Faster Germination Research Articles

Phytoremediation of mixed contaminated soil enhanced with electric current.

Brassica rapa is a plant species that can germinate and grow in mixed contaminated soil with PAH and metals (Cr, Pb and Cd). This plant was selected among 14 plant species for electro-phytoremediation tests because its fast germination and growth in contaminated soil. The influence of type of the electric field (AC, DC) and mode of application (continuous, periodic and polarity inversion) was studied in the electro-phytoremediation tests. The application of 1 ACV/cm potential gradient around B. rapa resulted in the effective elimination of anthracene and phenanthrene, but only minor metal removal. The results of this work suggest that alternating current (AC) may be the most suitable electric field for large scale applications. The spatial configuration of electrodes affects the distribution of the electric field in the soil. Various spatial distribution of electrodes have been tested and it has been identified that parallel anodes and cathodes on the soil surface are the most appropriate configuration for field scale applications. Other configurations can be used to concentrate the contaminant around the growing pant or to transport the contaminants from deep soil layers to the rhizosphere.

High salinity impacts germination of the halophyte Cakile maritima but primes seeds for rapid germination upon stress release.

Seed germination recovery aptitude is an adaptive trait of overriding significance for the successful establishment and dispersal of extremophile plants in their native ecosystems. Cakile maritima is an annual halophyte frequent on Mediterranean coasts, which produces transiently dormant seeds under high salinity, that germinate fast when soil salinity is lowered by rainfall. Here, we report ecophysiological and proteomic data about (1) the effect of high salt (200 mM NaCl) on the early developmental stages (germination and seedling) and (2) the seed germination recovery capacity of this species. Upon salt exposure, seed germination was severely inhibited and delayed and seedling length was restricted. Interestingly, non-germinated seeds remained viable, showing high germination percentage and faster germination than the control seeds after their transfer onto distilled water. The plant phenotypic plasticity during germination was better highlighted by the proteomic data. Salt exposure triggered (1) a marked slower degradation of seed storage reserves and (2) a significant lower abundance of proteins involved in several biological processes (primary metabolism, energy, stress-response, folding and stability). Yet, these proteins showed strong increased abundance early after stress release, thereby sustaining the faster seed storage proteins mobilization under recovery conditions compared to the control. Overall, as part of the plant survival strategy, C. maritima seems to avoid germination and establishment under high salinity. However, this harsh condition may have a priming-like effect, boosting seed germination and vigor under post-stress conditions, sustained by active metabolic machinery.

GERMINATION AND SEEDLINGS DEVELOPMENT OF THE THREATENED SPECIES Quillaja brasiliensis

ABSTRACT Brazil is a mega diverse country, but as consequence of habitat degradation several plant species are threatened. Quillaja brasiliensis is a rare and threatened tree species of the temperate forests of South America. We investigated protocols for germination, seedling growth and transplantation. We discuss some ecological matters that could affect the species’ establishment. We evaluated germination under a range of storage periods, temperature and light conditions, the effects of transplantation and the development of seedlings under two sowing methods. We found that seeds germinated rapidly and have a high germination rate. Temperature infl uenced germination vigour, and photoperiod infl uenced synchrony. There was increased and faster germination under controlled culture conditions. The high germination rate and rapid growth qualify Q. brasiliensis as a potential species for restoring degraded areas and enrichment programmes.

Early Growth Performances of Three Legumes (Albizia lebbeck, Leucaena leucocephala and Parkia biglobosa) and Their Effects on the Nitrogen Content of Three Soil Types

The fact that numerous benefits are derivable from certain tree legumes especially in the sphere of nitrogen fixation, soil fertility improvement, land reclamation and fodder cannot be over emphasized. Thus, early growth studies on the morphological indices of three leguminous /nitrogen fixing trees (Albizia lebbeck, Leucacea leucocephala and Parkia biglobosa) as influenced by different soil types and variation in their nitrogen fixation potentials were investigated. It was a 3 x 3 factorial experiment in completely randomized design comprising 2 factors (soil types and tree species) each at three levels. Initial / pre-experimental soil analysis, seed sowing/planting in three soil types (river sand, clay, loam) tending operations (watering, thinning, weeding, insect control), data collection on seedling emergence (S.E.), morphological growth parameters (plant height, number of leaves/branches, collar, leaf area) for 12 weeks, post experimental soil analysis and data analysis were carried out. Results indicated that A. lebbeck and P. biglobosa seeds sown in river sand and clayey soil respectively had the fastest germination/ S.E. rate (10 days after planting) and the least were seeds planted in clayey soil. Outstanding performances were observed in L. leucocephala and A. lebbeck seedlings planted in loamy soil while P. biglobosa was the least in most of treatment combinations. Analysis of variance indicated significant differences (at P?0.05) among all the morphological growth characters. There were variations in percentage nitrogen (%N) fixed, soil analysis showed that A. lebbeck seedlings in river sand had the highest value (6.29%N)\ and the least value (1.45%N) was observed in P. biglobosa (difference between initial and final soil analyses).

Hydropriming as inducer of salinity tolerance in sunflower seeds

ABSTRACT Sunflower is a species with multiple potentialities and its yield can be affected by the presence of soluble salts in the soil, which is common in arid, semi-arid and irrigated regions. The objective of this study was to evaluate the effect of hydropriming as inducer of salinity tolerance in seeds and seedlings of sunflower, hybrid MG305CP. The germination tests were set with four replicates of 50 seeds per treatment, maintained in germinator at 30 ºC for ten days. To simulate salinity, sodium chloride diluted in distilled water was used at electrical conductivities of 0 (control), 4, 8, 12 and 16 dS m-1. On the tenth day, the number of normal seedlings was counted and the length and dry matter of shoots and roots were determined. Seedling fresh matter was used to determine the contents of total chlorophyll, total soluble sugars and proline. The experimental design was completely randomized, in a 2 x 5 factorial scheme (with and without hydropriming and five levels of salinity). Hydroprimed sunflower seeds showed greater vigor expression, with higher number of normal seedlings and faster germination.

Comparing seeds germination of some local plant species on two hydroseeding mulches for post mining revegetation

The aims of this study were to determine seed germination rate of some local plant species in two hydroseeding mulches containing different tackifier concentration, as well as to determine the optimal hydroseeding mulch media composition for germinating seeds. This study used seeds of 13 local plant species: two species of Cyperaceae ( Cyperus brevifolius , C. javanicus ), five species of Leguminosae ( Cajanus cajan, Crotalaria pallida, Sesbania grandiflora, S. sesban, Tephrosia purpurea ), and six species of Poaceae ( Eleusine indica, Paspalum conjugatum, Sorghum timorense , S. bicolor , Sporobolus indicus, Themeda arundinaceae ) . Two hydroseeding mulch media with different tackifier composition were mixed with seeds of each species and then sowed in pots. Each treatment was repeated three times. Moistened cotton wool was used as control and comparative media for observing seed viability. Seed germination in mulch media was observed during 13 days. The results showed that only 8 of 13 species could be germinated: S. indicus, S. timorense , T. arundinaceae, C. cajan, C. pallida, S. grandiflora, S. sesban, and T. purpurea. The highest germination rate was shown by S. sesban (67%) in M 2 medium and the lowest one was shown by T. arundinaceae (2%) in both media. The fastest germination time was recorded for C. pallida and S. sesban seeds that germinated in 2 days after sowing (DAS) in both media, while S. timorense and T. arundinaceae seeds showed the lowest ones in 11 DAS. The fluid M 1 medium was optimal for seeds germination of S. sesban (50%) and S. grandiflora (35%), while the thicker M 2 medium was optimal for seeds germination of S. sesban (67%) and S. timorense (50%) in 13 DAS. The maximum germination rate was generally reached in 11 DAS.

Pre-germination treatment and different temperatures conditions on Echinacea purpurea seed germination

Echinacea purpurea (L) Moench, is a medicinal and herbaceous plant from Asteraceae family, and has an important role on economics of many communities. Germination is one of the main steps on understanding this specie. Thus, the aim of this study was to evaluate the effect of temperature conditions and precooling treatment on E. purpurea seed germination. This study was conducted on completely randomized design, with four repetitions and tree treatments, constituted by three germination temperatures (20°C, 30°C and 20-30°C) and two treatments, which is, breaking dormancy by precooling (5 oC) for seven days and the control sample without precooling. Gerbox was used for germination test. The germination was determined by primary root protrusion. As result, germinations were satisfactory on three temperatures at the two groups. The highest germination potential was observed in alternating temperature 20-30°C (97.00 ± 0.93%). Better germinations percentages were observed in precooling treatment (97.75 ± 0.62%) and in the treatment without precooling (95.58 ±0.54%). Temperature directly impacts coefficient of velocity of germination (CVG), with no statistical difference in the group subjected to precooling for temperatures of 20-30°C and in constant temperature of 30oC. However, on the group without precooling treatment, the alternating temperature gets better CVG. To mean germination time (MGT), temperature of 20-30°C get better result (2.92 ± 0.13). E. purpurea presents fast germination in less than five days.

Seed vigour contributes to yield improvement in dry direct‐seeded rainfed lowland rice

AbstractDry direct‐seeded rice (DSR) cultivation is widely spreading in tropical Asia, but drought and nutrient deficiency stresses often cause crop failure in rainfed lowlands. The objective of this study was to dissect the physio‐morphological characteristics associated with crop establishment and early vigour of DSR under drought and P deficiency conditions in the Philippines. It was found that new drought‐resistant cultivars bred for DSR (Rc348 and Rc192) had faster germination and sprout growth than popular irrigated rice cultivars (Rc222 and Rc10) under soil water deficit due to rapid moisture acquisition by the germinating seeds from drying soils. There was a significant correlation between seed moisture content and the reduction in seed dry weight, and between reduction in seed dry weight and shoot elongation under both control and drought stress treatments at the germination stage. At the seedling stage, the root growth of Rc348 under drought tended to be more vigorous with its higher root‐to‐shoot ratio compared to Rc222 and Rc10. The seedling vigour of Rc348 under P deficiency was also greater than that of Rc222 due to its greater root growth and P uptake. The yields of Rc348 and Rc192 grown under rainfed condition at the target drought‐prone site where a dry spell of 13 days occurred during crop establishment were higher (4.0–4.1 t ha−1) than the yield of Rc10 (3.0 t ha−1). These results suggest that quick germination and seedling vigour with quick root anchorage and great nutrient uptake capacity, even with limitations of soil moisture and nutrients, would be important traits for DSR in rainfed lowlands.

Evolutionary ecology of fast seed germination—A case study in Amaranthaceae/Chenopodiaceae

Germination is a vulnerable and risky step in a plant’s life cycle. Particularly under harsh environmental conditions, where time windows favourable for seedling establishment and survival are short or unpredictable, germination speed might play a highly adaptive role. We investigated the germination speed of 107 Amaranthaceae s.l. at two different temperatures and related the results to various plant and habitat traits taking into account the molecular phylogenetic relatedness of the species sampled.Germination speed is a fast evolving trait in Amaranthaceae s.l. It evolves towards significantly faster optima in C4 and halophyte lineages, albeit for different reasons. While C4 photosynthesis and fast germination are simply traits beneficial under the same environmental conditions, saline habitats, especially in subtropical regions, seem to select for fast germination. Heterospermy is probably much more common than currently known in Amaranthaceae s.l. and likely evolved as a bet-hedging strategy in lineages with fast seed germination. The evolution of germination speed is neither related to seed mass, an evolutionary stable trait, nor dependent on plant longevity and plant height. Correlation analyses of climate variables and germination speed suggest that there is an indirect effect of climate which is dependent on the ecological niche of the species.

Seed dormancy and germination of Halophila ovalis mediated by simulated seasonal temperature changes

The seagrass, Halophila ovalis plays an important ecological and sediment stability role in estuarine systems in Australia with the species in decline in many sites. Halophila ovalis is a facultative annual, relying mainly on recruitment from the sediment seed bank for the annual regeneration of meadows. Despite this, there is little understanding of seed dormancy releasing mechanisms and germination cues. Using H. ovalis seed from the warm temperate Swan River Estuary in Western Australia, the germination ecology of H. ovalis was investigated by simulating the natural seasonal variation in water temperatures. The proportion of germinating seeds was found to be significantly different among temperature treatments (p < 0.001). The treatment with the longest period of cold exposure at 15 °C followed by an increase in temperature to 20–25 °C (i.e. cold stratification) had the highest final mean germination of 32% and the fastest germination rate. Seeds exposed to constant mean winter temperatures of 15 °C had the slowest germination rate with less than two seeds germinating over 118 days. Thus temperature is a key germination cue for H. ovalis seeds and these data infer that cold stratification is an important dormancy releasing mechanism. This finding has implications for recruitment in facultative annual species like H. ovalis under global warming since the trend for increasing water temperatures in the region may limit seed-based recruitment in the future.

Efficiency of Cryoprotectants for In Vitro and Ex Vitro Germination of Cryopreserved Jatropha curcas Seeds

To investigate the effects of different cryoprotectants on germination and seedling development of jatropha (Jatropha curcas L.) seeds after cryopreservation, two experiments were performed under in vitro and ex vitro conditions. Nine treatments were used for both experiments, as follows: T1—No cryoprotectants (control); T2—glycerol 2 m (20 minutes); T3—sucrose 0.4 m (20 minutes); T4—glycerol 2 m (20 minutes) + PVS2 (10 minutes); T5—glycerol 2 m (20 minutes) + PVS2 + phloroglucinol 1% (10 minutes); T6—sucrose 0.4 m (20 minutes) + PVS2 (10 minutes); T7—sucrose 0.4 m (20 minutes) + PVS2 + phloroglucinol 1% (10 minutes); T8—glycerol 2 m (20 minutes) + sucrose 0.4 m (20 minutes) + PVS2 (10 minutes); and T9—glycerol 2 m (20 minutes) + sucrose 0.4 m (20 minutes) + PVS2 (10 minutes) + phloroglucinol 1% (10 minutes). After cryopreservation, seeds without cryoprotectants (T1) or with sucrose 0.4 m + PVS2 (T6) returned the best germination percentages after seven days of in vitro culture, 29.5% and 25%, respectively. However, they were not significantly different. For the ex vitro experiment, seed germination percentage was higher in organic substrate. These results indicate that cryopreservation of jatropha seeds can be accomplished without cryoprotectants, and faster germination is obtained in organic substrate.

Evaluation of the mature grain phytase candidate HvPAPhy_a gene in barley (Hordeum vulgare L.) using CRISPR/Cas9 and TALENs.

In the present study, we utilized TALEN- and CRISPR/Cas9-induced mutations to analyze the promoter of the barley phytase gene HvPAPhy_a. The purpose of the study was dual, validation of the PAPhy_a enzyme as the main contributor of the mature grain phytase activity (MGPA), as well as validating the importance of a specific promoter region of the PAPhy_a gene which contains three overlapping cis-acting regulatory elements (GCN4, Skn1 and the RY-element) known to be involved in gene expression during grain filling. The results confirm that the barley PAPhy_a enzyme is the main contributor to the MGPA as grains of knock-out lines show very low MGPA. Additionally, the analysis of the HvPAPhy_a promoter region containing the GCN4/Skn1/RY motif highlights its importance for HvPAPhy_a expression as the MGPA in grains of plant lines with mutations within this motif is significantly reduced. Interestingly, lines with deletions located downstream of the motif show even lower MGPA levels, indicating that the GCN4/SKn1/RY motif is not the only element responsible for the level of PAPhy_a expression during grain maturation. Mutant grains with very low MPGA showed delayed germination as compared to grains of wild type barley. As grains with high levels of preformed phytases would provide more readily available phosphorous needed for a fast germination, this indicates that faster germination may be implicated in the positive selection of the ancient PAPhy gene duplication that lead to the creation of the PAPhy_a gene.

Seed germination traits of desert perennials

While understanding that seed germination is crucial for ecological restoration activities, the seed traits of desert perennials are understudied. We experimentally determined germination traits of 43 species from 14 families from Hummock grasslands in the Great Sandy Desert, Australia. We defined morphological and physiological seed traits of framework species required for restoration and investigated the effects of fire and temperature on seed germination. We classified dormancy and explored the effect of Karrikinolide, a fire cue derived from smoke, on germination. Seeds of 38 (88%) out of 43 species were dormant: 13 (30%) with physical and 25 (58%) with physiological dormancy. Karrikinolide promoted seed germination of 9 (21%) species across all life-forms except trees, and widened the range of germination temperatures and increased germination rate of one species. Although high germination percentages were obtained over a wide temperature range, germination rate was affected by temperature. Non-dormant seeds and seeds pre-treated to overcome physical dormancy germinated quickly, with times to 50% germination of 1–5 days. Dormancy class differed between life-forms and families. Fast germination of non-dormant seeds is a trait that allows seeds to germinate during short periods of moisture availability. An absence of under-developed embryos is consistent with the global trends for hot deserts. A response to Karrikinolide shows that seed germination is related to a fire cue. These results will inform land managers of effective seed pre-treatments prior to seed broadcasting for restoration, and information on seed germination temperatures and rates will improve the understanding of when and where seeds could germinate in restored sites.

What can routine germination tests in seed banks tell us about the germination ecology of endemic and protected species?

Protocols for the conservation of threatened plants are often constrained by the absence of data on germination ecology. However, seed bank managers periodically monitor the viability of stored seed collections using germination tests. Here, we argue that data from those tests can and should be used to provide information on germination requirements of threatened species. Twelve taxa endemic to Portugal were used as a test case to determine the effect of incubation temperature and pretreatments upon germination and to identify major factors eliciting germination and releasing dormancy. We achieved maximum germination percentages &gt;95% for nine taxa. Temperature significantly affected the final germination and mean germination time in most taxa. Maximum and faster germination at cool temperatures (15 °C or alternate 20/10 °C) was the prevailing trend. Cold stratification improved germination in one species, suggesting physiological dormancy. Scarification increased the germination percentage of one species among those expected to exhibit physical dormancy. Seed bank data provided valuable information on germination ecology, which can be used in in-situ conservation and as a baseline for further germination studies. Given the increasing threats to plant diversity, accessibility to seed bank data are paramount.

Comparative anatomy and morphology of the fleshy fruit and the first record of seedlings in Olmeca reflexa in Bambusoideae (Poaceae)

Although the great majority of the genera in Poaceae possess the characteristic caryopsis fruit, a number of species in twelve genera in different clades in subfamily Bambusoideae have evolved bacoid or fleshy fruit. In this paper we describe the anatomy and morphology of the fleshy fruit of the Neotropical woody bamboo Olmeca reflexa and include remarks on its seedlings. We compare its main anatomical and morphological characters with other genera in Bambusoideae with this specialized type of caryopsis. Mature fruits in Olmeca reflexa are globose, and they vary from 2 to 4cm diameter; the pericarp surface is smooth and its texture is hard. In immature fruits, the endosperm occupies the central cavity in the form of mucilaginous ivory-white tissue, whereas in mature fruits the endosperm is vestigial. In the embryo, the scutellum is well developed, the plumule and radicle are basal, the embryo has a coleoptile enclosing the embryonic leaves, the coleorhiza and lower part of the scutellum are separated by a distinct cleft, and it does not have an epiblast. Fruits show similarities with the species of eleven other fleshy-fruited genera in Bambusoideae. Vestigial endosperm in mature fruits is found in species of Cyrtochloa, Dinochloa, Melocanna, Melocalamus, Ochlandra, Olmeca recta and Sphaerobambos but it is well developed in Alvimia, Guadua sarcocarpa and Stapletonia. Fleshy fruits in woody bamboos are highly specialized and a number of hypotheses have been proposed on their function, such as providing water and nutrients for fast germination and vigorous seedling growth.

Bacillus cereus in fresh ricotta: Comparison of growth and Haemolysin BL production after artificial contamination during production or post processing

Bacillus cereus is of particular concern for the production of fresh ricotta, due to the ability of spores to survive to the thermal treatment, leading to a potential germination, growth and toxin production in the product. This study aimed to evaluate the effect of a B. cereus contamination occurring in the whey used for the production of ricotta, or in the final product as post-production event.Four B. cereus strains (ATCC 14579 and three clinical isolates, GGu1, GPe2 and RCe1) were first evaluated for their ability to grow at different temperatures (from 5 to 55 °C) and spore survival rate to different thermal treatments (65, 70, 80 and 90 °C for 30, 15. 10 and 3 min, respectively). None of the strains showed to be psychrotrophic, as no growth below 10 °C was observed. Strains ATCC 14579 and GPe2 were the most resistant to thermal stresses and were selected for the inoculation tests.In the first trial, two aliquots of whey were inoculated with ATCC 14579 or GPe2 strain and used for the production of fresh ricotta samples, that were stored at 10 °C for 7 days (only GPe2) or 15 °C for 5 days (both the strains). In the second trial, the inoculation was made on fresh ricotta just after production. Samples were stored in the same conditions and analysed daily for the quantification of B. cereus vegetative cells and spores; the L2 component of Haemolysin BL was also quantified in the product.At 15 °C, a very fast germination of spores, followed by an active growth, was constantly observed in the two trials for both B. cereus strains. An earlier growth was detected in the whey-inoculated samples, suggesting the potential activation of spore germination caused by high temperatures reached during ricotta production. A slightly faster growth was observed for ATCC 14579 strain. At 10 °C, GPe2 strain showed a slow growth, with similar rates between whey- or product-inoculated ricotta samples. The production of HBL toxin was significant only in samples kept at 15 °C, starting from the 4th day of storage.In order to ensure the consumers’ protection, these results suggest the suitability of fresh ricotta as a substrate for the growth and metabolic activity of B. cereus, highlighting the need to prevent the contamination of the product and, above all, to apply a correct refrigeration during its storage.

Variability on morphological and ecological seed traits of Limonium avei (De Not.) Brullo &amp; Erben (Plumbaginaceae)

Limonium avei is an annual species occurring in the salt‐marshes and in limited surfaces of rocky areas around the Mediterranean coasts. Seed lots from five populations of this species, along a latitudinal gradient, were analyzed using an image analysis system to detect differences in seed morphology among populations. Germination requirements at constant (5–25°C) and alternating temperatures (25/10°C), both in light and in darkness, were evaluated for all populations, as well as the effect of the calyx removal on final seed germination and its rate. Morpho‐colorimetric analysis clearly identified seeds from different populations, habitats and substrates without misattributions among them. The calyx slowed the germination process, influencing both final germination and rate with respect to naked seeds. Seeds from all populations germinated with significantly higher percentages in the light, with respect to those incubated in the darkness, and showed rapid germination (time in days to reach 50% of germination: 0.5 days) at the warmer tested temperature (25°C). High germination (&gt;80%) was also detected for seeds of all the investigated populations, except for those from the Apulian region (South Italy, ca. 60%). Our results highlight that L. avei has a high variability in seed morphology, probably habitat induced, and a fast germination response for all populations. Rapid germination may be an adaptive strategy that allows L. avei seeds to take advantage of transient favorable conditions during the germination stage, to ensure seedling establishment under the unpredictable rainfall pattern in the Mediterranean climate.

Ankuri Technology for Seed Germination and Seedling Emergence of Rice in Cold Environment

Rice seed germination as well as seedling emergence in cold environment is a challenge for successful rice cultivation during dry (Boro) season in northern Bangladesh Experiments were conducted in two consecutive Boro seasons in Rajshahi to develop techniques for improving germination and seedling emergence under cold conditions.. Seeds of rice var. BRRI dhan29 and BRRI dhan50 were germinated following the traditional “Zag-method” and separately in a frame covered with air tight heat insulating plastic tripal (called Ankuri- germinator). Then vapor therapy was given inside Ankuri and maintained 25-350C with high humidity. External and internal temperatures of Ankuri were recorded. Seed germination was checked at 12 h interval. In another experiment, germinated seeds of BRRI dhan29 were sown on soil in trays followed by light irrigation. One set of trays was placed in Ankuri. Another two sets of trays were placed in the field with polythene covered and uncovered. Similar experiment using non-germinated dry seed was also conducted. Vapor therapy was applied in Ankuri only in and trays were checked regularly to observe the plumule and radicle growth. The germination rate (%) of the tested varieties in Ankuri ranged from 82-96% which was 64-92% in Zag-method. High variation of germination in Zag-method was due to improper temperature and humidity during the Zag period. Seed germination was faster in Ankuri which was observed within 2.5 days. This was also 2.5 days earlier in comparison with the Zag-method. Soaking period ranged 22-24 h outside in cold water/weather. But 18 h soaking in Ankuri resulted good germination. Irrespective of varieties, the growth was 5.4 and 1.7 times more respectively for plumule and radicle in Ankuri than Zag-method. Seedling emergence was 2-3 days earlier in both dry and soaked/germinated seeds sown in trays of Ankuri than the outside polythene covered trays. Seedling emergence failed in open-trays. Average air temperature from 18:00-9:00 was cooler (150C) than 9:00-18:00 period (150C). Ankuri maintained 25-350C and high humidity which favored seed germination and seedling growth. Therefore, Ankuri could be an effective seed germination technique with faster germination, radicle and plumule growth.Bangladesh Agron. J. 2016 19(2): 115-123

English

Moringa oleifera is a fruit species of economic interest to West African smallholder growers. To generate benei¬ts to poor rural communities, improved knowledge is needed on plantation management and selection of the most reliable seed sources. The aim of the study was to investigate variation in seed traits and germination rates among 12 provenances of M. oleifera from West Africa in the women gardening center named “Amicale des Forestieres du Burkina Faso (AMIFOB)” located at Ouagadougou, Burkina Faso (12°7’32’’N, 01°40’24’’W). The authors conducted an analysis of variance, a principal component analysis on seed traits variables (length, thickness and weight) and germination rates at 5 and 12 days after seed sowing, and finally ascending hierarchical classification based on similarity indices. The results showed significant variations (P<0.05) among provenances in seed traits: Ouahigouya provenance in the Sahelian area of Burkina Faso had the largest and heaviest seeds. Germination rate was significantly different after 5 days for Ouahigouya, Ouagadougou, Koudougou, Dano and Tamale provenances (P<0.05). Five days after seed sowing, the Sahelian provenance (Ouahigouya) recorded the greatest and fastest germination rate of 63%. Correlation analyses revealed no significant links between germination rate in 5 and 12 days after sowing and seed sizes. Seed traits and germination rates did not show clear cut distinct groups between Sahelian, Sudanian and sub Equatorial provenances. This research output provides an evidence of the genetic variability among M. oleifera provenances and hence the potential for future tree improvement programme. Key words: Seed variability, agroclimatic zone, Burkina Faso.

A Gusseted Thermogradient Table to Control Soil Temperatures for Evaluating Plant Growth and Monitoring Soil Processes.

Thermogradient tables were first developed in the 1950s primarily to test seed germination over a range of temperatures simultaneously without using a series of incubators. A temperature gradient is passively established across the surface of the table between the heated and cooled ends and is lost quickly at distances above the surface. Since temperature is only controlled on the table surface, experiments are restricted to shallow containers, such as Petri dishes, placed on the table. Welding continuous aluminum vertical strips or gussets perpendicular to the surface of a table enables temperature control in depth via convective heat flow. Soil in the channels between gussets was maintained across a gradient of temperatures allowing a greater diversity of experimentation. The gusseted design was evaluated by germinating oat, lettuce, tomato, and melon seeds. Soil temperatures were monitored using individual, battery-powered dataloggers positioned across the table. LED lights installed in the lids or along the sides of the gradient table create a controlled temperature chamber where seedlings can be grown over a range of temperatures. The gusseted design enabled accurate determination of optimum temperatures for fastest germination rate and the highest percentage germination for each species. Germination information from gradient table experiments can help predict seed germination and seedling growth under the adverse soil conditions often encountered during field crop production. Temperature effects on seed germination, seedling growth, and soil ecology can be tested under controlled conditions in a laboratory using a gusseted thermogradient table.