Seedling Root Length Research Articles

Emergence response of sunflower (Helianthus annuus) cultivars to supra-optimal soil temperatures

Seedling emergence is a sensitive stage during sunflower (Helianthus annuus L.) establishment. Abiotic stresses, such as high soil temperatures (above 40 °C), can cause delayed emergence resulting in uneven stand and ultimately poor yields. Therefore, the emergence and early growth responses of seven sunflower cultivars to four daily supra-optimal soil temperatures (DSST) of 35, 40, 45 and 50 °C were evaluated. The experiment was laid out as a randomised complete block design with four replications repeated twice in a glasshouse. Results clearly indicated that emergence index (EI) declined with an increase in soil temperature. A moderate decline was observed from DSST 35 °C to 45 °C, but from DSST 45 °C to 50 °C the decline was extreme. Root length of seedlings 24 h after planting were inconsistent between plantings. Root length at surface cracking and 48 h after surface cracking indicated that seedling root length at DSST 35 °C was longer than at DSST 45 °C and 50 °C. The lowest dry mass for both plantings was recorded at DSST 50 °C. Morphological differences were also visible for sunflower seedlings at the selected temperatures, but there were no definite visible differences between cultivars. Generally, deformed seedlings were observed at temperatures above DSST 40 °C.

AVALIAÇÃO DOS FITORREGULADORES AUXINA E GIBERELINA NA GERMINAÇÃO E CRESCIMENTO DO ARROZ

O arroz (Oryza sativa L.) é uma planta da família das Poaceas (gramíneas), sendo um dos cereais mais cultivados no mundo. Os fitorreguladores como auxina e giberilina podem influenciar o crescimento e desenvolvimento das plantas como o arroz. O objetivo deste estudo foi avaliar a germinação e o crescimento do arroz sob diferentes doses de fitorreguladores (auxina e giberelina). Foram conduzidos dois experimentos, o primeiro para determinar a germinação e comprimento radicular das sementes de arroz. O segundo experimento foi conduzido para determinar a altura, massa seca da parte área (MSPA) e o conteúdo nitrogênio (N) da parte aérea (NPA). Nos dois experimentos foram testadas quatro doses de auxina + giberelina: 0 (testemunha); 200; 500 e 1000 mL ha–1. O delineamento experimental foi inteiramente casualizado com cinco repetições para cada tratamento nos dois experimentos. A germinação das sementes e o comprimento radicular foram aumentados com a aplicação de auxina e giberelina. A altura e o NPA foram aumentados significantemente com a aplicação de auxina e giberelina. Concluiu-se que a aplicação de auxina e giberelina na cultura do arroz aumentaram a germinação e o comprimento radicular das sementes. Além disso, aumentou a altura e o conteúdo de nitrogênio nas plantas de arroz.

Developing eco-friendly biofungicide for the management of major seed borne diseases of rice and assessing their physical stability and storage life

Three plant oils (Cymbopogon citratus, Cymbopogon martini, and Pelargonium graveolens) were developed as EC formulations and tested for their physical stabilities. EC formulations (10EC, 20EC and 30EC) of C. citratus, C. martini and P. graveolens had emulsion stability, spontaneity property, heat and cold stability. EC formulated plant oils were screened against the major seed borne fungi of rice such as Curvularia lunata, Fusarium moniliforme, Bipolaris oryzae, and Sarocladium oryzae. The level of inhibition varied among the concentrations of EC formulations. Among the three EC formulations, that of C. citratus oil 30EC recorded 100% inhibition on the mycelial growth of test pathogens. In the blotter paper method, rice seeds treated with a formulation of C. citratus oil 30EC controlled the infection of C. lunata, F. moniliforme, B. oryzae and S. oryzae in rice seed to the tune of 66.0%, 60.4%, 66.0% and 69.1%, respectively. Seed soaking with formulation of C. citratus oil 30EC showed the highest percentage of normal seedlings, the lowest number of abnormal seedling and fresh ungerminated seeds when tested with the roll-towel method. Seed soaking with 30EC formulation of C. citratus oil increased seed germination, shoot length, root length and vigour of rice seedlings when tested with the plastic tray method. Transmission of pathogens from seed to seedling was reduced significantly by the 30EC formulation of C. citratus oil when tested with the plastic pot method. The effect of the storage life of the 30EC formulation of C. citratus oil showed that it had retained their antifungal effect till the end of the incubation period (120 days), and is able to inhibit the mycelial growth of all test pathogens to the 100% level.

Characterization of culturable bacteria isolated from hot springs for plant growth promoting traits and effect on tomato (Lycopersicon esculentum) seedling

To elucidate the functional diversity of hot spring bacteria, 123 bacteria were isolated and screened for evaluating their multifunctional plant growth promoting (PGP) properties. The antagonistic activity against different phytopathogens showed the presence of a high amount of biocontrol bacteria in the hot springs. During screening for PGP properties, 61.0% isolates showed production of indole acetic acid and 23.6% showed inorganic phosphate solubilization qualitatively. For production of extracellular enzymes, it was found that 61.0% isolates produced lipase, 56.9% produced protease, and 43.9% produced cellulase. In extreme properties, half of the isolates showed tolerance to 5% NaCl (w/v) and 48.8% isolates survived heat shock at 70°C. The identification of 12 multipotential bacteria based on 16S rRNA gene sequencing revealed that the bacteria belonged to Aneurinibacillus aneurinilyticus and Bacillus spp. Bacterization of tomato seeds showed that the hot spring bacteria promoted shoot height, fresh shoot weight, root length, and fresh root weight of tomato seedlings, with values ranging from 3.12% to 74.37%, 33.33% to 350.0%, 16.06% to 130.41%, and 36.36% to 318.18%, respectively, over the control. This research shows that multifunctional bacteria could be isolated from the hot springs. The outcome of this research may have a potential effect on crop production methodologies used in saline and arid environments.

Molecular characteristics of water-extractable organic matter from different composted biomasses and their effects on seed germination and early growth of maize

Four water extractable organic matter (WEOM) were obtained from composts made out of residues of: 1. artichoke (C-CYN), 2. artichoke/fennel (C-CYNF), 3. tomato/woodchips (C-TOM), 4. Municipal solid waste (C-MSW), and their bioactivity was tested for maize seed germination and maize seedling growth. The molecular properties of both original composts and their WEOM were characterized by spectroscopic (13C-CPMAS- and 1H NMR, FTIR-ATR), thermochemolysis-GC/MS, and thermal methods (TGA, DSC). While all WEOM had significant effects on plant growth, CYN-WEOM was the only material that concomitantly increased germination rate and primary and lateral root length of maize seedlings. The lignin-rich WEOM from green composts were generally more effective than those obtained from equally hydrophobic, but mainly alkyl-rich municipal organic wastes. A flexible conformational structure, due to the balanced content of aromatic compounds and carbohydrates, appeared to facilitate the release of bioactive molecules from WEOM suprastructures and stimulate plant growth.

Effect of Dark Septate Endophytic Fungus Gaeumannomyces cylindrosporus on Plant Growth, Photosynthesis and Pb Tolerance of Maize (Zea mays L.)

Dark septate endophytic (DSE) fungi are ubiquitous and cosmopolitan, and occur widely in association with plants in heavy metal stress environment. However, little is known about the effect of inoculation with DSE fungi on the host plant under heavy metal stress. In this study, Gaeumannomyces cylindrosporus, which was isolated from Pb-Zn mine tailings in China and had been proven to have high Pb tolerance, was inoculated onto the roots of maize (Zea mays L.) seedlings to study the effect of DSE on plant growth, photosynthesis, and the translocation and accumulation of Pb in plant under stress of different Pb concentrations. The growth indicators (height, basal diameter, root length, and biomass) of maize were detected. Chlorophyll content, photosynthetic characteristics (net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration), and chlorophyll fluorescence parameters in leaves of the inoculated and non-inoculated maize were also determined. Inoculation with G. cylindrosporus significantly increased height, basal diameter, root length, and biomass of maize seedlings under Pb stress. Colonization of G. cylindrosporus improved the efficiency of photosynthesis and altered the translocation and accumulation of Pb in the plants. Although inoculation with G. cylindrosporus increased Pb accumulation in host plants in comparison to non-inoculated plants, the translocation factor of Pb in plant body was significantly decreased. The results indicated that Pb was accumulated mainly in the root system of maize and the phytotoxicity of Pb to the aerial part of the plant was alleviated. The improvement of efficiency of photosynthesis and the decrease of translocation factor of Pb, caused by DSE fungal colonization, were efficient strategies to improve Pb tolerance of host plants.

Effect of seed coating, storage periods and storage containers on soybean (Glycine max (L.) Merrill) seed quality under ambient conditions

Soybean seed is classified as “poor storer” as it loses viability under warm and humid conditions and is invaded by storage fungi. The seed of soybean variety PS 1347, obtained from Breeder Seed Production Centre, G. B. Pant University of Agriculture and Technology, Pantnagar was used for storage study. Root length (cm), shoot length (cm), seedling fresh weight (g) and seedling dry weight (g) decreases with the increase in seed storage periods. Out of all chemical treatments, Flowable thiram @ 2.4 ml/kg (T2) and Polymer + vitavax 200 @ 2g/kg seed (T5) were found effective to maintain Seedling root length, shoot length, seedling fresh weight and seedling dry weight by producing vigorous seedlings. Seeds stored in cloth bags exhibited higher seed infection than in seed stored in polythene bags, irrespective of seed treatment and period of storage. Treatment T4 (Vitavax 200 @ 2 g/kg seed)and T5(Polymer + vitavax 200 @ 2 g/kg seed) exhibited minimum percent seed infection of Aspergillus flavus. Cloth bag was not found safe for longer storage of soybean seeds under ambient storage at Pantnagar.

Allelopathic activity of Nepeta nuda L. subsp. nuda water extracts

Abstract Nepeta nuda subsp. nuda is a medicinal plant growing wild in Bulgaria. Different species of Nepeta genus have been reported to possess allelopathic potential. The present study was conducted to observe its phytotoxic effects on T. aestivum and C. sativus L. seeds in laboratory conditions. Nepeta water extracts (NWE) prepared from aerial parts of plants at concentrations 2, 4, 6, 8, 10, 12 and 14 g/l were tested. The rate of seed germination, the root and shoot length, fresh and dry weight of seedlings were observed after treatment with NWE. As a control served seeds treated with distilled water. Germination was not affected, but NWE showed deterioration in seedling growth. Roots were more affected than shoots. The fresh and dry weights were reduced upon treatment with the extracts tested. These negative effects were dose-dependent. The overall results indicate presence of water soluble allelochemicals in Nepeta nuda subsp. nuda.

BIO-HERBICIDAL EFFICIENCY OF WITHANIA SOMNIFERA AGAINST IMPORTANT HIMALAYAN WEEDS

Objective: The aim of the study was to evaluate the bioherbicidal activity of Withania somnifera against germination and growth of noxious weeds of Himalaya i.e. Ageratum coenyzoides, Chenopodium album and Achyranthus aspera in a laboratory and foliar spray bioassay which will act as a tool of weed management in the Himalayan region.Methods: Root, stem and leaf aqueous extract of Withania somnifera at 100% concentration were applied to determine their effect on the seed germination and seedling growth of tested weeds under laboratory condition. Foliar spray bioassay was carried out by spraying extracts of Withania somnifera on three-month-old seedlings of weeds for two months. Germination and growth of weeds were assessed using growth parameters into account i.e. germination percentage, stem length, root length, fresh weight, dry weight, no of shoot branches and no of root branches.Results: The results revealed that all the aqueous extracts markedly suppressed germination and seedling growth of A. coenyzoides, C. album and A. aspera. Withania extracts remarkably effected germination, the growth of Ageratum coenyzoides in comparison to other studied weeds. The leaf extract of Withania was more pronounced than stem and root extracts in germination assay. Infoliarspray bioassay, aqueous leaf extracts of 100% w/v concentrations were sprayed on three month old seedlings of weeds at an interval of 5 d. All the aqueous extracts significantly suppressed shoot length, root length, fresh weight and dry weight of Ageratum coenyzoides, Chenopodium album and Achyranthus aspera seedling. In foliar spray bioassay, leaf extract suppressed the stem length, root length, fresh weight, dry weight, no. of root branches and no of shoot branches of studied weeds more commendably than stem and root extract. The suppression of growth parameters could be attributed to the presence of phytochemicals present in the extracts of Withaniasomnifera.Conclusion: The present study concludes that Withania somnifera contain bio-herbicidal compounds in leaf, stem and root as plant extracts adversely affect weed growth of studied weeds. Henceforth the strategy bio-control of weed is a safe and effective method which could prove a milestone in weed management in Mid-Himalaya.

EFFECT OF IRRIGATION INTERVALS AND SOME FOLIAR APPLICATION TREATMENTS ON DRY BEAN (PHASEOLUS VULGARIS . L) GROWTH, SEED YIELD AND QUALITY

Strategies such as foliar application of salicylic acid and potassium show particular possibilities for conserving irrigation water, aiding plant survival under dry conditions. In this study, two field experiments were carried out during the summer seasons of 2014 and 2015, to examine the response of bean (Phaseolus vulgaris .L) plants to the foliar application of salicylic acid (SA) at 10 and 20 ppm as well as potassium sulphate at 1 and 2% under three irrigation intervals i.e. 8, 12 or 16 days. The obtained results indicated that irrigation every 8 days improved vegetative growth in terms of plant height, number of leaves per plant and plant fresh and dry weights as well seed yield and quality i.e. germination percentage , mean germination time, seedling root length and seedling vigor index . All used foliar treatments i.e. salicylic acid at 10 and 20 ppm as well potassium sulphate at 1 and 2% improved vegetative growth ,seed yield and its quality. Foliar application with SA at 20 ppm was the best treatment in this regard. The interactions between irrigation every 8 days and foliar application with SA at 20 ppm gave the highest values of the studied vegetative, seed yield and quality characters. For obtaining high seed yield and quality of bean plants it could be recommended that, irrigation should be done every 8 days and plants should be sprayed with salicylic acid at 20 ppm three times during the growing season at 3, 5 and 7 weeks after sowing. However, in case of water shortage it is possible to extend the irrigation interval up to 16 days with three times foliar application of salicylic acid at 20 ppm to ameliorate the drought stress without decreasing the yield.

Allelopathy and Anti-mitotic Effects of Cuscuta campestris and Cuscuta monogyna Extracts on Plant Cell Division

Some natural compounds of plants including phenols and alkaloids induce mitosis depressive that are blocked cell division. Field dodder (Cuscuta campestris Yunck.) and eastern dodder (Cuscuta monogyna Vahl.) are the most widespread obligatory parasitic species. In the present study, end of summer 2015, field dodder and eastern dodder are collected from Alhagi maurorum Medik. host and Vine (Vitis sylvestris C.C.Gmel.) host respectively from Markazi province of Iran and identified by department of botany of Islamic Azad University of Saveh. The aerial parts of dodders were used for aqueous extract. Dodders alkaloid and poly phenol were visualized by TLC and Dragendorff (for alkaloid) and ferric salt (for poly phenol) reagents. Total phenols and alkaloid were measured by using the calibration and spectrophotometry methods. Root length and roots tip meristem model of onion bulbs and barley seedlings were utilized to allelopathy and antimitotic effects of dodders aqueous extracts. Standard cytotoxic 8-Hydroxyquinoline served as controls. The bulbs and barley seedlings were treated at various concentrations: 0.05, 0.1 and 0.2 mgml-1 (dw) of and aqueous extract of dodders and 8-Hydroxyquinoline for 6 and 12 h. The inhibitory effect of dodders extract were evaluated on the growth and mitotic activity (Mitotic index) of barley seedlings and onion root meristems and the effect was compared with standard 8-Hydroxyquinoline. The One Way ANOVA test was used for statistical analysis. The poly phenols of field dodder was condensed tannins (include flavonoids) but for eastern dodder hydrolysable tannins. Like 8-Hydroxyquinoline, both field and eastern dodders extracts significantly inhibited the growth of roots and mitotic activity in incubation time and dose-dependent manner. However, C. campestris extract was more allelopathy and antimitotic potent in this regard and produced root decay and mitosis arrest. The extract of dodders had inhibitory and mitosis depressive effect on root tip meristem cells. In the present study we found, the dodders aqueous extracts can been used to produce desirable effects as it pertains to chromosome condensation and spread, and though the roles of these chemicals in spindle fiber inhibition have been elucidated, as 8-Hydroxyquinoline.

Screening of F1 progeny for selection of superior hybrids in mulberry (Morus spp.) - A simple approach PART I: Screening of seedlings in relation to seed size

In mulberry (Morus spp.), the process of selection of promising hybrids from F1 population requires the screening of a large number of progenies and a long period. To develop a simple and faster approach for screening, studies were conducted using F1 seeds of two crosses. The details of screening studies conducted in relation to seed-size and seedling-size are reported separately in two parts. In this part, the F1 seeds were size-graded as small, medium and large seeds; their progenies were raised separately and screened in nursery. There was a considerable degree of variation in size of seeds and medium-size class seeds were in high percentage in both the crosses. The length, width and weight of seeds were also varied between the seed size classes significantly in both the crosses. The seed size classes differ with high significance in shoot length and Root collar diameter and also differ significantly in root length and weight of seedlings. The positive correlation between the seed size and growth of seedlings, seed size and germination, seed size and seedling survival in nursery indicated that size-grading of seeds and rejection of small seeds in the beginning of screening process may help to increase the efficiency of screening by increasing the chances of getting superior hybrids from limited progenies. However, confirmation on the performance of large seedlings from small seed size class may help to draw conclusion. Hence, the studies are continued with size- grading of seedlings in the next part of screening study.

Genetic analysis for rice seedling vigor and fine mapping of a major QTL qSSL1b for seedling shoot length.

Seedling vigor is an important agricultural trait as direct-seeded rice technology becomes widely applied. In order to investigate the genetic mechanisms underlying seedling vigor in rice, seeds of 132 recombinant inbred lines (RILs) derived from 93-11 and PA64s, harvested from Lingshui and Hangzhou were cultivated in the nutrient solution, and four indices for seedling vigor were measured including seedling shoot length (SSL), seedling root length (SRL), seedling wet weight (SWW) and seedling dry weight (SDW). Significant correlations were observed among the indices, and also between 1000-seed weight (TSW) and SWW or SDW. Combined with a high-resolution genetic map generated from sequencing of the RILs, 65 quantitative trait loci (QTLs) were detected on all chromosomes with interval of 1.93 Mb on average. Among 57 QTLs for seedling vigor, 28 were detected from seeds harvested in both sites and 33 were first identified. With BC3F2 derived from 93-11 and a CSSL harboring segments from PA64s in 93-11 background, a major QTL for SSL, qSSL1b was fine mapped within 80.5 kb between two InDel markers. Our study provides a platform for further cloning of the QTL and dissecting the molecular basis for seedling vigor at early seedling stage in rice.

High dilution preparations for organic production system of broccoli

The aim of this study was to evaluate the influence of high dilution preparations on seedlings growth and production of broccoli under organic system. Three experiments were conducted in a greenhouse with completely randomized design. Two others experiments were conducted under field conditions, and the experimental design was randomized in blocks. Both designs were done with four replications and nine treatments. The treatments consisted of high dilution preparations of Arnica montana, Silicea terra, Carbo vegetabilis and Sulphur at 6CH or 30CH, water was used as control. In greenhouse, plant height, root length and stem diameter of seedlings were evaluated, along with the fresh and dry mass of shoot and root. In field, fresh and dry mass of inflorescences, plant heigh and stem diameter were evaluated. Silicea terra at 30CH increased the stem diameter, root length and dry mass of shoot and root in the broccoli seedlings. Sulphur at 6CH increased the fresh and dry mass of broccoli inflorescences. Silicea terra at 6CH, Carbo vegetabilis, and Sulphur at 30CH increased the plant height in field experiments. This suggests that high dilution preparations can be utilized to increase the biomass production and others desirable characteristics of broccoli crop under organic system.

Germination of Sweet Sorghum Seeds in Different Water Potentials

The implantation of sweet sorghum has been shown as viable alternative in crop rotation in sugar cane plantation reform areas. The seed environment in the field is complex and several factors, such as different genotypes and osmotic stress, can negatively influence the seeds water uptake and, therefore, the sequence of germination events can be compromised. In this context, the objective of this study was to evaluate the different physiological responses of sweet sorghum seeds (Sorghum bicolor (L.) Moench) belonging to the hybrids CV 007 and CV 147 and cultivar BRS 506 when submitted to substrates with different water potentials (-0.1, -0.2, -0.3, -0.4, and -0.5 MPa) using solutions of polyethylene glycol (PEG 6000). The seeds remained in Biochemical Oxygen Demand-type germination chambers, under constant white light and the temperature of 25°C for 14 h in the high temperature and 10 h in the low temperature. The moisture of the substrates was regularly monitored. The physiological potential of the genotypes was evaluated using the following characteristics: first count, germination, germination speed index (GSI), root length, and fresh and dry weights of seedlings. In general, germination and early growth of seedlings were negatively affected by the reduction of water potentials below -0.1 MPa, which was also damaging to the GSI of the seeds. Germination and growth of seedlings of the hybrids CV 007 and CV 147 and of the cultivar BRS 506 were affected by reduced water potentials starting at -0.1 MPa. The seeds of hybrid CV 147 were more tolerant to simulated water stress with PEG 6000 than those of hybrid CV 007 and cultivar BRS 506.

Effects of light intensity on leaf microstructure and growth of rape seedlings cultivated under a combination of red and blue LEDs

The aim of this study was to evaluate the growth of rape (Brassica napus L.) seedlings under different light intensities to select appropriate conditions for cultivation in an indoor system. Seedlings were grown under different light intensities of red and blue light provided by light-emitting diodes (LEDs) and their self-adjustment ability and changes in leaf microstructure were evaluated. Light was supplied by red LEDs with peak wavelengths of 630 (R1) and 660 nm (R2) and by blue LEDs (B) with a peak wavelength of 445 nm (the light intensity ratio of R1:R2:B was 3:3:2), at intensities of 400 (R1R2B400), 300 (R1R2B300), and 200 μmol m−2 s−1 (R1R2B200). Natural solar light served as the control (C). Plant height, stem diameter, root length, leaf area, and dry weight of rape seedlings gradually increased with increasing light intensity. The seedlings in the R1R2B400 treatment grew more vigorously, while those in the R1R2B200 treatment were weaker. The photosynthetic pigment contents did not differ significantly between the R1R2B400 treatment and C, but were significantly lower in the R1R2B300 and R1R2B200 treatments. The highest intercellular CO2 concentration, stomatal conductance, and transpiration rate were in the R1R2B300 treatment. The highest photosynthetic rate was in the R1R2B400 treatment, and was related to more compact leaves, thicker and tidier palisade and spongy tissues, and well-developed chloroplasts. In contrast, the seedlings in the R1R2B200 treatment had disordered mesophyll cells, round chloroplasts, and fractured and fuzzy grana lamellae, all of which inhibited plant growth. In conclusion, the seedlings in the R1R2B400 treatment had well-developed leaves, which favored photosynthesis. Compared with the light intensities below 300 μmol m−2 s−1, the light intensity of 400 μmol m−2 s−1 provided by a combination of red and blue LEDs was beneficial for cultivating strong and healthy rape seedlings in an artificial system.

Effect of PEG8000 and NaCl on germination and seedling traits of tropical maize (Zea mays L.)

Among the different types of abiotic stresses, water isthe most damaging for crops. In the current research, the effect ofwater stress, induced with Polyethylene Glycol 8000 (PEG8000)and Sodium chloride (NaCl) solutions, was studied in maize genotypes.A randomized block design (RBD) with a factorial arrangementand four replications of 25 seeds each was used. The studiedmaize genotypes were RC2C39, RC2C51 (wild varieties of the Stateof Tabasco backcrossed with the endogamic line CML247 of the InternationalCenter for the Improvement of Maize and Wheat), wildTamulte, VS536, and Asgrow 7573 hybrid, study osmotic pressures(OP) were 0, -1.0, and -2.0 MPa. The percentage seed germination(G%), and seedling length (SL, in cm), root length (RL, in cm), freshseedling weight (FSW, in g), and fresh root weight (FRW, in g) wereevaluated on seedlings after 12 days of treatment imposition in thefive corn genotypes (Zea mays L.). The results showed significant differencesin the study variables before and after the stresses as theconcentrations of PEG8000 and NaCl increased. In general, theRC2C39, RC2C51, and VS536 genotypes had a better response toPEG8000 and NaCl as compared to wild Tamulte and Asgrow 7573hybrid for all measured variables. The OP of -2.0 MPa is suggestedto separate drought-tolerant from intolerant corn cultivars in theMexican tropical areas.

Plant growth-promoting properties of cultivable endophytic root nodule bacterial isolates from Acacia mangium Willd

<strong>The present study was conducted to isolate and characterize endophytic bacteria isolated from root nodules of <em>Acacia mangium</em> Willd and subsequently tested for plant growth promotion. A total of five bacterial isolates were successfully isolated and subjected to morphological and biochemical examination. The present study found that all isolates had almost similar morphologically but differed in growth rate. All isolates were negative on N-free and IAA tests, though positive on P solubilisation test. The present study demonstrated that the inoculation with isolate FSI3 had significantly improved (p<0.05) root and shoot dry weight of winged bean seedlings as compared to uninoculated control. However, the inoculation did not significantly alter (p>0.05) root and shoot length of winged bean seedlings. The present study suggests that the stimulatory effect by isolate FSI3 may be associated with P-solubilizing ability. A further test on isolate FSI3 is considered essential in future to uncover the several other possible plant growth-promoting mechanisms. </strong>

Effects of untreated and treated wastewater at the morphological, physiological and biochemical levels on seed germination and development of sorghum (Sorghum bicolor (L.) Moench), alfalfa (Medicago sativa L.) and fescue (Festuca arundinacea Schreb.)

Wastewater reuse in agriculture may help mitigate water scarcity. This may be reached if high quality treatments removing harmful pollutants are applied. The aim of the present study was to compare the effect of untreated (UTW) and treated wastewater (TW) on germination and seedlings development of alfalfa (Medicago sativa L.), fescue (Festuca arundinacea Schreb.) and sorghum (Sorghum bicolor (L.) Moench). UTW presented high turbidity (130 NTU), chemical and biological oxygen demand (COD, 719mgL−1, BOD5, 291mgL−1) and metal concentrations. These levels caused mortality (18% for fescue), decreased germination speed in seeds (37.5% for alfalfa) and reductions of root and stem length in seedlings (80% and 22% respectively for alfalfa). Adverse effects on seeds germination were reflected at the biochemical level by increased H2O2 levels (6 times for sorghum after 5days) and by increased Malondialdehyde (MDA) levels (more than 600 times for sorghum roots) during seedlings development. When TW was used, these parameters were close to control seeds ones. They were also dependent on plant species and developmental stage. Therefore, for efficient reclaimed wastewater reuse in irrigation, suitable crops, displaying wide tolerance to toxic contents during germination and later seedling development stages have to be selected.

The effect of drying temperatures and storage of seeds on the growth of soybean seedlings

Abstract: Drying of seeds reduces their moisture content to levels appropriate for storage. However, care in the temperatures applied in the process is necessary to avoid damage to the seeds that are dried. The aim of this study was to evaluate the effect of different drying temperatures and storage on the growth of soybean seedlings. Harvested with a moisture content of approximately 23% (w.b.), the seeds were dried at different temperatures (40, 50, 60, 70, and 80 °C) until reaching moisture content of 12.5 ± 0.7% (w.b.), and they were subsequently stored for 180 days in an environment without climate control. A germination test and evaluations of seedling performance were carried out every 45 days, determining the full length of the seedling and hypocotyl and root lengths, along with their respective dry matter weights. The results showed that: a) the increase in the temperature of drying air affects the physiological quality of soybean seeds, and this effect is accentuated over time, especially on root length; and b) the air temperature of 40 °C can be recommended for drying of soybean seeds in association with the storage time of 180 days under storage conditions without climate control.