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As differences in seed dormancy between Actinidia species have not been reported previously, in this study we characterized the variation in the dormancy of seeds in 13 kiwifruit species that originated from different regions of China and Taiwan, and for which mature plants are now growing in New Zealand orchards. Dormancy-breaking treatments, including cold-moist stratification, seed coat scarification and soaking in water and gibberellic acid (GA3), were tested for their efficacy in alleviating dormancy and improving final germination and germination rates. In addition, we assessed seed viability using RNA integrity analysis to distinguish dead seeds from dormant seeds. This study identified that dormancy type in Actinidia seeds is species-specific and can be morphological, morphophysiological or a combination of physiological and physical, and that seed RNA integrity is a useful metric to incorporate into seed dormancy studies. Our results also suggest that species originating from colder climates that experience large differences between winter minimum and summer maximum temperatures exhibit physiological dormancy and require cold-moist stratification, contrasting with species originating in milder climates. Interestingly, although not all seeds from all the species were dormant, the proportion of dormant seeds in each species did not correlate to the climatic data of the region from which they originated. These findings provide new insights into mechanisms of seed dormancy in kiwifruit. [ABSTRACT FROM AUTHOR]

As differences in seed dormancy between Actinidia species have not been reported previously, in this study we characterized the variation in the dormancy of seeds in 13 kiwifruit species that originated from different regions of China and Taiwan, and for which mature plants are now growing in New Zealand orchards. Dormancy-breaking treatments, including cold-moist stratification, seed coat scarification and soaking in water and gibberellic acid (GA3), were tested for their efficacy in alleviating dormancy and improving final germination and germination rates. In addition, we assessed seed viability using RNA integrity analysis to distinguish dead seeds from dormant seeds. This study identified that dormancy type in Actinidia seeds is species-specific and can be morphological, morphophysiological or a combination of physiological and physical, and that seed RNA integrity is a useful metric to incorporate into seed dormancy studies. Our results also suggest that species originating from colder climates that experience large differences between winter minimum and summer maximum temperatures exhibit physiological dormancy and require cold-moist stratification, contrasting with species originating in milder climates. Interestingly, although not all seeds from all the species were dormant, the proportion of dormant seeds in each species did not correlate to the climatic data of the region from which they originated. These findings provide new insights into mechanisms of seed dormancy in kiwifruit.

Abstract Background The silver wattle Acacia dealbata is a fast-growing tree from Australia that has become naturalised in different regions of the world, attaining invasive status in most of them. In Chile, A. dealbata reaches large abundances along banks and floodplains of invaded fluvial systems, suggesting that rivers may act as a vector for seed dispersal. As hydrochory has not been documented previously in this species, the aim of this study is to evaluate the potential for water dispersal of seeds of this invasive tree along rivers. Methods Seed samples from rivers were collected at three sites along two A. dealbata-invaded rivers within the Cachapoal basin, central Chile. Number of seeds collected was contrasted versus hydraulic and local conditions with RDA. Seed buoyancy and sedimentation velocity were determined and compared between sites with an ANCOVA. Finally, the probability of seed germination after long periods of immersion in water was assessed, simulating transport conditions in the flow. Germination results were tested with a GLM. Results Results indicate that increasing abundance of A. dealbata seeds in the flow is related to the level of turbulence of the flow. Seeds display high floatability but their sedimentation velocity is high when they do sink. Finally, silver wattle seeds can germinate after long periods (many weeks) of immersion in water; however, their probability of germination depends to a large extent on whether seeds are scarified or not. Conclusions Based on the evidence collected, we suggest that the seeds of A. dealbata have the necessary traits to be dispersed by rivers, this being the first research testing this hypothesis. The success of hydrochory of A. dealbata would depend on river flow turbulence, and whether there are natural mechanisms for scarifying the seeds either before or during transport. The proposed methodology can be used to assess river hydrochory for any tree species.

Saskatoon berry has become as important as a commercial fruit crop. One main goal is to release new plant cultivars well adapted to different climatic and soil conditions. Dormant seeds obtained from breeding are serious problems delaying the program. The seeds were directly extracted from fruits after harvest (unstored) or after storage at −18 °C for 6 months (stored) and subjected to modified stratification (3 °C) with KNO3, H2O2, NO, smoke-water (SW) or scarification using sandpaper or H2SO4 for 10, 20, 30, 40 min or treatments with pulsed radio frequency (PRF) or red light. The seeds were also subjected to warm–cool stratification (20/3 °C). Unstored seeds germinated in a higher percentage and with better uniformity (T75–T25) than stored seeds. Stored seeds positively affected the onset of seed germination (T1) and mean germination time (MGT). Dormancy breakage was promoted by stratification with KNO3, SW or scarification with sandpaper, H2SO4 or treatments with PRF. The recommended method for the breeding program of breaking seeds dormancy is when unstored seeds are subjected to stratification in KNO3 (0.2%) or SW (1:100). Depending on the applied methods, the percentage of seeds' germination increased to 87% compared to untreated (64%) control seeds. The positive effects of the selected methods persisted during seedling development by stimulating their growth and enhancing the chlorophyll content index (SPAD) and effective quantum yield of PSII of chlorophyll in leaves (ΦPSII). [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of inoculation with the biofertilizer IHPLUS®BF on seed germination of Leucaena leucocephala (Lam) de Witt cv. Cunningham. Materials and Methods: The study was carried out at the Pastures and Forages Research Station Indio Hatuey, located in the Perico municipality, Matanzas province, Cuba. To study the germination response of seeds of L. leucocephala cv. Cunningham, an experiment was carried out with a completely randomized design with a 3 x 4 factorial arrangement. The treatments were formed by the combination of two factors: a) imbibition time and b) dilutions of IHPLUS®BF. Three different times (8, 10 and 28 h) were combined with four dilutions (2,5; 5; 10; 15 mL L-1), and a control: seeds with thermal scarification treatment (water at 80 °C for two minutes). Results: Germination kinetics maintained a similar performance in all treatments. The best response was obtained with the combination of the thermal scarification method, with 28 hours of imbibition at 10 days and 96 % germination. Germination potential, speed index, average germination time and time to reach maximum germination performed best when the bioproduct was used with doses of 2,5, 5, 10 and 15 %, imbibed for 28 hours. These doses did not show significant differences among themselves and had higher germination efficiency and a minimum of six days to reach maximum germination. Conclusions: The effectiveness of IHPLUS®BF during the germination process of L. leucocephala cv. Cunningham seeds was proven, being the best combination the use at 5 % for 28 hours with higher germination efficiency. [ABSTRACT FROM AUTHOR]

Astragalus sikokianus is a rare Japanese perennial of the seashore that was reported to be extinct in the wild. The small seed size and deep dormancy of A. sikokianus make it difficult for direct seeding restoration in aspects of seed handling, transport, planting, and seedling establishment. For the large-scale economic restoration of dormant small-seeded species, seed pelleting combined with the breaking of dormancy was studied. Physiological (prechilling and plant hormones) and physical (hot water, hydrochloric acid, and sulfuric acid) seed dormancy break treatments were evaluated. The dormant broken seeds were used for pelleting. The effects of the substrate, pellet sizes, and their interactions on germination were measured. The scarification of five rubs of seeds placed between sandpapers completely broke the physical dormancy of A. sikokianus. Seed coat impermeability inhibited germination. Pelleted seeds ranging from 2.0 to 4.0 mm in diameter showed more than 90% germination on filter paper. The germination of the pelleted seeds was measured in commercial, field, and sand soil conditions. The highest germination was shown in sand (70–74% GP), regardless of the pellet size, whereas unpelleted scarified seeds germinated only 48%. These results suggest that small-seeded species with physical dormancy can be used for seed-based restoration after seed pelleting. [ABSTRACT FROM AUTHOR]

Accelerated global warming is leading to the loss of plant species diversity, and ex situ preservation of seeds is becoming an increasingly important aspect of species conservation. However, information on dormancy and germination is lacking in many endangered species. Amsonia elliptica (Apocynaceae) is the only Amsonia species native to Korea, and the South Korean Ministry of Environment has designated it Class II endangered wildlife. Nevertheless, the dormancy class and the dormancy breaking method for seeds of this species for germination are not precisely known. We identified the structure of A. elliptica seeds and the causes of dormancy, which inhibits germination. In addition, we tried to develop an effective germination promotion method by testing the wet stratified condition, which breaks dormancy, and the form of gibberellin that can replace it. Fresh seeds of A. elliptica imbibe water, but the covering layers (endosperm and seed coat) inhibit germination by mechanically restricting the embryo. Initial germination tests confirmed low embryo growth potential and physiological dormancy (PD). Restriction due to the covering layer was eliminated by seed scarification, and abnormal germination was observed. After 12 weeks of cold moist stratification at 4°C, only 12% of seeds germinated. However, 68.8% of seeds subjected to 8 weeks of warm moist stratification followed by 12 weeks of cold stratification germinated, indicating that warm stratification pretreatment before cold stratification is effective in breaking dormancy. A. elliptica seeds exhibited intermediate PD. Furthermore, 61.3% of seeds soaked in 500 mg/L GA4+7 for 14 days and incubated at 25/15°C germinated. Therefore, GA4+7 rapidly broke the dormancy of A. elliptica seeds compared with warm plus cold stratification treatment, thus providing an efficient method for seedling production. [ABSTRACT FROM AUTHOR]

Background: The silver wattle Acacia dealbata is a fast-growing tree from Australia that has become naturalised in different regions of the world, attaining invasive status in most of them. In Chile, A. dealbata reaches large abundances along banks and floodplains of invaded fluvial systems, suggesting that rivers may act as a vector for seed dispersal. As hydrochory has not been documented previously in this species, the aim of this study is to evaluate the potential for water dispersal of seeds of this invasive tree along rivers. Methods: Seed samples from rivers were collected at three sites along two A. dealbata-invaded rivers within the Cachapoal basin, central Chile. Number of seeds collected was contrasted versus hydraulic and local conditions with RDA. Seed buoyancy and sedimentation velocity were determined and compared between sites with an ANCOVA. Finally, the probability of seed germination after long periods of immersion in water was assessed, simulating transport conditions in the flow. Germination results were tested with a GLM. Results: Results indicate that increasing abundance of A. dealbata seeds in the flow is related to the level of turbulence of the flow. Seeds display high floatability but their sedimentation velocity is high when they do sink. Finally, silver wattle seeds can germinate after long periods (many weeks) of immersion in water; however, their probability of germination depends to a large extent on whether seeds are scarified or not. Conclusions: Based on the evidence collected, we suggest that the seeds of A. dealbata have the necessary traits to be dispersed by rivers, this being the first research testing this hypothesis. The success of hydrochory of A. dealbata would depend on river flow turbulence, and whether there are natural mechanisms for scarifying the seeds either before or during transport. The proposed methodology can be used to assess river hydrochory for any tree species. [ABSTRACT FROM AUTHOR]

Saskatoon berry has become as important as a commercial fruit crop. One main goal is to release new plant cultivars well adapted to different climatic and soil conditions. Dormant seeds obtained from breeding are serious problems delaying the program. The seeds were directly extracted from fruits after harvest (unstored) or after storage at −18 °C for 6 months (stored) and subjected to modified stratification (3 °C) with KNO3, H2O2, NO, smoke-water (SW) or scarification using sandpaper or H2SO4 for 10, 20, 30, 40 min or treatments with pulsed radio frequency (PRF) or red light. The seeds were also subjected to warm–cool stratification (20/3 °C). Unstored seeds germinated in a higher percentage and with better uniformity (T75–T25) than stored seeds. Stored seeds positively affected the onset of seed germination (T1) and mean germination time (MGT). Dormancy breakage was promoted by stratification with KNO3, SW or scarification with sandpaper, H2SO4 or treatments with PRF. The recommended method for the breeding program of breaking seeds dormancy is when unstored seeds are subjected to stratification in KNO3 (0.2%) or SW (1:100). Depending on the applied methods, the percentage of seeds’ germination increased to 87% compared to untreated (64%) control seeds. The positive effects of the selected methods persisted during seedling development by stimulating their growth and enhancing the chlorophyll content index (SPAD) and effective quantum yield of PSII of chlorophyll in leaves (ΦPSII).

Astragalus sikokianus is a rare Japanese perennial of the seashore that was reported to be extinct in the wild. The small seed size and deep dormancy of A. sikokianus make it difficult for direct seeding restoration in aspects of seed handling, transport, planting, and seedling establishment. For the large-scale economic restoration of dormant small-seeded species, seed pelleting combined with the breaking of dormancy was studied. Physiological (prechilling and plant hormones) and physical (hot water, hydrochloric acid, and sulfuric acid) seed dormancy break treatments were evaluated. The dormant broken seeds were used for pelleting. The effects of the substrate, pellet sizes, and their interactions on germination were measured. The scarification of five rubs of seeds placed between sandpapers completely broke the physical dormancy of A. sikokianus. Seed coat impermeability inhibited germination. Pelleted seeds ranging from 2.0 to 4.0 mm in diameter showed more than 90% germination on filter paper. The germination of the pelleted seeds was measured in commercial, field, and sand soil conditions. The highest germination was shown in sand (70–74% GP), regardless of the pellet size, whereas unpelleted scarified seeds germinated only 48%. These results suggest that small-seeded species with physical dormancy can be used for seed-based restoration after seed pelleting.

Coastalsand frostweed (Crocanthemum arenicola (Chapm.) Barnhart [Cistaceae]) is a back dune plant of the north central Gulf of Mexico endemic to coastal Florida, Alabama, and Mississippi. We initiated seed and cutting propagation experiments to test the effects of scarification, photoperiod, and temperature on germination of C. arenicola. In addition, we examined the effects of cutting maturity (vegetative or reproductive stems), auxin (IBA) concentration, and time of rooting on the percentage of cuttings with roots and the quality of rooted cuttings of C. arenicola. We conducted 3 single-factor experiments in which seeds were subjected to scarification treatments, photoperiod treatments, or a gradient of temperature treatments, and germination (radicle emergence) was monitored over time (2-4 wk). A two-factor greenhouse cutting experiment was conducted comparing cutting maturity and auxin concentration on root number and root length of C. arenicola 3 and 7 wk after sticking. We assessed cuttings for root class at 7 wk. Scarification by sandpaper abrasion (50-200 s) increased germination compared to a non-scarified control (=90% compared to 11% germination). Photoperiod had no effect on germination, with similar germination in the light and dark. Higher germination occurred under cooler temperatures than warmer temperatures. Rooting at 3 wk (51%) was lower compared to rooting at 7 wk (76%). More roots were present on vegetative cuttings compared to reproductive cuttings (4.2 compared to 2.7 roots per cutting). Root length and root class did not differ with the application of auxin. [ABSTRACT FROM AUTHOR]

Restoration programs face several challenges in degraded drylands and desert environments, such as high temperatures, soil salinity, water scarcity, loose soils with low water-holding capacity, and poor fertility. Seed-enhancement technologies (SETs) are proposed to improve soil physical and chemical properties, improve seed germination and seedling recruitment, and promote plant growth. SETs improve seed, seedling, and adult plant growth through three main approaches: adding materials to seed coats (seed coating), removing barriers of seed coats (seed scarification), and physiologically altering metabolites through priming (seed priming). These three main approaches (categories) are further divided into several other subcategories. This review aims to define the general categorization of SETs, adopt the proper SETs for arid lands, and indicate the benefits of SETs to overcome the biotic and abiotic barriers in agricultural systems and the ecological restoration of degraded dryland ecosystems. In general, integrating different seed-enhancement technologies (SETs) for rehabilitating degraded lands with a mixture of seeds from various species is recommended, especially since some technologies tend to be species-specific.

The paper presents development of a high-performance process for extracting oil from quinoa seeds (Chenopodium quinoa Willd.) by supercritical CO2 extraction. The pre-treatment of seeds involving mechanical scarification was applied. The abrasive material gradation and time of abrasion were optimized. Optimum scarification conditions were obtained using the abrasive gradation P40 at scarification time of 50-100 min. Under these conditions, a seed coat was obtained in an amount of 10% of the seed weight and it contained 20 g oil/100 g seed. The oil was separated from the seed coats by supercritical fluid extraction. Approximately 61% of oil recovery was obtained under extraction conditions: pressure 25 MPa, temperature 40° C and extraction time 120 min. From seeds containing 5.6 g oil/100 g seed, after scarification and extraction with supercritical carbon dioxide, approx. 1.2 g oil/100 g seed was obtained from the seed coat. [ABSTRACT FROM AUTHOR]

Dodonaea viscosa (Sapindaceae) is widespread in the mountainous highlands of the southwestern part of Kingdom of Saudi Arabia, where it is a medicinally important species for the people in Saudi Arabia. Seeds of this species were collected from Mount Atharb in Al-Baha region, at an altitude of 2100 m. The aims of this study were to determine if the seeds of D. viscosa have physical dormancy (i.e. a water-impermeable seed coat) and, if so, what treatments would break dormancy, and what conditions promote germination after dormancy has been broken. The dormancy-breaking treatments included: soaking of seeds in concentrated sulfuric acid (H 2 SO 4) for 10 min, immersion in boiling water for 10 min and exposure to 50 °C for 1 min. After seeds had been pre-treated with H 2 SO 4 , to break dormancy, they were incubated at constant temperatures from 5 to 35 °C, under 12-h photoperiods or in continuous darkness, and germination recorded. Salinity tolerance was investigated by incubating acid-scarified seeds in different concentrations of mM NaCl in the light at 25 °C. Untreated seeds had low final germination 30%. Seeds that had been acid-scarified, immersed in boiling water or exposed to 50 °C all achieved 91% subsequently when incubated at 25 °C. Thus, seeds of this species in Saudi Arabia have physical dormancy, which can be broken by all three treatments designed to increase the permeability of the testa. After pre-treatment, there was a broad optimum constant temperature for germination that ranged between 5 and 25 °C but germination was inhibited by higher temperatures (30 and 35 °C). Light had little effect on this germination response. Scarified seeds were also sensitive to salinity, with the highest germination in distilled water and complete inhibition in 400 mM NaCl. Seeds that failed to germinate in saline treatments were mostly able to germinate on transfer to distilled water, suggesting osmotic inhibition. [ABSTRACT FROM AUTHOR]

Chrysophyllum albidum is an important fruit tree species with peculiar hard seed coat and slow growth. This study investigated effectiveness of mechanical scarification on seed germination and fertilizer types on sustainable growth of C. albidum seedlings. Five batches of 50 seeds each were subjected to 5 mechanical scarification treatments. Uniform seedlings were subjected to NPK 15:15:15 and organo-mineral fertilizer treatments. The experiment was laid out in completely randomized design with 4 treatments replicated 3 times; T1 = Organo-mineral fertilizer, T2 = NPK 15:15:15, T3 = Organic fertilizer and T4 = Control. There were significant differences among the treatments on the germination (p<0.05). On the growth assessment, T3 gave the highest Shoot height (35.80cm) and leaf production (15). Highest collar diameter (0.87cm) and leaf area (13.40cm²) were recorded for T1. Mechanical scarification and growth media amendment with the use of organic and inorganic fertilizers catalyzed the growth of the species sustainably. [ABSTRACT FROM AUTHOR]

• Cold plasma boosts fenugreek seed germination and growth. • Long-lasting effects of plasma on seed coat modification. • No correlation between seed wettability and germination. • Etching of the seed coat stimulates metabolic activity. Pre-sowing cold plasma (CP) treatment of seeds is a proven method for enhancing seed germination and plant growth. This paper presents a study on the long-lasting effects of CP treatment on fenugreek (Trigonella foenum-graecum) seeds to elucidate the basic mechanism of plasma action and pave the way for future field experiments. The seeds were subjected to short-duration treatments (10 and 20 s) using the kINPen 11 plasma jet and then stored for 3 months before sowing. After this period, the treated seeds exhibited higher germination efficiency, and the resulting seedlings were longer and more vigorous compared to normal seedlings. The improvement in germination was particularly noticeable for a treatment time of 20 s. Although we observed the age-related hydrophobic recovery, the plasma-treated seeds consistently showed better wettability than the control group. However, no direct correlation was found between wettability and germination improvement. Scanning electron microscopy (SEM) analysis revealed increased surface roughness and microstructuring of the outer layers of the seed coat after plasma treatment, while X-ray photoelectron spectroscopy (XPS) indicated an increase in the O/C ratio, as well as the presence of calcium and potassium. These findings suggest that the argon plasma etched the uppermost layer of the seed coat, leading to structural changes. It is suspected that the observed faster germination and growth of plasma-treated seeds is seeds due to these long-lasting changes in the seed coat structure, which may disrupt its tissues and open access to the interior of the seed. Under appropriate conditions, this facilitates an increase in the metabolic activity of the embryo. Such a mechanism can be considered as plasma scarification of the seed. This study highlights the potential of cold plasma technology as a viable and simple strategy for improving seed germination and plant growth in the long term, with important implications for the agricultural sector. [Display omitted] [ABSTRACT FROM AUTHOR]

In 2014, this research was conducted at the Research Institute of Horticulture in Skierniewice, Poland. It was based on different red raspberry seed treatments with sulfuric acid during the scarification process. The seeds were obtained from crosses among ten parental forms, producing 55 hybrid families. During scarification, the seeds were subjected to concentrated sulfuric acid for 20, 30 and 40 minutes. Assessment of the germinated seeds, performed 2.5 months after the sowing, revealed different effects of the seed origin/pedigree and the applied scarification treatments. The best seed germination was recorded for the hybrid families where 'Radziejowa' (56.5% of germinated seeds), 'Laszka' (63.9%) and 'Sokolica' (73.5%) were the maternal forms, and the poorest one - where 'Polana' (6.2% of germinated seeds), 'Glen Ample' (32.5%) and 'Canby' (33.1%) were used as the maternal cultivars. The highest germination, on average for all the hybrid families, was obtained for seeds treated with H2SO4 for 30 min (45.3% of germinated seeds), and the lowest when the seeds were treated with H2SO4 for 40 min (35.6%).

Basalt milkvetch and western prairie clover are native perennial legumes distributed in the northern Great Basin and Columbia River Plateau of North America, with recent germplasm releases providing seed for revegetation. Although seed germination studies have identified scarification requirements for both species, and additional cold stratification for Astragalus filipes, no research has been conducted to optimize the likelihood of seedling emergence on rangeland sites. In this study, we planted both species in 3 locations in the northern Great Basin over 3 y. Seeds were planted in both fall and spring seasons, with emergence measured each June. For both species, there was variation in seedling emergence success across locations and years, with the Powell Butte, Oregon, location providing the highest emergence and the 2011-2012 winter season leading to the highest emergence. For A. filipes, the greatest seedling emergence occurred with fall plantings with scarified seed because of a need for cold stratification and a slow germination rate. For Dalea ornata, because of its hard seedcoat yet rapid germination, the greatest seedling emergence occurred with spring plantings with scarified seed. Our data indicate a need for scarifying seed for both species, but planting A. filipes in fall and planting D. ornata in spring. [ABSTRACT FROM AUTHOR]

• Proper seed source selection is key for tropical forest restoration/reforestation. • Piecewise structural equation models assessed phenotypic effects on seedling quality. • Scarification, not tree phenotype, drives germination success in Coulteria platyloba. • Provenance, rather than tree phenotype, affects seedling quality in C. platyloba. • Both natural and managed populations should be used as seed sources for this species. A major obstacle faced by reforestation/restoration programs is an insufficient supply of high-quality seed. Seed collection is commonly based on opportunistic strategies that only consider availability and distance to seed sources, but not seed quality. Although for commercial timber species from temperate ecosystems the selection of individuals with above-average phenotypes often results in high-quality seeds and seedlings, the validity of this criterion has not been assessed in tropical dry forests (TDF). By using the abundant TDF tree Coulteria platyloba as study model and piecewise structural equation modelling (pSEM), we examined the associations between germination success and seedling growth, and various tree, fruit and seed characteristics, for seeds from two provenances (natural vs. managed populations), that were either scarified or not. Unexpectedly, phenotypic attributes of trees, fruits and seeds had no effect on germination success, as this response variable depended on scarification only. Also, fruit quality was unrelated to tree size, but it was related to provenance. According to pSEM, the best supported path resulting in high quality seedlings established a relationship between managed populations, high quality fruits and seedlings with better roots systems, but only for seeds that were scarified and did not germinate very rapidly. Overall, the assessed relationships were complex, weak, and sometimes difficult to interpret. Nonetheless, these results provide guidance to improve seed source selection efforts that consider operation costs of nurseries and the success of future plantations. In TDF, selecting trees with above-average phenotypes as seed sources does not necessarily favour the quality of seedlings used to restore degraded areas. In these ecosystems, we recommend a seed collection strategy that combines managed and natural populations as seed sources to maximize genetic variability in future plantations, while improving nursery operation efficacy. [ABSTRACT FROM AUTHOR]

1. Seed manipulation by ants can play a key role in seed germination through two main behaviours: elaiosome detachment and seed scarification. Despite the fact that these behaviours are commonplace, their effects have only been quantified independently, and their consequences on seed germination remain controversial. 2. Here we experimentally investigate the effects of ant manipulation on seed germination, disentangling the contributions of these two ant behaviours to this process. To do so, under laboratory conditions, we studied the effects of seed manipulation by Acromyrmex subterraneus on germination of seeds from Mabea fistulifera, a myrmecochorous plant. We established six experimental treatments: (i) unmanipulated seeds; (ii) ant‐manipulated seeds with the elaiosome detached and scarified; (iii) ant‐manipulated seeds with the elaiosome detached and non‐scarified; (iv) hand‐manipulated seeds with the elaiosome remaining and scarified; (v) hand‐manipulated seeds with the elaiosome detached and scarified; and (vi) hand‐manipulated seeds with elaiosome detached and non‐scarified. 3. We found that both elaiosome detachment and seed scarification decreased seed germination rates. Moreover, there was no difference in germination rates whether the seeds were manipulated by researcher's hand or by ants, suggesting a lack of other ant‐manipulation effects on seeds. 4. The present study shows that manipulation by A. subterraneus can exert negative effects on germination of a myrmecochorous seed. Accordingly, we suggested that studies evaluating the benefits of myrmecochory for plants, based only on seed removal amount and distance, may be overestimating those benefits. Our results contribute to the understanding of the potential mechanisms influencing plant recruitment, especially for myrmecochorous plants inhabiting tropical forests. The effects of ant manipulation on seed germination were investigated experimentally, disentangling the contributions of elaiosome detachment and seed scarification to this process.Manipulation by Acromyrmex subterraneus ants negatively affects germination of Mabea fistulifera myrmecochorous seeds. It was found that both elaiosome detachment and seed scarification decreased seed germination rates.With regard to the independent effects of those behaviours, the study showed that scarification alone was responsible for the highest decrease in seed germination, followed by elaiosome detachment. [ABSTRACT FROM AUTHOR]

The Mexican yew (Taxus globosa) is important for the production of taxol, which is used to treat several types of cancer and its seeds undergo a latent period. The objectives of this research were to study the causes of seed dormancy in this species, the types of dormancy mechanisms it undergoes and how to break such dormancy. Seeds from two regions of Mexico (northern and central region) were evaluated using 12 pre-germination treatments. The treatments consisted of warm and cold stratification, applying 500 ppm of gibberellic acid (GA4/7) at different intervals, or using alternative seed scarification methods. In addition, embryo growth was studied and a protocol for in vitro embryo culture was also tested. Seeds from the central region did not germinate, probably because of inbreeding depression in seeds that came from small fragmented populations. In contrast, seeds from the northern region of Mexico subjected to warm plus cold stratification, warm plus cold stratification plus GA4/7 application, and warm stratification plus stratification with N2 plus GA4/7 application exhibited the highest germination rates (12-14 %). In vitro embryo culture indicated that only 30% of the embryos germinated. Thus, dormancy in the Mexican Yew seems to be caused by several factors, including both morphological and physiological factors. [ABSTRACT FROM AUTHOR]

The influence of increased zinc concentrations on seed germination, growth activity, photosynthetic apparatus, and water metabolism in two perennial grasses (Phleum pratense L. and Elytrigia repens (L.) Nevski) was studied in laboratory and vegetation experiments to assess plant metal tolerance. In laboratory conditions it was established that seeds of both species may germinate in a wide range of zinc concentrations. In vegetation experiments, the possibility of successful growth and accumulation of biomass of both grasses in the presence of high zinc concentration in the root medium was revealed. At the same time, high water contents in root and shoot tissues were maintained, as well as the necessary intensity of photosynthesis (due to maintenance of the efficiency of photosystem II and the amount of carotenoids). It was noted that the established high resistance of both species of grasses to zinc, as well as their ability to accumulate significant amounts of metal ions in the roots, indicates that P. pratense and E. repens may be used for phytoremediation of soils contaminated with zinc. [ABSTRACT FROM AUTHOR]

Highlights • CaCl 2 induced osmotic, nutritional, and toxic effects in C. tinctorius plants. • Root Mg uptake efficiency was maintained constant in all treatments. • The uptake selectivity of Mg over Ca substantially increased under CaCl 2 stress. • Mg use efficiency for chlorophyll synthesis was noticeably enhanced under CaCl 2 stress. • CaCl 2 salinity was the dominant stress that oriented plant physiological responses. Abstract CaCl 2 effects on growth, photosynthesis, and Mg nutrition were investigated in safflower ( Carthamus tinctorius L.) plants at low and optimal Mg availability. After seed germination on sand, obtained seedlings were grown under greenhouse conditions and subjected to 3 treatments for 4 weeks: control ( C: 1.5 mM Mg), CaCl 2 salinity ( S: 40 mM CaCl 2 ), and combined effects of CaCl 2 salinity and Mg deficiency ( DS: 0.1 mM Mg and 40 mM CaCl 2 ). The application of 40 mM CaCl 2 severely affected root, stem, young leaf, and old leaf growth. This was due to a combination of the three types of effects (osmotic, toxic, and nutritional). Indeed, in response to CaCl 2 presence under both Mg-sufficient and deficient conditions, photosynthetic activity was reduced by stomatal closure to prevent cell dehydration. As a consequence, plant water status was not severely affected in S treatment and this osmotic effect disappeared under Mg-deficient conditions (DS treatment). Membrane integrity was slightly impaired in both S and DS treatments. Mg and Ca imbalances were also detected although plants exhibited adaptive responses to cope with Mg deficiency coupled or not with excessive Ca accumulation. Treated plants substantially increased Mg/Ca uptake selectivity, which allowed them to maintain Mg uptake efficiency unaffected. They also markedly increased their Mg use efficiency for chlorophyll synthesis. Nevertheless, amongst the three salt effects, nutritional imbalances seem to be the most harmful component. As a whole, the responses of the plant to the combined effects of CaCl 2 application and Mg deficiency were dominated by salinity stress responses. [ABSTRACT FROM AUTHOR]

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Abstract: Many invasive plant species have fleshy fruits that are eaten by native frugivorous birds which disperse their seeds and may facilitate their germination, playing an important role in plant invasion success. The fleshy‐fruited shrub Cotoneaster franchetii (Rosaceae) is an important invasive alien in the mountainous regions of central Argentina. To determine the role of avian frugivorous in fruit removal of this species, we conducted a frugivore exclusion experiment including bagged and unbagged branches in 75 plants of C. franchetii. At the end of the dispersal period, we compared the percentage of missing fruits (removed by birds + naturally dropped) in unbagged branches with the percentage of naturally dropped fruits in bagged branches. To assess whether any mechanism acting on seeds during their passage through bird guts (de‐inhibition by pulp removal and/or seed scarification) affects seed germination of this species, we compared percentage and speed of germination among seeds obtained from faeces of the native frugivorous Turdus chiguanco, from manually de‐pulped fruits, and from intact fruits. The percentage of missing fruits per shrub in unbagged branches was significantly higher than the percentage of naturally dropped fruits in bagged branches, suggesting that frugivorous birds play an important role in fruit removal of C. franchetii in the study area. Seeds from bird faeces and from manually de‐pulped fruits germinated in higher percentage and faster than seeds from intact fruits. Germination percentage and speed of seeds from manually de‐pulped fruits were significantly higher than those of gut‐passed seeds. These results indicate that T. chiguanco increases and accelerates seed germination of C. franchetii through pulp removal, but not through seed scarification. Overall, our findings indicate that native frugivorous birds facilitate the dispersal and germination success of C. franchetii, likely playing an important role in its invasion throughout the mountainous region of central Argentina. [ABSTRACT FROM AUTHOR]

Trapa natans is an aquatic annual plant that grows in stagnant water and occupies an extremely wide, yet discontinuous native range across temperate Europe, Asia, and Africa, and is naturalized in North America and Australia. Despite its wide distribution and invasion success, its seed germination ecology is poorly known. We hypothesized that, due to its wide distribution range, T. natans seeds should germinate under a broad spectrum of environmental conditions. In the present study, freshly matured seeds were cold stratified and tested for germination over a range of temperatures in light/dark, and dark under aerobic and hypoxia conditions. Seed and seedling tolerance to freezing and desiccation also were determined. Freshly matured seeds were physiologically dormant, requiring 9 weeks of cold stratification to overcome the dormancy. Seeds tolerated freezing down to −14 °C, whereas those with an emerged hypocotyl exhibited a high sensitivity to freezing down to −4 °C. The non-dormant seeds germinated (75–100%) under almost all environmental conditions, i.e. constant 22 °C and alternating temperature of 14/6 °C to 30/22 °C and 30/10 °C, light and darkness, oxic and hypoxia, thus supporting our proposed hypothesis. Finally, seeds were found to be highly desiccation-sensitive, even at high relative humidity. Our findings suggest that the wide germination niche could help explain its broad distribution and invasion success at local and global scales. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: The goal of this research was to develop the electro‐culturing process for different species of plants including Arabidopsis thaliana and Mammillaria mathildae using IrO2‐Ta2O5|Ti | Ti (anode) electrodes while applying a constant direct current electric field. RESULTS: Germination rate was increased in both plant species, growth rate was also enhanced during early life stages of A. thaliana, while the size of the Cactaceae M. mathildae was also increased. Root structure was analyzed in an in vitro analysis using A. thaliana and several enhanced aspects were observed. CONCLUSIONS: This Testing showed that an electro‐culturing process was beneficial during testing as soil ions underwent electro‐migration allowing the permeation of the nutrients to the seeds. Furthermore, a decrease in pH was observed near the IrO2‐Ta2O5|Ti anodes, due to electrolysis of the water during the electro‐culture process (pH = 1), and generation of hydroxyl radicals (·OH) was observed during this electrolysis when seeds were exposed to low intensity direct current electric fields for a short time. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Scarification involves the partial removal of the seed coat on the side of the hilum, opposite the radicle, to speed up germination in acorns. The aim of this study was to determine the influence of scarification on the germination capacity of pedunculate oak acorns, selected and prepared for sowing. The diameter, length and mass of acorns were measured before and after scarification in four batches of acorns harvested from uneven-aged trees (76, 91, 131 and 161 years). The measured parameters were used to determine the correlations between acorn dimensions and mass, and to calculate the dimensional scarification index and the mass scarification index in acorns. Individual complete and scarified acorns from every batch were germinated on sand and peat substrate for 28 days. The analyzed acorns were characterized by average size and mass. Scarification decreased acorn mass by around 22% and acorn length by around 31% on average. Scarification and the elimination of infected acorns increased germination capacity from around 64% to around 81% on average. Acorns can be divided into size groups before scarification to obtain seed material with varied germination capacity. Larger acorns with higher germination capacity can be used for sowing in container nurseries, whereas smaller acorns with lower germination capacity can be sown in open-field nurseries. [ABSTRACT FROM AUTHOR]

Aim of study: The purpose was to determine the type of dormancy and the optimal germination conditions of Phillyrea angustifolia (Oleaceae) seeds. Area of study: Germination requirements of P. angustifolia seeds collected from wild plants growing in the province of Ávila (Central Spain) were studied. Materials and methods: Seed water uptake was measured. Seeds with and without an endocarp were germinated at different temperatures, and several treatments were tested. Main results: The lignified endocarp interferes mechanically with the emergence of the radicle, and the treatments that achieved the highest germination percentages were the total removal of the endocarp with pliers (84%) or the immersion in liquid nitrogen for 1 min (97%). Scarification with concentrated sulphuric acid did not significantly increase germination compared to the control seeds, and treatments with dry heat or wet heat were detrimental to seed germination. The optimum temperature for germination was 15 ºC. A pre-sowing treatment of soaking in distilled water for 24 h slightly increased germination speed. Neither cold stratification at 5 ºC nor soaking in a gibberellic acid solution improved seed germination. Research highlights: Phillyrea angustifolia seeds have physiological dormancy – that is, the embryo does not have enough growth potential to overcome the mechanical restriction of the lignified endocarp. The seeds do not exhibit physical dormancy, given their water-permeable lignified endocarp. Our results suggest that the optimum germination protocol for P. angustifolia would be the total removal of the endocarp or immersion in liquid nitrogen for 1 min, followed by immersion in distilled water for 24 h and then seed incubation at 15 ºC in light or darkness.

Background: Mycoheterotrophic plants are one of the most difficult plant groups to conserve because they are entirely dependent on symbiotic fungi. Establishment of viable culture systems would greatly aid their conservation. We describe a simple culture system for the mycoheterotrophic orchid, Gastrodia pubilabiata, that does not require laboratory facilities. The orchid is symbiotic with leaf-litter-decomposing fungi. Results: Gastrodia pubilabiata seeds were incubated in plastic boxes or glass bottles filled with leaf litter collected from the natural habitat of the species. Seed germination was observed after 35 days and seedling development followed. Fungal isolates from seedlings were identified as Mycenaceae (Basidiomycota), a leaf-litter-decomposing mycorrhizal fungus of Gastrodia species. Conclusion: Our method can be used to conserve endangered mycoheterotrophic plants associated with leaf litter-decomposing fungi efficiently, and can also serve as a model system for physiological and molecular studies of such plants. [ABSTRACT FROM AUTHOR]

Background: Dimorphic seeds from Suaeda aralocaspica exhibit different germination behaviors that are thought to be a bet-hedging strategy advantageous in harsh and unpredictable environments. To understand the molecular mechanisms of Suaeda aralocaspica dimorphic seed germination, we applied RNA sequencing and small RNA sequencing for samples collected at three germination stages. Results: A total of 79,414 transcripts were assembled using Trinity, of which 57.67% were functionally annotated. KEGG enrichment unveiled that photosynthesis and flavonol biosynthesis pathways were activated earlier in brown seed compared with black seed. Gene expression analysis revealed that nine candidate unigenes in gibberellic acid and abscisic acid signal transduction and 23 unigenes in circadian rhythm-plant pathway showed distinct expression profiles to promote dimorphic seed germination. 194 conserved miRNAs comprising 40 families and 21 novel miRNAs belonging to 20 families in Suaeda aralocaspica were identified using miRDeep-P and Mfold. The expression of miRNAs in black seed was suppressed at imbibition stage. Among the identified miRNAs, 59 conserved and 13 novel miRNAs differentially expressed during seed germination. Of which, 43 conserved and nine novel miRNAs showed distinct expression patterns between black and brown seed. Using TAPIR, 208 unigenes were predicted as putative targets of 35 conserved miRNA families and 17 novel miRNA families. Among functionally annotated targets, genes participated in transcription regulation constituted the dominant category, followed by genes involved in signaling and stress response. Seven of the predicted targets were validated using 5'rapid amplification of cDNA ends or real-time quantitative reverse transcription-PCR. Conclusions: Our results indicate that specific genes and miRNAs are regulated differently between black and brown seed during germination, which may contribute to the different germination behaviors of Suaeda aralocaspica dimorphic seeds in unpredictable variable environments. Our results lay a solid foundation for further studying the roles of candidate genes and miRNAs in Suaeda aralocaspica dimorphic seed germination. [ABSTRACT FROM AUTHOR]

Seeds from the Texas Northern Blackland Prairie ecotype of western soapberry (Sapindus saponaria L. var. drummondii (Hook. & Arn.) L.D. Benson [Sapindaceae]) were collected, stored, pretreated (with sulfuric acid scarification and stratification), and germinated for the purposes of silviculture projects. Seeds were scarified for 0, 20, 40, and 60 min using 96% sulfuric acid (H2SO4) and half were stratified at 2 to 5.5 °C (35.5-42 °F) for 45 d. Results from the pretreatment methods were significantly different (stratification, P < 0.001; scarification, P = 0.039), with the greatest difference being between mean germination percentage for non-stratified and stratified seeds at 14.67% and 60.33%, respectively. For both stratification methods, the 20-min acid scarification method produced the highest germination percentages; however, germination occurred without acid scarification in both stratified and non-stratified seeds. This outcome could indicate the ecotype lacked physical dormancy or that a less volatile seed scarification pretreatment method, such as peat moss storage, could be a viable germination method. [ABSTRACT FROM AUTHOR]

Low temperature is a limiting factor of seed germination and plant growth. In this study, two independent experiments were conducted to investigate the effects of low temperature on germination, early seedling growth and antioxidant systems in two provenances of Elymus nutans Griseb. (Damxung, DX and Gannan, GN). The seeds and early seedlings of DX were more tolerant to low temperture than those of GN. Low temperature (5°C) negatively affected seed Germination Percentage (GP), Germination Energy (GE) and the First Germination Time (FGT) in both provenances of E. nutans. Low temperature also increased Mortality Percentage (MP) when compared with control plants grown at 25°C. Low temperature treatments significantly reduced length and fresh/dry weight of shoots and roots in the two accessions after 29 days of exposure to 5°C. In the second experiment, after 5 days of low temperature treatment, DX exhibited significantly higher Chlorophyll (Chl) and Carotenoid (Car) content as well as increased activities of Peroxidase (POD), SuperOxide Dismutase (SOD), Catalase (CAT). In contrast we observed lower Electrolyte Leakage (EL) and reduction of the amounts of MalonDiAldehyde (MDA), Hydrogen peroxide (H2O2) and superoxide radical ( O•- 2 ). We conclude that GN is more susceptible to low temperature than DX due to more severe oxidative damage resulting from Reactive Oxygen Species (ROS) and lower antioxidant enzyme activities. [ABSTRACT FROM AUTHOR]

In 2014, this research was conducted at the Research Institute of Horticulture in Skierniewice, Poland. It was based on different red raspberry seed treatments with sulfuric acid during the scarification process. The seeds were obtained from crosses among ten parental forms, producing 55 hybrid families. During scarification, the seeds were subjected to concentrated sulfuric acid for 20, 30 and 40 minutes. Assessment of the germinated seeds, performed 2.5 months after the sowing, revealed different effects of the seed origin/pedigree and the applied scarification treatments. The best seed germination was recorded for the hybrid families where 'Radziejowa' (56.5% of germinated seeds), 'Laszka' (63.9%) and 'Sokolica' (73.5%) were the maternal forms, and the poorest one - where 'Polana' (6.2% of germinated seeds), 'Glen Ample' (32.5%) and 'Canby' (33.1%) were used as the maternal cultivars. The highest germination, on average for all the hybrid families, was obtained for seeds treated with H2SO4 for 30 min (45.3% of germinated seeds), and the lowest when the seeds were treated with H2SO4 for 40 min (35.6%). [ABSTRACT FROM AUTHOR]

BACKGROUND Brassica spp. sprouts are rich in nutrients and bioactive compounds, especially glucosinolates and phenolic acid derivatives, and the composition of these young germinating seeds can be altered by several external factors. In this study two cabbage varieties ( Brassica oleracea var. capitata, red and white) were studied using seed priming ( KCl 50 mmol L−1; NaCl 150 mmol L−1) and MeJA spraying (25 µmol L−1) to elicit the phytochemical content of edible sprouts. RESULTS The red variety was richer in glucosinolates and phenolic compounds than the white one but not in mineral nutrients. Seed priming enhanced the potassium (K) content and flavonols in both varieties, while the total content of glucosinolates was reduced after seed priming only in the red variety. The white variety responded better than the red one to KCl seed priming, increasing the flavonols (89%). Salinity did not induce any change in the phytochemical content of these two varieties. Elicitation with sprayed MeJA was effective in significantly increasing the content of indolic glucosinolates glucobrassicin (5.7-fold) and neoglucobrassicin (9.7-fold) in the red cultivar. In the white variety, in addition to glucobrassicin (19.4-fold) and neoglucobrassicin (9.4-fold), 4-hydroxyglucobrassicin (2.3-fold) was also enhanced. MeJA also elicited significant amounts of anthocyanins (41%) and chlorogenic acid derivatives (329%) in the white variety. CONCLUSION KCl seed priming and MeJA elicitation promoted the phytochemical composition of the cabbage varieties, especially in the white variety. The application of NaCl resulted in less efficient elicitation. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) inhibits seed germination and the regulation of ABA biosynthesis has a role in maintenance of seed dormancy. The key rate-limiting step in ABA biosynthesis is catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED). Two hydroxamic acid inhibitors of carotenoid cleavage dioxygenase (CCD), D4 and D7, previously found to inhibit CCD and NCED in vitro, are shown to have the novel property of decreasing mean germination time of tomato (SolanumlycopersicumL.) seeds constitutively overexpressing LeNCED1. Post-germination, D4 exhibited no negative effects on tomato seedling growth in terms of height, dry weight, and fresh weight. Tobacco (Nicotiana tabacum L.) seeds containing a tetracycline-inducible LeNCED1 transgene were used to show that germination could be negatively and positively controlled through the chemical induction of gene expression and the chemical inhibition of the NCED protein: application of tetracycline increased mean germination time and delayed hypocotyl emergence in a similar manner to that observed when exogenous ABA was applied and this was reversed by D4 when NCED expression was induced at intermediate levels. D4 also improved germination in lettuce (Lactuca sativa L.) seeds under thermoinhibitory temperatures and in tomato seeds imbibed in high osmolarity solutions of polyethylene glycol. D4 reduced ABA and dihydrophaseic acid accumulation in tomato seeds overexpressing LeNCED1 and reduced ABA accumulation in wild type tomato seeds imbibed on polyethylene glycol. The evidence supports amode of action of D4 through NCED inhibition, and thismolecule provides a lead compound for the design of NCED inhibitors with greater specificity and potency. [ABSTRACT FROM AUTHOR]

Prosopis juliflorais a perennial shrub introduced in the 1980s to the Baringo District in central Kenya, and became highly invasive starting around the late 1990s. This period coincides with a shift of the composition of ruminant herds from formerly cattle to goats in this area. To assess the possible role of this shift in herd structure onP. julifloraspread, we conducted feeding trials and germination tests to determine the capacity of seeds to survive the passage through the intestinal tract of goats and cattle, comparing germination with chemically scarified and untreated seeds. Recovery of seeds eight days after ingestion was lower from goats (7%) than from cattle (15%) dung. Germination dynamics were similar for seeds that had been manually extracted from pods with those recovered after intestinal passage. Chemically scarified seeds germinated fastest and reached a germination rate of 100% within five days. While no apparent scarification effect was observed, the main contribution of endozoochorous dispersal ofProsopisseeds is their release from the enclosing pod segments, their dispersal away from the mother plant and possibly the provision of nutrients by the dung for their establishment and initial growth. [ABSTRACT FROM PUBLISHER]

Two of the most troublesome weeds in soybean, cotton, and corn in cropping systems of mid-south United States (US) are Senna obtusifolia and Xanthium strumarium. Understanding their population dynamics, particularly weed seedling emergence patterns, is important for the timely implementation and the success of weed management strategies. Identifying the sources of variation of emergence patterns could greatly improve our ability to predict emergence timing. A three-years field study was conducted to determine the effect of environmental conditions on S. obtusifolia and X. strumarium seedling emergence and seedbank potential. The experiment was conducted with two seed sources; X. strumarium burs and S. obtusifolia seeds from a single maternal plant source, and X. strumarium burs and S. obtusifolia seeds from multiple maternal plant sources, both being exposed either to 5 cm burial depth (buried) or left on the soil surface (soil surface) in the fallow or planted in spring after their storage under chilled (chill) or room temperature (no chill) conditions. X. strumarium and S. obtusifolia seedling emergence was lower from burs and seeds that were planted in the soil in September as compared with the chill and/or no chill seeds/burs stored for six months. X. strumarium seedling emergence was reduced from 37 to 1% when burs were left on the soil surface when compared to buried burs. S. obtusifolia seedling emergence was reduced from 47 to 13% when seeds were left on the soil surface as compared to buried. At the end of the experimental period, the soil seedbank of X. strumarium had been significantly depleted, whereas the remaining seeds of S. obtusifolia were viable.

Post-translational modifications of histones play important roles in modulating many essential biological processes in both animals and plants. These covalent modifications, including methylation, acetylation, phosphorylation, ubiquitination, SUMOylation and so on, are laid out and erased by histone-modifying enzymes and read out by effect or proteins. Recent studies have revealed that a number of developmental processes in plants are under the control of histone post-translational modifications, such as floral transition, seed germination, organogenesis and morphogenesis. Therefore, it is critical to identify those protein domains, which could specifically recognize these post-translational modifications to modulate chromatin structure and regulate gene expression. In the present review, we discuss the recent progress in understanding the structure and function of the histone methylation readers in plants, by focusing on Arabidopsis thaliana proteins. [ABSTRACT FROM AUTHOR]

Seeds of most Great Basin lupine (Lupinus spp. [Fabaceae]) species are physically dormant and thus, difficult to establish in uniform stands in seed production fields. We designed this study to examine 5 seed scarification techniques, each with 11 levels of application (including a non-scarified control), to reduce the physical seed dormancy of longspur lupine (L. arbustus Douglas ex Lindl.), silvery lupine (L. argenteus Pursh), hairy bigleaf lupine (L. prunophilus M.E. Jones), and silky lupine (L. sericeus Pursh). These 4 perennial Great Basin lupine species are of interest for both rehabilitation and restoration of degraded rangelands. We evaluated 10 treatments of each of 5 scarification methods, one mechanical, 2 thermal, and 2 chemical (sulfuric acid and sodium hypochlorite) techniques on the above-mentioned species. The sulfuric acid and the mechanical scarification treatments significantly improved germination for both silvery and silky lupine. Additionally, one thermal scarification method (60 s at 95 °C [203 °F]) was effective for silvery lupine. Both sulfuric acid and sodium hypochlorite scarification methods had treatment levels that significantly improved germination of hairy bigleaf lupine. For longspur lupine, all treatments within the 5 scarification methods either decreased or were not a significant improvement of germination as compared with the control, except for the treatment of soaking the seeds for 35 s at 95 °C (203 °F). We found scarification to be an effective tool for reducing physical dormancy in silvery lupine, hairy bigleaf lupine, and silky lupine, thus allowing for a more efficient use of limited seeds. [ABSTRACT FROM AUTHOR]

The effects of temperature and relative humidity (RH) on germination of Fusarium graminearum ascospores, and of dry periods (DP) of different lengths and of temperature and RH during DP on ascospore survival were studied both in vitro and in planta. Optimal temperatures for ascospore germination at 100% RH were 20 and 25°C; germination was <5% when ascospores were incubated at 20°C and RH < 93.5%. Viable ascospores were found at all tested combinations of DP duration (0 to 48 h) x temperature (5 to 40°C) or RH (32.5 to 100% RH). Germination declined as DP duration and temperature increased. Germination was lower for ascospores kept at 65.5% RH during the DP than at 76.0, 32.5, or 93.5% RH. Equations were developed describing the relationships between ascospore germination, DP duration and temperature or RH during DP. Durum wheat spikes were inoculated with ascospores and kept dry for 0 to 48 h at approximately 15°C and 65% RH; plants were then kept in saturated atmosphere for 48 h tofavor infection. Fungal biomass, measured as F. graminearum DNA by quantitative polymerase chain reaction. declined as DP increased to 24 and 48 h at 3 and 9 days postinfection but not in spikes at maturity. [ABSTRACT FROM AUTHOR]

Seed dispersal by ants is common in arid lands. The seeds of myrmecochorous plants bears an elaiosome, an appendage that acts as a reward for ants. Once an ant identifies an elaiosome-bearing seed, it carries the diaspore to the nest, removes the elaiosome and discards the seed. During elaiosome removal, ants also scarify the seed, which may favor seed germination or facilitate pathogen attack. Some elaiosomes are hygroscopic and therefore, this could increase water intake and retention. We assessed the effect of elaiosome removal, seed scarification and fungal infection on germination in Cnidoscolus aconitifolius , a plant species common in the arid tropics of the Americas. The effects of elaiosome removal on ant attraction and seed removal were also assessed. According to the results, the elaiosome of C. aconitifolius increases the attractiveness of its seeds to ants, but did not affect seed removal or seed germination. Also, the elaiosome significantly increased the chance of pathogen attack on the seed. The benefits of elaiosome removal on seed germination were mediated by physical scarification, with greater germination in scarified seeds without elaiosomes. Seed scarification did not affect the likelihood of fungal attack. • During seed dispersal, ants detach the elaiosome and discard the seeds intact. • Effects of elaiosome detachment on ants, seed removal and germination were assessed. • Elaiosomes increased ant attraction and pathogen attack in Cnidoscolus aconitifolius. • Elaiosomes per se are not relevant to seed removal and germination. • Effects of elaiosome on seed germination are mediated by scarification. [ABSTRACT FROM AUTHOR]

The soil seed bank has a limited role in the seasonal dry tropical forest regeneration process, but seed removal and germination can also be limiting factors during the early forest recovery. In central Veracruz, Mexico, the soil seed bank was determined en five fallows and two forests. Seed bank decreased from fallow to forest (1303 to 101 seeds m-2); herbs and grasses predominated thus the similarity between species composition of seed bank and vegetation was low. Seed removal and germination were evaluated for Acacia cochliacantha, Caesalpinia cacalaco, Ipomoea wolcottiana and Senna atomaria in contrasting habitats represented by pasture, fallow and forest. Seed removal was determined under treatments of total access, rodent exclosure, and insect exclosure. Caesalpinia (largest seeds) displayed the lowest seed removal (5%), whereas Senna (63%) and Ipomoea (29%) displayed the highest. Rodent exclosure reduced seed removal for Ipomoea (medium-sized seeds); and insect exclosure reduced removal for Senna and Acacia (small seeds). With the exception of Senna (18% germination), the scarified seeds displayed the highest germination percentage (53-99%). For all species, germination was higher in forest than in open habitats, only Senna seeds displayed the lowest germination percentage in the forest habitat. Results suggested that in the dry forest of Veracruz, seed removal may not limit forest regeneration; however seeds must be scarified for use in restoration activities.

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing 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.)

We report the effects of storage time and pretreatment on seed germination of Fokienia hodginsii. Lower mean germination was observed in seeds stored for 2 years (6.41 ± 1.23 seeds/replicate) compared with those stored for 1 year (8.52 ± 1.06 seeds/replicate). Seeds collected from a southern location had statistically higher mean germination (9.67 ± 1.28 seeds/replicate) than those collected from a northern location (7.99 ± 1.36 seeds/replicate). Higher mean T50 was observed in seeds stored for 2 years (37.02 ± 4.43 days) compared with those stored for 1 year (30.69 ± 5.06 days). Mean germination of untreated fresh seeds was 9.97 ± 1.34 seeds/replicate and that of treated fresh seeds in 60°C water was 12.95 ± 1.24 seeds/replicate. Fresh seeds treated with 50°C and 70°C water had a significantly lower mean germination compared with untreated seeds and seeds treated in 60°C water. Mean T50 was lowest in seeds treated with 60°C water. [ABSTRACT FROM AUTHOR]

The degree of seed scarification in the frugivore gut, partly dependent on gut retention time, is a key component in determining the extent to which gut passage alters germination performances. Another potential benefit of gut passage arises as a result of the removal of fruit pulp which otherwise may act as a germination inhibitor. Using experiments designed to disentangle the respective effects of pulp removal (germination deinhibition) and seed scarification, and gut retention time as an explanatory variable, we investigated the effect of gut passage on germination performances (percentage and latency) of five tropical tree species dispersed by the western lowland gorilla ( Gorilla g. gorilla ). The percentage of seeds germinating after gut passage increased for three species, respectively, through the effects of scarification only, deinhibition only, and scarification and deinhibition combined. A negative scarification effect was observed for one species, and no effect of gut passage for another. Passage through the gut led to a decrease in germination latency of three species, as a result of the depulping of seeds. However, seed scarification resulted in germination delays for another species. The gut retention time of the five species averaged 39–56 h and had no effect on intra-specific germination performances except for one species whose germination probability increased as gut retention time increased. As gut retention time often correlates with dispersal distance, the fact that gut retention time per se does not reduce seed viability of these tropical tree species may have positive implications for their population dynamics and maintenance of genetic diversity. If no detrimental effect of gut retention time on germination performance is a general trait among tropical species, the extirpation of large frugivores with long gut retention time, such as the western lowland gorilla, would likely have negative long-term implications for tropical forests. [ABSTRACT FROM AUTHOR]

Questions Translocation of topsoil and its seed bank for ecological restoration is increasingly popular. How representative is the soil seed bank of the extant vegetation at the source site? What influence does the transfer process have on germinant density, species and plant functional type composition? Does smoke and heat treatment of transferred topsoil enhance germination and potential for restoration success? Location Banksia woodland of the Swan Coastal Plain, Western Australia. Methods To assess the efficacy of topsoil transfer for return of native plant species, we measured topsoil seed bank characterisitcs in situ proir to vegetation clearing, and immediately after transfer of the topsoil to an adjacent, degraded mediterranean-type woodland in southwest Australia. Glasshouse germination of topsoil samples from 24 pre- and 24 post-transfer plots was used to quantify the effects of transfer and soil depth on germinant density, species richness, plant functional types and seed bank similarity to in situ vegetation. Application of germination cues (heat + smoke) was used to explore the impact of topsoil transfer on seed germination and emergence. Results Topsoil transfer significantly reduced germinant densities (pre-transfer 1692-4239 germinants·m−2, post-transfer 795-1016 germinants·m−2; t = 6.7, P < 0.001) and shifted community structure ( MRPP: A = 0.13, P < 0.001), including a reduction of woody species density by 81%. For the majority of functional types, heat and smoke failed to stimulate additional germination post-transfer, suggesting soil transfer simulated the effect of fire-related germination cues. Conclusion Although topsoil transfer translocated many viable native seeds, potential restoration success was hindered by reduced germinant densities. This was mostly attributable to a dilution effect associated with mixing of transferred topsoil, so that many seeds were buried too deep to emerge. However, total reductions were greater than expected based on dilution alone, suggesting some seed mortality during the transfer process. Transfer shifted composition towards dominance by annual species, suggesting the need for topsoil transfer to be supplemented by other restoration techniques. [ABSTRACT FROM AUTHOR]

In the last decades a new goal for agriculture is to develop environmentally friendly innovative technologies. One of the interest solutions, in perspective, is the treatment of plants with low power microwave irradiation in order to obtain a higher and healthier production. This approach could also contribute to mitigation of harmful effects produced by excessive use of chemical products in treatment of seeds and also field culture phytoprotection. Investigating effects of microwave irradiation, on the germination of common bean (Phaseolus vulgaris L. cv. Ardeleana) seeds, and on the growth and development of bean plantules, in specific experimental conditions. The trial was developed within Laboratories of the Advanced Research Centre for Environmental Protection and Assessment of Life Quality from USAMV Cluj-Napoca. The growing experiment of 10 - 8 days (with 49 individuals each) was developed until the seeds have grown up to 15 cm height, in conditions of microwave irradiated and no irradiated conditions. The studied parameters were: length of stems, length of roots, and seedling vigour index. Data were statistically processed with STATISTICA v 6.0 Office. The studied parameters were quantified by biometric approach (length of stems and roots). The use of low power microwave irradiation in germination of common bean in laboratory conditions may be taken into consideration for large scale cultivation. Further research is needed in order to establish appropriate practices for the success of this innovative technique. [ABSTRACT FROM AUTHOR]

My preliminary, nonreplicated study suggests that 20% hydrochloric acid, commonly known as muriatic acid, can be used to effectively scarify honeylocust (Gleditsia triacanthos L. [Fabaceae]) seeds. Seeds were soaked for 1 to 24 h in muriatic acid. Almost no treatment effects were seen until 10 h of soaking, after which percentage germination peaked at 74% after 18 h of treatment. Although percentage germination was lower than with sandpaper scarification and sulfuric acid scarification, muriatic acid may have applicability, and be a safer, less labor-intensive option, for treating seeds of other native species that require scarification. [ABSTRACT FROM AUTHOR]