Effects of Scarification and Substrates on Seed Germination Quality for Domestication of Stereospermum kunthianum(Bignoniaceae)

The demand for medicinal plants at the origin of phyto-drugs,like all ethnobotanical plants,threatens their existence today.The aim of this work was to determine suitable methods for optimizing the possibilities of regenerating Stereospermum kunthianum.To achieve this objective,3 levels of mechanical scarification(light scarification,medium scarification and deep scarification)were applied to the seeds of this species using a rough instrument,and 5 days after germination,the seedlings were transplanted into 5 types of substrate to study their effects on seedling growth.The length of the seedlings was measured using a graduated ruler.The results obtained showed that the best latency time was 2 days for average seed scarifications.The highest germination half-time was 4.00±0.06 days observed for average seed scarification,the highest germination speed was 22.50±1.00 and the highest germination rate was 100.00%±0.00%for average scarification.The homogeneous substrate mixes black earth/woodsilk and Fine sand/woodsilk were more effective for seedling growth(1.9 cm/day in the juvenile state)and development.Medium seed scarification is the most effective method for regenerating Stereospermum kunthianum,and the black earth/wood shavings substrate mix is the best for its cultivation.

Overcoming the Physical Seed Dormancy in Bambara Groundnut （Vigna subterranea L.） by Scarification： A Seed Quality Study

Bambara groundnut （Vigna subterranea L.） is a neglected African crop legume with potential to play a significant role as astaple and industrial crop in sub-Saharan Africa. The crop can compete with Phaseolus vulgaris and Glycine max under harshcondition associated with climate change. However, there are some challenges associated with successful production of bambaragroundnut, such as poor crop establishment due to physical seed dormancy. This study was conducted to investigate the effect ofscarification on overcoming seed dormancy in bambara groundnut. Bambara groundnut landrace seeds were characterized by seedcoat colour （cream, light brown and brown） in order to determine the effects of mechanical （sand paper） and chemical （sulphuric acid）seed scarification on germination and emergence. A completely randomized design with three replications was used. Thousand grainmass （TGM）, mean germination time （MGT）, germination vigour index （GVI）, seedling root to shoot ratio, seedling dry mass andfield emergence were determined. Thousand grain mass increased with the decrease in seed coat colour pigmentation. Brown seedshad the highest final germination and field emergence, and cream seeds had the least. Imposing chemical or mechanical scarificationimproved germination as compared to no scarification. However, seedling establishment was vigorous in seeds that were notscarified. Seed quality in bambara groundnut is highly influenced by scarification and seed coat colour. The practical implications ofthe study are that producers can use scarification to improve bambara groundnut germination, however further research through seedenhancements is still needed for seedling establishment under field conditions.

Prolonged Seed Dormancy in <i>Phyllanthus emblica</i>L. Can Be Overturned by Seed Scarification and Gibberellin Pre Treatment

Phyllanthus emblica L. is an important constituent of Ayurvedic medicine and a fresh fruit species in the market in Sri Lanka. Therefore, it has a high potential to be established as a commercial fruit crop. The seeds of P. emblica are semi orthodox and exhibit a long dormancy period hindering the natural sexual propagation. Therefore, it still remains as an underutilized fruit crop in Sri Lanka due to its lack of quality planting material and poor propagation techniques. Long term dormancy also causes a big challenge in germinating seeds to create populations in breeding programs. In order to promote P. emblica from its underutilized status, what seems most feasible is to develop a method to break up the seed dormancy artificially. In order to do so, the methods of breaking the dormancy of P. emblica seeds have to be studied. Therefore, the aim of this study was to identify a method to break up the seed dormancy of P. emblica. The seeds were extracted from 21 trees belonging to three different districts in Sri Lanka. The selected viable seeds were subjected to four different pre treatments: none treated seeds (i.e. control), seeds scarified, seeds scarified and treated with 1% gibberellin and seed coat removed and followed by seeds treated with 1% gibberellin. From the four treatments, seed dormancy was overturned with a germination percentage of 43% by the seed pre treatment where the seeds were scarified and treated with 1% gibberellin and no other pre treatment methods were successful in breaking the dormancy. This suggests that the natural germination potential of P. emblica seeds is very low and it can be overridden by seed scarification and gibberellin pre treatment.

Effect of Mechanical and Chemical Scarification on Germination of Dodder (Cuscuta campestris Yunck.) Seed

Experiments were carried out to evaluate the effect of seed treatment on germination of Cuscuta campestris. This may provide the possible ways to overcome the problem of dormancy in Cuscuta campestris. The experiments were conducted in the Laboratory of Crop Production and Horticulture, Modibbo Adama University of Technology, Yola, Adamawa State, Nigeria, using mechanical scarification and tetraoxosulphate (VI) acid (H2SO4). For the mechanical scarification the treatments were unscarified, scarified using sandpaper and scarified using gravel arranged in a completely randomized design (CRD) and replicated four times. For the tetraoxosulphate (VI) acid (H2SO4) scarification, the treatment of control, 9:1, 7:3, 1:1, 4:6, 3:7, 2:8 and 1:9 H2SO4 were laid out in a Split plot design and replicated three times. The mechanical scarification was not significant (P ≤ 0.05), a rapid increase of germination from day 3 to day 9 was observed, and the highest rate of germination percentage (14% - 22%) obtained on day 9. Tetraoxosulphate (VI) acid treatment of 4:6 concentrations significantly gave the highest C. campestris seeds germination percentage (40.07%) compared with the rest of the treatments, while the time of soaking the seeds in the tetraoxosulphate (VI) acid showed that soaking the seeds for 1 minute significantly gave the highest percentage germination (39.98%) of C. campestris compared with the 3 and 5 minutes soaking treatments. It can be concluded that sulphuric acid of 4:6 concentrations treatments has the potentiality to break dormancy of C. campestris seeds.

Effects of site preparation methods on soil physical properties and outplanting success of coniferous seedlings in boreal forests

This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of forests.This study was conducted on 12 forest sites in taiga forests of the European part of Russia.A total of 54 plots were set up to assess seedling survival;root collar diameter,height,and heigh increment were measured for 240 seedlings to assess growth.In the rooting layer,240 soil samples were taken to determine physical properties.The study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina sites.However,reduced soil moisture was noted,particularly in mounds,resulting in increased aeration.In Myrtillus sites,there were increased bulk density,reduced soil moisture,and total porosity in the mounds.Mounding treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration porosity.In the Myrtillus and Polytrichum sites,patch scarification had no effects on physical properties.In Polytrichum sites,survival rates,heights,and heigh increments of bareroot Norway spruce seedlings in mounds were higher than in patches;however,the same did not apply to diameter.In Cladina and Myrtillus sites,there was no difference in growth for bareroot and containerised seedlings with different soil treatments.Growing conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth.

Study of the Germination of Scarified Seeds of Burkea africana Hook. For Its Domestication in Chad

The objective of this work was to determine new approaches that could improve the germination quality of Burkea africana seeds under reproducible conditions and by means available to farmers with a view to its propagation. The tests concerned the influence of three pre-germinative treatments. It is about the light scarification (Scl), medium scarification (Scm) and deep scarification (Scd) of seeds in order to determine some parameters of germination that are the latency time, the time of germination, the rate of germination and the speed of germination. The treated seeds were sown in transparent germinators lined with hydrophilic paper and then after the appearance of radicles, the plants were transplanted on five types of substrates (black soil, fine sand, sawdust, mixtures 1/1 of sawdust-black soil and 1/1 of sawdust-fine sand). The results obtained by the deep (Scp) and medium (Scm) scarification compared to those of the light scarification and the control, showed a clear reduction of the lag time (3 days/15 days (control). At the 5% threshold, germination times 6.27 × 10-1 (Scd) and 6.01 × 10-1 (Scm) were significantly influenced. Germination rates 4.18 × 10-1 (Scd) and 3.92 × 10-1 (Scm) are also influenced by the pretreatment. Germination rates are significantly improved (80%). Regardless of the under treatment, the substrate “sawdust and fine sand” improves the germination of scarified seeds by 14.07% more compared to the substrate “fine sand” at the 5% threshold. The mechanical scarification and the type of substrates thus influence positively and homogeneously the germination of seeds of Burkea africana. The domestication of this species is thus possible and can be considered for useful purposes.

Breaking seed dormancy in Cupressus atlantica Gaussen,an endemicand threatened coniferous tree in Morocco

Cupressus atlantica Gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improve seed germination, different pre-treatments were conducted on C. atlantica seeds after storage for different periods （one, two and five years） including： scarification with sandy paper; soaking seeds in hot distilled water at 60℃ and 80℃ for 15 min and soaking seeds for 48 h in a gibberellic acid （GA3） at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially an exogenous dormancy （physical dormancy） due to the hard seed coat （hardseededness）. Exogenous application of gibberellic acid （GA3） at 1,000 mg.L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination （8-10 days） and low values of mean germination times （MGT）. However, germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value, suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the ex-situ conservation of such endemic and endangered species where the production of seeds is irregular over the years.

Effects of silviculture treatments in a hurricane-damaged forest on carbon storage and emissions in central Hokkaido, Japan

Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm （understory vegetation removal） led to the largest amount of carbon stored （64.7 t·ha^-1 C）. Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid （L. gmelinii var. japonica × L. kaempferi） plantation （80.3 t·ha^-1 C）. The plantation of Abies sachalinensis was not successful at accumulating carbon （40.5·ha^-1 C）. The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha^-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.

Effects of variation in seed sources and pre-sowing treatments on seed germination of Tamarindus indica: a multi-purpose tree species in Bangladesh

We investigated the morphology and germination of Tamarindus indica seeds in order to discover the ef- fects of variation in seed sources and pre-sowing treatments on germination. The experiment was carried out in the nursery of the Forestry and Wood Technology Discipline, Khulna University, Bangladesh. Seeds were collected from different but healthy trees from various locations in Bangladesh and subjected to four pre-sowing treatments, i.e., control, immersion in cold water （4℃ for 24 h）, immersion in hot water （80℃ for 10 min） and scarification with sand paper. Seed germination was carried out in poly-bags with a mixture of topsoil and cow dung in the ratio of 3：1. The average length of the fresh seeds was 1.35 ＋ 0.26 cm, their width 1.07 ＋ 0.20 cm and thickness 0.69 ＋ 0.11 cm. The results revealed that pre-sowing treatments affected the germination process of seeds, which significantly increased the germination percentage with the cold water （81.67%） and scarification with sand paper （82.33%） treatments, compared with those in the control （58.33%） and hot water treatment （59.00%）. In all treatments germination started on average within 5 to 7 days after the start of the treatments and were completed from 13 to 19 days later. The greatest success in germination （82.33%） was found in scarification with sand paper, followed with 81.67% in the cold water treatment. The results of analyses of variance （ANOVA） showed significant differences （p 〈 0.05） in germination closing dates, seed germination periods and germination percentages among the treatments but no significant difference among seed sources. However, the effect of the interaction between seed source variation and pre-treatment differed significantly in seed germination closing dates and germination percentages. We recommend cold water treatment （submersion of seed at a temperature of 4℃ for a 24-h period） for seed germination of T. indica in rural Bangladesh.

Conditions and Stimulation for Germination in Glycyrrhiza uralensis Fisch Seeds

Evaluation of seed quality is the key to seed distributing and seeding of Glycyrrhiza uralensis Fisch, as an important species for pharmacy and soil conservation. Here, we study the effects of light and temperature on seed germination and mechanical and chemical scarification on breaking the seed coat. Seeds were collected in 2004, 2005, and 2006, placed in Petri dishes, and incubated at constant temperature 20, 25, and 30℃, and alternating temperature 15-25, 20-30, 15-30, and 20-35℃ under either an 8h photoperiod or total darkness for 28 consecutive days. Different methods were used to break the dormancy owing to hard seededness in this species such as chemical scarification by immersing in concentrated sulphuric acid for 5, 10, 15, 20, 25, 30, 45, and 60 min, in 0.2% KNO3 solution to saturate the seedbed, and prechilling for 7 d at 7℃ and mechanical scarification by cutting. The results showed that alternating temperature at 20-30℃ with 8 h photoperiod and 16 h darkness was optimum for G. uralensis seed germinating in the laboratory. Hard seeds were broken by concentrated sulphuric acid soaking or mechanical scarification by cutting. Germination of seeds harvested in two different years was both promoted by immersing for 30-45 min in concentrated sulphuric acid. KNO3 solution was ineffective for reducing hard seeds. During seed germinating, the first count was on the 7th day and the last count was on the 14th day.

Optimal and synchronized germination of Robinia pseudoacacia,Acacia dealbata and other woody Fabaceae using a handheld rotary tool:concomitant reduction of physical and physiological seed dormancy

The Fabaceae(legume family) is one of the largest families of plants with a worldwide distribution and a major role in agriculture and in agroforestry.A hard seed coat impermeable to water is a typical feature of several species.Physical dormancy delays and reduces germination so that mechanical,physical and chemical scarification methods have been classically used to break seed dormancy of many species.We evaluate the effectiveness of a methodology to scarify seeds of several woody Fabaceae of ecological and economical importance,including Robinia pseudoacacia and Acacia dealbata and the shrubs Cytisus scoparius,C.multiflorus and Ulex europaeus.We describe the optimized use of a handheld rotary tool(HRT),and compare its effectiveness with other scarification methods reported to break dormancy such as boiling or dry heating.Total germination and/or speed of germination were enhanced after the application of the HRT,with germination percentages significantly higher than those achieved by other methods of scarification.Based on a thorough literature review,a mode of action for the HRT is suggested which could operate by breaking the physical and physiological dormancy of treated seeds through thecombined action of coat abrasion and moderate temperatures.Considering these results,we recommend the application of this rapid,effective,low-cost and highly reproducible HRT method to break seed dormancy and enhance germination of these species and others with similar dormancy constraints.

Enhancement of seed germination in Macaranga peltata for use in tropical forest restoration

We used pre-sowing treatments v/z., soaking seeds in concen- trated sulphudc acid （CSA）, gibberellic acid （GA）, combined treatment of CSA ＋ GA and mechanical scarification to overcome seed dormancy and enhance synchronous germination of Macaranga peltata seeds. We analysed percent seed germination data by logistic regression and con- finned that except in GA treatment, time and acid concentration together were crucial for enhancing germination. The combination treatment of CSA and GA resulted in higher percent germination （up to 74%） than either treatment used separately, but produced defective seedlings （26%）. Mechanical scarification of seed coat had the greatest impact in enhanc- ing germination （78%） and reducing imbibition time （6 days） against the control （0%）. Germination studies and SEM analysis confirmed that seed germination in M. peltata was inhibited by seed coat dormancy.

Horizontal transmission of HIV infection in an HIV-exposed child—An avoidable tragedy

Exposure to infected blood/blood products through blood transfusion and use of contaminated sharp objects remain an important source of HIV infection. This report describes the case of a 52-month-old male child of an HIV-infected mother in whom perinatal infection was successfully prevented by maternal and infant antiretroviral therapy, elective cesarean section, and avoidance of breast-feeding. A DNA PCR test at 6 weeks was negative and a rapid antibody test at 18 months was seronegative. He presented to the Paediatric infectious disease unit with chronic fever, cough, diarrhea and weight loss 7 months after receiving a commercially donated blood (in a rural private hospital) and scarification marks (by a traditional healer) for a febrile illness with convulsion. He was found to be seropositive with severe immunosuppression. He however died a month after being initiated on antiretroviral drug.

Natural Regeneration on Planted Clearcuts—The Easy Way to Mixed Forest?

Establishing mixed stands by stimulating natural in combination with planting could potentially ensure adequate stocking and meet shifting demands for forest products. Two long-term experiments were separately established in former Norway spruce (Picea abies L. Karst) stands in southern Sweden to be able to evaluate mixed forest establishment and management. The treatment plots were treated with different intensity of soil scarification (disc trenching, soil inversion and control) to test effects of soil disturbance on regeneration success. Five years later, both experiments were used for a first evaluation, where seedlings of all naturally regenerated tree species were counted together with estimates of the cover and height of other vegetation. This was made in sample plots in symmetric grids. Testing the effects of scarification and distance to seed source on natural regeneration of silver birch (Betula pendula Roth.) and downy birch (B. pubescens Ehrh.) showed that both scarification type and degree of soil disturbance significantly affected seedling counts but only if seed sources were close. In conclusion, conventional management practices for regenerating coniferous forest may be suitable for establishing mixed forest stands with combinations of planted and naturally regenerated seedlings.

Lichen-Spruce Woodland Early Indicators of Ecological Resilience Following Silvicultural Disturbances in Québec’s Closed-Crown Forest Zone

Lichen woodlands (LW) located in the closed-crown boreal forest are not a successional stage moving towards a closed black spruce feathermoss stand (FM), but an alternative stable state, due to their previous forest history, and the occurrence of LWs located nearby closed-crown FM stands. Therefore, afforestation in those LWs through site preparation and plantation could shift back LW into FM stands. We implemented an experimental design with different combinations of silvicultural treatments in both site types (LW, FM). We monitored the evolution of plant diversity and the physiology of three bio-indicators (Picea mariana, Kalmia angustifolia, Rhododendron groenlandicum) in different microsites created by the silvicultural treatments. The return to the initial composition was noticed only two years after treatments, especially in the LW stands, thus indicating a higher level of early ecosystem resilience in LWs compared to FM stands. Mean species cover, especially in the FM stands, decreased the most in the skid trails created by logging, probably due to a lack of acclimation of bryophytes to open stand conditions. Conversely, ericaceous shrubs and lichens found in the LWs were already acclimated to open stand conditions, which give to LWs a restructuring advantage compared to FM plant communities after silvicultural treatments. Overall, FM and LW short-term resilience was similar, indicating equally efficient ecosystem reorganization in both stands. The comparable early resilience in managed LW and FM stands, in terms of plant biodiversity, contradicts the presumed fragility of LW stands, especially in this case where LWs are assumed to be an alternative stable state created by compound disturbances. Silvicultural treatments maintained the functional group diversity in LWs, a key element for ecosystem resilience. Therefore, this study support the idea that plantation following site preparation in LWs could be a valuable management strategy to reach several objectives, such as increasing forest carbon sinks.