating wing seeds of V. pyramidalis were released in the rainy season and aided floating in watercourses, characterizing hydrochory. Clusia nemorosa and V. pyramidalis germinated (2-6 days) more rapidly than P. fissinervium (9 days). Seasonality, dispersal modes, and optimal germination conditions modulated the fruiting of the species examined, whose reproductive strategies responded to environmental drivers such as precipitation, favoring germination during the rainy season. [ABSTRACT FROM AUTHOR]

The present study was conducted in 2017 to evaluate provenance variation in seed morphological and germination characteristics and seedling growth performance of Acacia senegal variety senegal. Seeds were collected from high-yielding gum trees selected randomly from 12 sources in Kordofan. Seed morphological and germination characteristics and seedling growth performance were determined. To compare the performance of differences in a certain characteristic among provenances, analysis of variance was used. However, a hierarchical cluster analysis was performed to identify homogenous provenances based on similar characteristics. Results of the statistical analysis revealed significant differences in seed morphological and germination characteristics but no difference in seedling growth parameters among the 12 provenances. However, hierarchical cluster analysis resulted in different groups among provenances regardless of the rainfall isohyets. With respect to germination characteristics, provenances differed significantly in terms of total germination, the number of days required to have 50% of total seeds germinated, and germination speed. Six provenances scored full germination capacity. No significant differences were detected among provenances for the number of days required to have the first seed germinated. Seeds from all provenances required only 3-5.6 days for the first germination event to occur, indicating faster initiation of seed germination. Fifty percent of seeds from Umkraidim took around 15 days to germinate while only 4 days were required to germinate the same amount of seeds from Umsadain and Umruwaba provenances. The findings of this study might be useful for determining the suitable seed sources for afforestation and reforestation programs if the purpose of plantation establishment is gum production. [ABSTRACT FROM AUTHOR]

The effects of hydrogel granules mixed with peat substrate on germination, morphological and physiological parameters of plugged seedlings were tested in tomato seedlings, at two different irrigation regimes. Due to hydrogel presence, the germination speed was increased, whereas mean germination time was significantly reduced. Slight improvement was recorded regarding final germination, but no effect was found regarding the synchronisation index and seedling vigour index. Due to addition of hydrogel granules a significant increase occurred in dry matter of shoots and plants. No effect was found regarding dry matter of roots, but the presence of hydrogel granules significantly reduced the length of tap root. Interestingly, stomata conductance and chlorophyll index were higher than in control plants. No statistically significant interaction was found between hydrogel variants and irrigation frequency, i.e., the effect of different levels of hydrogel variants did not depend on irrigation frequency. Therefore, we recommend mixing hydrogel capsules into the substrate of plug seedlings to improve the morphological and physiological parameters of seedlings and reduce water and fertiliser leaching into the environment. [ABSTRACT FROM AUTHOR]

Seed germination is an important agronomic trait that affects crop yield and quality. Rapid and uniform seed germination traits are required in agricultural production. Although several genes are involved in seed germination and have been identified in Arabidopsis and rice, the genetic basis governing seed germination in maize remains unknown. Herein, we conducted a genome-wide association study to determine the genetic architecture of two germination traits, germination speed, and consistency, in a diverse panel. We genotyped 321 maize inbred populations with tropical, subtropical, or temperate origins using 1219401 single-nucleotide polymorphism markers. We identified 58 variants that were associated with the two traits, and 12 of these were shared between the two traits, indicating partial genetic similarity. Moreover, 36 candidate genes were involved in seed germination with functions including energy metabolism, signal transduction, and transcriptional regulation. We found that favorable variants had a greater effect on the tropical subpopulation than on the temperate. Accumulation of favorable variants shortened germination time and improved uniformity in maize inbred lines. These findings contribute significantly to understanding the genetic basis of maize seed germination and will contribute to the molecular breeding of maize seed germination. [ABSTRACT FROM AUTHOR]

Quantification of germination characteristics between herbicide-resistant and -susceptible weeds might provide methods to control resistant weeds and permit better prediction of evolution and persistence of herbicide resistance. This study aimed to compare the germination characteristics of Asian minor bluegrass (Polypogon fugax) populations that are resistant or susceptible to quizalofop-p-ethyl under controlled conditions, which the resistance mechanism is involved in glutathione S-transferases (GSTs) metabolism-based resistance. No major differences in seed germination were found at diverse temperatures, pH ranges, and light conditions. However, a significant difference that seed response to a gradient of osmotic and salt stress between the resistant and susceptible P. fugax populations were found. Two stress response genes (P5CS-1 and CDPK-2) in P. fugax were likely involved in germination rate as well as germination speed in response to these stresses. Subsequently, population verification demonstrated that P5CS-1 and CDPK-2 genes may be linked to the resistance mechanism. Additionally, the two genes play an important role in response to salt stress and osmotic stress as shown by transcript abundance after stress treatments. Our findings suggest that the variation of the germination characteristics in P. fugax associates with the presence of GST-endowed resistance mechanism. [ABSTRACT FROM AUTHOR]

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Seed germination is an important agronomic trait that affects crop yield and quality. Rapid and uniform seed germination traits are required in agricultural production. Although several genes are involved in seed germination and have been identified in Arabidopsis and rice, the genetic basis governing seed germination in maize remains unknown. Herein, we conducted a genome-wide association study to determine the genetic architecture of two germination traits, germination speed, and consistency, in a diverse panel. We genotyped 321 maize inbred populations with tropical, subtropical, or temperate origins using 1219401 single-nucleotide polymorphism markers. We identified 58 variants that were associated with the two traits, and 12 of these were shared between the two traits, indicating partial genetic similarity. Moreover, 36 candidate genes were involved in seed germination with functions including energy metabolism, signal transduction, and transcriptional regulation. We found that favorable variants had a greater effect on the tropical subpopulation than on the temperate. Accumulation of favorable variants shortened germination time and improved uniformity in maize inbred lines. These findings contribute significantly to understanding the genetic basis of maize seed germination and will contribute to the molecular breeding of maize seed germination.

Quantification of germination characteristics between herbicide-resistant and -susceptible weeds might provide methods to control resistant weeds and permit better prediction of evolution and persistence of herbicide resistance. This study aimed to compare the germination characteristics of Asian minor bluegrass (Polypogon fugax) populations that are resistant or susceptible to quizalofop-p-ethyl under controlled conditions, which the resistance mechanism is involved in glutathione S-transferases (GSTs) metabolism-based resistance. No major differences in seed germination were found at diverse temperatures, pH ranges, and light conditions. However, a significant difference that seed response to a gradient of osmotic and salt stress between the resistant and susceptible P. fugax populations were found. Two stress response genes (P5CS-1 and CDPK-2) in P. fugax were likely involved in germination rate as well as germination speed in response to these stresses. Subsequently, population verification demonstrated that P5CS-1 and CDPK-2 genes may be linked to the resistance mechanism. Additionally, the two genes play an important role in response to salt stress and osmotic stress as shown by transcript abundance after stress treatments. Our findings suggest that the variation of the germination characteristics in P. fugax associates with the presence of GST-endowed resistance mechanism.

The 60 Hz electromagnetic field effects during the germination process in seeds of Vigna unguiculata L. with more than one year of storage was determined. Three electromagnetic treatments (2.00; 4.00 and 6.00 mT) were performed. A local electromagnetic stimulator device (BioNaK-03) (Patent No.22602/1999) was used. Each induction was applied to 100 seeds without imbibition (SSI) per treatment and the same to imbibition seeds (ICS) during 9 minutes. Two control groups (SSI and SCI) were established. Percentage of germination, germination speed and length of shoot and radicle were evaluated. At the end, 13.3 % of germination in imbibed and treated seeds with 2.00 mT was increased. A reduction in 54 % of this parameter to 4.00 mT in seeds without imbibition was obtained. Likewise, the highest value in shoot length in the seedlings of green bean for the plants that received the electromagnetic treatment was observed. At the same time, a reduction in the length of the radicle for the treatment of 6.00 mT was obtained. The results, although not entirely conclusive, show that the application of a magnetic treatment of 2.00 mT for 9 minutes improved the germination and growth of V. unguiculata seeds.

The Capsicum genus has significant economic importance since it is cultivated and consumed worldwide for its flavor and pungent properties. In 2021, Mexico produced 3.3 billion tons on 45,000 hectares which yielded USD 2 billion in exports to the USA, Canada, Japan, etc. Soil type has a dramatic effect on phosphorus (P) availability for plants due to its ion retention. In a previous study, novel fungal isolates were shown to solubilize and mineralize P in different kinds of soils with different P retention capacities. The aim of this work was to study the effects of the mineralogy of different kinds of “milpa” soils on the germination, biomass production, and P absorption of chili plants (Capsicum annuum). The germination percentage, the germination speed index, and the mean germination time were significantly increased in the plants treated with dual inoculation. Foliar phosphorus, growth variables, and plant biomass of chili plants grown in a greenhouse were enhanced in different soil types and with different inocula. Correlation studies suggested that the most significant performance in the foliar P concentration and in the growth response of plants was achieved in Vertisol with dual inoculation of 7 × 106 mL−1 spores per chili plant, suggesting this would be an appropriate approach to enhance chili cultivation depending on the soil type. This study stresses the importance of careful analysis of the effect of the soil type in the plant–microbe interactions.

Aluminium (Al) is solubilized into a phytotoxic form [Al(H2O)6 3+] in acid soil, which is known as Al3+. Al toxicity is the primary growth-limiting factor for plants in acid soils. Breeding of rice for enhanced Al tolerance considered to be an important approach for increasing grain yield in acid soils. In the present endeavour, we studied the effects of toxic levels of Al on vigour of rice seedlings under hydroponics and finally grouped the genotypes with varied degree of tolerance to Al toxicity based on vigour index. Good seed germination (%), high speed of germination and high vigour index indicate uniform crop stand. Germination ranged from 72-99.50%. It was significantly high for almost all genotypes (-80%) except three. The speed of germination ranged from 9.75 to 29.99 in control. Most of the genotypes showed high speed of germination (-15.00) except a few. Remarkable reduction in seedling vigour has been reported earlier under stressed environments. Low seedling vigour has been identified as the key factor responsible for poor germination and uneven seedling establishment. Based on the vigour index, nine genotypes were classified as tolerant, 19 as moderately tolerant and 12 as susceptible. Among the tolerant genotypes, UBKVR-3 showed maximum value for vigour index followed by UBKVR 19, UBKVR 9, UBKVR 8, Parijat, MTU 1075 and Radhunipagal. Most susceptible genotypes based on seedling vigour were found to be Pusa Basmati, Aiswarya and Pratikha. It is to be mentioned that till now there is no clear and distinct divisions of vigour index for classification into different levels of tolerance towards Al toxicity. In our study, we have identified distinct classes for grouping of genotypes endowed with different levels of tolerance. The values of the vigour index depend upon root length, shoot length or some other characters used for calculation of vigour index. The magnitude of the vigour index may not be useful for classification uniformly across the crops as well as genotypes within the crop. Hence, the procedure used in this work may overcome the above mentioned constraints. [ABSTRACT FROM AUTHOR]

Exhaustion of stratospheric ozone found at a height of 10–30 km around the world causes the solar UV-B (280–320 nm) radiation to penetrate through the atmosphere more, and thus to reach the Earth’s surface quicker. The protective ozone layer gets damaged by human activities constantly, and the increasing levels of UV radiation present threats to all life forms, plants, animals, and even microorganisms. However, the studies conducted on the effects of UV radiation on plants, and especially forest trees, are rather limited. In this study, it was aimed to identify the effects of UV-B radiation on some germination and seedling characteristics of Anatolian black pine seeds. Within the scope of the study, seeds were exposed to UV-B radiation for 5, 10, 20, 30, 40, 50, and 60 min for germination experiments; and the germination speed (GS) was calculated as the ratio of the germinated seeds to the solid seeds at the end of the 7th day, whereas the germination percentage (GP) was calculated as the ratio of the germinated seeds to the solid seeds at the end of the 35th day. The seeds reserved for the seedling experiment were exposed to UV-B radiation for 1, 3, 5, and 7 h. With the measurements made at the end of the day, the seedling length (SL), the terminal bud length (TBL), the branch number (BN), the root collar diameter (RCD), the stem fresh weight (SFW), the root fresh weight (RFW), the stem dry weight (SDW) and the root dry weight (RDW), and the rooting percentage (RP) were determined. Variance analysis and Duncan test were applied to the obtained data with the help of SPSS package program. The study results revealed that the exposure time to increased UV-B radiation significantly affected all characters; the least affected character was RP, and that the most affected characters were RDW, SDW, and RCD. As a result of the study, it was found that even the applications with the lowest intensity took effect in most of the characters, that the seedling development decreased by more than 80% in terms of some characters at the end of 7-h application, and that even the decrease in the RP character, which was the least affected by the 7-h UV-B application, was above 50%. [ABSTRACT FROM AUTHOR]

Anthyllis barba-jovis is a salt and drought tolerant evergreen shrub, native of the western-central Mediterranean coasts, with ornamental characteristics that make it worthy to be exploited for commercial use as an ornamental and landscape plant. Therefore, the present study aimed to determine germination as affected by seed-coat, temperature, photoperiod, and seed storage period, as a first approach to introduce the species into the floriculture industry. Seeds scarified or non-scarified, recently harvested or after storage at room temperature in the dark for 12, 24, or 36 months were placed for germination in vitro on Murashige and Skoog (MS) medium, under 16 h photoperiod (LD) or continuous darkness, at 5–35 °C, at 5 °C intervals. Seed pre-treatment by mechanical scarification with sandpaper highly promoted their germinability. Seeds germinated in all treatments at varying percentages. Photoperiod had no significant effect on germination. Cardinal temperatures for germination were defined at 35 °C and 5 °C (possibly even lower, particularly for up to 1-year-old seeds, which germinated at 30–58% at 5 °C when scarified). Temperatures from 15 to 25 °C were optimal for germination of recently harvested or 1-year-old seeds (82–98% when scarified), whereas older seeds germinated at higher percentages at 20 °C (65–97% when scarified), thus long storage affected both the range of optimal temperatures for germination and the germination percentage. Storage reduced germination mostly of non-scarified seeds. Three years after harvesting A. barba-jovis seeds germinated at high percentages (77%) at 20 °C and LD when scarified, while without scarification germination was less than 10% in all treatments.

Algal extracts provide a safe regime for enhancing crop productivity under stressful conditions. The present study evaluated the efficiency of aqueous and ethanolic extracts of the brown alga Dictyota dichotoma in alleviation of salt stress on germination of rice seeds. Firstly, seeds were germinated using the aqueous extract of D. dichotoma at concentrations of 0, 5, 10, 20, and 50 g L−1, prepared either at room temperature (RTE) or by boiling (BLE). The % germination of rice increased from 84% in non-treated seeds to 100% when treated with 20 g L−1 BLE, although this treatment caused reduced uniformity of germination. Embryo growth was maximum at 20 g L−1 of both extracts with superiority of BLE over RTE. In the second experiment, the effect of 20 g L−1 aqueous and ethanolic extracts relative to a balanced nutrient supply on germination of seeds treated with 0, 40, 90, and 170 mM NaCl was investigated. Salinity reduced % germination with delayed onset but high uniformity of germination, whereas algal amendments counterbalanced the effect of salinity to a greater extent relative to the nutrient supply. Upon withdrawal of salt stress, seeds promptly recovered, with more efficient recovery of seeds exposed to 170 mM than from 90 mM NaCl. The lower recovery of salt-treated seeds compared with the control seed germination suggests that rice suffered from the toxic ion effect of salinity on embryo rather than from the osmotic effect. Extracts of D. dichotoma can enhance and also alleviate salinity stress on rice seed germination. [ABSTRACT FROM AUTHOR]

A comprehensive study on breaking dormancy of mountain ash(Sorbus luristanica Bornm.) endemic species is still lacking. Here, the high efficient potentials of multiwall carbon nanotubes were used to break seed dormancy and improve seed germination in mountain ash. First, the seeds were primed with different concentrations of the nano-material including 0, 75, 150, 250, 350 and 500 mg l-1 during 24 hours. Then warm (two weeks) and cold (three or four months) stratifications were performed. The results showed that the seeds require cold stratification for at least 3 months. After the cold stratification period, the seeds were transferred to petri dishes in germinator. Daily seed germinations were recorded during 22 days. Eventually seed germination parameters such as seed germination percent, germination speed as well as mean germination time were calculated and compared. To understand the effects of nano-materials on the seedlings from different treatments, the subsequent growth of seeds was studied. The results revealed that all germination parameters were improved by 350 mg l-1 treatment. The microscopic seed observations showed that the nano-priming treatments led to seed endocarp abrasion and increased oxygen and moisture infiltration into seeds. Increasing root height growth was associated with the most considerable effects of treatments. Conclusively, it seems that increase in seedling moisture is one of the functional mechanisms of the MWCNT.

The 60 Hz electromagnetic field effects during the germination process in seeds of Vigna unguiculata L. with more than one year of storage was determined. Three electromagnetic treatments (2.00; 4.00 and 6.00 mT) were performed. A local electromagnetic stimulator device (BioNaK-03) (Patent No.22602/1999) was used. Each induction was applied to 100 seeds without imbibition (SSI) per treatment and the same to imbibition seeds (ICS) during 9 minutes. Two control groups (SSI and SCI) were established. Percentage of germination, germination speed and length of shoot and radicle were evaluated. At the end, 13.3% of germination in imbibed and treated seeds with 2.00 mT was increased. A reduction in 54% of this parameter to 4.00 mT in seeds without imbibition was obtained. Likewise, the highest value in shoot length in the seedlings of green bean for the plants that received the electromagnetic treatment was observed. At the same time, a reduction in the length of the radicle for the treatment of 6.00 mT was obtained. The results, although not entirely conclusive, show that the application of a magnetic treatment of 2.00 mT for 9 minutes improved the germination and growth of V. unguiculata seeds. [ABSTRACT FROM AUTHOR]

A one factor laboratory experiment was conducted in the Department of Biology, College of Education for Women, Anbar University to study the effect of salinity levels of irrigation water on the rate, speed of germination and the growth development of piumule and root for six types of vegetable crops. The crops used in the study, namely celery, Spinach, Parsley, Garden Cress, Cauliflower, Swiss chard. A completely randomized design (CRD) with three replications was used, the one factor used in this study was irrigation water with different levels of salinity which are 0, 0.6, 1.75, 2.9, 3.9 and 4.9 ds.m-1, the aforementioned levels took the symbols of 1, 2,3,4,5 and 6 respectively. A Petri dishes and sterile filter papers were used for cultivation. The obtained results indicated that there were significant differences in terms of speed of germination, where there were significant differences for celery and cauliflower seeds at level (4-5-6), while the speed of germination of Parsley and Swiss chard was significant at the level (6). Whilst the significant were at level (3) for Garden Cress, while there were no significant differences for Spinach seeds. Regarding the percentage of germination, also the significant differences were observed for the seeds of celery, where it was significant at all salinity levels, while in spinach and cauliflower seeds the percentage of germination was significant at the levels (5-6), meanwhile, the significant was at the levels (4-5-6) for Parsley seeds, while the seeds of Garden Cress was significant at the level (3). They were not significant for Swiss chard seeds. So as to the length of piumule, there were significant differences at the levels (4-5-6) for each of celery and Garden Cress seeds, whereas the significant difference was observed at the levels (2-5-6) for spinach and cauliflower seeds and at level (5-6) for Swiss Chard seeds and in all levels of Parsley seeds. Also, there were significant differences in the root length of the seeds at level (4-5-6) for celery seeds, Garden Cress and Swiss Chard and at level (5-6) for spinach and cauliflower seeds and all the levels were significant for Parsley seeds. [ABSTRACT FROM AUTHOR]

Proper Seed germination and establishment is one of the most important issues in pre-planting treatments. Seed osmopriming is proposed as a pre-emergence treatment to increase the characteristics germination and seedling establishment, especially in unfavorable conditions. The effects of osmopriming on germination (germination percentage, maximum daily average germination, germination rate, mean germination time, germination value) of Scots pine, black pine and Turkish pine under controlled conditions in order to determine the best treatment were investigated in this research. A factorial experiment was conducted as a completely randomized design with three replicates. Main factors included the time (0, 1, 2 and 3 days) and osmotic potential (0.8, 1.2 and 1.5 MPa) using polyethylene glycol 6000. The results indicated that there were significant differences between treatments on germination characteristics in all three species, and all studied traits were improved by osmopriming. The highest germination factors were recorded for Scots pine and black pine treated with 1day in concentrations of 0.8 MPa (polyethylene glycol 6000) and for Turkish pine were obtained with 2 days in the concentration of 1.2 MPa in compared with control treatment. So it can be suggested that in order to increase the quantity and quality of production in seedlings nursery of these species, the pre-planting treatments should be considered further.

Functional traits can have intraspecific and interspecific variations essential in the structure and dynamics of natural communities. These traits may have implications in the germination and seedling establishment phases in seeds. The objective of this study was to evaluate the effect of variations in mass, volume, and nutrient content (C, N, and P) on the germination of eight species representative of the tropical dry forest (TDF). Our results showed that seed size, both in terms of mass and volume, did not predict germination rates or percentages, nor were they related to nutrient content. In contrast, N content was the most important trait in the germination phase. Larger seeds did not germinate more or faster, but they could offer better resistance against desiccation, since they had higher C/N ratios in their tissues, a characteristic of orthodox seeds. The species A. guachapele, B. arborea, H. crepitans, and V. tortuosa presented a high biological potential in terms of their regeneration capacity, particularly, because the characteristics of their seeds, as well as the nutrient content, revealed consistent implications in their reproductive success, promoting high germination percentages in less time. In general, the results obtained in this study provide basic knowledge for future research, offering starting points for further exploration of species-specific adaptations and how they may be affected by the environment., (© 2024. The Author(s).)

A laboratory experiment was carried out in the Seed Technology Laboratory, Department of Field Crop Sciences, College of Agricultural Engineering Sciences, University of Baghdad during the period 2010-2019. That was to evaluate bread wheat seeds stored in spikes in their field emergence and seedling vigour. Seeds, of stored spikes were compared with naked seeds, treated with cruise and untreated. All three treatments of seeds were grown in the laboratory and traits of days to last day of emergence, days to emerge, % of emergence, and other trails were recorded. Seeds of stored with thein spikes gave better values in days to last day of emergence, days of emergence, percent of emergence, length of plumule, seedling vigour and speed of emergence. The percent of emergence was decreased with increased years of storage, but those stored in their spikes were less affected. It was concluded that storing bread wheat with spikes had better results in field emergence as compared to seeds threshed and stored. [ABSTRACT FROM AUTHOR]

The flowers of plants of the genus Ludwigia are an important source of food for several species of bees. In the current study, we conducted an experiment with the aim to describe the reproductive biology and phenology of L. nervosa; to identify the species of visiting bees; analyze the foraging behavior of bees; and to investigate whether the reproductive success of the species is related to the foraging activity of bees. We found that the flowers received visits from several native bee species (n = 7), in addition of the exotic honey bees which came to be the dominant species. During visits the majority of the bees foraged in both resources, pollen and nectar. The significantly higher production of fruits in open pollinated pollination experiment compared to artificial cross pollination, suggests honey bees as effective pollinator of this plant species in the study site. Pollen deposition occurs efficiently, given the absence of pollen limitation. Despite massive visitation of honey bees, Ludwigianervosa is attractive to native bees, and therefore it may help to sustain population of both native and exotic pollinators in fragmented humid areas.

The genus Sideritis L. belonging to Lamiaceae family is represented with more than 150 species worldwide.. The genus is represented in Turkey by 46 species and 53 taxon within two sections among which 39 are endemic. Endemism rate (79.5%) in Turkey is quite high because Turkey is one of the two major gene centers of the genus. Sideritis species are known among people with different local names such as mountain tea, highland tea, sage, sarıkız tea and tail tea. According to some recent researches, extracts obtained from Sideritis species were shown to have antistress, antiulcer, analgesic, antioxidant, antibacterial, anti-inflammatory and insecticidal effects. The interest in and the demand for this plant species has increased particularly due to its antioxidant effect. Seed germination studies of this species have great importance on determination of production strategies of medical and aromatic plants. This study was conducted to determine the effects of some pre-treatments (ethylene, gibberellin, mannitol, seaweed and cold pre-treatment) on germination of Sideritis perfoliata L. which is naturally grown in western Anatolia. The study was carried out at 25/15oC day/night temperature conditions. The experiments were performed according to completely randomized design with 3 replications at Adnan Menderes University, Faculty of Agriculture, Field Crops Laboratory. Significant differences were determined between applications with respect to germination rates and germination vigor values.

A laboratory factorial (2 × 5) experiment was carried out based on completely randomized block in four replications to evaluate the effect of plant species and concentration of their allelopathic extracts on seed germination and seedling growth of purslane weed (Portulaca oleraceae L.). The first factor studied was plant species (Artemisia sieberi and Salvia syriaca) and the second one the concentration percentage of plant ethanol extract (0.0, 5 %, 10 %, 15 % and 20 %). The effect of Artemisia on germination reduction of purslane was stronger compared to Salvia. The results indicated that higher extract concentration led to decreased germination percentage, germination speed and seedling growth indices of purslane including leaf length, leaf number, leaf width, leaf dry mass, stem mass and stem length. The effect of Artemisia was higher than that of Salvia. In a complementary experiment, the effect plant residues of Artemisia and Salvia (0.0, 1, 2, 3 and 4 g kg-1 soil) were evaluated in a factorial experiment base on completely randomized block design with three replications. The results of field experiment showed that plant residues significantly (P ≤ 0.01) reduced capsule number per plant, seed number per capsule, seed production and shoot dry mass, while its effect on 1000-seed mass was not substantial. The effect of plant species and the interaction of plant species and their allelopathic extracts concentration had no major impact on the above-mentioned properties. The increase in plant residues in soil, led to the reduction of growth and seed production of purslane induced by plant number per unit area and capsule per plant. Artemisia sieberi Bess. and Salvia syriaca L. residues can be successfully used for non-chemical control of purslane weed.

The genus Sideritis L. belonging to Lamiaceae family is represented with more than 150 species worldwide.. The genus is represented in Turkey by 46 species and 53 taxon within two sections among which 39 are endemic. Endemism rate (79.5%) in Turkey is quite high because Turkey is one of the two major gene centers of the genus. Sideritis species are known among people with different local names such as mountain tea, highland tea, sage, sarıkız tea and tail tea. According to some recent researches, extracts obtained from Sideritis species were shown to have antistress, antiulcer, analgesic, antioxidant, antibacterial, anti-inflammatory and insecticidal effects. The interest in and the demand for this plant species has increased particularly due to its antioxidant effect. Seed germination studies of this species have great importance on determination of production strategies of medical and aromatic plants. This study was conducted to determine the effects of some pre-treatments (ethylene, gibberellin, mannitol, seaweed and cold pre-treatment) on germination of Sideritis perfoliata L. which is naturally grown in western Anatolia. The study was carried out at 25/15oC day/night temperature conditions. The experiments were performed according to completely randomized design with 3 replications at Adnan Menderes University, Faculty of Agriculture, Field Crops Laboratory. Significant differences were determined between applications with respect to germination rates and germination vigor values.

Light conditions during fungal growth are well known to cause several physiological adaptations in the conidia produced. In this study, conidia of the entomopathogenic fungi Metarhizium robertsii were produced on: 1) potato dextrose agar (PDA) medium in the dark; 2) PDA medium under white light (4.98 W m −2 ); 3) PDA medium under blue light (4.8 W m −2 ); 4) PDA medium under red light (2.8 W m −2 ); and 5) minimum medium (Czapek medium without sucrose) supplemented with 3 % lactose (MML) in the dark. The conidial production, the speed of conidial germination, and the virulence to the insect Tenebrio molitor (Coleoptera: Tenebrionidae) were evaluated. Conidia produced on MML or PDA medium under white or blue light germinated faster than conidia produced on PDA medium in the dark. Conidia produced under red light germinated slower than conidia produced on PDA medium in the dark. Conidia produced on MML were the most virulent, followed by conidia produced on PDA medium under white light. The fungus grown under blue light produced more conidia than the fungus grown in the dark. The quantity of conidia produced for the fungus grown in the dark, under white, and red light was similar. The MML afforded the least conidial production. In conclusion, white light produced conidia that germinated faster and killed the insects faster; in addition, blue light afforded the highest conidial production. [ABSTRACT FROM AUTHOR]

Salt tolerance of four Egyptian Vicia faba L. cultivars – Nubaria 1, Nubaria 2, Sakha 1 and Giza 3 – was investigated at germination in relation to seed size. The variability in seed size was wide as seed index of Giza 3 was about half that of Nubaria 1. The four investigated cultivars can withstand up to 150 mM NaCl; with marginal reductions in germination capacity but with marked reductions in speed of germination and embryo growth. The vague genotypic variability among the four cultivars in germination parameters emerged more clearly under salt stress. The response of early emergence of the embryo to salt stress seems to differ from that of the subsequent extension of embryonic axis; since based on magnitude and speed of germination Nubaria 1 was the most salt sensitive cultivar but exhibited relatively high salt tolerance on the basis of embryo growth. The salt-sensitive Nubaria 1 produced smaller embryo, with shorter and thicker radicles than the other three cultivars. Germination speed and embryo growth were maximum but lag period was minimum for the medium-sized seeds. Length and thickness of the emerging radicles were affected more by the genotype than by salinity stress and nutrient supply during germination. The beneficial effects of nutrients on seed germination and embryo growth were more evident in the salt-tolerant Nubaria 2 than in the salt-sensitive Nubaria 1. [ABSTRACT FROM AUTHOR]

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Smoke-tree(Cotinus coggygria Scop.)is one of the endemic valuable shrub species of Iran which has only distributed in the Arasbaran Forests. Natural regeneration of this specie is mostly asexual with the shape of root-sucker, and its sexual reproduction is rarely possible. Considering the importance of this specie as well as difficult germination of the seeds naturally, an effort was made through the present study, for the first time in Iran, to examine the effects of several treatments on the improvement of seed germination of this specie, and to introduce the best treatment. In order to break the physical and physiological dormancies, the seeds were soaked in 98% concentration sulphuric acid for 5 and 50 minutes and cold stratified at 4°c for 30 and 60 days. In addition, both of the mentioned treatments, soaking in 98% concentration sulphuric acid for 5, 20 and 50 minutes with cold stratified at 4°C for 60 days, were simultaneously utilized to break both physical and physiological dormancies. The experimental design was completely randomized design (CRD) with three replications in which 30 seeds were planted per replicate. The results of analysis of variance showed that the selected treatments had significant effects (p < 0.01) on all the traits including germination rate, germination speed, and seed vigor index. Furthermore, comparison of the means resulted by the Duncan tests revealed that the best results were obtained by simultaneously application of both the treatments of soaking in 98% concentration sulphuric acid for 20 minutes and cold stratification at 4°C for 60 days. Totally, the results of this study demonstrated the positive effects of the selected treatments on breaking the seed dormancies of this shrub, and the results may be considered in reforestation programs.

Seed priming has been used to advance germination and stand in several crops, but relevant research on faba bean (Vicia faba L.) is scarce. Laboratory and field trials were carried out for two years to study the effect of hydro-priming on faba bean germination and field performance in spring sowing. In laboratory trials, the effects of hydro-priming for 0, 8, 16, 24, 36, and 48 h on final germination percentage, germination speed, Timson’s germination index, mean germination time, mean daily germination, synchronization index, and seedling vigor index were studied. All hydro-priming treatments improved germination parameters of faba bean seeds, except for final germination percentage and mean daily germination compared with non-primed seeds. Averaged over priming duration treatments, hydro-priming improved germination speed by 16.2%, germination synchrony by 20.7%, and seedling vigor index by 13.4%. All hydro-priming durations improved germination synchrony, while hydro-priming for 8, 16, and 24 h provided the highest values of germination speed (2.56, 2.58, and 2.37 seeds day−1, respectively). Hydro-priming for 8 and 16 h provided the lowest values of mean germination time (5.81 and 5.96 days, respectively). In field trials, hydro-priming periods of 0, 8, 16, and 24 h were compared. On average, seed hydro-priming did not affect significantly seedling emergence 14 days after sowing in the first year, but significantly improved seedling emergence by 34.4% in the second year. No significant effect of seed hydro-priming was noted in the number of plants at 28 and 35 days after sowing. Seed priming for 8 h resulted in higher fresh weight at anthesis by 22.3% and 8.6% in the first and the second year, respectively, than the non-primed control. Similarly, seed priming for 8 h provided higher seed yield by 12.0% in the first year and by 5.9% in the second year compared with non-primed control. Overall, seed hydro-priming accelerated faba bean germination and seedling emergence, but the magnitude of the response was associated with the environment and was more evident under limited soil moisture after sowing, whereas the beneficial effect of priming was masked when rainfall followed sowing. Similarly, the beneficial effect of priming on seed yield was more pronounced with limited soil moisture after anthesis.

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this work was to evaluate the effect of saline stress on germination and initial growth of canafistula (Peltophorum dubium (Sprengel) Taubert), tamboril (Enterolobium contortisiliquum (Vell.) Morong.) and pau-formiga (Triplaris americana L.), in addition to determining the maximum tolerance to the presence of NaCl in imbibitions solution. A completely randomized design with four replicates of 50 seeds was used in factorial scheme 3 x 5. The response of the three species to five levels of osmotic potentials (0.0; -0.3; -0.6; -1.2 e -1.8 MPa) was evaluate, simulating saline stress with NaCl. At 28 days after sowing, germination percentage; germination speed index (GSI); germination time; root length and root shoot s and total dry mass were evaluated. Germination and initial growth of tamboril and canafístula were negatively affected by saline concentration increase of the medium. Pau-formiga showed more tolerance to saline stress, presenting an increase in the mean values of germination percentage, GSI, length of the largest root and total dry mass production in osmotic potentials varying from -0.81 to -1.15 MPa. The highest average production of shoot, roots and total dry mass was observed in tamboril seedlings. [ABSTRACT FROM AUTHOR]

The germination behavior of a plant influences its fitness, persistence, and evolutionary potential, as well as its biotic environment. This can have major effects on the invasive potential of a species. We review the findings of four types of experimental studies comparing basic germination characteristics of invasive versus non-invasive congeners, in their non-native or native distribution range; invasive alien versus native species; and invasive species in their native versus non-native distribution range. Early and/or rapid germination is typical of invasive species rather than their non-invasive congeners, and represents a pre-adaptation from which many invasive and naturalized species benefit. It also occurs more often in invasive than native species, suggesting that competition mitigation or avoidance in the early stages of a plant's life, via the exploitation of vacant germination niches, might be more useful than a superior competitive ability in novel environments. This is further supported by a tendency of invasive species to germinate earlier and/or faster and have broader germination cues in their non-native than in their native range. It is also supported by broader germination requirements being reported for invasive species than their non-invasive or native congeners. In contrast, high percentage germination is not a consistent predictor of invasiveness, suggesting that the incorporation of a larger fraction of seed production into the soil seed bank rather than high germination is a better (or safer) strategy in novel environments. These patterns indicate that differences in the germination behavior of alien and native species contribute to the invasiveness of many species, although evidence under natural conditions is needed. The role of such differences in the establishment and spread of invasive species in novel environments and their long-term impact on community dynamics requires further study. [ABSTRACT FROM AUTHOR]

O sucesso das plantas na colonização de novas áreas está fortemente relacionado ao comportamento germinativo das sementes nas condições ambientais locais. O objetivo deste trabalho foi comparar o desempenho germinativo da exótica invasora Leucaena leucocephala ao das leguminosas (Caesalpinia ferrea, nativa e C. pulcherrima, exótica) não consideradas invasoras. Sementes não escarificadas foram expostas às temperaturas de 15, 20, 25, 30, 35 e 40 °C, sob um fotoperíodo de 12 horas, durante 100 dias. Tanto a porcentagem final quanto a velocidade de germinação apresentaram diferenças significativas entre as três espécies. C. ferrea teve baixo desempenho, com temperatura ótima para a germinação a 25°C, porcentagem de germinação de 59% e IVG de 0,68 sementes d-1. Já C. pulcherrima, apresentou altas porcentagens de germinação em todas as temperaturas testadas, com faixa ótima entre 20-40 °C. As sementes de L. leucocephala apresentaram as menores porcentagens de germinação e temperatura ótima de 35 °C. O desempenho germinativo desta exótica não se sobressai ao das demais espécies estudadas e fatores como a pressão de propágulos, escarificação natural e bom desempenho em outras fases da vida devem contribuir para seu perfil de invasora.Success in establishing and colonizing new areas is directly related to germination behaviour of seeds under local environmental conditions. This work aimed to compare germination performance of the exotic invader Leucaena leucocephala to two legumes (Caesalpinia ferrea, native, and C. pulcherrima, exotic) which are not considered invasive. Non-scarified seeds were exposed to constant temperatures of 15, 20, 25, 30, 35 and 40ºC, within a photoperiod of 12 hours, for 100 days. Both final germination percentage and germination speed showed significant differences among the three species. C. ferrea had low germination percentage, with optimal germination temperature at 25ºC, reaching germination percentage of 59% and germination speed of 0.68 seeds d-1. In contrast, C. pulcherrima had high germination percentages at all temperatures tested, with highest germinability from 20 to 40ºC. Seeds of L. leucocephala had the lowest germination percentage and optimal germination temperature was 35ºC. The germination performance of this exotic is not outstanding, and factors such as propagule pressure, natural scarification and good performance in other life stages must contribute to its invasiveness.

Objetivou-se realizar a caracterização fitotécnica dos frutos e avaliar o efeito da remoção do tegumento da semente e do uso do GA3 e do bioestimulante (Stimulate®) sobre a germinação de sementes dos porta-enxertos de citros Flying Dragon e citrumelo Swingle. A caracterização fitotécnica compreendeu a massa do fruto, o diâmetro transversal e longitudinal e a espessura da "casca" e a contagem de sementes viáveis e inviáveis por fruto. Realizou-se um experimento para cada porta-enxerto, em casa de vegetação sob nebulização intermitente, e as avaliações foram a cada 3 dias, após o início do processo germinativo, verificando-se porcentagem de germinação e índice de velocidade de germinação. A utilização do GA3 e a retirada do tegumento em sementes do porta-enxerto Flying Dragon aumentam a porcentagem de germinação e o índice de velocidade de germinação, e para o porta-enxerto citrumelo Swingle, a retirada do tegumento das sementes aumenta a porcentagem de germinação e o índice de velocidade de germinação.The objective was phytotechnical characterization of fruits, assess the effect of removing the husk of the seed, the influence of GA3 and growth promoter (Stimulate®) on the germination of seeds of rootstock Flying Dragon and citrumelo Swingle. The phytotechnical characterization included the weight of the fruit, transverse and longitudinal diameter and thickness of the "peel" and the counting of viable and unviable seeds per fruit. There was an experiment for each rootstock in green house under intermitent mist and the evaluations were every 3 days after the beginning of the germination process, there is percentage of germination and germination speed. The use of GA3 and removal of seed husk of the rootstock Flying Dragon increase the germination percentage and germination speed, and the rootstock citrumelo Swingle removal of the husk of seeds increase the germination percentage and the germination speed.

A germinação é um processo fundamental na dinâmica populacional das plantas daninhas. Sendo assim, a presente pesquisa teve como objetivo analisar a interação entre temperatura e luz sobre a germinação de uma nova variedade da planta daninha vassourinha-de-botão (Borreria densiflora var. latifolia), sob condições de câmara de germinação. Foi estudada a influência de cinco temperaturas (20, 25, 30 e 35 ºC constantes e alternada 20-30 ºC), em presença de fotoperíodo de 12h e escuro constante sobre a germinação, no delineamento experimental aleatorizado em blocos, com quatro repetições. Avaliaram-se a porcentagem de germinação acumulada e a velocidade do processo, sendo a última avaliada pelo índice de velocidade de germinação. Os dados foram submetidos à análise da variância pelo teste F, seguido do teste de Tukey a 0,05 de probabilidade. A germinação ocorreu preferencialmente na presença de luz, com interação significativa somente entre presença de luz e temperatura. Constatou-se, portanto, o fotoblastismo positivo desta nova variedade de B. densiflora. A maior porcentagem de germinação ocorreu na alternância de 20-30 ºC, seguida das temperaturas de 25, 30 e 35 ºC, e a velocidade de germinação aumentou com o aumento da temperatura. Os resultados deste estudo evidenciam que a dinâmica populacional desta planta daninha é influenciada principalmente por amplitudes térmicas, temperaturas mais elevadas (acima de 25 ºC) e condições de luminosidade, justificando, assim, sua ocorrência nas regiões tropicais do Norte e Nordeste do Brasil.Germination is a fundamental process in weed population dynamics. Thus, this research aimed to evaluate the interaction between temperature and light upon the germination of a new variety of the weed vassourinha-de-botão (Borreria densiflora var. latifolia), under germination chamber conditions. The influence of five temperatures (20, 25, 30 and 35 ºC constant and alternated 20-30 ºC), in presence of 12h-photoperiod and constant dark conditions upon the germination was studied, under a randomized complete-block design, with four replications. Accumulated germination percentage and germination speed were evaluated, being the latter evaluated through the germination speed index. Data were submitted to analysis of variance through F test, followed by Tukey test at probability of 0.05. Germination occurred preferentially in presence of light, with significant interaction only between temperature and presence of light. We observed, thus, the positive photoblastism of this new variety of B. densiflora. The highest germination percentage occurred under the alternated temperature 20-30 ºC, followed by the temperatures 25, 30 and 35 ºC, and the germination speed increased with the increase of the temperature. The results obtained in this research show that the population dynamics of this weed is influenced mainly by thermic amplitudes, higher temperatures (over 25 ºC) and conditions of presence of light, explaining, therefore, its occurrence in the North and Northeastern tropical regions of Brazil.

A germinação de sementes de salsa (Petroselinum sativum Hoffm.) é lenta e desuniforme, sendo a contagem do teste padrão de germinação recomendada aos 10 e 28 dias e a emergência em campo é relativamente longa, justificando o uso de técnicas que acelerem e uniformizem o processo germinativo: um método promissor é o osmocondicionamento. No presente trabalho, objetivou-se avaliar os efeitos dos diferentes potenciais de osmocondicionamento, com PEG 6000, na germinação de sementes de salsa e identificar o potencial osmótico ótimo para aumentar a germinação destas sementes. Sementes das cultivares Lisa e Portuguesa de dois lotes, adquiridas no comércio local foram osmocondicionadas pelo método de imersão direta das mesmas em soluções aquosas com potencial hídrico: 0,0, -0,5, -1,0 e -1,5 MPa, obtidos com a adição de PEG 6.000, sob aeração constante a 25ºC por 144 horas, como testemunha utilizaram-se sementes não osmocondicionadas. As variáveis analisadas foram: porcentagem de germinação (10 e 28 dias), velocidade de germinação e índice de velocidade de germinação. O osmocondicionamento aumenta a porcentagem e a velocidade de germinação de sementes de salsa, sendo que, o potencial osmótico indicado situa-se entre -1,0 e -1,5 MPa.The germination of parsley seeds (Petroselinum sativum Hoffm.) is slow and asynchronous, being that the counting of the test germination standard is recommended on the 10th and 28th day. In field emergence is relatively long; which justifies the use of techniques that increase germination speed and uniformity. A promising method is osmopriming. In the present study, our goal was to evaluate the effect of different potentials of osmopriming, with PEG 6000, in the germination of parsley seeds, and to identify optimum osmotic potential to increase the germination of these seeds. Parsley seeds of the Lisa and Portuguesa cultivars from two lots were bought locally and were primed by the method of direct immersion of the seeds in water solutions with osmotic potential: 0.0, -0.5, -1.0 and -1.5 MPa, obtained with the addition of PEG 6,000, under constant aeration at 25ºC for 144 hours, with one control (unprimed seeds). Percentage of germination (at 10 and 28 days), index of germination speed, and speed of germination were evaluated. Osmopriming increased the speed and percentage of germination of parsley seeds, being that the indicated osmotic potential is between -1.0 and -1.5 MPa.