Germinable Seeds Research Articles

Analytical performance and “receiver operating characteristic curve” analysis of resazurin assay for seed-viability estimation in flax

ABSTRACT Germination capacity is an important parameter of seed viability. The direct germination test destroys the seed. Viability evaluation by nondestructive tests allows the saving of seeds for storage and future use. However, predictive values of most nondestructive tests have not been adequately determined. This study investigated performance parameters and optimized assay conditions for a nondestructive colorimetric resazurin seed-viability test of flax seeds (Linum usitatissimum L.). In this study, 800 seeds were tested by resazurin test before germination. Optimization of resazurin test conditions and cutoff value was determined via a “receiver operating characteristic curve” analysis. We found that the optimal incubation time was 2 h. We proposed to measure sample absorption at 595 nm for better seed-viability estimation by resazurin test due to spectral properties of dye. We improved sensitivity of the resazurin test by using measurements adjusted to blank absorption at 595 nm (sensitivity 91%) or to sample absorption at 490 nm (sensitivity 95% versus 81% before corrections). The resazurin test reliably predicted germinable seeds in 72–73% cases and ungerminable seeds in 92–95% cases, with a sensitivity of 91–95% and a specificity of 71–74%. Therefore, the easy and low-cost resazurin test exhibited analytical performance similar to more expensive instrumental tests and can be suitable for nondestructive seed-viability estimation.

Effect of Water Soaking on Physical and Engineering Properties of Paddy (Basmati-370)

Physical and engineering properties of paddy seeds plays a crucial role in designing and development of drum’s orifice shape and size in drum seeder. The physical and engineering properties of dry, soaked (12 hours soaking) and pregerminated (24 hours soaking + 12 hours incubation) paddy (Bsmati-370) seeds were studied to finalize these dimensions. The average value for; length, width, thickness and equivalent diameter (mm) varies from 9.95 to 10.55, 10.98 to 11.61, 12.01 to 12.53 mm; 1.95 to 2.12, 2.41 to 2.57, 2.67 to 2.90 mm; 1.70 to 1.74, 2.06 to 2.18, 2.29 to 2.48 mm; and 3.07 to 3.20, 3.55 to 3.68, 3.81 to 4.11 mm for dry, soaked and pre germinated seeds respectively. The aspect ratio and sphericity were found to be 0.19, 0.24, 0.28 and 30, 32.88 and 34.70% for dry, soaked and pregerminated seeds respectively. There was an increase in volume, aspect ratio and terminal velocity by 21, 26.31 and 15.31 % and 39.98, 47.36 and 18.91% for soaked seed and pre germinated seed over the dry seed respectively.

Free-Grazing versus Enclosure Lead to an Increase in the Germination of the Leymus chinensis Seed Bank in the Hulunbuir Grassland

Leymus chinensis is a primary plant in the meadow steppe and typical steppe of China. With global warming and increasing grazing intensity, grassland degradation is being exacerbated. To better protect the L. chinensis grassland in this area and provide a theoretical basis for restoring it, this paper compared the germinable seed bank in the soil and the germination characteristics of L. chinensis (including initial germination time, duration of germination, germination termination time, germination dynamics, and germination index) in free-grazing and enclosed areas. At the same time, combining information about the density of L. chinensis on the ground and previous research results, a comprehensive analysis was conducted. The major results were: (1) there was no significant difference in the number of germinable seeds in the soil between the free-grazing area and the enclosed area, and these seeds were mainly concentrated in the 0–2 cm soil layer. (2) The free-grazing area resulted in a significant increase in the number of germinable L. chinensis seeds and advanced the initial germination time. (3) The number of soil germinated seeds and the number of L. chinensis germinated seeds decreased with the increase in soil depth. (4) Livestock grazing behaviours increased seed burial, thus improving the L. chinensis germination rate. At the same time, the L. chinensis seed bearing percentage and seed quality and the number of germinable L. chinensis seeds were significantly higher in the free-grazing area than in the enclosed area. However, this result still needs to be further explored.

Non-viviparous pre-dispersal seed germination in Amaranthaceae in the cold deserts of Central Asia

In the broad context of understanding the relationship between timing of seed germination and adaptation of a plant species to its habitat, the purpose of this study was to purse an observation of pre-dispersal seed germination of Salsola brachiata (Amaranthaceae) in late winter 2021 in the Amaranthaceae species-rich cold deserts in northwest China (Central Asia). We searched for pre-dispersal germination in species of Amaranthaceae growing in sand dunes (S), salt deserts (SD) and gravel deserts (GD). We examined 69 species in 155 populations in autumn 2021 and 52 species in 12 populations in early spring 2022. No seeds of any of the 69 species germinated on the mother plants in autumn 2021, while 30 of 52 species (57.7%) did so during snowmelt in early spring 2022. The rank order of species with few to many seeds germinated on the mother plants was annuals (66.7%) > small shrubs (23.3%) > small trees (6.7%) > shrubs (3.3%). The number of species in S, SD, and GD with pre-dispersal germinated seeds was 16 of 27 (59.3%), 15 of 31 (48.4%), and 15 of 30 (50.0%), respectively. The high species occurrence of pre-dispersal germination in early spring suggested that it might be adaptive in the unpredictable-rainfall growing-season environment of the cold deserts of Central Asia, a center of diversity of Amaranthaceae. However, preliminary studies on seedling/juvenile survival of S. brachiata showed that those from post-dispersal soil-germinated seeds had the best survival, suggesting that pre-dispersal seed germination may be maladaptive.

Composition and Spatial Variation of Germinable Seed Bank in Burned Nothofagus pumilio Forests in Patagonia Argentina

The availability of soil-stored seed determines initial plant functional types in post-fire landscapes. We evaluated the post-fire regeneration of Nothofagus pumilio forests, in Patagonia, Argentina, analyzing the soil seed bank (SSB) and the above-ground vegetation (AV). At three sites: La Colisión, Río Turbio and Monte Zeballos, burned in 2008, 1980 and 1941, respectively, we sampled the SSB and AV in two transects from the edge of the remaining forest, up to 90 m within the burned area, and recorded the emergence (198 soil samples) and presence of vascular species. To determine the effect of the distance to the remnant forest on the germinable seed bank, we performed simple linear regression analysis through the use of linear mixed-effect models, and we analyzed the similarity between the composition of SSB and AV with PERMANOVA. The emergence of plant growth forms had different patterns in relation to the distance from the forest in the three sites, which might be associated with the time of fire occurrence, and specific characteristics of each site. The emergence of N. pumilio was registered at more than one distance at the recent burning site. Herbs constituted the main source of cover with 69% of the composition, and native/endemic species represented 71%. This study contributes to the understanding of the relationship between the seed bank and standing vegetation and a better understanding of the resilience of post-fire N. pumilio forests. Our findings suggest that from 15–20 m from the edge, the SSB would be insufficient to ensure the spontaneous recovery of the forest, making active restoration necessary in order to tend to a recovery of the structure and functionality of the original community.

Transcriptome Analysis Reveals Genes and Pathways Associated with Salt Tolerance during Seed Germination in Suaeda liaotungensis.

Seed germination is susceptible to external environmental factors, especially salt stress. Suaeda liaotungensis is a halophyte with strong salt tolerance, and the germination rate of brown seeds under 1000 mM NaCl treatment still reached 28.9%. To explore the mechanism of salt stress response during brown seed germination in Suaeda liaotungensis, we conducted transcriptomic analysis on the dry seeds (SlD), germinated seeds under the control condition (SlG_C), and salt treatment (SlG_N). Transcriptome analysis revealed that 13314 and 755 differentially expressed genes (DEGs) from SlD vs. SlG_C and SlG_C vs. SlG_N were detected, respectively. Most DEGs were enriched in pathways related to transcription regulation and hormone signal transduction, ROS metabolism, cell wall organization or biogenesis, and carbohydrate metabolic process in two contrasting groups. Compared with the control condition, POD and CAT activity, H2O2, soluble sugar, and proline contents were increased during germinated seeds under salt stress. Furthermore, functional analysis demonstrated that overexpression of SlNAC2 significantly enhanced salt tolerance during the germination stage in Arabidopsis. These results not only revealed the tolerant mechanism of brown seed germination in response to salinity stress but also promoted the exploration and application of salt-tolerant gene resources of Suaeda liaotungensis.

ИСПОЛЬЗОВАНИЕ ЛАЗЕРНОГО ИМПУЛЬСНОГО ИЗЛУЧЕНИЯ И РАСТВОРОВ ЭКОПЕРОКСИДА ДЛЯ АКТИВАЦИИ СЕМЯН САХАРНОЙ СВЕКЛЫ

Sugar beet, a biennial industrial agricultural crop, is used for the production of ethanol, biofuels, sugar and contains up to 70% sucrose. It is difficult to obtain seeds, the collection of which takes place in the second year of cultivation of root crops. The possibility of accelerating seed activation, increasing germination by methods of pre-sowing treatment of dry seeds: laser pulsed radiation and ecoperoxide solutions was studied. The first test indicating the beginning of seed awakening (one hour after treatment) was a test for determining the release of metabolites into the aqueous culture medium. The metabolites determined by spectrophotometry. They have a characteristic absorption spectrum in the UV region with a clear maximum at λmax – 207 nm and absorption up to the boundary with the visible region of 
 λmax – 330 nm. A copper vapor laser was used. Parameters: simultaneous generation of two wavelengths – green 510.5 nm and yellow 578.2 nm. The duration of the radiation pulse is 15 ns, the repetition rate is 10 kHz. The irradiation time is 10, 20, 90 s. The greatest effect of seed germination stimulation at 10 s of irradiation exceeded the control by 30%. Increasing the interval to 24 hours or more between irradiation and placing seeds for germination reduced the number of germinated seeds. Ecoperoxide was obtained by high-energy non-contact exposure to distilled water with high-voltage electric discharge streamers. An increase in seed germination by 30-40% was noted when they came into contact with a peroxide solution for 30 minutes.

Counting and Classification of Seed Using Machine Learning Methods

Deep learning, machine learning and image processing techniques have become important tools used in facilitating agricultural work and developing solutions to different problems in the production phase. In this study, a seed number and type detection algorithm was developed using YOLO deep learning architecture, a real-time object detection algorithm employing the CNN structure in AugeLab Studio sofware. With the developed model average loss factor of 0.417 was achieved after 3000 iterations. As a result of the analysis, it has been determined that the bean classification accuracy varies between 97% and 100%, while the chickpea classification accuracy varies between 91% and 100%. In addition, the total number of 11 beans and 10 chickpea seeds in a single image was determined with 100% accuracy. The results demonstrated that AugeLab, a software employing artificial inteligence based image processing techniques, can be used by seed production companies, agricultural biotechnology laboratories and seed certification institutions in counting and classification of seeds. It can also be used in variety and/or species separation, separating and detecting germinated seeds, or detecting and proportioning foreign mixtures in seed certification processes within shorter time and less costs.

Metabolomics and flavoromics analysis of chemical constituent changes during roasting of germinated Sacha inchi (Plukenetia volubilis L.).

This study examined the changes in metabolites together with the flavor profiles of germinated Sacha inchi seeds during roasting by using gas chromatography. The results indicated that roasting partially increased the browning index, amino acid levels, total phenolic content, and antioxidant capacity, but slightly decreased the levels of reducing sugars. Oxidized and rancid compounds were significantly decreased at a 180°C roasting temperature. Pyrazine, furan, and pyrrole were Maillard reaction products that were increased at 180°C of roasting. Roasting at 145°C for 45min after germination for 4days was determined to be the optimal conditions for roasting germinated Sacha inchi seeds, which reduced the off-flavor and burned taste. The roasted germinated Sacha inchi seed contains higher amino acids than raw seed, which could be used as an alternative source for food products and supplements. In addition, the roasted germinated seeds at 4days were recommended for food applications.

Seed Transmission of Pathogens: Non-Canonical Immune Response in Arabidopsis Germinating Seeds Compared to Early Seedlings against the Necrotrophic Fungus Alternaria brassicicola.

The transmission of seed-borne pathogens by the germinating seed is responsible for major crop diseases. The immune responses of the seed facing biotic invaders are poorly documented so far. The Arabidopsis thaliana/Alternaria brassicicola patho-system was used to describe at the transcription level the responses of germinating seeds and young seedling stages to infection by the necrotrophic fungus. RNA-seq analyses of healthy versus inoculated seeds at 3 days after sowing (DAS), stage of radicle emergence, and at 6 and 10 DAS, two stages of seedling establishment, identified thousands of differentially expressed genes by Alternaria infection. Response to hypoxia, ethylene and indole pathways were found to be induced by Alternaria in the germinating seeds. However, surprisingly, the defense responses, namely the salicylic acid (SA) pathway, the response to reactive oxygen species (ROS), the endoplasmic reticulum-associated protein degradation (ERAD) and programmed cell death, were found to be strongly induced only during the latter post-germination stages. We propose that this non-canonical immune response in early germinating seeds compared to early seedling establishment was potentially due to the seed-to-seedling transition phase. Phenotypic analyses of about 14 mutants altered in the main defense pathways illustrated these specific defense responses. The unexpected germination deficiency and insensitivity to Alternaria in the glucosinolate deficient mutants allow hypothesis of a trade-off between seed germination, necrosis induction and Alternaria transmission to the seedling. The imbalance of the SA and jasmonic acid (JA) pathways to the detriment of the JA also illustrated a non-canonical immune response at the first stages of the seedling.

Density-dependent effects on the reproductive outcome of a native tree at tropical restored habitats

Plants are involved in different interactions with animals that may have contrasting effects on their reproductive output. However, as multitrophic interactions are resource-mediated and density-dependent, the frequency at which these interactions occur is modulated by the demographical characteristics of the populations of interacting species. For example, while plant aggregation may increase pollinator attraction and consequently, pollination success, an increased seed set may also attract more seed predators. Therefore, the intensity of pollination and seed predation events may affect plant population dynamics. Although multitrophic plant-animal interactions are crucial for maintaining biodiversity in terrestrial ecosystems, they have seldom been studied together, especially in restored habitats. To fill this gap, we used five restoration sites that used Inga vera trees at different densities to evaluate how density-dependent effects impact fruit set, seed predation, seed germination rate and the number of viable germinated seeds (i.e., the net effect of pollination and seed predation). Using structural equation models to assess the isolated effects of each predictor variable in each response variable and the cascading effects of each response variable on another, we found that density-dependent effects influenced I. vera reproduction. While I. vera trees in high density presented higher fruit set and seed predation rates, trees in low-density plantations presented lower fruit set, but seed predators consumed fewer seeds. The contrasting results of final seed germination rates revealed that density-dependent effects are pivotal to plant establishment and population dynamics. We argue that the study of density-dependent multitrophic plant-animal interactions is essential to guarantee that the efforts done in restoration initiatives can turn into successful results in terms of restoring ecosystem structure and stability.

Improving accessibility and bioactivity of raw, germinated and enzymatic-treated spelt (Triticum spelta L.) seed antioxidants by fermentation

Lactic acid, alcoholic, combined and spontaneous fermentation of raw, germinated and enzymatic-treated spelt seeds significantly improved the content of extractable and bound phenolics and considerably increased the extractable:bound ratio, and therefore positively affected the accessibility of the spelt antioxidants. The highest extractable and bound individual phenolic contents and in vitro antioxidant activities of extracts were obtained following fermentation of germinated spelt seeds with Saccharomyces cerevisiae, while for enzymatic-treated seeds, Lactobacillus plantarum (alone or with S. cerevisiae) was the most effective. For extractable phenolics, trans-ferulic acid increased the most in yeast-fermented germinated seeds (2922%); for bound phenolics, cis-ferulic acid showed the greatest relative increase in yeast-fermented raw spelt seeds (466%). Spontaneous fermentation of germinated and enzymatic-treated samples decreased intracellular oxidation most effectively, probably due to apigenin derivatives. Cellular uptake of bound hydroxycinnamic acids was significantly higher than that of extractable hydroxycinnamic acids; however, the latter were more efficient in vivo antioxidants.

From germination to seedling development: the effects of smoke on a native and an invasive grass species of the Cerrado

AbstractThe Brazilian Cerrado, a Neotropical savanna, is a fire-prone ecosystem where the ground layer biomass consists mainly of graminoids. However, as for other savannas, the effects of fire cues (such as smoke) on Cerrado grasses do not present a clear pattern, either for germination or seedling development. Smoke can stimulate different stages of the plant life cycle, which can alter the community and invasion processes. So far, most research on the subject focuses on germination, not addressing post-germinative phases, a sensitive stage of plant development. Here, we investigated the effect of smoke on a native (Echinolaena inflexa) and an invasive (Urochloa decumbens) grass species common in the Cerrado. We analysed germinative parameters and seedling mass and length after exposing the seeds to dry smoke for 5, 10, 15 or 20 min. Seedling development was assessed by measuring shoot and root systems after cultivating germinated seeds for 3, 7 or 15 d. Smoke did not affect germination percentages. However, fumigation reduced the mean germination time of both species and the germination onset of E. inflexa. U. decumbens had higher length values in all periods of cultivation, whereas mass values only surpassed that of E. inflexa at 15 d. Smoke exposure reduced the aboveground length of 7-d seedlings of U. decumbens, and mass of 15-d plants of both species. Also, smoke enhanced the root investment of the native and invasive species in different cultivation periods. Therefore, studying post-germinative parameters on seedling development may bring further insights into the smoke effects.

Vertical distribution of soil seed bank and the ecological importance of deeply buried seeds in alkaline grasslands.

BackgroundSoil seed banks play a central role in vegetation dynamics and may be an important source of ecological restoration. However, the vast majority of seed bank studies examined only the uppermost soil layers (0–10 cm); hence, our knowledge on the depth distribution of seed bank and the ecological significance of deeply buried seeds is limited. The aim of our study was to examine the fine-scale vertical distribution of soil seed bank to a depth of 80 cm, which is one of the largest studied depth gradients so far. Our model systems were alkaline grasslands in East-Hungary, characterised by harsh environmental conditions, due to Solonetz soil reference group with Vertic horizon. We asked the following questions: (1) How do the seedling density and species richness of soil seed bank change along a vertical gradient and to what depth can germinable seeds be detected? (2) What is the relationship between the depth distribution of the germinable seeds and the species traits?MethodsIn each of the five study sites, four soil cores (4 cm diameter) of 80 cm depth were collected with an auger for soil seed bank analysis. Each sample was divided into sixteen 5-cm segments by depth (320 segments in total). Samples were concentrated by washing over sieves and then germinated in an unheated greenhouse. Soil penetration resistance was measured in situ next to each core location (0–80 cm depth, 1-cm resolution). We tested the number and species richness of seedlings observed in the soil segments (N = 320), using negative binomial generalized linear regression models, in which sampling layer and penetration resistance were the predictor variables. We ran the models for morphological groups (graminoids/forbs), ecological groups (grassland species/weeds) and life-form categories (short-lived/perennial). We also tested whether seed shape index, seed mass, water requirement or salt tolerance of the species influence the vertical distribution of their seed bank.ResultsGerminable seed density and species richness in the seed bank decreased with increasing soil depth and penetration resistance. However, we detected nine germinable seeds of six species even in the deepest soil layer. Forbs, grassland species and short-lived species occurred in large abundance in deep layers, from where graminoids, weeds and perennial species were missing. Round-shaped seeds were more abundant in deeper soil layers compared to elongated ones, but seed mass and ecological indicator values did not influence the vertical seed bank distribution. Our research draws attention to the potential ecological importance of the deeply buried seeds that may be a source of recovery after severe disturbance. As Vertisols cover 335 million hectares worldwide, these findings can be relevant for many regions and ecosystems globally. We highlight the need for similar studies in other soil and habitat types to test whether the presence of deep buried seeds is specific to soils with Vertic characteristics.

Effect of two seeding rates on yield and yield components of winter and spring faba bean

ABSTRACT In Central European cropping systems, there is increasing interest in winter faba bean (Vicia faba L. minor), which is traditionally used as a spring crop. But limited knowledge on yield and yield formation and optimum seeding rate exist. Therefore, the purpose of this assessment was to compare soil coverage, yield and yield components of two winter faba bean varieties (Diva and Hiverna) with a spring faba bean (Alexia) with two seeding rates (SR), 25 versus 50 germinable seeds m−2 (S), in a two-year field experiment under Pannonian climate conditions in eastern Austria. Both winter faba bean varieties produced a high grain yield with 25 S, whereas that of Alexia tended to be higher with 50 S. The grain yield of Diva and Hiverna was with 25 S and that of Diva also with 50 S higher than that of Alexia. The higher SR caused in winter faba beans a higher intraspecific competition resulting in less stems plant−1. Pod density of Alexia was higher with 50 S compared to 25 S, while grains pod−1 and thousand kernel weight of all three varieties were not affected by SR. Results show that winter faba bean can be sown in Central Europe with lower seeding rates compared to spring faba bean without suffering a grain yield loss.

Rationale for dosing and mixing germinated flax seeds with wheat flour

The reasons of low quality and changes of the diet are analyzed, the nutritional value of bakery products and the use of non-traditional sources in new developments of high value technologies are considered. The general scheme of bakery products production technology is given, where the parameters of the kneading process and the connection between the factors influencing the complex system of dough formation and the characteristics of the finished product are revealed.Ways of using germinated flax seeds in recipes based on wheat and rye-wheat bread with preservation of high organoleptic characteristics are proposed and selected. The analysis and the ways of regulation of structural and mechanical properties of dough on the basis of factors of influence are given: – usage of thick rye leaven and first-class flour 30:70 and supreme quality wheat flour with addition of germinated flaxseed (15% of the mass of wheat flour); – usage of thick rye leaven and first-class flour 50:50 with addition of germinated flaxseed (10% of the mass of wheat flour); – the usage of thick rye leaven and first-class flour 50:50 with addition of 20% of germinated flaxseed and also adding supreme quality wheat flour (15% of the mass of wheat flour). The even distribution of GFS in flour due to efficient mixing in determining the nature of the process is considered. Influential parameters were chosen: duration of mixing and non-variable factor – frequency of revolutions of the working body of the mixer. The quality of mixing of the mixture based on the key component – GFS – was evaluated. The quality of mixing was determined by the coefficient of variation of the key component of the mixture, i.e. GFS. Mixing curves are constructed – dependence of the coefficient of variation on the duration of mixing and the optimal mixing time is determined, which corresponds to the first minimum value of the coefficient of variation of the mixing curve. Three stages of kneading are distinguished: I (0…60 s) – zone of intensive mixing; ІІ (60…120 s) – zone of slow mixing and ІІІ (120…180 с) – zone of segregation. The recommendations to be followed for effective mixing of flour with GFS in production conditions are given.

Analysis of winter wheat varieties suitable for cultivation in conditions of flooding

The purpose of the research is to study the reaction of winter wheat varieties to artificially simulated flooding and to identify forms resistant to this factor in the field conditions. In a series of laboratory experiments to study the adaptation of winter wheat seeds to lack of oxygen (hypo- and anoxia) in 2019-2021 and field studies in 2017-2021, the objects of research were 10 varieties of winter wheat. The depressing effect of laboratory hypoxia is manifested in severe germination depression and a large number of defective seeds. The number of rotted seeds ranged from 49.8 to 79.9%, the number of non-normal germinated seeds ranged from 1.3 to 8.4%. The following varieties were characterized by a low degree of germination process inhibition: Angelina (43.7%), Anfisa (41.6%), Boyarka (31.5%). Moreover, the coefficient of variation (CV) of germinating seeds over the years in these varieties was the lowest – 15.3-26.4%. A high degree of conjugacy of the selected varieties with the HTCMin September was noted: plant germination in autumn (r=+0.864 ...+0.982), the number of preserved plants after overwintering (r=+0.229...+0.745), yield (r=+0.454 ...+0.622). The positive conjugacy of the HTCMof March on the number of preserved plants after overwintering was revealed (r=+0.601). Field studies have shown that the largest number of preserved plants in the field were formed by the varieties Anfisa (77.8%), Boyarka (72.8%), and Angelina (74.4%). These varieties can be recommended for conditions of lowlands, poorly permeable soils, and other places where the soil may be waterlogged in autumn or spring, including accumulation and stagnation of precipitation.

Nutritional evaluation and transcriptome analyses of short-time germinated seeds in soybean (Glycine max L. Merri.)

Germination is a common practice for nutrition improvement in many crops. In soybean, the nutrient value and genome-wide gene expression pattern of whole seeds germinated for short-time has not been fully investigated. In this study, protein content (PC), water soluble protein content (WSPC), isoflavone compositions were evaluated at 0 and 36 h after germination (HAG), respectively. The results showed that at 36HAG, PC was slightly decreased (P > 0.05) in ZD41, J58 and JHD, WSPC and free isoflavone (aglycones: daidzein, genistein, and glycitein) were significantly increased (P < 0.05), while total isoflavone content was unchanged. Transcriptomic analysis identified 5240, 6840 and 15,766 DEGs in different time point comparisons, respectively. GO and KEGG analysis showed that photosynthesis process was significantly activated from 18HAG, and alternative splicing might play an important role during germination in a complex manner. Response to hydrogen peroxide (H2O2) was found to be down regulated significantly from 18 to 36HAG, suggesting that H2O2 might play an important role in germination. Expression pattern analysis showed the synthesis of storage proteins was slowing down, while the genes coding for protein degradation (peptidase and protease) were up regulated as time went by during germination. For genes involved in isoflavone metabolism pathway, UGT (7-O-glucosyltransferase) coding genes were significantly up regulated (40 up-DEGs vs 27 down-DEGs), while MAT (7-O-glucoside-6′′-O-malonyltransferase) coding genes were down regulated, which might explain the increase of aglycones after germination. This study provided a universal transcriptomic atlas for whole soybean seeds germination in terms of nutrition and gene regulation mechanism.

Low passive restoration potential following invasive woody species removal in oak woodlands

The restoration of oak woodlands often requires removal and management of woody invasive plants. This can trigger germination of the soil seed bank, which can alter restoration trajectories. In degraded deciduous woodlands generally, it is unclear whether the soil seed bank will contribute native plant material in sufficient quantities to help achieve restoration goals and allow practitioners to rely on passive restoration without supplemental seeding. To support restoration decision‐making around passive or active restoration in three Rhamnus cathartica‐invaded forest preserves in the Chicago region, we asked: (1) Does the soil seed bank differ from standing aboveground vegetation at reference and unrestored sites? and (2) Can the species richness, Shannon diversity, floristic quality (measured by abundance‐weighted mean coefficients of conservatism), or density of germinable seeds of native species in the soil seed bank be predicted by a site's restoration status (reference or unrestored)? We found that species composition differed significantly between aboveground vegetation and the soil seed bank at reference and unrestored sites, with a significant interaction between restoration status and location. Despite high variation among the three forest preserves, restoration status also predicted native species richness, diversity, floristic quality, and seed density in the soil seed bank, with unrestored sites significantly lower than reference sites in all measures. Results suggest that reintroduction of native seeds will be necessary to fully restore desired native plant communities in oak woodlands following the removal of invasive woody plants.

Constraints on tree seedling establishment after fires: passing the germination bottlenecks.

Persistence and colonization by tree species in an environment following a fire depends on the effects on seed germination and seedling development. We used seeds of Kielmeyera coriacea and Qualea parviflora as a model to test the effects of high temperatures on germination and initial development of tree seedlings. We exposed the seeds to heat flow (70, 100, 130, 150 or 170 °C) for 2 or 5 min and compared the germination with that of unheated seeds (control). Seedlings were then harvested after 3, 7 or 15 days to evaluate aerial and root mass, root:shoot ratio, presence of cotyledon opening, true leaves, and secondary roots. We found no effect on germination for seeds exposed to temperatures ≥150 °C. However, germination was significantly reduced for seeds exposed to 100 °C for both 2 and 5 min. The mass of 15-day-old K. coriacea seedlings was smaller when seeds were heated at 70 °C for 5 min or at temperatures higher or equal to 100 °C. Qualea parviflora seedlings did not show any difference in mass, but there were marginal differences in the presence of roots and the opening of cotyledons. Kielmeyera coriacea seedlings allocated biomass faster than Q. parviflora. High temperatures affect both quantity and quality of germinable seeds, as well as biomass allocation during initial seedling development. These factors may explain the decrease in seedlings observed after fire, suggesting a bottleneck effect that influences population dynamics and species persistence in systems with frequent fires.