In a laboratory trial three chickpea varieties viz, Karak-I, Karak-III and Shenghar were tested against the phytotoxicity of five weed species: Parthenium hysterophorus L., Phragmites australis (Cav.) Trin., Datura alba L., Cyperus rotundus L. and Convolvulus arvensis L.in January 2013. The weed extracts were prepared at the rate of 120 g/L (w/v) after shade dry. The results indicated highly significant inhibitory effect of all the tested weed species on the chickpea varieties. The results also showed that the chickpea variety Karak-III was more susceptible to the phytotoxcity of the tested weed extracts. Among the extract, C. arvensis proved much toxic in term of inhibition of germination by giving only 43.33% germination in comparison with control where 97.50% germination was recorded. On the other hand, the effect of P. australis extract was found a little stimulator by speeding the seed germination in all varieties and giving a low (2.21) mean germination time (MGT) value. From the current results it can be concluded that the infestation of C. arvensis can pollute the soil by accumulating toxic chemicals that leads to the germination failure and growth suppression in chickpea. Therefore, the prevention and removal of C. arvensis in the chickpea growing areas could be recommended. In addition, P. australis must be tested against chickpea weeds (chickpea varieties withstand against its phytotoxcity), so that it can be popularized as bioherbicide in chickpea if it gave promising results in controlling chickpea weeds.
Guava seeds are produced as a waste product by the guava processing industry. Their high carbohydrate contents may suit the carbohydrate needs of the feed sector but their high dietary fiber content limits their feed value. The feed values of fruit seeds can be improved through germination, which involves the mobilization of nutrients through seed enzymes and alters the seed carbohydrate composition. The changes of selected carbohydrates in guava (Psidium guajava L.) seeds brought by germination to those in red bean (Vigna angularis) and winter wheat (Triticum aestivum L.) were compared. The contents of soluble carbohydrates, digestible starch, resistant starch and cellulose in the seeds were determined. The radial diffusion method was used to detect carbohydrate-degrading enzymes in the seed extracts. Guava seeds were rich in cellulose (402.2 mg/g), which decreased progressively during germination, probably through the action of cellulase. Winter wheat contained the highest starch content (412.2 mg/g) and also distinct quantities of α-amylase and cellulase. The starch contents of all the seeds decreased, but the soluble carbohydrate contents in red beans and guava seeds increased significantly by the end of germination, suggesting the transient oversupply of reserve metabolites. The content of hydrolyzed polysaccharides increased in the germinated seeds with detectable amounts of cellulose-degrading enzymes present, indicating improved value as feed. Further research is warranted to explore the potential of guava seeds as a source of low-cost animal feed supplements.
Nitrate reduotase is induced by nitrate in excised embryos and germinating intact seedlings of rice (Oryza sativa L.). The enzyme is induced 24 hr after imbibition. The rate of enzyme formation increases with the age of seedlings. There is a lag period of 30 to 40 min between the addition of substrate and the formation of nitrate reductase. Formation of the enzyme is promoted by the presence of ammonium. Chloramphenicol, actinomycin D and cycloheximide effectively inhibit the formation of nitrate reductase.Rice seedlings can assimilate nitrate from the beginning of germination. However, the utilization of nitrate is completely suppressed by the presence of ammonium. As soon as ammonium is depleted from the medium, nitrate utilization is resumed. Ammonium inhibits the first step of nitrate reduction, i.e., NO(-) (3) --> NO(-) (2), but does not inhibit the assimilation of nitrite. This provides an example of feedback inhibition in higher plants.
Weed infestation is a persistent problem for centuries and continues to be major yield reducing issue in modern agriculture. Chemical weed control through herbicides results in numerous ecological, environmental, and health-related issues. Moreover, numerous herbicides have evolved resistance against available herbicides. Plant extracts are regarded as an alternative to herbicides and a good weed management option. The use of plant extracts is environmentally safe and could solve the problem of herbicide resistance. Therefore, laboratory and wire house experiments were conducted to evaluate the phytotoxic potential of three Fabaceae species, i.e., Cassia occidentalis L. (Coffee senna), Sesbania sesban (L.) Merr. (Common sesban) and Melilotus alba Medik. (White sweetclover) against seed germination and seedling growth of some broadleaved weed species. Firstly, N-hexane and aqueous extracts of these species were assessed for their phytotoxic effect against lettuce (Lactuca sativa L.). The extracts found more potent were further tested against germination and seedling growth of four broadleaved weed species, i.e., Parthenium hysterophorus L. (Santa-Maria), Trianthema portulacastrum L. (Pigweed), Melilotus indica L (Indian sweetclover). and Rumex dentatus L. (Toothed dock) in Petri dish and pot experiments. Aqueous extracts of all species were more toxic than their N-hexane forms for seed germination and seedling growth of lettuce; therefore, aqueous extracts were assessed for their phytotoxic potential against four broadleaved weed species. Aqueous extracts of all species proved phytotoxic against T. portulacastrum, P. hysterophorus, M. indica and R. dentatus and retarder their germination by 57, 90, 100 and 58%, respectively. Nevertheless, foliar spray of C. occidentalis extract was the most effective against T. portulacastrum as it reduced its dry biomass by 72%, while M. alba was effective against P. hysterophorus, R. dentatus and M. indica and reduced their dry biomass by 55, 68 and 81%, respectively. It is concluded that aqueous extracts of M. alba, S. sesban and C. occidentalis could be used to retard seed germination of T. portulacastrum, P. hysterophorus, M. indica and R. dentatus. Similarly, aqueous extracts of C. occidentalis can be used to suppress dry biomass of T. portulacastrum, and those of M. alba against P. hysterophorus, R. dentatus. However, use of these extracts needs their thorough testing under field conditions.
Germinated brown rice (GBR) is rich in bioactive compounds, which confer GBR with many functional properties. Evidence of its hypocholesterolemic effects is emerging, but the exact mechanisms of action and bioactive compounds involved have not been fully documented. Using type 2 diabetic rats, we studied the effects of white rice, GBR, and brown rice (BR) on lipid profile and on the regulation of selected genes involved in cholesterol metabolism. Our results showed that the upregulation of apolipoprotein A1 and low-density lipoprotein receptor genes was involved in the hypocholesterolemic effects of GBR. Additionally, in vitro studies using HEPG2 cells showed that acylated steryl glycoside, gamma amino butyric acid, and oryzanol and phenolic extracts of GBR contribute to the nutrigenomic regulation of these genes. Transcriptional and nontranscriptional mechanisms are likely involved in the overall hypocholesterolemic effects of GBR suggesting that it may have an impact on the prevention and/or management of hypercholesterolemia due to a wide variety of metabolic perturbations. However, there is need to conduct long-term clinical trials to determine the clinical relevance of the hypocholesterolemic effects of GBR determined through animal studies.
Photobiomodulation relies on the transfer of energy from incident photons to a cell photoacceptor. For many years the concept of photobiomodulation and its outcome has been based upon a belief that the sole receptor within the cell was the mitochondrion. Recently, it has become apparent that there are other photoacceptors operating in different regions of the electromagnetic spectrum. Alternative photoacceptors would appear to be water and mechanisms regulating calcium homeostasis, despite a direct effect of laser photonic energy on intracellular calcium concentration outwith mitochondrial activity or influence, have not been clearly demonstrated. Therefore, to increase the knowledge of intracellular‑calcium and laser photon interaction, as well as to demonstrate differences in irradiation profiles with modern hand-pieces, we tested and compared the photobiomodulatory effect of 808 nm and 980 nm diode laser light by low- and higher-energy (60s, 100 mW/cm2, 100 mW/cm2, 500 mW/cm2, 1000 mW/cm2, 1500 mW/cm2, 2000 mW/cm2) irradiated with a "standard" (Gaussian fluence distribution) hand-piece or with a "flat-top" (uniform fluence) hand-piece. For this purpose, we used the eukaryote unicellular-model Dictyostelium discoideum. The 808 nm and 980 nm infrared laser light, at the energy tested directly affect the stored Ca2+ homeostasis, independent of the mitochondrial respiratory chain activities. From an organism perspective, the effect on Ca2+-dependent signal transduction as the regulator of spore germination in Dictyostelium, demonstrates how a cell can respond quickly to the correct laser photonic stimulus through a different cellular pathway than the known light-chromophore(mitochondria) interaction. Additionally, both hand-piece designs tested were able to photobiomodulate the D. discoideum cell; however, the hand-piece with a flat-top profile, through uniform fluence levels allows more effective and reproducible effects.
An investigation was made to see the salt tolerance of 10 weed species of rice. Properly dried and treated seeds of weed species were placed on 9 cm diameter petridishes lined with Whatman No. 1 filter paper under 6 salinity regimes, viz. 0 (control), 4, 8, 16, 24 and 32 dS m(-1). The petri dishes were then kept in germinator at 25 +/- 1.0 degrees C and 12 hr light. The number of germinated seeds were recorded daily. The final germination percentage, germination index (GI), seedling vigour index, mean germination time and time for 50% germination were estimated. Root and shoot lengths of the weed seedlings were measured at 20 days after salt application and relative growth values were calculated. Results revealed that salinity decreased final germination percentage, seed of germination as measured by GI, and shoot and root length in all the species. Germination of most of the weed seeds was completely arrested (0) at 32 dS m(-1) salinity except in E. colona (12%) and C. iria (13.9%). The species C. iria, E. colona, J. linifolia and E. crusgalli showed better germination (above 30%) upto 24 dS m(-1) salinity level and were regarded as salt-tolerant weed species. J. linifolia, F. miliacea, L. chinensis and O. sativa L. (weedy rice) were graded as moderately tolerant and S. zeylanica, S. grosus and C. difformis were regarded as least tolerant weed species.
Advancement in materials synthesis largely depends up on their diverse applications and commercialisation. Antifungal effects of phytogenic silver nanoparticles (AgNPs) were evident, but the reports on the effects of the same on agricultural crops are scant. Herein, we report for the first time, size dependent effects of phytogenic AgNPs (synthesised using Stevia rebaudiana leaf extract) on the germination, growth and biochemical parameters of three important agricultural crops viz., rice (Oryza sativa L), maize (Zea mays L) and peanut (Arachis hypogaea L). AgNPs with varied sizes were prepared by changing the concentration and quantity of the Stevia rebaudiana leaf extract. As prepared AgNPs were characterized using the techniques, such as high-resolution transmission electron microscopy, particle size and zeta potential analyser. The measured (dynamic light scattering technique) average sizes of particles are ranging from 68.5 to 116 nm. Fourier transform infrared studies confirmed the participation of alcohols, aldehydes and amides in the reduction and stabilisation of the AgNPs. Application of these AgNPs to three agricultural crop seeds (rice, maize and peanut) resulted in size dependent effects on their germination, growth and biochemical parameters such as, chlorophyll content, carotenoid and protein content. Further, antifungal activity of AgNPs also evaluated against fungi, Aspergillus niger.
Naturally occurring seedlings of Neuwiedia veratrifolia were found in three localities in Sabah, Borneo, Malaysia. Seedlings consisted of an irregular oblong protocorm and a terminal leafy rooted shoot. Protocorms contained mycotrophic tissue of the kind typical of orchid mycorrhiza (tolypophagy). This finding demonstrates an important synapomorphy between Neuwiedia and other orchids and strongly supports the monophyly of Orchidaceae in the broad sense, including apostasiod orchids.
Conyza sumatrensis (Retz.) E. H. Walker is an obnoxious weed, emerging as an invasive species globally. Seed germination biology of four populations of the species stemming from arid, semi-arid, temperate, and humid regions was determined in this study. Seed germination was recorded under six different environmental cues (i.e., light/dark periods, constant and alternating day and night temperatures, pH, salinity, and osmotic potential levels) in separate experiment for each cue. Populations were main factor, whereas levels of each environmental cue were considered as sub-factor. The impact of seed burial depths on seedling emergence was inferred in a greenhouse pot experiment. Seed germination was recorded daily and four germination indices, i.e., seed germination percentage, mean germination time, time to reach 50% germination, and mean daily germination were computed. Tested populations and levels of different environmental cues had significant impact on various seed germination indices. Overall, seeds stemming from arid and semi-arid regions had higher seed germination potential under stressful and benign environmental conditions compared to temperate and humid populations. Seed of all populations required a definite light period for germination and 12 hours alternating light and dark period resulted in the highest seed germination. Seed germination of all populations occurred under 5-30°C constant and all tested alternate day and night temperatures. However, the highest seed germination was recorded under 20°C. Seeds of arid and semi-arid populations exhibited higher germination under increased temperature, salinity and osmotic potential levels indicating that maternal environment strongly affected germination traits of the tested populations. The highest seed germination of the tested populations was noted under neutral pH, while higher and lower pH than neutral had negative impact on seed germination. Arid and semi-arid populations exhibited higher seed germination under increased pH compared to temperate and humid populations. Seed burial depth had a significant effect on the seedling emergence of all tested populations. An initial increase was noted in seedling emergence percentage with increasing soil depth. However, a steep decline was recorded after 2 cm seed burial depth. These results indicate that maternal environment strongly mediates germination traits of different populations. Lower emergence from >4 cm seed burial depth warrants that deep burial of seeds and subsequent zero or minimum soil disturbance could aid the management of the species in agricultural habitats. However, management strategies should be developed for other habitats to halt the spread of the species.
Limited information is available that seed biopriming with plant growth-promoting Enterobacter spp. play a prominent role to enhance vegetative growth of plants. Contrary to Enterobacter cloacae, Enterobacter hormaechei is a less-studied counterpart despite its vast potential in plant growth-promotion mainly through the inorganic phosphorus (P) and potassium (K) solubilization abilities. To this end, 18 locally isolated bacterial pure cultures were screened and three strains showed high P- and K-solubilizing capabilities. Light microscopy, biochemical tests and 16S rRNA gene sequencing revealed that strains 15a1 and 40a were closely related to Enterobacter hormaechei while strain 38 was closely related to Enterobacter cloacae (Accession number: MN294583; MN294585; MN294584). All Enterobacter spp. shared common plant growth-promoting traits, namely nitrogen (N2) fixation, indole-3-acetic acid production and siderophore production. The strains 38 and 40a were able to produce gibberellic acid, while only strain 38 was able to secrete exopolysaccharide on agar. Under in vitro germination assay of okra (Abelmoschus esculentus) seeds, Enterobacter spp. significantly improved overall germination parameters and vigor index (19.6%) of seedlings. The efficacy of root colonization of Enterobacter spp. on the pre-treated seedling root tips was confirmed using Scanning Electron Microscopy (SEM). The pot experiment of bioprimed seeds of okra seedling showed significant improvement of the plant growth (> 28%) which corresponded to the increase of P and K uptakes (> 89%) as compared to the uninoculated control plants. The leaf surface area and the SPAD chlorophyll index of bioprimed plants were increased by up to 29% and 9% respectively. This report revealed that the under-explored species of P- and K-solubilizing Enterobacter hormaechei sp. with multiple plant beneficial traits presents a great potential sustainable approach for enhancement of soil fertility and P and K uptakes of plants.
Water is one of the most important precious resources found on the earth, and are most often affected by anthropogenic activities and by industry. Pollution caused by human beings and industries is a serious concern throughout the world. Population growth, massive urbanization, rapid rate of industrialization and modern techniques in agriculture have accelerated water pollution and led to the gradual deterioration of its quality. A large quantity of waste water disposed of at sea or on land has caused environmental problems which have led to environmental pollution, economic losses and chemical risks caused by the wastewater, and its impact on agriculture. However, waste water which contain nutrients and organic matter has possible advantages for agricultural purposes. Therefore, the presented study was undertaken to assess the impact of Dairy Effluent (treated and untreated waste water) on seed germination, seedling growth, dry matter production and the biochemical parameters of lady's fingers (Abelmoschus esculentus L.).
MAIN CONCLUSION: The propagation of Rafflesia spp. is considered to be important for future development of ornamental and other applications. Thus far, the only successful propagation technique has been grafting. This mini-review succinctly emphasizes what is known about Rafflesia species. Members of the genus Rafflesia (Rafflesiaceae), which are holoparasitic plants known to grow on a host vine, Tetrastigma sp., are widely spread from the Malayan Peninsula to various islands throughout Indonesia. The plant's geographical distribution as well as many other aspects pertaining to the basic biology of this genus have still not been studied. The young flower buds and flowers of wild Rafflesia hasseltii Suringar, Rafflesia keithii Meijer and Rafflesia cantleyi Solms-Laubach are used in local (Malaysia and Indonesia) traditional ethnomedicine as wound-healing agents, but currently no formal published research exists to validate this property. To maintain a balance between its ethnomedicinal and ornamental use, and conservation, Rafflesia spp. must be artificially cultivated to prevent overexploitation. A successful method of vegetative propagation is by host grafting using Rafflesia-impregnated Tetrastigma onto the stem of a normal Tetrastigma plant. Due to difficulties with culture contamination in vitro, callus induction was only accomplished in 2010 for the first time when picloram and 2,4-D were added to a basal Murashige and Skoog medium, and the tissue culture of holoparasitic plants continues to be extremely difficult. Seeds harvested from fertile fruit may serve as a possible method to propagate Rafflesia spp. This paper provides a brief synthesis on what is known about research related to Rafflesia spp. The objective is to further stimulate researchers to examine, through rigorous scientific discovery, the mechanisms underlying the ethnomedicinal properties, the flowering mechanisms, and suitable in vitro regeneration protocols that would allow for the fortification of germplasm conservation.
Garcinia mangostana is a tropical fruit plant rich in antioxidant and bears recalcitrant seeds. The extent of water loss and low temperature tolerable by recalcitrant seed varies from regular orthodox seeds. Present study generates transcriptome resources for G. mangostana to postulate potential transcriptome differences between recalcitrant and orthodox seeds during seed germination process. Raw reads of pooled samples used for the assembly have been deposited in genbank accession SRR5412332.
In the midst of the major soil degradation and erosion faced by tropical ecosystems, rehabilitated forests are being established to avoid the further deterioration of forest lands. In this context, cellulolytic, nitrogen-fixing (N-fixing), phosphate-solubilizing bacteria are very important functional groups in regulating the elemental cycle and plant nutrition, hence replenishing the nutrient content in forest soils. As is the case for other potential plant growth-promoting (PGP) rhizobacteria, these functional bacteria could have cross-functional abilities or beneficial traits that are essential for plants and can improve their growth. This study was conducted to isolate, identify, and characterize selected PGP properties of these three functional groups of bacteria from tropical rehabilitated forest soils at Universiti Putra Malaysia Bintulu Sarawak Campus, Malaysia. The bacteria were isolated based on their colonial growth on respective functional media, identified using both molecular and selected biochemical properties, and were assessed for their functional quantitative activities as well as PGP properties based on seed germination tests and indole-3-acetic acid (IAA) production. Out of the 15 identified bacterial isolates that exhibited beneficial phenotypic traits, a third belong to the genus Burkholderia and a fifth to Stenotrophomonas sp., with both genera consisting of members from two different functional groups. The results of the experiments confirm the multiple PGP traits of some selected bacterial isolates based on their respective high functional activities, root and shoot lengths, and seedling vigor improvements when bacterized on mung bean seeds, as well as significant IAA production. The results of this study suggest that these functional bacterial strains could potentially be included in bio-fertilizer formulations for crop growth on acid soils.
Due to the increasing production and use of nanoparticles in various sectors such as electronic industries and healthcare,
concerns about the unknown effects caused by the presence of these materials in the natural environment and agricultural
systems were on the rise. Because of the growing trend of ZnO nanoparticles (nZnO) which is one of the most widely
used nanoparticles being released into the environment, it has attracted the attention for more studies to be done on
the effects of this nanoparticle on organisms. This study was carried out to investigate the phytotoxicity effect of nZnO
on groundnut seedlings in Murashige and Skoog (MS) medium. The experimental treatments of this study include eight
concentrations of nZnO (10, 30, 50, 100, 200, 400, 1000 & 2000 mg.L-1) added to MS medium and MS medium without
nanoparticles have been used as control treatment. For the first 6 days after sowing, germination percent and germination
rate index were calculated by counting the germinated seeds every day. Groundnut seedlings were incubated for 3 weeks
in optimum condition and after that, seedling characteristics such as length, wet and dry weight of radicle and plumule
were measured. The water content of radicle and plumule were also calculated. The results of this study showed that
radicle and plumule length of groundnut seedlings were affected by nZnO exposure, in a way that length of radicles in 50
mg.L-1 nZnO and higher concentrations was significantly lower than that of control treatment and the shortest plumule
length was observed in 2000 mg.L-1 nZnO concentration treatment. Both the radicle and plumule wet weight were also
decreased as the nanoparticle concentration was increased. However, despite the decreasing in radicle and plumule dry
weight with increasing in nZnO concentration, this increase was not significant. However radicle dry weight in 10 mg.L-1
nZnO was significantly higher than nZnOtreatments with 200 mg.L-1 concentration and higher concentrations. Moreover,
observations of this study did not show any significant difference between the water content of nZnO concentration
treatments and control treatment.
In this study, the antimicrobial, antioxidant, phytotoxic and phytochemical properties of defatted seeds of Jatropha curcas were evaluated. A crude methanolic extract of defatted seeds was tested against three fungal strains - Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus - and five bacteria: Escherichia coli and Klebsiella pneumoniae (Gram negative) and Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus (Gram positive). The methanolic extract was diluted in dimethylsulfoxide to final concentrations of 1, 2, 3, 4 and 5 mg/10 mL. The largest zones of inhibition against K. pneumoniae, M. luteus and B. subtilis were achieved using the concentration of 5 mg/10 mL. The concentration of 1 mg/10 mL was most effective against S. aureus and E. coli. In a 1, 1-diphenyl-2-picrylahydrazyl (DPPH) radical scavenging assay, the 5 mg/10 mL concentration of the Jatropha seed extract showed the strongest activity. Higher concentrations of the Jatropha seed extract (10 mg/50 mL and 5 mg/50 mL) significantly inhibited the germination of radish seeds and had negative effects on radish seedling relative water content, shoot length, root length, seedling fresh weight and seedling dry weight (p<0.05). Phytochemical analyses of the defatted seeds detected alkaloids (7.3%), flavonoids (0.39%) and soluble phenolics (mg gallic acid equivalents/g extract). Based on these results, it was inferred that J. curcas seeds contain active ingredients that are effective against pathogenic microbes and therefore could be used to formulate drugs to treat various diseases.
The purpose of this study was to investigate the basis of the optimal hydration status for cryopreservation of intermediate oily seeds using Citrus as a model.
Amino acid profiles, protein digestibility, corrected amino acid scores (PDCAAS), chemical scores, essential amino acid indexes, and calculated biological values of controlcowpea flour (CCF), germinated cowpea flour (GCF) prepared from cowpeas germinated at 25 degrees C for either 24 h or 48 h and weaning foods prepared from cowpea flours were determined. Locally available rice, cowpea flour, banana-pumpkin slurry, and skim milk powder and sucrose in the ratio 35:35:15:15:5 were used to formulate weaning food containing not less than 15% protein. The ingredients were cooked into a slurry and oven-dried to produce flakes. The nutritional and sensory qualities of the weaning products were evaluated. Germination had little effect on the amino acid profile of cowpeas. In vitro protein quality and starch digestibility were improved in germinated cowpea flour. The PDCAAS of 24 h germinated cowpea flour (GCF) weaning food was higher (55.49%) than CCF-weaning food (46.74%). Vitamin A activity in 24 h GCF weaning food was higher than in CCF-weaning food. In vitro starch digestibilities of 24 h GCF and 48 h GCF-weaning foods were higher than that of CCF weaning food. The 24 h GCF-weaning food which had a higher overall acceptability score by sensory panelist than 48 h GCF and CCF-weaning food is recommended for household consumption.
Proximate content and fatty acid composition of germinated and non-germinated legumes (kidney, mung, soy bean and peanut) and rice varieties (red, black, Barrio, brown and milled) were evaluated. In germinated samples, moisture content increased significantly while carbohydrate, protein and fat were decreased significantly. Total dietary fibre was increased in germinated samples except germinated kidney and mung bean. Germination also increased saturated fatty acids (SFA) in legumes, black, red and brown rice. Monounsaturated fatty acids (MUFA) decreased in all samples except germinated kidney, soy and Barrio rice. Polyunsaturated fatty acids (PUFA) increased in some germinated samples (mung bean, peanut, red, brown, Barrio and white rice) but decreased in other legume and rice samples. Generally, palmitic acid increased while stearic, oleic and linoleic acids decreased after germination. Overall, the proximate content and fatty acids of legume and rice varieties changed after germination and may be used as alternate resources for individuals with lifestyle diseases.