Incorporation of compost and biochar enhances yield and medicinal compounds in seeds of water-stressed Trigonella foenum-graecum L. plants cultivated in saline calcareous soils.

BACKGROUND: The combination of compost and biochar (CB) plays an important role in soil restoration and mitigation strategies against drought stress in plants. In the current study, the impact of CB was determined on the characteristics of saline calcareous soil and the productivity of fenugreek (Trigonella foenum-graecum L.) plants. The field trials examined CB rates (CB0, CB10 and CB20 corresponding to 0, 10, and 20 t ha‒1, respectively) under deficit irrigation [DI0%, DI20%, and DI40% receiving 100, 80, and 60% crop evapotranspiration (ETc), respectively] conditions on growth, seed yield (SY), quality, and water productivity (WP) of fenugreek grown in saline calcareous soils. RESULTS: In general, DI negatively affected the morpho-physio-biochemical responses in plants cultivated in saline calcareous soils. However, amendments of CB10 or CB20 improved soil structure under DI conditions. This was evidenced by the decreased pH, electrical conductivity of soil extract (ECe), and bulk density but increased organic matter, macronutrient (N, P, and K) availability, water retention, and total porosity; thus, maintaining better water and nutritional status. These soil modifications improved chlorophyll, tissue water contents, cell membrane stability, photosystem II photochemical efficiency, photosynthetic performance, and nutritional homeostasis of drought-stressed plants. This was also supported by increased osmolytes, non-enzymatic, and enzymatic activities under DI conditions. Regardless of DI regimes, SY was significantly (P ≤ 0.05) improved by 40.0 and 102.5% when plants were treated with CB10 and CB20, respectively, as similarly observed for seed alkaloids (87.0, and 39.1%), trigonelline content (43.8, and 16.7%) and WP (40.9, and 104.5%) over unamended control plants. CONCLUSIONS: Overall, the application of organic amendments of CB can be a promising sustainable solution for improving saline calcareous soil properties, mitigating the negative effects of DI stress, and enhancing crop productivity in arid and semi-arid agro-climates.

Kinetin mitigates Cd-induced damagesto growth, photosynthesis and PS II photochemistry of Trigonella seedlings by up-regulating ascorbate-glutathione cycle.

Cytokinins (CKs) plays a key role in plant adaptation over a range of different stress conditions. Here, we analyze the effects of a cytokinin (i.e., kinetin, KN) on the growth, photosynthesis (rate of O2 evolution), PS II photochemistry and AsA-GSH cycle in Trigonella seedlings grown under cadmium (Cd) stress. Trigonella seeds were sown in soil amended with 0, 3 and 9 mg Cd kg-1 soil, and after 15 days resultant seedlings were sprayed with three doses of KN, i.e.,10 µM (low, KNL), 50 µM (medium, KNM) and 100 µM (high, KNH); subsequent experiments were performed after 15 days of KN application, i.e., 30 days after sowing. Cadmium toxicity induced oxidative damage as shown by decreased seedling growth and photosynthetic pigment production (Chl a, Chl b and Car), rates of O2-evolution, and photochemistry of PS II of Trigonella seedlings, all accompanied by an increase in H2O2 accumulation. Supplementation with doses of KN at KNL and KNM significantly improved the growth and photosynthetic activity by reducing H2O2 accumulation through the up-regulation AsA-GSH cycle. Notably, KNL and KNM doses stimulated the rate of enzyme activities of APX, GR and DHAR, involved in the AsA-GSH cycle thereby efficiently regulates the level of AsA and GSH in Trigonella grown under Cd stress. The study concludes that KN can mitigate the damaging effects of Cd stress on plant growth by maintaining the redox status (>ratios: AsA/DHA and GSH/GSSG) of cells through the regulation of AsA-GSH cycle at 10 and 50 µM KN under Cd stress conditions. At 100 µM KN, the down-regulation of AsA-GSH cycle did not support the growth and PS II activity of the test seedlings.

Effect of Elicitation with Iron Chelate and Sodium Metasilicate on Phenolic Compounds in Legume Sprouts.

Seven-day-old sprouts of fenugreek (Trigonella foenum-graecum L.), lentil (Lens culinaris L.), and alfalfa (Medicagosativa L.) were studied. The legume seeds and then sprouts were soaked each day for 30 min during 6 days with water (control) or mixture of Fe-EDTA and sodium silicate (Optysil), or sodium silicate (Na-Sil) alone. Germination and sprout growing was carried out at temperature 20 ± 2 °C in 16/8 h (day/night) conditions. Phenolic compounds (free, ester, and glycosides) content were determined by HPLC-ESI-MS/MS using a multiple reaction monitoring of selected ions. Flavonoids and phenolic acids were released from their esters after acid hydrolysis and from glycosides by alkaline hydrolysis. The presence and high content of (-)-epicatechin (EC) in fenugreek sprouts was demonstrated for the first time. Applied elicitors decreased the level of free EC in fenugreek and alfalfa sprouts but enhanced the content of its esters. Besides, elicitors decreased the content of quercetin glycosides in lentil and fenugreek sprouts but increased the content of quercetin and apigenin glycosides in alfalfa sprouts. The applied elicitors decreased the glycoside levels of most phenolic acids in lentil and p-hydroxybenzoic acid in fenugreek, while they increased the content of this acid in alfalfa. The mixture of iron chelate and sodium silicate had less effect on changes in flavonoid and phenolic acid content in legume sprouts than silicate alone. In general, the used elicitors increased the content of total phenolic compounds in fenugreek and alfalfa sprouts and decreased the content in lentil sprouts. Among the evaluated elicitors, Optysil seems to be worth recommending due to the presence of iron chelate, which can be used to enrich sprouts with this element.

Reserve Mobilization, Membrane Damage and Solutes Leakage in Fenugreek Imbibed with Urban Treated Wastewater.

The study aimed to determine the impact of treated domestic wastewater on seed germination, seedling growth and reserve mobilization from Fenugreek (Trigonellafoenum graecum L.). Seeds were germinated by soaking in distilled water (H2O) or wastewater treated with various methods: activated sludge processes (T1), facultative lagoons treatment (T2) and dilution. Results show high levels of organic matter (OM), suspended solids (TSS) and nutrients in TWW (T2) than that of TWW (T1). The embryo length and biomass of fenugreek imbibed by TWW were higher in TWW (T2) compared with TWW (T1). There was more reduction in free amino acids and soluble sugar contents in fenugreek treated with TWW (T1) than treated by TWW (T2). Important solutes leakage is recorded by measuring electric conductivity during seed imbibition with TWW. Improving the quality of wastewater by dilution (50%) stimulated germination of seeds and the growth of the tested plant. Moreover, it significantly reduces the solutes leakage and enhanced seed metabolites accumulation.

A phytotoxic impact of phenolic compounds in olive oil mill wastewater on fenugreek "Trigonella foenum-graecum".

The objective of this study is the determination of the chemical structure of nine phenolic molecules responsible for the phytotoxic action on the germination of the plant species "Trigonella foenum-graecum". The phytotoxic action was evaluated by calculating the germination index of the plant species for a period of 5 days of incubation. The analysis of the physicochemical properties of phenolic molecules shows that hydrophobicity is a key factor in phytotoxicity. The sublethal concentration varies as follows: hydroquinone (0.91 mM), 4-aminophenol (0.85 mM), phenol (0.75 mM), gallic acid (0.59 mM), caffeic acid (0.56 mM), 3,5-di-tert-butylcatechol (0,45 mM), quercetin (0.33 mM), oleuropein (0.3 mM), and catechol (0.13 mM). Phytotoxicity varies depending on the nature and position of the substituents on the aromatic ring. The reactivity of this type of molecule is partly linked to the presence of catechol function that can play the main role in phytotoxicity of the Fenugreek.

The growth impairment of salinized fenugreek (Trigonella foenum-graecum L.) plants is associated to changes in the hormonal balance.

Fenugreek is a legume cultivated for its medicinal value, especially in arid and semi-arid regions, where soil salinity is an increasing problem. In fact, salinity is one of the major environmental factors limiting plant growth and productivity. Plant hormones are known to play vital roles in the ability of the plants to acclimatize to varying environments by mediating growth, development, and nutrient allocation. Thus, to gain insights about the role of plant hormones in the growth responses of salinized fenugreek plants (Trigonella foenum-graecum L.), a medium-term experiment was conducted under moderate (100 mM NaCl) and high (200 mM NaCl) salinity levels. Results showed that moderate, but especially high salinity stress, impaired shoot growth, total leaf area and leaf number. Salinity also provoked a reduction in relative water content, stomatal conductance and photosynthesis-related pigments, but, surprisingly, photosynthetic rate increased in the leaves of fenugreek plants. Na accumulated in the leaves, particularly at high salinity levels, while most mineral nutrients decreased. Furthermore, important changes in the main hormone classes were observed, associated to growth reduction under salinity. The active cytokinin form, trans-zeatin, and active cytokinin and gibberellin concentrations decreased with salinity in the leaves of fenugreek plants, whereas the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid, accumulated in the roots of fenugreek plants, especially at high salinity levels. Importantly, leaf abscisic acid concentrations increased under salinity, which could limit leaf transpiration to adapt growth to the stressful conditions. Therefore, plant hormones seem to play a critical role in the growth responses of fenugreek plants under salinity stress and they could have potential interest in salt tolerance programmes for this species.

Effect of planting time and vermicompost on the proteomic pattern of fenugreek (Trigonella foenum-graecum)

The fenugreek is one of the most important medicinal plants belongs to Fabaceae, originated in West Asia, Iran and Mediterranean regions. This research included a qualitative study of fenugreek proteins using SDS-PAGE electrophoresis on polyacrylamide gel and the separation of protein bands of fenugreek leaves in different treatments of vermicompost fertilizer and cultivating dates. Results showed that a band (about 80 kDa) on the first planting date (May 31) is observed in all samples except for sample a1 (10 t/ha vermicompost on May 31). Another significant difference was the band contained in the third planting date (31 September) and in the molecular weight of about 15 kDa, which was not seen in other dates. This difference can be due to the synthesis of this protein with the mentioned weight under the conditions of reducing the temperature in the early fall. It also showed more differences in two-dimensional electrophoresis, for example, in 14 kDa and PI in the range of 4.5-4.7 in treatment without fertilizer, no protein expression was observed, which was consistent with the results of the SDS-PAGE test.

Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli Cells Artificially Internalized into Vegetable Seeds during Germination.

Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process. Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after postinternalization seed surface decontamination. Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger (P < 0.05) than the EHEC populations. Significantly larger Salmonella populations were recovered from the cotyledon and seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pregerminated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study. Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production.IMPORTANCE The internalization of microorganisms into vegetable seeds could occur naturally and represents a possible pathway of vegetable seed contamination by human pathogens. The present study investigated the ability of two important bacterial pathogens, Salmonella and enterohemorrhagic Escherichia coli (EHEC), when artificially internalized into vegetable seeds, to grow and disseminate along vegetable sprouts/seedlings during germination. The data from the study revealed that the pathogen cells artificially internalized into vegetable seeds caused the contamination of different tissues of sprouts/seedlings and that pathogen growth on germinating seeds is bacterial species and vegetable seed-type dependent. These results further stress the necessity of using pathogen-free vegetable seeds for edible sprout production.

Exogenous IAA differentially affects growth, oxidative stress and antioxidants system in Cd stressed Trigonella foenum-graecum L. seedlings: Toxicity alleviation by up-regulation of ascorbate-glutathione cycle.

In the present study, effect of exogenous indole-3-acetic acid at their different levels (i.e. low; IAAL, 10µM and high; IAAH, 100µM) were studied on growth, oxidative stress biomarkers and antioxidant enzymes (SOD, POD, CAT and GST), and metabolites (AsA and GSH) as well as enzymes (APX, GR and DHAR) of ascorbate-glutathione cycle in Trigonella foenum-graecum L. seedlings grown under cadmium (Cd1, 3mgCd kg(-1) soil and Cd2, 9mgCd kg(-1) soil) stress. Cadmium (Cd) at both doses caused reduction in growth which was correlated with enhanced lipid peroxidation and damage to membrane as a result of excess accumulation of O2(•-) and H2O2. Cd also enhanced the oxidation of AsA and GSH to DHA and GSSG, respectively which give a clear sign of oxidative stress, despite of accelerated activity of enzymatic antioxidants: SOD, CAT, POD, GST as well as APX, DHAR (except in Cd2 stress) and GR. Exogenous application of IAAL resulted further rise in the activities of these enzymes, and maintained the redox status (> ratios: AsA/DHA and GSH/GSSG) of cells. The maintained redox status of cells under IAAL treatment declined the level of ROS in Cd1 and Cd2 treated seedlings thereby alleviated the Cd toxicity and this effect was more pronounced under Cd1 stress. Contrary to this, exogenous IAAH suppressed the activity of DHAR and GR and disturbed the redox status (< ratios: AsA/DHA and GSH/GSSG) of cells, hence excess accumulation of ROS further aggravated the Cd induced damage. Thus, overall results suggest that IAA at low (IAAL) and high (IAAH) doses affected the Cd toxicity differently by regulating the ascorbate-glutathione cycle as well as activity of other antioxidants in Trigonella seedlings.

Performance of fenugreek bioinoculated with Rhizobium meliloti strains under semi-arid condition.

Rhizobium meliloti strains were isolated from the fields of S.D. Agricultural University (Gujarat, India) and were maintained in the Congo Red Yeast Extract Mannitol Agar medium. These strains were tested for their effectiveness for fenugreek crop grown under semi-arid condition. Among the six Rhizobium strains, FRS-7 strain showed best plant growth parameters like shoot length, shoot dry weight, shoot total nitrogen, root length, root dry weight, root total nitrogen, seed yield, 1000 grain weight, number of root nodules, and nodules fresh and dry weight. The performance of this strain was better as compared to 20 kgN ha(-1) treatment through urea and was even far better over control plot. Seed yields obtained with FRS-7 during two years were 10.14 and 9.66 q ha(-1); which was about 36.8% and 45.9% high over control. This strain resulted in saving of about 20 kgN ha(-1) accompanied with better crop yield and soil health. Results of the present experiments can be utilized in integrated nutrient management for cultivation of fenugreek in semi-arid areas to provide sustainability to agricultural productivity in such regions.

Physiological responses of fenugreek seedlings and plants treated with cadmium.

The bioaccumulation efficiency of cadmium (Cd) by fenugreek (Trigonella foenum-graecum) was examined using different concentrations of CdCl2. The germination rate was similar to control except at 10 mM Cd. However, early seedling growth was quite sensitive to the metal from the lowest Cd level. Accordingly, amylase activity was reduced substantially on treatment of seeds with 0.5, 1, and 10 mM Cd. Cadmium also affected various other plant growth parameters. Its accumulation was markedly lower in shoots as compared to roots, reducing root biomass by almost 50 %. Plants treated with 1 and 5 mM Cd presented chlorosis due to a significant reduction in chlorophyll b especially. Furthermore, at Cd concentrations greater than 0.1 mM, plants showed several signs of oxidative stress; an enhancement in root hydrogen peroxide (H2O2) level and in shoot malondialdehyde (MDA) content was observed. Conversely, antioxidant enzyme activities (superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)) increased in various plant parts. Likewise, total phenolic and flavonoid contents reached their highest values in the 0.5 mM Cd treatment, consistent with their roles in quenching low concentrations of reactive oxygen species (ROS). Consequently, maintaining oxidant and antioxidant balance may permit fenugreek to hyperaccumulate Cd and allow it to be employed in extremely Cd polluted soils for detoxification purposes.

Matrix effects for calcium and potassium K-X-rays, in fenugreek plants grown in iron rich soils.

The present work comprises the matrix effects study of the plant system (plant and soil) for macronutrients Ca and K with elevated levels of iron in the soil. The earlier derived matrix effect terms from fundamental relations of intensities of analyte and substrate elements with basic atomic and experimental setup parameters had led to iterative determination of enhanced elements rather than avoiding their enhancement. The relations also facilitated the evaluations of absorption for close Z interfering constituents (like Ca and K) in samples of a lot of particular category with interpolation of matrix terms with elemental amounts. The process has already been employed successfully for potato, radish, rice and maize plants. On similar lines, the observed prominent change in interpolation parameters for the plants in the present experiment serves as a tool to check the toxicity/contamination of the growing medium.

Morphological and biochemical behavior of fenugreek (Trigonella foenum-graecum) under copper stress.

The effects of copper on germination and growth of fenugreek (Trigonella foenum-graecum) was investigated separately using different concentrations of CuSO4. The germination percentage and radical length had different responses to cupric ions: the root growth increased with increasing copper concentration up to 1 mM Cu²âº and was inhibited thereafter. In contrast, the germination percentage was largely unaffected by concentrations of copper below 10 mM. The reduction in root growth may have been due to inhibition of hydrolytic enzymes such as amylase. Indeed, the average total amylolytic activity decreased from the first day of treatment with [Cu²âº] greater than 1 mM. Furthermore, copper affected various plant growth parameters. Copper accumulation was markedly higher in roots as compared to shoots. While both showed a gradual decrease in growth, this was more pronounced in roots than in leaves and in stems. Excess copper induced an increase in the rate of hydrogen peroxide (H2O2) production and lipid peroxidation in all plant parts, indicating oxidative stress. This redox stress affected leaf chlorophyll and carotenoid content which decreased in response to augmented Cu levels. Additionally, the activities of proteins involved in reactive oxygen species (ROS) detoxification were affected. Cu stress elevated the ascorbate peroxidase (APX) activity more than two times at 10 mM CuSO4. In contrast, superoxide dismutase (SOD) and catalase (CAT) levels showed only minor variations, only at 1 mM Cu²âº. Likewise, total phenol and flavonoid contents were strongly induced by low concentrations of copper, consistent with the role of these potent antioxidants in scavenging ROS such as H2O2, but returned to control levels or below at high [Cu²âº]. Taken together, these results indicate a fundamental shift in the plant response to copper toxicity at low versus high concentrations.

Enhancement of root growth and nitrogen fixation in Trigonella by UV-exclusion from solar radiation.

A field experiment was conducted to study the impact of solar UV on root growth and nitrogen fixation in Trigonella foenum-graecum. Plants were grown in iron mesh cages covered with polyester filters that could specifically cut off UV-B (280-315 nm) or UV-A + B (280-400 nm) part of the solar spectrum. The control plants were grown under a polythene filter transmissible to UV. Root biomass, number of nodules and nodule fresh weight were enhanced after exclusion of solar UV. Nitrogenase activity was significantly enhanced by 120% and 80% in the UV-B and UV-A + B excluded plants respectively. Along with nitrogenase there was concomitant increase in leghemoglobin and hemechrome content in the nodules after exclusion of solar UV. These components of sunlight limits nitrogen fixation and their elimination can enhance nitrogen fixation with agricultural advantages like reduction in the use of fertilizers.

Glyphosate, alachor and maleic hydrazide have genotoxic effect on Trigonella foenum-graecum L.

In the present study effects of herbicides glyphosate (GP), alachlor (AL) and maleic hydrazide (MH) is studied on mitotic cells of Trigonella foenum-graecum L. Seeds of T. foenum-graecum L. treated with a series of concentrations ranging from 0.1%, 0.2%, 0.3%, 0.4% and 0.5% for 1, 2 and 6 h and their effect on mitotic index and chromosomal aberrations was studied. The results indicate that these herbicides reduced mitotic index in dose-dependent manner. In addition, increase in the percentage of abnormal mitotic plates was observed in herbicide treated groups which was both concentration and time dependent. Commonly observed abnormalities were c-mitosis, laggards, bridges, stickiness, c-anaphase, precocious separation, un-equal distribution and fragments. The result of the present investigation indicates that commonly used herbicides GP, AL and MH have significant genotoxic effect on T. foenum-graecum plant.

Fertigation effect of distillery effluent on agronomical practices of Trigonella foenum-graecum L. (Fenugreek).

The fertigation effect of distillery effluents concentrations such as 5%, 10%, 25%, 50%, 75% and 100% were studied on Trigonella foenu-graecu (Pusa early bunching) along with control (bore well water). On irrigation of soil with different effluents up to 90 days of harvesting, it was observed that there was a significant effect on moisture content (P < 0.001), EC, pH, Cl(-), total organic carbon (TOC), HCO3⁻, CO3⁻², Na(+), K(+), Ca(2+), Mg(2+), Fe(2+), TKN, NO3²â», PO4³â», and SO4²â» (P < 0.0001) and insignificant effect on WHC and bulk density (P > 0.05).There was no significant change in the soil texture of the soil. Among various concentrations of effluent irrigation, the irrigation with 100% effluent concentration decreased pH (16.66%) and increased moisture content (30.82%), EC(84.13%), Cl(-) (292.37%), TOC (4311.61%), HCO3⁻ (27.76%), CO3⁻² (32.63%), Na +) (273%), K(+) (31.59%), Ca(2+) (729.76%), Mg(2+) (740.47%), TKN (1723.32%), NO3²â» (98.02%), PO4³â» (337.79%), and SO4²â» (77.78%), Fe(2+) (359.91%), Zn (980.48%), Cu (451.51%), Cd (3033.33%), Pb (2350.00%), and Cr (2375.00%) in the soil. The agronomical parameters such as shoot length, root length, number of leaves, flowers, pods, dry weight, chlorophyll content, LAI, crop yield, and HI of T. foenum-graecum were recorded to be in increasing order at low concentration of the effluent, i.e., from 5% to 50% and in decreasing order at higher effluent concentration, i.e., from 75% to 100% as compared to control. The enrichment factor of various heavy metals was ordered for soil Cd>Cr> Pb>Zn>Cu>Fe and for T. foenum-graecum plants Pb>Cr>Cd>Cu>Zn>Fe after irrigation with distillery effluent.

Assessment of the efficacy of Aspergillus sp. EL-2 in textile waste water treatment.

Fungal biomass has the ability to decolorize a wide variety of dyes successfully through a number of mechanisms. A brown rot isolate, previously identified as Aspergillus sp. EL-2, was used in the aerobic treatment of textile waste water efficiently. In the current work, the treated waste water was tested chemically using more than one combined treatment. Microbial toxicity, phytotoxicity, genotoxicity and cytotoxicity were also studied to assess the toxicity level for each treatment. The obtained data suggest that the contribution of more than one mode of treatment is essential to ensure complete destruction of the by-products. The use of gamma irradiation (25 kGy) after the bioremediation step led to the decrease of the by-products of biodegradation as observed by visible spectrum and Fourier transfer infra red spectroscopy (FT-IR). The toxicity assessment presented variable results indicating the need for more than one toxicity test to confirm the presence or absence of hazardous compounds. Brown rot fungus could be used efficiently in the treatment of textile waste water without the risk of obtaining high carcinogenic or genotoxic compounds, especially if combined treatment is employed.

Contribution of Glomus intraradices inoculation to nutrient acquisition and mitigation of ionic imbalance in NaCl-stressed Trigonella foenum-graecum.

The study aimed to investigate the effects of an AM fungus (Glomus intraradices Schenck and Smith) on mineral acquisition in fenugreek (Trigonella foenum-graecum) plants under different levels of salinity. Mycorrhizal (M) and non-mycorrhizal (NM) fenugreek plants were subjected to four levels of NaCl salinity (0, 50, 100, and 200 mM NaCl). Plant tissues were analyzed for different mineral nutrients. Leaf senescence (chlorophyll concentration and membrane permeability) and lipid peroxidation were also assessed. Under salt stress, M plants showed better growth, lower leaf senescence, and decreased lipid peroxidation as compared to NM plants. Salt stress adversely affected root nodulation and uptake of NPK. This effect was attenuated in mycorrhizal plants. Presence of the AM fungus prevented excess uptake of Na(+) with increase in NaCl in the soil. It also imparted a regulatory effect on the translocation of Na(+) ions to shoots thereby maintaining lower Na(+) shoot:root ratios as compared to NM plants. Mycorrhizal colonization helped the host plant to overcome Na(+)-induced Ca(2+) and K(+) deficiencies. M plants maintained favorable K(+):Na(+), Ca(2+):Na(+), and Ca(2+):Mg(2+) ratios in their tissues. Concentrations of Cu, Fe, and Zn(2+) decreased with increase in intensity of salinity stress. However, at each NaCl level, M plants had higher concentration of Cu, Fe, Mn(2+), and Zn(2+) as compared to NM plants. M plants showed reduced electrolyte leakage in leaves as compared to NM plants. The study suggests that AM fungi contribute to alleviation of salt stress by mitigation of NaCl-induced ionic imbalance thus maintaining a favorable nutrient profile and integrity of the plasma membrane.

Performance of some Ethiopian fenugreek (Trigonella foenum-graecum L.) germplasm collections as compared with the commercial variety Challa.

Systematic breeding efforts on fenugreek have so far been neglected in Ethiopia. For this, 143 random samples of fenugreek accessions along with a commercial variety were used in this study to evaluate the potential of the land races. The field experiment was conducted at Haramaya University research station during 2011 main cropping season. Treatments were arranged in a 12x12 simple lattice design. The highest biomass and seed yielding accessions were generally concentrated more in the categories of yellow and green seed colors. When compared with the commercial variety, above 27% of the tested accessions performed significantly better in terms of seed yield indicating that significant yield gains could be secured by simple selection. However, further evaluation over wider environments is necessary to arrive at conclusive points for such quantitative traits. Green and yellow seeded accessions are widely distributed over all the country and over half of the accessions (63%) had green seed color. High seed yield bearing accessions were those collected from northwest and central part of Ethiopia, while accessions collected from eastern and northwestern Ethiopia were strikingly bold seed size. This variability would provide a basis for improving the crop in breeding program.

[Characterization of root nodule and rhizobium of a Leguminosae ephemeral plant--Trigonella arcuata C. A. Mey in Xinjiang].

OBJECTIVE: We studied root nodule proliferation, nodule microstructure, genetic cluster and stress resistance of the rhizobium of Trigonella arcuata. METHODS: We characterized root nodule and rhizobium with various soil matrixes cultivation, paraffin section, resin semi-ultrathin section techniques, and 16S rRNA gene cluster analysis. RESULTS: (1) Plants grew in mixed soil (nutritious garden soil: poplar zone soil: desert sands = l:1:1), had the most nodule proliferation and bore the most pods. The shapes of nodule were palm- or ginger-like; (2) Microstructure of the nodule revealed five different parts differentiated within the nodule: epidermis (E), cortex (C), vascular bundle (VB), infected cells (IC) and uninfected cells (UIC); (3) Genetic cluster analysis of the full length 16S rRNA gene sequence (1377 bp) indicated that the rhizobium isolated shared the highest identities with Sinorhizobium meliloti; (4) The rhizobium could grow between 4 and 60 degrees C (20 min), pH 6.0-12.0 and 0-2% NaCl. For the antibiotic sensitivity, the rhizobium could not grow normally in medium with 25 microg/mL Kanamycin, Streptomycin or Cephalothin, except for 100 microg/mL Ampicillin. CONCLUSION: Good conditions of soil matrixes were important for nodulation of T. arcuata; A large quantity of cells in fascicular nodules were infected by rhizobia; 16S rRNA gene sequence of T. arcuata shared the highest identities with that of Sinorhizobium meliloti, and this strain was able to tolerate relatively higher temperature and alkalin.